p.17 #1 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
mklass wrote:
Oh I read it, and it was nothing as bad as what I and seeing. Nor do other lenses exhibit the pincushioning that I have. However an adapter without glass can certainly cause the image to display improperly if it does not accurately reflect the specified flange focal distance. Nikon Z is 16mm. Sony E is 18mm. That means the TZE must be only 2. What if it is off a bit, either consistently or inconsistently around the flange?
And if the flange distance is not consistent around the mount the plane of focus will be horribly tilted and you will have one side of the image soft and one sharp. If it is consistently too long you can’t focus to infinity. If it is too short you’ll lose some close focus, but other than that fine. Many cheaper adapters go a bit too short on purpose just to make sure they don’t end up long by accident. And none of these cases cause pincushion distortion of course. Simple geometry.
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p.17 #2 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
mklass wrote:
Oh I read it, and it was nothing as bad as what I and seeing. Nor do other lenses exhibit the pincushioning that I have. However an adapter without glass can certainly cause the image to display improperly if it does not accurately reflect the specified flange focal distance. Nikon Z is 16mm. Sony E is 18mm. That means the TZE must be only 2. What if it is off a bit, either consistently or inconsistently around the flange?
If an adapter is off a little bit it can affect a lenses performance and how it affects it depends on the lens. If a lens is to thick it works like a very short extension tube. You will get a tiny bit shorter MFD and you may not get focus at infinity. If the lens has a floating element you might see a bit more CA, but a tiny bit more extension isn't going to affect distortion any thing more than a tiny bit. Many of us often put extension tubes of many mm on our lenses and we don't see huge differences in distortion.
An adapter can be a little bit short as well. That means the rear element is a little closer to the sensor than the lens designer intended. This can lead to a bit more CA with a lens with a floating element, and it can mean the lens will focus to infinity much sooner than the marking on the lens. It also can mean the MFD is longer than the lens is rated for, but again it isn't going to affect distortion any thing more than a tiny bit.
If you really think it is the thickness of the adapter, then you can check out the infinity focus and the MFD to see how much the lens deviates from specs and whether it is too thin (longer MFD, hits infinity sooner--this is more likely) or too thick (shorter MFD, doesn't hit infinity focus), and you can adjust the adapter. If it is too thin you can shim it, and if it is too thick you can sand it down (or get another one; too thick adapters are rare because manufacturer know people recognize not be able to focus at infinity more than they recognize the MFD is a bit longer than specs, so they tend to make adapters a bit too thin).
I have used lots and lots of adapters (about 50) and I have yet to see any one of them affect distortion. Suffice it to say I agree with kwalsh. I think what you are seeing is the native distortion of these lenses without corrections and if you want to use these lenses on your Nikon Z cameras you will either have to live with the distortion or correct it in post.
p.17 #3 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
Yea, might be nice to tone it down a lil. I own the lens, I hadn’t noticed that distortion. It may well be there, but I didn’t have to run a search cause I haven’t seen anything to feel the need.
kwalsh wrote:
No, it is exactly what it should be without corrections. See here:
This isn't rocket science folks. Many lenses meant for mirrorless cameras have a fair bit of distortion meant to be corrected. Cut off the metadata path for those corrections and of course you are going to see a fair bit of distortion.
And seriously. The web is full of reviews that illustrate this clearly. I mean it is a bit of a step past "let me Google that for you" but a little due diligence before posting would help...
EDIT: Ah, sorry for being a grumpy-pus. I must need a snack.
Anyway, everything is fine and working just the way it should....Show more →
Sep 27, 2020 at 08:36 PM
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p.17 #4 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
mklass wrote:
Oh I read it, and it was nothing as bad as what I and seeing. Nor do other lenses exhibit the pincushioning that I have. However an adapter without glass can certainly cause the image to display improperly if it does not accurately reflect the specified flange focal distance. Nikon Z is 16mm. Sony E is 18mm. That means the TZE must be only 2. What if it is off a bit, either consistently or inconsistently around the flange?
Keep in mind distortion is focus distant dependent for many lenses (i.e., the amount of distortion varies with the focus distance). In addition, the reported distortion of a lens like 1.68% for the Sigma 45 f/2.8 DN is typically at infinity. When you take a shot like yours that is much closer than infinity, then the distortion could differer significantly from the reported percentage at infinity. So, you need to know the distortion of these lenses at the focus distance you are testing and not just the distortion at infinity to know if the lens is showing more or less distortion than would be expected for the lens.
p.17 #5 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
I will borrow my friends A7 in a few days and test my lenses in the native format without correction.
And not all reviews mention distortion as an issue. In fact, many say noting at all, good or bad, about distortion.
I have never had a Sigma Global Vision lens display anything close to this much distortion. If this is typical for this lens, then it doesn't deserve the Art designation at all. If fact, I think Sigma should be ashamed of it.
And Nikons Z lenses don't have distortion like this.
Sep 27, 2020 at 11:40 PM
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p.17 #6 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
mklass wrote:
I will borrow my friends A7 in a few days and test my lenses in the native format without correction.
And not all reviews mention distortion as an issue. In fact, many say noting at all, good or bad, about distortion.
I have never had a Sigma Global Vision lens display anything close to this much distortion. If this is typical for this lens, then it doesn't deserve the Art designation at all. If fact, I think Sigma should be ashamed of it.
And Nikons Z lenses don't have distortion like this.
I think you are confusing corrected and uncorrected performance. The correction for distortion is often baked in these days and you have to take careful steps to make sure it isn't used. If you do test lenses on a Sony body, then you need to make sure to take steps to avoid the built-in corrections. On Sony cameras that usually means taping over the electrical contacts or the baked in corrections will be applied.
As to whether Z lenses have this much distortion. Here is Thom Hogan's review of the Z 14-30 f/4S:
In the review he notes that at 14mm it has distortion that is, "well above the 3% threshold at which you almost certainly have to correct it." So, yes Z lenses have distortion too, but corrections are built in with Z cameras.
Like it or not, it has become a common strategy of pretty much all modern lens brands to utilize built in software corrections, particularly of distortion and vignetting, to allow better control of other aberrations that can't be controlled with software corrections. Nikon does it. Sony does it. Canon does it. Zeiss does it with their Batis lenses. Even Leica does it with their SL lenses, and yes Sigma does it as well.
p.17 #7 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
mklass wrote:
I will borrow my friends A7 in a few days and test my lenses in the native format without correction.
Read up on how to actually truly disable corrections then or you may end up fooling yourself. I'm not familiar with Sony but with many other manufacturers this is impossible to do with any camera settings or RAW converter settings on many converters (LR/ACR especially). You may need to shoot RAW and then delete particular EXIF fields to actually disable the corrections or else use particular 3rd party converters that ignore them. DCRAW is always a pretty safe choice for getting output with corrections ignored.
And not all reviews mention distortion as an issue. In fact, many say noting at all, good or bad, about distortion.
Many reviewers aren't particularly thorough. And many test lenses as they are intended to be used as an integrated system with corrections applied.
I have never had a Sigma Global Vision lens display anything close to this much distortion.
I don't know which lenses are Sigma Global Vision branded so this may in fact be the worst one. That said, many of their lenses and everyone else's lenses designed for mirrorless mounts have a lot of distortion that is intended to be corrected. Usually it is corrected automatically without the user noticing.
If this is typical for this lens, then it doesn't deserve the Art designation at all. If fact, I think Sigma should be ashamed of it.
This is a philosophical argument and you aren't the first to feel that way. Fundamentally aberration correction is a bag of trade offs. If you want less distortion you are going to get more of something else that can't be corrected in software. With DSLRs in order to keep OVF framing close to the final output significant automated software distortion correction wasn't an option. And of course a lens design for film has no options for software correction either. With an EVF only pathway now the designers have more options when it comes to the best final image quality. Some fraction of photographers feel "cheated" when they become aware of how modern lens design for mirrorless systems deals with that optimization problem.
For instance the Nikon Z 24-70/2.8S which is so good some have called it the new "benchmark" for 24-70/2.8 zooms has 3% distortion at the 24 and 70 ends of it. But no one ever sees that unless they go to great lengths to disable corrections. And the end result of the lens design with intentionally high distortion meant to be corrected in software is one of the highest IQ 24-70/2.8 lenses ever built.
And Nikons Z lenses don't have distortion like this.
They sure do! And because the corrections are seamlessly integrated from the camera to the RAW converters with no user option to disable them you've never noticed. Nor have many reviewers. But the distortion is there on many Z lenses. Pretty severe on some, even with "S" labels.
And nothing special about Nikon or Sigma in this regard. As Steve pointed out pretty much every manufacturer does it. It results in overall the best final image quality. No point in having perfect optical distortion correction if the corners are then full of coma, astigmatism and field curvature.
p.17 #8 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
Well put, you and Steve.
I wish I'd saved the source a few years ago, but also read from some lens designers that correcting distortion optically ALSO has penalties in sharpness, which is usually the arguments against software corrections. So it makes perfect sense to "give" on that design parameter for other benefits, when it can A) be corrected easily and B) correcting it optically wouldn't yield great gains in sharpness in the finished image.
kwalsh wrote:
Read up on how to actually truly disable corrections then or you may end up fooling yourself. I'm not familiar with Sony but with many other manufacturers this is impossible to do with any camera settings or RAW converter settings on many converters (LR/ACR especially). You may need to shoot RAW and then delete particular EXIF fields to actually disable the corrections or else use particular 3rd party converters that ignore them. DCRAW is always a pretty safe choice for getting output with corrections ignored.
Many reviewers aren't particularly thorough. And many test lenses as they are intended to be used as an integrated system with corrections applied.
I don't know which lenses are Sigma Global Vision branded so this may in fact be the worst one. That said, many of their lenses and everyone else's lenses designed for mirrorless mounts have a lot of distortion that is intended to be corrected. Usually it is corrected automatically without the user noticing.
This is a philosophical argument and you aren't the first to feel that way. Fundamentally aberration correction is a bag of trade offs. If you want less distortion you are going to get more of something else that can't be corrected in software. With DSLRs in order to keep OVF framing close to the final output significant automated software distortion correction wasn't an option. And of course a lens design for film has no options for software correction either. With an EVF only pathway now the designers have more options when it comes to the best final image quality. Some fraction of photographers feel "cheated" when they become aware of how modern lens design for mirrorless systems deals with that optimization problem.
For instance the Nikon Z 24-70/2.8S which is so good some have called it the new "benchmark" for 24-70/2.8 zooms has 3% distortion at the 24 and 70 ends of it. But no one ever sees that unless they go to great lengths to disable corrections. And the end result of the lens design with intentionally high distortion meant to be corrected in software is one of the highest IQ 24-70/2.8 lenses ever built.
They sure do! And because the corrections are seamlessly integrated from the camera to the RAW converters with no user option to disable them you've never noticed. Nor have many reviewers. But the distortion is there on many Z lenses. Pretty severe on some, even with "S" labels.
And nothing special about Nikon or Sigma in this regard. As Steve pointed out pretty much every manufacturer does it. It results in overall the best final image quality. No point in having perfect optical distortion correction if the corners are then full of coma, astigmatism and field curvature.
p.17 #10 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
I got a used TZE-01 from another member here. I tested it on my Sony 24-105mm and it focuses instantly and silently. So that part is great. However was shocked to see noticeable pincushion distortion at 105mm!!!
I don't subscribe to Lightroom and I am not sure if there are good free programs to correct distortion.
I have Luminar 4 but the distortion correction is just one manual slider which does the job somewhat. So wondering what all other options do we have. Would it be possible to pass in correct EXIF data of the lens to assist the software to auto correct in the future firmware releases?
p.17 #11 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
Also another thing that makes me worry a bit is there is some play in the adapter and the body specially when a heavy lens like 24-105mm, which may be a bigger problem with 70-200mm etc. How are you all dealing with this? Do you have similar play?
p.17 #12 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
Pincushion distortion at the long end of a zoom is a common thing. Usually the wide end will have barrel distortion, somewhere in the middle will be mostly distortion free, then pincushion at the long end.
If the software supports correction profiles manually applying the Sony 24-105 profile should work. Or a similar lens, usually found through trial and error (other midrange zooms are good candidates). As for other options, it depends how deep you want to go (it's a textbook problem). There's probably free software somewhere that lets you enter in the coefficients manually and you can guess your way to a good solution. If you want to go nuts, you can custom calibrate your copy at 105mm with a target.
I'm worried about the play too. If the little retaining pin is released the lens could drop right off. I'm considering some sort of heat-shrink to seal the adapter to the lens, but I don't know how well it works for that large a diameter.
p.17 #13 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
I took the Z5 + TZE01 + Sony 24-105mm to the store to test it out in the field. Anyone else think the adapter very finnicky when you turn on the camera 50% of the times it refuses to even try and focus and I see a red box. I have to manually adjust the lens body and turn on and off the camera to make it work. I feel the play in the adapter is causing the contact to be broken off and requiring adjustment in the position of the contact to make it work. Once it starts to work, it works perfectly.
PS: I had the camera hanging on a strap. The weight of the lens may have made it to loose contact when walking around.
p.17 #17 · TZE-01 Owners Unite! Images/Evaluation Data for Techart Sony E > Nikon Z Autofocus Adapter / image picture pictu
leo11877,
I've had the same thing happen with my adapter and the FE 24-105 on my Z7. Seems the adapter has play in it and when it moves just a little the contact pins on the lens and adapter get misaligned and the AF will not work at all. Have to move the lens back and forth until they make proper contact again, the the AF works. But it is very unreliable.
Robert E
