16-35 f4: Mostly likely cause of soft Left & Right Edges?

Started 4 months ago | Questions
nkistrup
nkistrup Senior Member • Posts: 2,568
16-35 f4: Mostly likely cause of soft Left & Right Edges?

Renting this lens for use on a Sony A7iii, converted to infrared.  Using the Sigma MC-11 lens adapter.

After reading the user reviews on B&H Photo's site, numerous reviews on the Internet, and looking at images taken with lens on PixelPeeper.com, convinced that the softness issues on the right & left sides, but not the bottom,  has to be due to one of the following:

  1. Infrared compatibility issue: Lens was designed for visible light use.
  2. Photographer is being a nitpicky jerk: Edge softness doesn't jump out while looking at the image on the screen ... only when I magnify to 100%.  Saw some of this in the photos in PixelPeeper site, but not to the extent that I'm seeing it.
  3. Lens sample variation: Maybe I got a less than stellar copy from Lensrentals.com?  Some reviewers mentioned that.  This is my first experience w. a Canon lens.  Have seen it w. Sony, Tamron, & Nikon, but not Zeiss or Voigtlander.
  4. Compositional Choices designed to find lens flaws: Most of the photos that I saw taken w. this lens on the PixelPeeper web site, didn't highlight bricks & similar objects at the edges.  Many of may photos did.

All photos were taken raw, and converted using Capture One; tried DxO PhotoLab, and they came out worse.  Tried with the Canon 16-35 f4 lens profile, as well as the generic one.  And a tripod was used.

Here are the photos, full size & with EXIFINFO: https://graphitepaddle.smugmug.com/Infrared-photography/Lens-testing/Canon-16-35-f4/

Like this lens a lot.  MF & AF work great.  Focal length is a nice complement to my Tamron 28-75 f2.8.  At the least, doing more testing this weekend.  But wondering if I need to rent another copy, in case of copy variation?

Niels

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“Photography is inspired by beauty, captured with passion.”
? Destin Sparks

 nkistrup's gear list:nkistrup's gear list
Olympus XZ-1 Nikon D7100 Sony a7 III Sony a6400 Nikon AF-S DX Nikkor 17-55mm f/2.8G ED-IF +10 more
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Doppler9000 Regular Member • Posts: 327
Re: 16-35 f4: Mostly likely cause of soft Left & Right Edges?
3

nkistrup wrote:

Renting this lens for use on a Sony A7iii, converted to infrared. Using the Sigma MC-11 lens adapter.

After reading the user reviews on B&H Photo's site, numerous reviews on the Internet, and looking at images taken with lens on PixelPeeper.com, convinced that the softness issues on the right & left sides, but not the bottom, has to be due to one of the following:

  1. Infrared compatibility issue: Lens was designed for visible light use.
  2. Photographer is being a nitpicky jerk: Edge softness doesn't jump out while looking at the image on the screen ... only when I magnify to 100%. Saw some of this in the photos in PixelPeeper site, but not to the extent that I'm seeing it.
  3. Lens sample variation: Maybe I got a less than stellar copy from Lensrentals.com? Some reviewers mentioned that. This is my first experience w. a Canon lens. Have seen it w. Sony, Tamron, & Nikon, but not Zeiss or Voigtlander.
  4. Compositional Choices designed to find lens flaws: Most of the photos that I saw taken w. this lens on the PixelPeeper web site, didn't highlight bricks & similar objects at the edges. Many of may photos did.

All photos were taken raw, and converted using Capture One; tried DxO PhotoLab, and they came out worse. Tried with the Canon 16-35 f4 lens profile, as well as the generic one. And a tripod was used.

Here are the photos, full size & with EXIFINFO: https://graphitepaddle.smugmug.com/Infrared-photography/Lens-testing/Canon-16-35-f4/

Like this lens a lot. MF & AF work great. Focal length is a nice complement to my Tamron 28-75 f2.8. At the least, doing more testing this weekend. But wondering if I need to rent another copy, in case of copy variation?

Niels

The left and right sides of a 24 x 36 frame are significantly farther away from the center than are the top and bottom. If you look at MTF diagrams, you will see, in general, that as one moves away from the center, the image degrades at a higher than linear rate.

Wide zooms are probably the most challenging lenses to design, in terms of balancing the inevitable trade offs, as well.

Could this explain what you are seeing?

nkistrup
OP nkistrup Senior Member • Posts: 2,568
Re: 16-35 f4: Mostly likely cause of soft Left & Right Edges?

Doppler9000 wrote:

nkistrup wrote:

Renting this lens for use on a Sony A7iii, converted to infrared. Using the Sigma MC-11 lens adapter.

After reading the user reviews on B&H Photo's site, numerous reviews on the Internet, and looking at images taken with lens on PixelPeeper.com, convinced that the softness issues on the right & left sides, but not the bottom, has to be due to one of the following:

  1. Infrared compatibility issue: Lens was designed for visible light use.
  2. Photographer is being a nitpicky jerk: Edge softness doesn't jump out while looking at the image on the screen ... only when I magnify to 100%. Saw some of this in the photos in PixelPeeper site, but not to the extent that I'm seeing it.
  3. Lens sample variation: Maybe I got a less than stellar copy from Lensrentals.com? Some reviewers mentioned that. This is my first experience w. a Canon lens. Have seen it w. Sony, Tamron, & Nikon, but not Zeiss or Voigtlander.
  4. Compositional Choices designed to find lens flaws: Most of the photos that I saw taken w. this lens on the PixelPeeper web site, didn't highlight bricks & similar objects at the edges. Many of may photos did.

All photos were taken raw, and converted using Capture One; tried DxO PhotoLab, and they came out worse. Tried with the Canon 16-35 f4 lens profile, as well as the generic one. And a tripod was used.

Here are the photos, full size & with EXIFINFO: https://graphitepaddle.smugmug.com/Infrared-photography/Lens-testing/Canon-16-35-f4/

Like this lens a lot. MF & AF work great. Focal length is a nice complement to my Tamron 28-75 f2.8. At the least, doing more testing this weekend. But wondering if I need to rent another copy, in case of copy variation?

Niels

The left and right sides of a 24 x 36 frame are significantly farther away from the center than are the top and bottom. If you look at MTF diagrams, you will see, in general, that as one moves away from the center, the image degrades at a higher than linear rate.

Wide zooms are probably the most challenging lenses to design, in terms of balancing the inevitable trade offs, as well.

Could this explain what you are seeing?

Possibly.  That's why I went to the PixelPeeper site.  Some photos showed signs of it, but most didn't.  (Was it the photographer's post processing skills that sharpened things up.)

Have a Sony 10-18 f4 lens on an APS-C body (a6400).  Shooting at 11mm is close the 16-35 f4 a@ 16mm.  Will try to compare images from the two lenses at similar fields of view.

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“Photography is inspired by beauty, captured with passion.”
? Destin Sparks

 nkistrup's gear list:nkistrup's gear list
Olympus XZ-1 Nikon D7100 Sony a7 III Sony a6400 Nikon AF-S DX Nikkor 17-55mm f/2.8G ED-IF +10 more
Doppler9000 Regular Member • Posts: 327
Re: 16-35 f4: Mostly likely cause of soft Left & Right Edges?

nkistrup wrote:

Doppler9000 wrote:

nkistrup wrote:

Renting this lens for use on a Sony A7iii, converted to infrared. Using the Sigma MC-11 lens adapter.

After reading the user reviews on B&H Photo's site, numerous reviews on the Internet, and looking at images taken with lens on PixelPeeper.com, convinced that the softness issues on the right & left sides, but not the bottom, has to be due to one of the following:

  1. Infrared compatibility issue: Lens was designed for visible light use.
  2. Photographer is being a nitpicky jerk: Edge softness doesn't jump out while looking at the image on the screen ... only when I magnify to 100%. Saw some of this in the photos in PixelPeeper site, but not to the extent that I'm seeing it.
  3. Lens sample variation: Maybe I got a less than stellar copy from Lensrentals.com? Some reviewers mentioned that. This is my first experience w. a Canon lens. Have seen it w. Sony, Tamron, & Nikon, but not Zeiss or Voigtlander.
  4. Compositional Choices designed to find lens flaws: Most of the photos that I saw taken w. this lens on the PixelPeeper web site, didn't highlight bricks & similar objects at the edges. Many of may photos did.

All photos were taken raw, and converted using Capture One; tried DxO PhotoLab, and they came out worse. Tried with the Canon 16-35 f4 lens profile, as well as the generic one. And a tripod was used.

Here are the photos, full size & with EXIFINFO: https://graphitepaddle.smugmug.com/Infrared-photography/Lens-testing/Canon-16-35-f4/

Like this lens a lot. MF & AF work great. Focal length is a nice complement to my Tamron 28-75 f2.8. At the least, doing more testing this weekend. But wondering if I need to rent another copy, in case of copy variation?

Niels

The left and right sides of a 24 x 36 frame are significantly farther away from the center than are the top and bottom. If you look at MTF diagrams, you will see, in general, that as one moves away from the center, the image degrades at a higher than linear rate.

Wide zooms are probably the most challenging lenses to design, in terms of balancing the inevitable trade offs, as well.

Could this explain what you are seeing?

Possibly. That's why I went to the PixelPeeper site. Some photos showed signs of it, but most didn't. (Was it the photographer's post processing skills that sharpened things up.)

Have a Sony 10-18 f4 lens on an APS-C body (a6400). Shooting at 11mm is close the 16-35 f4 a@ 16mm. Will try to compare images from the two lenses at similar fields of view.

The degradation is steeper toward the edge at wider focal lengths and wider apertures, which might help explain the variations.

These are at f/4.  The x axis is distance from the center, in mm.

nkistrup
OP nkistrup Senior Member • Posts: 2,568
16-35 f4, in Infrared vs. Sony 10-18 f4 in visible light

Agreed that wide lengths will suffer more from edge softness.  But still think the Canon 16-35 should be doing better.

Took a photo w. the Canon @ f11, vs. f8 for the Sony (DoF should be the same); Canon shot at 16mm, Sony at 11mm, which should be close.  Here are the results:

Sony 10-18 f4

Canon 16-35 f4

In both cases, cropped the lower right 1200x1200.

Canon is definitely softer.  So back to my original question: Is the Canon lens a poor copy, or Does it suffer from softer edges in infrared?

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“Photography is inspired by beauty, captured with passion.”
? Destin Sparks

 nkistrup's gear list:nkistrup's gear list
Olympus XZ-1 Nikon D7100 Sony a7 III Sony a6400 Nikon AF-S DX Nikkor 17-55mm f/2.8G ED-IF +10 more
Igor Sotelo Regular Member • Posts: 461
Re: 16-35 f4, in Infrared vs. Sony 10-18 f4 in visible light

nkistrup wrote:

Agreed that wide lengths will suffer more from edge softness. But still think the Canon 16-35 should be doing better.

Took a photo w. the Canon @ f11, vs. f8 for the Sony (DoF should be the same); Canon shot at 16mm, Sony at 11mm, which should be close. Here are the results:

Sony 10-18 f4

Canon 16-35 f4

In both cases, cropped the lower right 1200x1200.

Canon is definitely softer. So back to my original question: Is the Canon lens a poor copy, or Does it suffer from softer edges in infrared?

Lenses for APS-C are smaller and less expensive to make and easier to make sharp at the edges.

The trade of using cropped sensors however, is lower high iso performance, and a stop less of subject isolation compared to FX.

 Igor Sotelo's gear list:Igor Sotelo's gear list
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Doppler9000 Regular Member • Posts: 327
Re: 16-35 f4, in Infrared vs. Sony 10-18 f4 in visible light

Igor Sotelo wrote:

nkistrup wrote:

Agreed that wide lengths will suffer more from edge softness. But still think the Canon 16-35 should be doing better.

Took a photo w. the Canon @ f11, vs. f8 for the Sony (DoF should be the same); Canon shot at 16mm, Sony at 11mm, which should be close. Here are the results:

Sony 10-18 f4

Canon 16-35 f4

In both cases, cropped the lower right 1200x1200.

Canon is definitely softer. So back to my original question: Is the Canon lens a poor copy, or Does it suffer from softer edges in infrared?

Lenses for APS-C are smaller and less expensive to make and easier to make sharp at the edges.

The trade of using cropped sensors however, is lower high iso performance, and a stop less of subject isolation compared to FX.

Exactly.  In addition, it is an entirely different lens, so the comparison provides no insight.

I think you will need to compare the lens to a known good copy of the same lens, and/or use the lens on a FF visible spectrum camera to gain insight into what is causing the issues you see.

nkistrup
OP nkistrup Senior Member • Posts: 2,568
Re: 16-35 f4, in Infrared vs. Sony 10-18 f4 in visible light

Igor Sotelo wrote:

nkistrup wrote:

Agreed that wide lengths will suffer more from edge softness. But still think the Canon 16-35 should be doing better.

Took a photo w. the Canon @ f11, vs. f8 for the Sony (DoF should be the same); Canon shot at 16mm, Sony at 11mm, which should be close. Here are the results:

Sony 10-18 f4

Canon 16-35 f4

In both cases, cropped the lower right 1200x1200.

Canon is definitely softer. So back to my original question: Is the Canon lens a poor copy, or Does it suffer from softer edges in infrared?

Lenses for APS-C are smaller and less expensive to make and easier to make sharp at the edges.

Fair enough.

The trade of using cropped sensors however, is lower high iso performance, and a stop less of subject isolation compared to FX.

Thanks Igor, but actually accounted for the DoF in my test shots: Sony photo was taken at f8, while the Canon photo was taken at f11.  (New to FF, struggle with difference.)

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“Photography is inspired by beauty, captured with passion.”
? Destin Sparks

 nkistrup's gear list:nkistrup's gear list
Olympus XZ-1 Nikon D7100 Sony a7 III Sony a6400 Nikon AF-S DX Nikkor 17-55mm f/2.8G ED-IF +10 more
nkistrup
OP nkistrup Senior Member • Posts: 2,568
Re: 16-35 f4, in Infrared vs. Sony 10-18 f4 in visible light

Doppler9000 wrote:

Igor Sotelo wrote:

nkistrup wrote:

Agreed that wide lengths will suffer more from edge softness. But still think the Canon 16-35 should be doing better.

Took a photo w. the Canon @ f11, vs. f8 for the Sony (DoF should be the same); Canon shot at 16mm, Sony at 11mm, which should be close. Here are the results:

Sony 10-18 f4

Canon 16-35 f4

In both cases, cropped the lower right 1200x1200.

Canon is definitely softer. So back to my original question: Is the Canon lens a poor copy, or Does it suffer from softer edges in infrared?

Lenses for APS-C are smaller and less expensive to make and easier to make sharp at the edges.

The trade of using cropped sensors however, is lower high iso performance, and a stop less of subject isolation compared to FX.

Exactly. In addition, it is an entirely different lens, so the comparison provides no insight.

I think you will need to compare the lens to a known good copy of the same lens, and/or use the lens on a FF visible spectrum camera to gain insight into what is causing the issues you see.

Decided to reach out to Life Pixel, who sold me the converted A7iii body. Infrared is the culprit ==>

"... edges are soft for all wide angle and super wide angle lenses on any converted camera due to barrel distortion."

Conclusion: Another copy of the lens might be a little sharper.  Fighting another quirk of infrared photography, so my options are:

  1. Search for a group of wide primes.  So far, only the Irix 15mm has both the sharpness & is IR hot spot free.
  2. Scrap the idea of going wide in IR.
  3. Stop pixel peeping & live with it.

Thanks to both you & Igor for chiming in.

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“Photography is inspired by beauty, captured with passion.”
? Destin Sparks

 nkistrup's gear list:nkistrup's gear list
Olympus XZ-1 Nikon D7100 Sony a7 III Sony a6400 Nikon AF-S DX Nikkor 17-55mm f/2.8G ED-IF +10 more
Doppler9000 Regular Member • Posts: 327
Re: 16-35 f4, in Infrared vs. Sony 10-18 f4 in visible light

nkistrup wrote:

Doppler9000 wrote:

Igor Sotelo wrote:

nkistrup wrote:

Agreed that wide lengths will suffer more from edge softness. But still think the Canon 16-35 should be doing better.

Took a photo w. the Canon @ f11, vs. f8 for the Sony (DoF should be the same); Canon shot at 16mm, Sony at 11mm, which should be close. Here are the results:

Sony 10-18 f4

Canon 16-35 f4

In both cases, cropped the lower right 1200x1200.

Canon is definitely softer. So back to my original question: Is the Canon lens a poor copy, or Does it suffer from softer edges in infrared?

Lenses for APS-C are smaller and less expensive to make and easier to make sharp at the edges.

The trade of using cropped sensors however, is lower high iso performance, and a stop less of subject isolation compared to FX.

Exactly. In addition, it is an entirely different lens, so the comparison provides no insight.

I think you will need to compare the lens to a known good copy of the same lens, and/or use the lens on a FF visible spectrum camera to gain insight into what is causing the issues you see.

Decided to reach out to Life Pixel, who sold me the converted A7iii body. Infrared is the culprit ==>

"... edges are soft for all wide angle and super wide angle lenses on any converted camera due to barrel distortion."

Conclusion: Another copy of the lens might be a little sharper. Fighting another quirk of infrared photography, so my options are:

  1. Search for a group of wide primes. So far, only the Irix 15mm has both the sharpness & is IR hot spot free.
  2. Scrap the idea of going wide in IR.
  3. Stop pixel peeping & live with it.

Thanks to both you & Igor for chiming in.

The issue might be both the camera and the lens, it still might be worthwhile checking the lens.

Here is a Flickr image, among others, from the 16-35mm 2.8 in IR.  This is on a GFX, which has a diagonal about 28% longer than a FF frame, so this might be a lens to look at.

https://www.flickr.com/photos/joshhimes/46683921442/in/album-72157677731983338/

I use the EF S 10-18mm which is pretty great in IR, on my 850nm converted Fuji X. I’m sure it would vignette on FF, but it might give you enough FOV. I haven’t peeped the corners, however.

nkistrup
OP nkistrup Senior Member • Posts: 2,568
Re: 16-35 f4, in Infrared vs. Sony 10-18 f4 in visible light

Doppler9000 wrote:

nkistrup wrote:

Doppler9000 wrote:

Igor Sotelo wrote:

nkistrup wrote:

Agreed that wide lengths will suffer more from edge softness. But still think the Canon 16-35 should be doing better.

Took a photo w. the Canon @ f11, vs. f8 for the Sony (DoF should be the same); Canon shot at 16mm, Sony at 11mm, which should be close. Here are the results:

Sony 10-18 f4

Canon 16-35 f4

In both cases, cropped the lower right 1200x1200.

Canon is definitely softer. So back to my original question: Is the Canon lens a poor copy, or Does it suffer from softer edges in infrared?

Lenses for APS-C are smaller and less expensive to make and easier to make sharp at the edges.

The trade of using cropped sensors however, is lower high iso performance, and a stop less of subject isolation compared to FX.

Exactly. In addition, it is an entirely different lens, so the comparison provides no insight.

I think you will need to compare the lens to a known good copy of the same lens, and/or use the lens on a FF visible spectrum camera to gain insight into what is causing the issues you see.

Decided to reach out to Life Pixel, who sold me the converted A7iii body. Infrared is the culprit ==>

"... edges are soft for all wide angle and super wide angle lenses on any converted camera due to barrel distortion."

Conclusion: Another copy of the lens might be a little sharper. Fighting another quirk of infrared photography, so my options are:

  1. Search for a group of wide primes. So far, only the Irix 15mm has both the sharpness & is IR hot spot free.
  2. Scrap the idea of going wide in IR.
  3. Stop pixel peeping & live with it.

Thanks to both you & Igor for chiming in.

The issue might be both the camera and the lens, it still might be worthwhile checking the lens.

Here is a Flickr image, among others, from the 16-35mm 2.8 in IR.

https://www.flickr.com/photos/joshhimes/46683921442/in/album-72157677731983338/

I use the EF S 10-18mm which is pretty great in IR, on my 850nm converted Fuji X. I’m sure it would vignette on FF, but it might give you enough FOV. I haven’t peeped the corners, however.

Photo is too small to really check for sharpness.  And Kolari Vision has that lens flagged for hot spot issues.

Leaning toward ordering the 16-35 f4.  Will test as much as I can this weekend, but think I was being critical of this lens.

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“Photography is inspired by beauty, captured with passion.”
? Destin Sparks

 nkistrup's gear list:nkistrup's gear list
Olympus XZ-1 Nikon D7100 Sony a7 III Sony a6400 Nikon AF-S DX Nikkor 17-55mm f/2.8G ED-IF +10 more
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