Time to let it go? Sony FE 600mm f/4
p.2 #1Time to let it go? Sony FE 600mm f/4
nmerc_photos wrote:
Reasonable thing to do when there is no quality gain you can perceive. I can perceive such a difference. I like using the 300GM + 2x for scouting, but when I come across a worthwhile subject under good conditions I tend to be a bit miffed if I don't have the big gun with me.
Maybe you are living in a place like Florida and get away with less cropping. Or you shoot a lower resolution. Or you aren't obsessing about feathers. Or your presentation flattens out the difference. Or you flatten details with AI in post anyway. I would certainly not generally recommend the cash layout, but I would also not wana part from my 600.…
At the 600mm focal length, it's pretty universally accepted that there's little to no qualitative difference between the 600GM and 300GM + 2x. Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of. It's purely a 1 stop of light difference for ~$4K extra, that also comes with double the weight.
Do you have a citation for this claim or a reference, where someone has compared the 600/4 versus 300/2.8 x2 with proper thoroughness?
Daran wrote
nmerc_photos wrote
I recently sold my 600GM in favor of the 300GM + 2x. In terms of optical quality, it is indistinguishable to me.Maybe you are living in a place like Florida and get away with less cropping. Or you shoot a lower resolution. Or you aren't obsessing about feathers. Or your presentation flattens out the difference. Or you flatten details with AI in post anyway. I would certainly not generally recommend the cash layout, but I would also not wana part from my 600.
At the 600mm focal length, it's pretty universally accepted that there's little to no qualitative difference between the 600GM and 300GM + 2x. Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of. It's purely a 1 stop of light difference for ~$4K extra, that also comes with double the weight.
Do you have a citation for this claim or a reference, where someone has compared the 600/4 versus 300/2.8 x2 with proper thoroughness?
Aug 21, 2026 at 10:18 AM
p.2 #2Time to let it go? Sony FE 600mm f/4
nmerc_photos wrote:
Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of.
Citation needed. I have both. The 600 is only a bit sharper in the center but significantly sharper and has much less CA away from the center compared to the 300*2. If you present the same heavily cropped but otherwise perfect shot, you can tell them apart. See e.g. https://www.fredmiranda.com/forum/topic/1849568/4&year=2024#16499657
That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting out shooting before heat haze develops is certainly more important than which lens to bring.
Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of.
Citation needed. I have both. The 600 is only a bit sharper in the center but significantly sharper and has much less CA away from the center compared to the 300*2. If you present the same heavily cropped but otherwise perfect shot, you can tell them apart. See e.g. https://www.fredmiranda.com/forum/topic/1849568/4&year=2024#16499657
That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting out shooting before heat haze develops is certainly more important than which lens to bring.
Aug 21, 2026 at 10:46 AM
p.2 #3Time to let it go? Sony FE 600mm f/4
With every lens I've owned the keeper rate any time I add a 2x to a lens goes down. How much or how important that is to your shooting is unique. I have always been able to get good shots with a 2x, but at the cost of missing many others. How does the 300 and 2x do with fast and accurate AF? Is there a dramatic fall in in number of keepers in a sequence or initial acquisition? I'm sure when both a bare 600 and 300 with a 2x nail the shot they are close to the same in image quailty, but I'm more concerned with how many misses are there with a 2x.
Daran wrote:
Citation needed. I have both. The 600 is only a bit sharper in the center but significantly sharper and has much less CA away from the center compared to the 300*2. If you present the same heavily cropped but otherwise perfect shot, you can tell them apart. See e.g. https://www.fredmiranda.com/forum/topic/1849568/4&year=2024#16499657
That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting...Show more →
Daran wrote:
nmerc_photos wrote
Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of.That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting...Show more →
Aug 21, 2026 at 10:54 AM
p.2 #4Time to let it go? Sony FE 600mm f/4
timgangloff wrote:
With every lens I've owned the keeper rate any time I add a 2x to a lens goes down. How much or how important that is to your shooting is unique. I have always been able to get good shots with a 2x, but at the cost of missing many others. How does the 300 and 2x do with fast and accurate AF? Is there a dramatic fall in in number of keepers in a sequence or initial acquisition? I'm sure when both a bare 600 and 300 with a 2x nail the shot they are close to the same...Show more →Citation needed. I have both. The 600 is only a bit sharper in the center but significantly sharper and has much less CA away from the center compared to the 300*2. If you present the same heavily cropped but otherwise perfect shot, you can tell them apart. See e.g. https://www.fredmiranda.com/forum/topic/1849568/4&year=2024#16499657
That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting out shooting before heat haze develops is certainly more important than which lens to bring.
The 300 takes the 2x amazingly well. In practice you'll mostly forget you are using a TC. Larger flying birds should work fine (maybe a tad better than the 200-600G, which is no slouch), but for flight shots of swallows, song birds, I would drop the TC.
With every lens I've owned the keeper rate any time I add a 2x to a lens goes down. How much or how important that is to your shooting is unique. I have always been able to get good shots with a 2x, but at the cost of missing many others. How does the 300 and 2x do with fast and accurate AF? Is there a dramatic fall in in number of keepers in a sequence or initial acquisition? I'm sure when both a bare 600 and 300 with a 2x nail the shot they are close to the same...Show more →
Daran wrote
nmerc_photos wrote
Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of.That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting out shooting before heat haze develops is certainly more important than which lens to bring.
The 300 takes the 2x amazingly well. In practice you'll mostly forget you are using a TC. Larger flying birds should work fine (maybe a tad better than the 200-600G, which is no slouch), but for flight shots of swallows, song birds, I would drop the TC.
Aug 21, 2026 at 11:10 AM
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p.2 #5Time to let it go? Sony FE 600mm f/4
Knut. wrote:
Reasonable thing to do when there is no quality gain you can perceive. I can perceive such a difference. I like using the 300GM + 2x for scouting, but when I come across a worthwhile subject under good conditions I tend to be a bit miffed if I don't have the big gun with me.
Maybe you are living in a place like Florida and get away with less cropping. Or you shoot a lower resolution. Or you aren't obsessing about feathers. Or your presentation flattens out the difference. Or you flatten details with AI in post anyway. I would certainly not generally recommend the cash layout, but I would also not wana part from my 600.…
At the 600mm focal length, it's pretty universally accepted that there's little to no qualitative difference between the 600GM and 300GM + 2x. Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of. It's purely a 1 stop of light difference for ~$4K extra, that also comes with double the weight.Do you have a citation for this claim or a reference, where someone has compared the 600/4 versus 300/2.8 x2 with proper thoroughness?
Daran wrote:
Citation needed. I have both. The 600 is only a bit sharper in the center but significantly sharper and has much less CA away from the center compared to the 300*2. If you present the same heavily cropped but otherwise perfect shot, you can tell them apart. See e.g. https://www.fredmiranda.com/forum/topic/1849568/4&year=2024#16499657
That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting...Show more →
Any search engine or AI can find countless examples
You can also use the many threads already on FredMiranda discussing this, or look at Daran's testing and commentary and that thread that is already linked.
https://shuttermuse.com/sony-300mm-f-2-8-gm-teleconverter-performance/
https://cameradecision.com/blog/Sony-FE-300mm-F28-GM-with-20x-TC-vs-Sony-FE-600mm-F4-GM-Which-is-sharper
https://arihazeghiphotography.com/blog/sony-fe-300mm-f-2-8-g-master-oss-review/
https://www.australianphotography.com/gear/review-sony-300mm-f/2-8-gm-oss-lens
https://www.the-digital-picture.com/Reviews/Sony-FE-300mm-F2-8-GM-OSS-Lens.aspx
https://www.fredmiranda.com/forum/topic/1904270/
https://bcgforums.com/threads/sony-300gm-question.52674/
timgangloff wrote:
With every lens I've owned the keeper rate any time I add a 2x to a lens goes down. How much or how important that is to your shooting is unique. I have always been able to get good shots with a 2x, but at the cost of missing many others. How does the 300 and 2x do with fast and accurate AF? Is there a dramatic fall in in number of keepers in a sequence or initial acquisition? I'm sure when both a bare 600 and 300 with a 2x nail the shot they are close to the same...Show more →Citation needed. I have both. The 600 is only a bit sharper in the center but significantly sharper and has much less CA away from the center compared to the 300*2. If you present the same heavily cropped but otherwise perfect shot, you can tell them apart. See e.g. https://www.fredmiranda.com/forum/topic/1849568/4&year=2024#16499657
That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting out shooting before heat haze develops is certainly more important than which lens to bring.
I very rarely, if ever, shoot the 300GM with a 1.4x or bare, so I'm not a good judge of how much better the AF is in those situations.
I can say that I'm not aware of any instances of me missing AF with the 2x attached though. And I didn't feel any subjective difference with it compared to the 600GM or 600GM + 1.4x.
However, I came from the Nikon side where I was constantly missing images due to the AF. I think in general Sony's AF and tracking is so good that pretty much any modern lens is a nonissue.
I do hear a lot of people say the older lenses like the 200-600 miss focus or are too slow to acquire it, and that's on the bare lens. Even worse with 1.4x or 2x.
As best I can tell, people say the 300GM bare has the best AF of all Sony lenses, with the 1.4x is basically the same, and with the 2x it is a slight hit.
nmerc_photos wrote
Daran wrote
nmerc_photos wrote
I recently sold my 600GM in favor of the 300GM + 2x. In terms of optical quality, it is indistinguishable to me.Maybe you are living in a place like Florida and get away with less cropping. Or you shoot a lower resolution. Or you aren't obsessing about feathers. Or your presentation flattens out the difference. Or you flatten details with AI in post anyway. I would certainly not generally recommend the cash layout, but I would also not wana part from my 600.
At the 600mm focal length, it's pretty universally accepted that there's little to no qualitative difference between the 600GM and 300GM + 2x. Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of. It's purely a 1 stop of light difference for ~$4K extra, that also comes with double the weight.
Daran wrote:
nmerc_photos wrote
Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of.That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting...Show more →
Any search engine or AI can find countless examples
You can also use the many threads already on FredMiranda discussing this, or look at Daran's testing and commentary and that thread that is already linked.
https://shuttermuse.com/sony-300mm-f-2-8-gm-teleconverter-performance/
https://cameradecision.com/blog/Sony-FE-300mm-F28-GM-with-20x-TC-vs-Sony-FE-600mm-F4-GM-Which-is-sharper
https://arihazeghiphotography.com/blog/sony-fe-300mm-f-2-8-g-master-oss-review/
https://www.australianphotography.com/gear/review-sony-300mm-f/2-8-gm-oss-lens
https://www.the-digital-picture.com/Reviews/Sony-FE-300mm-F2-8-GM-OSS-Lens.aspx
https://www.fredmiranda.com/forum/topic/1904270/
https://bcgforums.com/threads/sony-300gm-question.52674/
timgangloff wrote:
With every lens I've owned the keeper rate any time I add a 2x to a lens goes down. How much or how important that is to your shooting is unique. I have always been able to get good shots with a 2x, but at the cost of missing many others. How does the 300 and 2x do with fast and accurate AF? Is there a dramatic fall in in number of keepers in a sequence or initial acquisition? I'm sure when both a bare 600 and 300 with a 2x nail the shot they are close to the same...Show more →
Daran wrote
nmerc_photos wrote
Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of.That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting out shooting before heat haze develops is certainly more important than which lens to bring.
I very rarely, if ever, shoot the 300GM with a 1.4x or bare, so I'm not a good judge of how much better the AF is in those situations.
I can say that I'm not aware of any instances of me missing AF with the 2x attached though. And I didn't feel any subjective difference with it compared to the 600GM or 600GM + 1.4x.
However, I came from the Nikon side where I was constantly missing images due to the AF. I think in general Sony's AF and tracking is so good that pretty much any modern lens is a nonissue.
I do hear a lot of people say the older lenses like the 200-600 miss focus or are too slow to acquire it, and that's on the bare lens. Even worse with 1.4x or 2x.
As best I can tell, people say the 300GM bare has the best AF of all Sony lenses, with the 1.4x is basically the same, and with the 2x it is a slight hit.
Aug 21, 2026 at 03:51 PM
p.2 #6Time to let it go? Sony FE 600mm f/4
I certainly notice an AF slowdown with the 2x on the 300GM compared to the 1.4x and compared to the bare 600GM. It is most evident if you aren't prefocused in the ball park of your next BIF that passes by. I've certainly missed shots because of this where I feel the 600GM would drive it to the bird faster.
I also feel the 600GM will produce a higher critically sharp hit rate during a given BIF sequence but in a lot of cases the 300/2x isn't a big enough hit to really matter nor make you regret your decision for that outing.
But I have shot every possible BIF with the 300/2x and had success. This includes swallows and even passerines like finches in flight.
I think one must keep in mind that even if the 600GM has better AF, the 300/2x provides so much better agility that your keeper rate for handheld BIF may end up better in the end. Especially if one is out for multiple hours where fatigue will certainly set in handholding the 600GM compared to the 300/2x.
If we are just talking about static bird images then yes there is an IQ advantage to the 600 but I also agree that you aren't going to be able to tell which lens shot which image if given a blind selection of varied shots. With an exact comparison shot at f/5.6 you probably can tell when carefully viewed at 1:1. But that probably doesn't matter.
I've said this a 100 times over the past year or more and I'll say it again. If I was forced to only keep one lens (and TCs) I'd keep my 300GM over all the rest.
I also feel the 600GM will produce a higher critically sharp hit rate during a given BIF sequence but in a lot of cases the 300/2x isn't a big enough hit to really matter nor make you regret your decision for that outing.
But I have shot every possible BIF with the 300/2x and had success. This includes swallows and even passerines like finches in flight.
I think one must keep in mind that even if the 600GM has better AF, the 300/2x provides so much better agility that your keeper rate for handheld BIF may end up better in the end. Especially if one is out for multiple hours where fatigue will certainly set in handholding the 600GM compared to the 300/2x.
If we are just talking about static bird images then yes there is an IQ advantage to the 600 but I also agree that you aren't going to be able to tell which lens shot which image if given a blind selection of varied shots. With an exact comparison shot at f/5.6 you probably can tell when carefully viewed at 1:1. But that probably doesn't matter.
I've said this a 100 times over the past year or more and I'll say it again. If I was forced to only keep one lens (and TCs) I'd keep my 300GM over all the rest.
Aug 22, 2026 at 06:24 AM
p.2 #7Time to let it go? Sony FE 600mm f/4
Daran wrote:
Citation needed. I have both. The 600 is only a bit sharper in the center but significantly sharper and has much less CA away from the center compared to the 300*2. If you present the same heavily cropped but otherwise perfect shot, you can tell them apart. See e.g. https://www.fredmiranda.com/forum/topic/1849568/4&year=2024#16499657
That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting...Show more →
Thanks for the link to your tests.
It's not even close. 600/4 just has biting acutance, 300 + 2x is nice but not particularly close.
Of course, atmospherics will render the results identical in many cases in the field...
nmerc_photos wrote
Nobody in the world could accurately and repeatedly tell one lens from the other in blind tests, that we're aware of.That said, the 300*2 is still pretty good, even with the TC. Without TC the 300 is even better than the 600. And without a direct comparison, I could not tell them apart, but that is true for most lenses. Only under very good circumstances does this difference even exist. Getting...Show more →
Thanks for the link to your tests.
It's not even close. 600/4 just has biting acutance, 300 + 2x is nice but not particularly close.
Of course, atmospherics will render the results identical in many cases in the field...
Aug 22, 2026 at 07:22 AM