Sony 100-400 f/4.5
p.4 #1Sony 100-400 f/4.5
This is what I was looking for
"I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close."
and I'm not surprised.
"I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage."
I don't think anyone will expect a slower zoom with 2X will beat one of the best prime with 2X
Thank you
arbitrage wrote:
A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lens
Thanks for sharing these Geoff. Looks like AF works great even with 2X. Would you say it's on par with 300/2.8 with 2X for AF?
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage.
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600....Show more →
"I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close."
and I'm not surprised.
"I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage."
I don't think anyone will expect a slower zoom with 2X will beat one of the best prime with 2X
Thank you
arbitrage wrote:
Jemini wrote
arbitrage wrote
Stop measurebating and go out and shoot the damn lens.A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lens
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600....Show more →
Jun 14, 2026 at 05:45 PM
p.4 #2Sony 100-400 f/4.5
The IQ with the 1.4x being about the same as the 200-600 is as expected and in line with other tests I've seen. IQ was never a concern with a GM lens. But the news about the AF and tracking prowess is what's most important and it looks like there's no need to worry and the 100-400 could definitely replace the 200-600. I still have no interest in pairing it with a 2x and now pray we can get a excellent 600/800mm prime from Sony that is around the $5-6K mark.
Jun 14, 2026 at 06:56 PM
p.4 #3Sony 100-400 f/4.5
duncangr wrote:
A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lensThanks for sharing these Geoff. Looks like AF works great even with 2X. Would you say it's on par with 300/2.8 with 2X for AF?
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage.
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.Can you post links to full resolution uncropped files or the RAW files. So far I am not blown away but it's hard to judge anything without seeing the full resolution originals.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with...Show more →
When I compared my "old" 100-400 to the new one with some backyard test shots today the new lens had a bit more contrast and just slightly sharper. But they are very close. I do have a very sharp copy of the old 100-400...noticeably sharper than the 1st copy I owned.
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different purposes. I won't be selling my old one just because I bought the new one. The old one still has the benefit of smaller footprint and maximum magnification.
You would buy the new one if you want a smoother zoom mechanism and 2/3 stops of extra light to work with.
The biggest problem I have with the new lens is that it is now making me have to decide what lens to go out and shoot with. It has been such an easy choice up until now as I would just grab the 300GM and TCs and be happy. But this lens is fun to shoot with so now I have to think about it. Once the new toy honeymoon period wears off we will see which one I gravitate to more.
arbitrage wrote
Jemini wrote
arbitrage wrote
Stop measurebating and go out and shoot the damn lens.A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lens
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with...Show more →
When I compared my "old" 100-400 to the new one with some backyard test shots today the new lens had a bit more contrast and just slightly sharper. But they are very close. I do have a very sharp copy of the old 100-400...noticeably sharper than the 1st copy I owned.
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different purposes. I won't be selling my old one just because I bought the new one. The old one still has the benefit of smaller footprint and maximum magnification.
You would buy the new one if you want a smoother zoom mechanism and 2/3 stops of extra light to work with.
The biggest problem I have with the new lens is that it is now making me have to decide what lens to go out and shoot with. It has been such an easy choice up until now as I would just grab the 300GM and TCs and be happy. But this lens is fun to shoot with so now I have to think about it. Once the new toy honeymoon period wears off we will see which one I gravitate to more.
Jun 14, 2026 at 07:04 PM
p.4 #4Sony 100-400 f/4.5
arbitrage wrote:
A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lensThanks for sharing these Geoff. Looks like AF works great even with 2X. Would you say it's on par with 300/2.8 with 2X for AF?
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage.
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.Can you post links to full resolution uncropped files or the RAW files. So far I am not blown away but it's hard to judge anything without seeing the full resolution originals.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpgWhen I compared my "old" 100-400 to the new one with some backyard test shots today the new lens had a bit more contrast and just slightly sharper. But they are very close. I do have a very sharp copy of the old 100-400...noticeably sharper than the 1st copy I owned.
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different...Show more →
How often will you be at 100-399mm? I know with my birding my 200-600 spends 95% of the time at 550-600mm, and only occasionally when shooting large waders do I need to use less than 500mm. This is why I'd love to see a intermediately fast 600mm prime to pair with the 100-400.
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
duncangr wrote
arbitrage wrote
Jemini wrote
arbitrage wrote
Stop measurebating and go out and shoot the damn lens.A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lens
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpg
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different...Show more →
How often will you be at 100-399mm? I know with my birding my 200-600 spends 95% of the time at 550-600mm, and only occasionally when shooting large waders do I need to use less than 500mm. This is why I'd love to see a intermediately fast 600mm prime to pair with the 100-400.
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
Jun 14, 2026 at 09:01 PM
p.4 #5Sony 100-400 f/4.5
I think, particularly due to the very light weight of the Sony 300, there may be just as many who would prefer no built in TC with the benefit of weight and cost compared to heavier and more expensive built in TC.
Sony decided 300 prime.
Canon decided 100-300 2.8 for considerably more weight and cost.
Nikon decided 120-300 with TC. Weight and cost unknown, but both will exceed the Sony.
All are correct decisions for some, obviously none are correct for everyone.
It's just as logical to say Canon and Nikon missed a golden opportunity to make a 300 prime as light and cheap as the Sony.
Pixel Perfect wrote:
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
Sony decided 300 prime.
Canon decided 100-300 2.8 for considerably more weight and cost.
Nikon decided 120-300 with TC. Weight and cost unknown, but both will exceed the Sony.
All are correct decisions for some, obviously none are correct for everyone.
It's just as logical to say Canon and Nikon missed a golden opportunity to make a 300 prime as light and cheap as the Sony.
Pixel Perfect wrote:
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
Jun 15, 2026 at 12:45 AM
p.4 #6Sony 100-400 f/4.5
Pixel Perfect wrote:
A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lensThanks for sharing these Geoff. Looks like AF works great even with 2X. Would you say it's on par with 300/2.8 with 2X for AF?
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage.
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.Can you post links to full resolution uncropped files or the RAW files. So far I am not blown away but it's hard to judge anything without seeing the full resolution originals.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpgWhen I compared my "old" 100-400 to the new one with some backyard test shots today the new lens had a bit more contrast and just slightly sharper. But they are very close. I do have a very sharp copy of the old 100-400...noticeably sharper than the 1st copy I owned.
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different purposes. I won't be selling my old one just because I bought the new one. The old one still has the benefit of smaller footprint and maximum magnification.
You would buy the new one if you want a smoother zoom mechanism and 2/3 stops of extra light to work with.
The biggest problem I have with the new lens is that it is now making me have to decide what lens to go out and shoot with. It has been such an easy choice up until now as I would just grab the 300GM and TCs and be happy. But this lens is fun to shoot with so now I have to think about it. Once the new toy honeymoon period wears off we will see which one I gravitate to more.How often will you be at 100-399mm? I know with my birding my 200-600 spends 95% of the time at 550-600mm, and only occasionally when shooting large waders do I need to use less than 500mm. This is why I'd love to see a intermediately fast 600mm prime to pair with the 100-400.
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
I probably would have added the 100-400 to the bag if it had a built in TC.
arbitrage wrote
duncangr wrote
arbitrage wrote
Jemini wrote
arbitrage wrote
Stop measurebating and go out and shoot the damn lens.A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lens
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpg
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different purposes. I won't be selling my old one just because I bought the new one. The old one still has the benefit of smaller footprint and maximum magnification.
You would buy the new one if you want a smoother zoom mechanism and 2/3 stops of extra light to work with.
The biggest problem I have with the new lens is that it is now making me have to decide what lens to go out and shoot with. It has been such an easy choice up until now as I would just grab the 300GM and TCs and be happy. But this lens is fun to shoot with so now I have to think about it. Once the new toy honeymoon period wears off we will see which one I gravitate to more.
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
I probably would have added the 100-400 to the bag if it had a built in TC.
Jun 15, 2026 at 12:55 AM
p.4 #7Sony 100-400 f/4.5
Pixel Perfect wrote:
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
And how much more expensive would they have been, since the OM 150-400mm f/4.5 TC 1.25 IS PRO Lens is $8,600US?
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
And how much more expensive would they have been, since the OM 150-400mm f/4.5 TC 1.25 IS PRO Lens is $8,600US?
Jun 15, 2026 at 01:05 AM
p.4 #8Sony 100-400 f/4.5
arbitrage wrote:
A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lensThanks for sharing these Geoff. Looks like AF works great even with 2X. Would you say it's on par with 300/2.8 with 2X for AF?
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage.
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.Can you post links to full resolution uncropped files or the RAW files. So far I am not blown away but it's hard to judge anything without seeing the full resolution originals.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpgWhen I compared my "old" 100-400 to the new one with some backyard test shots today the new lens had a bit more contrast and just slightly sharper. But they are very close. I do have a very sharp copy of the old 100-400...noticeably sharper than the 1st copy I owned.
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different...Show more →
The ergonomics on the new one might still be a worthwhile upgrade as long as the IQ remains the same. The zoom on the old one is a nightmare.
duncangr wrote
arbitrage wrote
Jemini wrote
arbitrage wrote
Stop measurebating and go out and shoot the damn lens.A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lens
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpg
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different...Show more →
The ergonomics on the new one might still be a worthwhile upgrade as long as the IQ remains the same. The zoom on the old one is a nightmare.
Jun 15, 2026 at 02:22 AM
p.4 #9Sony 100-400 f/4.5
arbitrage wrote:
A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lensThanks for sharing these Geoff. Looks like AF works great even with 2X. Would you say it's on par with 300/2.8 with 2X for AF?
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?I feel the 300GM/2xTC is better AF hit rate than the 100-400/2xTC. Just that extra 1.33 stops of light will give it the advantage.
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.Can you post links to full resolution uncropped files or the RAW files. So far I am not blown away but it's hard to judge anything without seeing the full resolution originals.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpgWhen I compared my "old" 100-400 to the new one with some backyard test shots today the new lens had a bit more contrast and just slightly sharper. But they are very close. I do have a very sharp copy of the old 100-400...noticeably sharper than the 1st copy I owned.
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different...Show more →
Old 100-400 will not autofocus fast enough when zooming the lens. Probably a combination of weight of focus group and how close the lens is to parfocal.
New 100-400/4.5 does not seem to have the same issue.
duncangr wrote
arbitrage wrote
Jemini wrote
arbitrage wrote
Stop measurebating and go out and shoot the damn lens.A few samples at 400mm and 800mm shot handheld from my kayak yesterday. I'm satisfied. Banger lens
If that's the case I can have the 1.4X glued to the lens all the time. Your thoughts on comparison to 200-600?
I think the 100-400/1.4TC is better AF than the 300GM/2xTC. But I think the IQ is fairly close.
For just IQ I think the 100-400/1.4TC is about equal to the 200-600 for perched birds. But as soon as you start shooting action I find the 100-400/1.4TC to be way, way better. I was really impressed with the hit rate on the Purple Martins with the 1.4TC. The handling of the 100-400/1.4TC is also way nicer than the 200-600. Only thing I'd give the nod to the 200-600 would be the smoothness of the zoom ring.
The bare lens is really, really good also. I'm not sure how it would compare to the 300GM/1.4TC but I think they are fairly close for IQ and AF speed. I think bare 300GM is still the sharpest and fastest AF I've ever used.
A couple of reference images - taken with the old smaller, cheaper, lighter 100-400 - and the A1. Be sure to zoom right in on the eyes - you might have to save the images as a local copy first because FM doesn't seem to allow zooming in on the images.
I doubt any lens can improve much on these but the ergonomics on the new 100-400 with the new zoom ring might make it easier to use.
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_6_2658_1_DxO-edit.jpg
https://duncangroenewald.com/img/wildlife/birds/welcome-swallow/DG1_2020802_7_4066_DxO-DeNoiseAI-standard.jpg
The new 100-400 is not going to give any meaningful IQ advantage over the old one. The old one is a very sharp lens (copy dependent). I also don't think AF is going to be much different.
The new lens is not a replacement for the old one. They serve different...Show more →
Old 100-400 will not autofocus fast enough when zooming the lens. Probably a combination of weight of focus group and how close the lens is to parfocal.
New 100-400/4.5 does not seem to have the same issue.
Jun 15, 2026 at 04:18 AM
p.4 #10Sony 100-400 f/4.5
Pixel Perfect wrote:
How often will you be at 100-399mm? I know with my birding my 200-600 spends 95% of the time at 550-600mm, and only occasionally when shooting large waders do I need to use less than 500mm. This is why I'd love to see a intermediately fast 600mm prime to pair with the 100-400.
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
If you are "95% of the time at 550-600mm" then the 100-400/4.5 is fairly pointless for you. Get the 300GM instead.
300/2.8 has a bigger NA than 400/4.5, so 300/2.8 should have higher angular resolution. Higher angular resolution means distant subjects will be sharper.
The teleconverter (TC) question isn't that straightforward. If the sensor resolution is high enough relative to the lens's optical performance, adding a TC will reduce image quality compared to cropping. Sony's strategy appears to be leveraging higher-resolution sensors, allowing users to crop aggressively while avoiding the optical compromises that can come with a teleconverter.
How often will you be at 100-399mm? I know with my birding my 200-600 spends 95% of the time at 550-600mm, and only occasionally when shooting large waders do I need to use less than 500mm. This is why I'd love to see a intermediately fast 600mm prime to pair with the 100-400.
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
If you are "95% of the time at 550-600mm" then the 100-400/4.5 is fairly pointless for you. Get the 300GM instead.
300/2.8 has a bigger NA than 400/4.5, so 300/2.8 should have higher angular resolution. Higher angular resolution means distant subjects will be sharper.
The teleconverter (TC) question isn't that straightforward. If the sensor resolution is high enough relative to the lens's optical performance, adding a TC will reduce image quality compared to cropping. Sony's strategy appears to be leveraging higher-resolution sensors, allowing users to crop aggressively while avoiding the optical compromises that can come with a teleconverter.
Jun 15, 2026 at 04:28 AM
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p.4 #11Sony 100-400 f/4.5
A high grade 180-600/4-5.6 w/1.4x internal would solve many problems. However, the cheap folks would complain about it being too expensive and the wimpy folks would complain about it being too heavy. 
EBH
EBH
Jun 15, 2026 at 05:20 AM
p.4 #12Sony 100-400 f/4.5
EB-1 wrote:
A high grade 180-600/4-5.6 w/1.4x internal would solve many problems. However, the cheap folks would complain about it being too expensive and the wimpy folks would complain about it being too heavy.
EBH
In photography, skill is more important than money and brains more important than brawn.
A high grade 180-600/4-5.6 w/1.4x internal would solve many problems. However, the cheap folks would complain about it being too expensive and the wimpy folks would complain about it being too heavy.
EBH
In photography, skill is more important than money and brains more important than brawn.
Jun 15, 2026 at 07:04 AM
p.4 #13Sony 100-400 f/4.5
cpe1991 wrote:
EBHIn photography, skill is more important than money and brains more important than brawn.
When I hire a photographer I'm telling them what I want and expecting something relevant in their portfolio - that's the art part. Whatever equipment they use to achieve it is not my problem if it meets the technical requirements of the output.
But the question was about the lens speed and resolution for teles. 95mm diameter can be limiting for long teles, but is right around the acceptable level for some purposes. 112mm, 125mm, 143mm and larger offer more potential reach.
EBH
EB-1 wrote
A high grade 180-600/4-5.6 w/1.4x internal would solve many problems. However, the cheap folks would complain about it being too expensive and the wimpy folks would complain about it being too heavy.EBH
When I hire a photographer I'm telling them what I want and expecting something relevant in their portfolio - that's the art part. Whatever equipment they use to achieve it is not my problem if it meets the technical requirements of the output.
But the question was about the lens speed and resolution for teles. 95mm diameter can be limiting for long teles, but is right around the acceptable level for some purposes. 112mm, 125mm, 143mm and larger offer more potential reach.
EBH
Jun 15, 2026 at 08:11 AM
p.4 #14Sony 100-400 f/4.5
aCuria wrote:
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.If you are "95% of the time at 550-600mm" then the 100-400/4.5 is fairly pointless for you. Get the 300GM instead.
300/2.8 has a bigger NA than 400/4.5, so 300/2.8 should have higher angular resolution. Higher angular resolution means distant subjects will be sharper.
The teleconverter (TC) question isn't that straightforward. If the sensor resolution is high enough relative to the lens's optical performance, adding a TC will reduce image quality compared to cropping. Sony's strategy appears to be leveraging higher-resolution sensors, allowing users to crop aggressively while avoiding the optical compromises that can come with a teleconverter.
I think until there is careful testing, we never know whether cropping or using a teleconverter will result in a better image. What is true is a better teleconverter (or one that just works better with the lens) will increase the performance of the system and higher resolution sensors tend to do better with cropping than lower resolution sensors. Whether any particular lens will work better with a spefic TC on a specific camera vs. using the bare lens and cropping is something that would need to be tested.
It seems that TCs, including tuning them to specific lenses, have gotten better optically. It is also true that sensors have gotten more resolution. What isn't clear is whether it is better to crop or use a TC. I suspect which one is better depends on the specific setup. Certainly the TC, the lens, and how they work together and potentially the camera too could influence which approach works better, and what works better also needs to be defined by the photographer's goals for the image.
If I had to hazard a guess based on people's use, I would guess that the Sony 300 f/2.8 GM gets better results with the TCs than it would with cropping. That seems to be how people use that lens, but I haven't seen evidence of that better performance. Is that true with the new 100-400 f/4.5? It would be great to see some testing to get some data on that point.
Pixel Perfect wrote
How often will you be at 100-399mm? I know with my birding my 200-600 spends 95% of the time at 550-600mm, and only occasionally when shooting large waders do I need to use less than 500mm. This is why I'd love to see a intermediately fast 600mm prime to pair with the 100-400.Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
300/2.8 has a bigger NA than 400/4.5, so 300/2.8 should have higher angular resolution. Higher angular resolution means distant subjects will be sharper.
The teleconverter (TC) question isn't that straightforward. If the sensor resolution is high enough relative to the lens's optical performance, adding a TC will reduce image quality compared to cropping. Sony's strategy appears to be leveraging higher-resolution sensors, allowing users to crop aggressively while avoiding the optical compromises that can come with a teleconverter.
I think until there is careful testing, we never know whether cropping or using a teleconverter will result in a better image. What is true is a better teleconverter (or one that just works better with the lens) will increase the performance of the system and higher resolution sensors tend to do better with cropping than lower resolution sensors. Whether any particular lens will work better with a spefic TC on a specific camera vs. using the bare lens and cropping is something that would need to be tested.
It seems that TCs, including tuning them to specific lenses, have gotten better optically. It is also true that sensors have gotten more resolution. What isn't clear is whether it is better to crop or use a TC. I suspect which one is better depends on the specific setup. Certainly the TC, the lens, and how they work together and potentially the camera too could influence which approach works better, and what works better also needs to be defined by the photographer's goals for the image.
If I had to hazard a guess based on people's use, I would guess that the Sony 300 f/2.8 GM gets better results with the TCs than it would with cropping. That seems to be how people use that lens, but I haven't seen evidence of that better performance. Is that true with the new 100-400 f/4.5? It would be great to see some testing to get some data on that point.
Jun 15, 2026 at 09:06 AM
p.4 #15Sony 100-400 f/4.5
EB-1 wrote:
A high grade 180-600/4-5.6 w/1.4x internal would solve many problems. However, the cheap folks would complain about it being too expensive and the wimpy folks would complain about it being too heavy.
EBH
And those are the people that form the majority of Sony's customers.
A high grade 180-600/4-5.6 w/1.4x internal would solve many problems. However, the cheap folks would complain about it being too expensive and the wimpy folks would complain about it being too heavy.
EBH
And those are the people that form the majority of Sony's customers.
Jun 15, 2026 at 09:36 AM
p.4 #16Sony 100-400 f/4.5
Steve Spencer wrote:
I think until there is careful testing, we never know whether cropping or using a teleconverter will result in a better image. What is true is a better teleconverter (or one that just works better with the lens) will increase the performance of the system and higher resolution sensors tend to do better with cropping than lower resolution sensors. Whether any particular lens will work better with a spefic TC on a specific camera vs. using the bare lens and cropping is something that would need to be tested.
It seems that TCs, including tuning them to specific lenses,...Show more →
Unless the Airy disk is humongous, when is the last time you found a high quality lens that did not benefit from a 1.4x TC? The main differences are whether that equates closer to 1.3x or 1.1x. A 2x is a different issue, with relatively fewer lenses being worthwhile.
EBH
I think until there is careful testing, we never know whether cropping or using a teleconverter will result in a better image. What is true is a better teleconverter (or one that just works better with the lens) will increase the performance of the system and higher resolution sensors tend to do better with cropping than lower resolution sensors. Whether any particular lens will work better with a spefic TC on a specific camera vs. using the bare lens and cropping is something that would need to be tested.
It seems that TCs, including tuning them to specific lenses,...Show more →
Unless the Airy disk is humongous, when is the last time you found a high quality lens that did not benefit from a 1.4x TC? The main differences are whether that equates closer to 1.3x or 1.1x. A 2x is a different issue, with relatively fewer lenses being worthwhile.
EBH
Jun 15, 2026 at 12:44 PM
p.4 #17Sony 100-400 f/4.5
EB-1 wrote:
It seems that TCs, including tuning them to specific lenses, have gotten better optically. It is also true that sensors have gotten more resolution. What isn't clear is whether it is better to crop or use a TC. I suspect which one is better depends on the specific setup. Certainly the TC, the lens, and how they work together and potentially the camera too could influence which approach works better, and what works better also needs to be defined by the photographer's goals for the image.
If I had to hazard a guess based on people's use, I would guess that the Sony 300 f/2.8 GM gets better results with the TCs than it would with cropping. That seems to be how people use that lens, but I haven't seen evidence of that better performance. Is that true with the new 100-400 f/4.5? It would be great to see some testing to get some data on that point.Unless the Airy disk is humongous, when is the last time you found a high quality lens that did not benefit from a 1.4x TC? The main differences are whether that equates closer to 1.3x or 1.1x. A 2x is a different issue, with relatively fewer lenses being worthwhile.
EBH
My point is that I have seen almost no comparisons. The post I was responding to takes the opposite position as yours. He (aCuria) was arguing that cropping is almost always better. You are arguing that the 1.4X TC is almost always better the 2X TC not so much. I actually don't know and would like to see comparisons that actually test to see which is better with particular lens and TC combinations. Relevant to this thread, I would love to see whether this new lens performs bettwer with the 1.4X TC and the 2X TC than it does cropping to the same perspective.
Steve Spencer wrote
I think until there is careful testing, we never know whether cropping or using a teleconverter will result in a better image. What is true is a better teleconverter (or one that just works better with the lens) will increase the performance of the system and higher resolution sensors tend to do better with cropping than lower resolution sensors. Whether any particular lens will work better with a spefic TC on a specific camera vs. using the bare lens and cropping is something that would need to be tested.It seems that TCs, including tuning them to specific lenses, have gotten better optically. It is also true that sensors have gotten more resolution. What isn't clear is whether it is better to crop or use a TC. I suspect which one is better depends on the specific setup. Certainly the TC, the lens, and how they work together and potentially the camera too could influence which approach works better, and what works better also needs to be defined by the photographer's goals for the image.
If I had to hazard a guess based on people's use, I would guess that the Sony 300 f/2.8 GM gets better results with the TCs than it would with cropping. That seems to be how people use that lens, but I haven't seen evidence of that better performance. Is that true with the new 100-400 f/4.5? It would be great to see some testing to get some data on that point.
EBH
My point is that I have seen almost no comparisons. The post I was responding to takes the opposite position as yours. He (aCuria) was arguing that cropping is almost always better. You are arguing that the 1.4X TC is almost always better the 2X TC not so much. I actually don't know and would like to see comparisons that actually test to see which is better with particular lens and TC combinations. Relevant to this thread, I would love to see whether this new lens performs bettwer with the 1.4X TC and the 2X TC than it does cropping to the same perspective.
Jun 15, 2026 at 12:51 PM
p.4 #18Sony 100-400 f/4.5
Steve Spencer wrote:
My point is that I have seen almost no comparisons. The post I was responding to takes the opposite position as yours. He (aCuria) was arguing that cropping is almost always better. You are arguing that the 1.4X TC is almost always better the 2X TC not so much.
They are both right, you need to pick your poison. Cropping and using a TC both give you en enlarged image with less DOF and more noise (they both capture about the same amount of light from your bird). The TC1.4 will put twice as many pixels on the bird. But it will also degrade the IQ (CA, contrast, sharpness especially off center, etc) to some extend.
So if you already have plenty of pixels on your subject, the overall IQ is better when sticking with cropping. But if you have insufficient pixels on your subject, the TC will help (to a degree).
My point is that I have seen almost no comparisons. The post I was responding to takes the opposite position as yours. He (aCuria) was arguing that cropping is almost always better. You are arguing that the 1.4X TC is almost always better the 2X TC not so much.
They are both right, you need to pick your poison. Cropping and using a TC both give you en enlarged image with less DOF and more noise (they both capture about the same amount of light from your bird). The TC1.4 will put twice as many pixels on the bird. But it will also degrade the IQ (CA, contrast, sharpness especially off center, etc) to some extend.
So if you already have plenty of pixels on your subject, the overall IQ is better when sticking with cropping. But if you have insufficient pixels on your subject, the TC will help (to a degree).
Jun 15, 2026 at 04:57 PM
p.4 #19Sony 100-400 f/4.5
Daran wrote:
They are both right, you need to pick your poison. Cropping and using a TC both give you en enlarged image with less DOF and more noise (they both capture about the same amount of light from your bird). The TC1.4 will put twice as many pixels on the bird. But it will also degrade the IQ (CA, contrast, sharpness especially off center, etc) to some extend.
So if you already have plenty of pixels on your subject, the overall IQ is better when sticking with cropping. But if you have insufficient pixels on your subject, the TC will help...Show more →
I agree. Using the TC results in more pixels, which let's you downsize the image if you match output size which generally improves image quality, but the TC degrades the image quality as you say. The question is which matters more and either factor can be more important depending on how much the TC degrades optical performance and how many pixels you need. Obviously if you need more pixels than the crop allows the TC will be the better option, and if the TC doesn't work very well with the lens then cropping is going to be more likely to work. In practice, however, I think you need to compare each method to know how well the TC works with the lens before you can know which approach is likely to be better for a particular lens with a particular type of shooting.
Steve Spencer wrote
My point is that I have seen almost no comparisons. The post I was responding to takes the opposite position as yours. He (aCuria) was arguing that cropping is almost always better. You are arguing that the 1.4X TC is almost always better the 2X TC not so much.So if you already have plenty of pixels on your subject, the overall IQ is better when sticking with cropping. But if you have insufficient pixels on your subject, the TC will help...Show more →
I agree. Using the TC results in more pixels, which let's you downsize the image if you match output size which generally improves image quality, but the TC degrades the image quality as you say. The question is which matters more and either factor can be more important depending on how much the TC degrades optical performance and how many pixels you need. Obviously if you need more pixels than the crop allows the TC will be the better option, and if the TC doesn't work very well with the lens then cropping is going to be more likely to work. In practice, however, I think you need to compare each method to know how well the TC works with the lens before you can know which approach is likely to be better for a particular lens with a particular type of shooting.
Jun 15, 2026 at 06:08 PM
p.4 #20Sony 100-400 f/4.5
Steve Spencer wrote:
Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.If you are "95% of the time at 550-600mm" then the 100-400/4.5 is fairly pointless for you. Get the 300GM instead.
300/2.8 has a bigger NA than 400/4.5, so 300/2.8 should have higher angular resolution. Higher angular resolution means distant subjects will be sharper.
The teleconverter (TC) question isn't that straightforward. If the sensor resolution is high enough relative to the lens's optical performance, adding a TC will reduce image quality compared to cropping. Sony's strategy appears to be leveraging higher-resolution sensors, allowing users to crop aggressively while avoiding the optical compromises that can come with a teleconverter.I think until there is careful testing, we never know whether cropping or using a teleconverter will result in a better image. What is true is a better teleconverter (or one that just works better with the lens) will increase the performance of the system and higher resolution sensors tend to do better with cropping than lower resolution sensors. Whether any particular lens will work better with a spefic TC on a specific camera vs. using the bare lens and cropping is something that would need to be tested.
It seems that TCs, including tuning them to specific lenses,...Show more →
I pretty much agree with all your points. I think this can be tested with pixel shift, I suspect pixel shift + crop will beat TC without pixel shift for most lenses. Testing different pixel shift levels could give an indication of how many pixels are needed on the sensor natively before the TC becomes redundant for each lens.
Once Sony starts producing 100-200MP sensors there may be a day where TCs become redundant for all lenses
aCuria wrote
Pixel Perfect wrote
How often will you be at 100-399mm? I know with my birding my 200-600 spends 95% of the time at 550-600mm, and only occasionally when shooting large waders do I need to use less than 500mm. This is why I'd love to see a intermediately fast 600mm prime to pair with the 100-400.Sony missed a golden opportunity with the 300GM in not including built-in 1.4x TC IMO and similarly with the new 100-400. Would have loved to even see them copy OM and have included a built-in 1.25x if not 1.4x.
300/2.8 has a bigger NA than 400/4.5, so 300/2.8 should have higher angular resolution. Higher angular resolution means distant subjects will be sharper.
The teleconverter (TC) question isn't that straightforward. If the sensor resolution is high enough relative to the lens's optical performance, adding a TC will reduce image quality compared to cropping. Sony's strategy appears to be leveraging higher-resolution sensors, allowing users to crop aggressively while avoiding the optical compromises that can come with a teleconverter.
It seems that TCs, including tuning them to specific lenses,...Show more →
I pretty much agree with all your points. I think this can be tested with pixel shift, I suspect pixel shift + crop will beat TC without pixel shift for most lenses. Testing different pixel shift levels could give an indication of how many pixels are needed on the sensor natively before the TC becomes redundant for each lens.
Once Sony starts producing 100-200MP sensors there may be a day where TCs become redundant for all lenses
Jun 15, 2026 at 08:01 PM