Sony 100-400 f/4.5
p.5 #1Sony 100-400 f/4.5
Imagemaster wrote:
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?
Of course dearer but OM Pro lenses are no guide, they a ludicrously overpriced because they believe you are getting a 300-800 f/4.5. OM lenses are dearer than Gm lenses in Australia.
Also if you want to save money no one is stopping you buying the 100-400 f/4.5-5.6 which is still available. IMO a 100-400 f/4.5 with built-in 1.25x would have been about $6K.
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.
Firstly 300GM is over 4x the price of the 200-600G in Australia and having done the whole 300 f/2.8+2x many years ago, I couldn't wait to use a much longer FL for my birding. 300GM is stop gap at best and I'm not into relying on a 2x TC any more.
Secondly 100-400 is extremely versatile and can be used for a lot of stuff outside wildlife and birding. So a 100-400 + 1.4x is IMO a much better option than a 300 f/2.8 + 2x. I get a more flexible lens, I get something that even with a 1.4x is lighter, has better AF, better OS, 75% more magnification at mfd, balances better, and has same IQ as a 200-600G anyway.
So I disagree totally 300GM is a better option especially when the 100-400 is about 25% cheaper.
Edited on Jun 16, 2026 at 05:14 PM · View previous versions
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.Of course dearer but OM Pro lenses are no guide, they a ludicrously overpriced because they believe you are getting a 300-800 f/4.5. OM lenses are dearer than Gm lenses in Australia.
Also if you want to save money no one is stopping you buying the 100-400 f/4.5-5.6 which is still available. IMO a 100-400 f/4.5 with built-in 1.25x would have been about $6K.
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.
Firstly 300GM is over 4x the price of the 200-600G in Australia and having done the whole 300 f/2.8+2x many years ago, I couldn't wait to use a much longer FL for my birding. 300GM is stop gap at best and I'm not into relying on a 2x TC any more.
Secondly 100-400 is extremely versatile and can be used for a lot of stuff outside wildlife and birding. So a 100-400 + 1.4x is IMO a much better option than a 300 f/2.8 + 2x. I get a more flexible lens, I get something that even with a 1.4x is lighter, has better AF, better OS, 75% more magnification at mfd, balances better, and has same IQ as a 200-600G anyway.
So I disagree totally 300GM is a better option especially when the 100-400 is about 25% cheaper.
Edited on Jun 16, 2026 at 05:14 PM · View previous versions
Jun 16, 2026 at 12:31 AM
p.5 #2Sony 100-400 f/4.5
EB-1 wrote:
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.
This also depends on your sensor resolution. For a low resolution sensor (or when recording video), the effect of enlarging the airy disk may be irrelevant, whereas on a high resolution sensor even the 1.4x reduces pixel level sharpness noticeably. One more reason why folks disagree on whether using TCs is worthwhile.
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.
This also depends on your sensor resolution. For a low resolution sensor (or when recording video), the effect of enlarging the airy disk may be irrelevant, whereas on a high resolution sensor even the 1.4x reduces pixel level sharpness noticeably. One more reason why folks disagree on whether using TCs is worthwhile.
Jun 16, 2026 at 05:47 AM
p.5 #3Sony 100-400 f/4.5
Has anyone compared the 100-400mm f4.5 + TC 2x vs the 200-600mm f6.3 + TC 1.4x?
Jun 16, 2026 at 02:58 PM
p.5 #4Sony 100-400 f/4.5
DWOfPaul wrote:
Has anyone compared the 100-400mm f4.5 + TC 2x vs the 200-600mm f6.3 + TC 1.4x?
Did a very quick IQ comparison. It is close but the 100-400/2x was resolving some finer details on the $5 bill I shot when zoomed in to 200%. It had just slightly better contrast. But very close.
The 100-400 is a much nicer lens to use, handhold and AF for BIF is way more consistent. 100-400 balances much better in the hand.
Has anyone compared the 100-400mm f4.5 + TC 2x vs the 200-600mm f6.3 + TC 1.4x?
Did a very quick IQ comparison. It is close but the 100-400/2x was resolving some finer details on the $5 bill I shot when zoomed in to 200%. It had just slightly better contrast. But very close.
The 100-400 is a much nicer lens to use, handhold and AF for BIF is way more consistent. 100-400 balances much better in the hand.
Jun 16, 2026 at 07:19 PM
p.5 #5Sony 100-400 f/4.5
Planetwide wrote:
-When shooting the brick wall, the lens was sharp wide open across the frame at 200-400mm. Stopping down to f/6.3 made a very small improvement in the center and midframe, but the corners were actually better in some cases at the maximum aperture. Basically, it was fully sharp wide open.
-At 100mm, the corners were softer but also on my copy the left edge was soft and didn't become convincingly sharp until f/10. The right side was better, but overall I could see that peak resolution was better from 200-400mm across the frame. If Sony decided to optimize for the long end then that would seem to be a good design choice, at least for my uses.
-I shot the slanted target, the roof, and found that sharp detail ran along the red line as shown below (this example at 200mm):
This tilt in the plane of focus seems to be present across 100-400mm, but it is more pronounced at 100mm and eases at 400mm, but it is still there to some degree. I think for those shooting sports or birds or those who shoot where having a flat plane is not critical, you will be happy, because even the flat target looked good. I am not sure yet because I want to also shoot landscape and I haven't determined if this is acceptable for my uses. I have other Sony telephoto zooms including the 50-150 and 70-200 II and they don't have this behavior, so I am wondering if another copy might do better.This might be a silly question, but did you lock out the OSS for the test? I have run into similar problems on Canon, where the IS was tilting the sensor...
It's not a silly question, and I try to disable OSS when testing, except that with this long a lens, small vibrations have a big impact, and since I have to be outside to have enough space to test at 400mm, OSS was necessary for many of my test shots. I also took quite a few at shutter speeds from 1/500s-1/2000s and I don't believe OSS is even active on the high end of that. Overall, I shot enough that do believe there is some drift in focus along the Z axis. I also got to try a second copy and I think I may keep that one. Both are at their weakest at 100mm and both are weaker on the left edge, for whatever reason, but this second copy sharpens up at the edges at relatively wider apertures. It is very good at 200mm. At 400mm I have had trouble with testing due to heat distortion, but at the moment I think it is good enough for landscape/cityscape. I am going to do more real world shooting to confirm.
ketang wrote
FWIW I received mine today and, being a pixel peeper, did a number of brick wall tests (at enough of a distance and with enough adjustments and repetition to make an initial conclusion) as well as shooting up to an angle to a slanted target (a roof) to see what was happening on the Z-axis. I used the A7R VI on a tripod and remote shutter, electronic shutter, and when there was wind increased my shutter speed to around 1/500s as needed. I found a few things:-When shooting the brick wall, the lens was sharp wide open across the frame at 200-400mm. Stopping down to f/6.3 made a very small improvement in the center and midframe, but the corners were actually better in some cases at the maximum aperture. Basically, it was fully sharp wide open.
-At 100mm, the corners were softer but also on my copy the left edge was soft and didn't become convincingly sharp until f/10. The right side was better, but overall I could see that peak resolution was better from 200-400mm across the frame. If Sony decided to optimize for the long end then that would seem to be a good design choice, at least for my uses.
-I shot the slanted target, the roof, and found that sharp detail ran along the red line as shown below (this example at 200mm):
This tilt in the plane of focus seems to be present across 100-400mm, but it is more pronounced at 100mm and eases at 400mm, but it is still there to some degree. I think for those shooting sports or birds or those who shoot where having a flat plane is not critical, you will be happy, because even the flat target looked good. I am not sure yet because I want to also shoot landscape and I haven't determined if this is acceptable for my uses. I have other Sony telephoto zooms including the 50-150 and 70-200 II and they don't have this behavior, so I am wondering if another copy might do better.
It's not a silly question, and I try to disable OSS when testing, except that with this long a lens, small vibrations have a big impact, and since I have to be outside to have enough space to test at 400mm, OSS was necessary for many of my test shots. I also took quite a few at shutter speeds from 1/500s-1/2000s and I don't believe OSS is even active on the high end of that. Overall, I shot enough that do believe there is some drift in focus along the Z axis. I also got to try a second copy and I think I may keep that one. Both are at their weakest at 100mm and both are weaker on the left edge, for whatever reason, but this second copy sharpens up at the edges at relatively wider apertures. It is very good at 200mm. At 400mm I have had trouble with testing due to heat distortion, but at the moment I think it is good enough for landscape/cityscape. I am going to do more real world shooting to confirm.
Jun 16, 2026 at 09:09 PM
p.5 #6Sony 100-400 f/4.5
Alex Phan wrote:
Hoping @Alex Phan@@ got the lens to Leofoto so they can get working on one!!Skin is available this weekend
Foot replacement already done. USA warehouse expecting shipment soon.
Any update on the skin or foot? Preorder link?
I don't see the skin on the alphagvrd website yet.
arbitrage wrote
Also for those thinking about replacement feet the bolt pattern is not the same as the 400GM/600GM/Canon lenses. It is also not the same as the 400-800 (someone confirmed this on BCG forum). So we are stuck waiting for someone to make a foot with this new bolt pattern.Hoping @Alex Phan@@ got the lens to Leofoto so they can get working on one!!
Foot replacement already done. USA warehouse expecting shipment soon.
Any update on the skin or foot? Preorder link?
I don't see the skin on the alphagvrd website yet.
Jun 17, 2026 at 06:01 AM
p.5 #7Sony 100-400 f/4.5
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
Jun 17, 2026 at 08:55 AM
p.5 #8Sony 100-400 f/4.5
Does it matter what anyone calls it?
Anyway, to actually answer your question, I don't think it makes a variable aperture zoom.
I'd say it makes two constant aperture zooms.
So in the case of hypothetical Sony 100-400 f4.5 built in TC, you get 100-400 f4.5, or 140-560 f6.3.
Particularly with Sony internal zooms, zooming is a one finger, very low effort action.
Switching a built in TC is more effort.
So while you can switch TC in / out during shooting, zooming can be done 'mid sequence'.
I suppose the extra dexterous people could switch built in TC during a sequence, I think it's not a realistic function.
The only difference between built in and external TC is speed of switch.
With external TC, nobody uses 'variable aperture zoom' to describe each option.
In fact, manufacturers use the same terminolgy (ie, 2 constant aperture zooms) to describe built in TCs with zooms.
(of the 2 examples I know of, OM 150-400, Canon 200-400)
Lethimcook wrote:
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
Edited on Jun 17, 2026 at 09:18 AM · View previous versions
Anyway, to actually answer your question, I don't think it makes a variable aperture zoom.
I'd say it makes two constant aperture zooms.
So in the case of hypothetical Sony 100-400 f4.5 built in TC, you get 100-400 f4.5, or 140-560 f6.3.
Particularly with Sony internal zooms, zooming is a one finger, very low effort action.
Switching a built in TC is more effort.
So while you can switch TC in / out during shooting, zooming can be done 'mid sequence'.
I suppose the extra dexterous people could switch built in TC during a sequence, I think it's not a realistic function.
The only difference between built in and external TC is speed of switch.
With external TC, nobody uses 'variable aperture zoom' to describe each option.
In fact, manufacturers use the same terminolgy (ie, 2 constant aperture zooms) to describe built in TCs with zooms.
(of the 2 examples I know of, OM 150-400, Canon 200-400)
Lethimcook wrote:
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
Edited on Jun 17, 2026 at 09:18 AM · View previous versions
Jun 17, 2026 at 09:09 AM
p.5 #9Sony 100-400 f/4.5
Lethimcook wrote:
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
Part of the value of built-in TCs is that they are tuned to the lens and therefore lead to better performance. Sometimes that is quite noticeable. Canon builds TC into the 400 f/2.8 and 600 f/4 RF lenses and the built-in TCs produce better results than the ir regular modular TC. I think that is the primary reason to build in a TC. Modularity is good, but so is better performance and if you are going to spend over ten thousand for a lens, spending a couple thousand more for optimal TC performance seems like something a lot of people willing to spend that kind of money would want.
With regard to just making a zoom lens a variable aperture lens instead, I don't think it is that easy. I think adding a TC and making a variable aperture lens are very different designs and no variable aperture zoom that I know of has performance at 1.4X less than the max aperture at 1.4X less than the max focal length. So, for example, if the 100-400 f/4.5 was a 140-560 lens, I have never seen a variable aperture zoom that would be f/4.5 at 400, so you would be sacrificing versatility at 400, and at least some of the focal length range below that, to make it a variable aperture zoom instead of a fixed aperture zoom that also takes a TC.
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
Part of the value of built-in TCs is that they are tuned to the lens and therefore lead to better performance. Sometimes that is quite noticeable. Canon builds TC into the 400 f/2.8 and 600 f/4 RF lenses and the built-in TCs produce better results than the ir regular modular TC. I think that is the primary reason to build in a TC. Modularity is good, but so is better performance and if you are going to spend over ten thousand for a lens, spending a couple thousand more for optimal TC performance seems like something a lot of people willing to spend that kind of money would want.
With regard to just making a zoom lens a variable aperture lens instead, I don't think it is that easy. I think adding a TC and making a variable aperture lens are very different designs and no variable aperture zoom that I know of has performance at 1.4X less than the max aperture at 1.4X less than the max focal length. So, for example, if the 100-400 f/4.5 was a 140-560 lens, I have never seen a variable aperture zoom that would be f/4.5 at 400, so you would be sacrificing versatility at 400, and at least some of the focal length range below that, to make it a variable aperture zoom instead of a fixed aperture zoom that also takes a TC.
Jun 17, 2026 at 09:13 AM
p.5 #10Sony 100-400 f/4.5
I just finished testing my Sony 100-400mm F4.5 lens. It is as follows at F4.5
100mm - Sharp across the frame with a slight degradation into the corners. The right side is ever so slightly worse. The right side is not worse than the MTF for the lens as published by Sony.
135mm - Sharp across the frame. A very slight drop off in the right side corners. sharpening eliminates this drop off.
200mm - Sharp across the entire frame, with perfect corners.
300mm - Sharp across the entire frame, with perfect corners.
400mm - Sharp across the entire frame, with perfect corners.
Edited on Jun 17, 2026 at 09:43 AM · View previous versions
100mm - Sharp across the frame with a slight degradation into the corners. The right side is ever so slightly worse. The right side is not worse than the MTF for the lens as published by Sony.
135mm - Sharp across the frame. A very slight drop off in the right side corners. sharpening eliminates this drop off.
200mm - Sharp across the entire frame, with perfect corners.
300mm - Sharp across the entire frame, with perfect corners.
400mm - Sharp across the entire frame, with perfect corners.
Edited on Jun 17, 2026 at 09:43 AM · View previous versions
Jun 17, 2026 at 09:29 AM
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p.5 #11Sony 100-400 f/4.5
A7R6, upper corners at 100mm, no sharpening
Top Left
Top Right
Top Left
Top Right
Jun 17, 2026 at 09:38 AM
p.5 #12Sony 100-400 f/4.5
Steve Spencer wrote:
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.Part of the value of built-in TCs is that they are tuned to the lens and therefore lead to better performance. Sometimes that is quite noticeable. Canon builds TC into the 400 f/2.8 and 600 f/4 RF lenses and the built-in TCs produce better results than the ir regular modular TC. I think that is the primary reason to build in a TC. Modularity is good, but so is better performance and if you are going to spend over ten thousand for a lens, spending a couple thousand more for optimal TC performance seems like something a lot of...Show more →
That certainly seems logical, but I don't think it's always true. I seem to recall Nikon users saying the 180-400 with built in converter wasn't as sharp as it was using an external 1.4x.
Lethimcook wrote
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
That certainly seems logical, but I don't think it's always true. I seem to recall Nikon users saying the 180-400 with built in converter wasn't as sharp as it was using an external 1.4x.
Jun 17, 2026 at 09:44 AM
p.5 #13Sony 100-400 f/4.5
scott f wrote:
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.Part of the value of built-in TCs is that they are tuned to the lens and therefore lead to better performance. Sometimes that is quite noticeable. Canon builds TC into the 400 f/2.8 and 600 f/4 RF lenses and the built-in TCs produce better results than the ir regular modular TC. I think that is the primary reason to build in a TC. Modularity is good, but so is better performance and if you are going to spend over ten thousand for a lens, spending a couple thousand more for optimal TC performance seems like something a lot of people willing to spend that kind of money would want.
With regard to just making a zoom lens a variable aperture lens instead, I don't think it is that easy. I think adding a TC and making a variable aperture lens are very different designs and no variable aperture zoom that I know of has performance at 1.4X less than the max aperture at 1.4X less than the max focal length. So, for example, if the 100-400 f/4.5 was a 140-560 lens, I have never seen a variable aperture zoom that would be f/4.5 at 400, so you would be sacrificing versatility at 400, and at least some of the focal length range below that, to make it a variable aperture zoom instead of a fixed aperture zoom that also takes a TC.That certainly seems logical, but I don't think it's always true. I seem to recall Nikon users saying the 180-400 with built in converter wasn't as sharp as it was using an external 1.4x.
If that were true, then that would be a fail from Nikon for that lens. They ought to be able with a dedicated tuned TC get better performance than a generic TC that has to work with many different lenses and if they can't, then they should just introduce the lens without a buit-in TC, IMO. Maybe there was a construction issue with that lens and they had trouble making it to specifications and when the TC was engaged in at least some copies it didn't operate as it was designed.
Steve Spencer wrote
Lethimcook wrote
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
With regard to just making a zoom lens a variable aperture lens instead, I don't think it is that easy. I think adding a TC and making a variable aperture lens are very different designs and no variable aperture zoom that I know of has performance at 1.4X less than the max aperture at 1.4X less than the max focal length. So, for example, if the 100-400 f/4.5 was a 140-560 lens, I have never seen a variable aperture zoom that would be f/4.5 at 400, so you would be sacrificing versatility at 400, and at least some of the focal length range below that, to make it a variable aperture zoom instead of a fixed aperture zoom that also takes a TC.
If that were true, then that would be a fail from Nikon for that lens. They ought to be able with a dedicated tuned TC get better performance than a generic TC that has to work with many different lenses and if they can't, then they should just introduce the lens without a buit-in TC, IMO. Maybe there was a construction issue with that lens and they had trouble making it to specifications and when the TC was engaged in at least some copies it didn't operate as it was designed.
Jun 17, 2026 at 09:53 AM
p.5 #16Sony 100-400 f/4.5
Steve Spencer wrote:
I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.Part of the value of built-in TCs is that they are tuned to the lens and therefore lead to better performance. Sometimes that is quite noticeable. Canon builds TC into the 400 f/2.8 and 600 f/4 RF lenses and the built-in TCs produce better results than the ir regular modular TC. I think that is the primary reason to build in a TC. Modularity is good, but so is better performance and if you are going to spend over ten thousand for a lens, spending a couple thousand more for optimal TC performance seems like something a lot of people willing to spend that kind of money would want.
With regard to just making a zoom lens a variable aperture lens instead, I don't think it is that easy. I think adding a TC and making a variable aperture lens are very different designs and no variable aperture zoom that I know of has performance at 1.4X less than the max aperture at 1.4X less than the max focal length. So, for example, if the 100-400 f/4.5 was a 140-560 lens, I have never seen a variable aperture zoom that would be f/4.5 at 400, so you would be sacrificing versatility at 400, and at least some of the focal length range below that, to make it a variable aperture zoom instead of a fixed aperture zoom that also takes a TC.That certainly seems logical, but I don't think it's always true. I seem to recall Nikon users saying the 180-400 with built in converter wasn't as sharp as it was using an external 1.4x.If that were true, then that would be a fail from Nikon for that lens. They ought to be able with a dedicated tuned TC get better performance than a generic TC that has to work with many different lenses and if they can't, then they should just introduce the lens without a buit-in TC, IMO. Maybe there was a construction issue with that lens and they had trouble making it to specifications and when the TC was engaged in at least some copies it didn't operate as it was designed.
Totally agree. I might inflame Nikon users with this comment, but I used to shoot Nikon, and until the Z mount came along, I didn't find their teleconverters very good at all. The 2x was terrible with most lenses I owned.
scott f wrote
Steve Spencer wrote
Lethimcook wrote
This might be a silly thought but don't built in TCs on zooms just make the lens a variable aperture zoom?I for one agree with the approach of the 300GM without TCs. It's lightweight, and anyone that wants a TC can buy the appropriate one, and then shift said TCs onto the lens they want to use at the moment. It's modular. Rather than pay for a built-in TC 3-4 times you just pay once, and deal with the quirks of putting them on or off lenses.
With regard to just making a zoom lens a variable aperture lens instead, I don't think it is that easy. I think adding a TC and making a variable aperture lens are very different designs and no variable aperture zoom that I know of has performance at 1.4X less than the max aperture at 1.4X less than the max focal length. So, for example, if the 100-400 f/4.5 was a 140-560 lens, I have never seen a variable aperture zoom that would be f/4.5 at 400, so you would be sacrificing versatility at 400, and at least some of the focal length range below that, to make it a variable aperture zoom instead of a fixed aperture zoom that also takes a TC.
Totally agree. I might inflame Nikon users with this comment, but I used to shoot Nikon, and until the Z mount came along, I didn't find their teleconverters very good at all. The 2x was terrible with most lenses I owned.
Jun 17, 2026 at 09:56 AM
p.5 #19Sony 100-400 f/4.5
For those of you who are thinking about a cover for this lens, I have always liked the RolanPro covers. This was a straightforward install, I will adjust a little once I use it for a month or so. Ordered off of Amazon from China, fast shipment, 4 days via FedEx.
The hood was the most difficult, more or less. Just had to realign the release 5x or so. Everything else is velcro.
https://www.amazon.com/dp/B0H32D2PKL?th=1
Of course, I just noticed I forgot to remove the numerical labels
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Edited on Jun 17, 2026 at 12:53 PM · View previous versions
The hood was the most difficult, more or less. Just had to realign the release 5x or so. Everything else is velcro.
https://www.amazon.com/dp/B0H32D2PKL?th=1
Of course, I just noticed I forgot to remove the numerical labels
.Edited on Jun 17, 2026 at 12:53 PM · View previous versions
Jun 17, 2026 at 12:24 PM
p.5 #20Sony 100-400 f/4.5
I bought my first RolanPro for my 200-600. The neoprene ones might resist impact better , but they make the lenses too big. I've skins too. I like the RolanPro the best.
Jun 17, 2026 at 12:45 PM