Schneider 28mm f2.8 Componon Perf Stacked is Extremely Good

RobertOToole · Post by **RobertOToole** » Thu Dec 27, 2018 9:43 pm

Posted a test of the Componon 2.8/28 on my site , this is a really surprisingly good performer stacked. Be sure to check out the 2500 pixel images to get an idea of the image quality.

Full test link on my site with lots more info on the lens and lots of images:
https://www.closeuphotography.com/schne ... onon-lens/

QUICK REVIEW

-Excellent image quality and extremely consistent corner performance

-Better performance than any non-HR objective that I have tested from 3-4x (The Nikon S Fluor 4x 0.20 test at 3.2x is coming soon)

-Better than the Mitutoyo 5x M plan at 4.3x and that also means better than any 4 or 5x non-HR Nikon or Olympus that I have ever tested (The Nikon S Fluor 4x 0.20 test at 3.2x is coming soon)

-Sharpest at f2.8 - f3.1

-Very good CA correction

-All metal barrel, no plastic

-V-mount

-Excellent used prices on the used market-Ebay ($350 new in the box now BTW)

This is the setup used for the test images. The Componon is in reverse with the hood mounted on the rear of the lens.

This is how the lenses are mounted inside the Thorlabs tubes.

3.2x SETUP INFORMATION

Front lens: Schneider Kreuznach 2.8/28 Componon lens reverse mounted
Rear lens: Mejiro 90mm f5.6 line scan lens normally mounted focused at infinity
Stacked lens nominal aperture: f/3.1
Stacked lens effective aperture: f/9.9

Camera: Sony A6300
Sensor size: APS-C 23.5 × 15.6 mm. 28.21 mm diagonal. 3.92 micron sensor pitch
Flash: Godox TT350s wireless flash x 2 with one Godox X1s 2.4G wireless flash transmitter
Vertical stand: Nikon MM-11 with a Nikon focus block

For this test a stack of images was made with 4 micron steps, and was repeated for each aperture. The sharpest frame was then chosen using Photoshop at 100% actual pixel view. Separate images were selected for center, edge, and corner if needed. Each image was processed in PS CC with identical settings with all noise reduction and lens correction turned off, all settings were zeroed out (true zero) and the same settings were used for all of the images. All of the images shown here are single files.

All of the images below are heavily compressed, down to 30 quality so be sure to click on the images to open the full size version in a new window. You can also right button, or two finger click to save the image to examine in a different app.

Un-Cropped 2500 Pixel Image

100% Center Crop

100% Corner Crop

The Mejiro+Componon lens stack is really good, just about flawless from edge to edge. The full size image is even more impressive than the 2500 pixel image!

More at 3.2x

Un-cropped 2500 Pixel Image

100% Center Crop

100% Corner Crop

4.3x SETUP INFORMATION

Componon 2.8/28
Front lens: Schneider Kreuznach 2.8/28 Componon lens reverse mounted
Rear lens: Schneider Makro-Symmar 5.6/120 line scan lens normally mounted focused at infinity
Stacked lens nominal aperture: f/3.1
Stacked lens effective aperture: f/13.33

Mitutoyo 5x/0.14 M Plan APO
Objective: Mitutoyo 5x M Plan APO
Tube lens: Thorlabs ITL200 reversed and on short focus for 4.3x
Stacked lens nominal aperture: f/3.57
Stacked lens effective aperture: f/15.35

Camera: Sony A6300
Sensor size: APS-C 23.5 × 15.6 mm. 28.21 mm diagonal. 3.92 micron sensor pitch
Flash: Godox TT350s wireless flash x 2 with one Godox X1s 2.4G wireless flash transmitter
Vertical stand: Nikon MM-11 with a Nikon focus block

For this test a stack of images was made with 2 micron steps, and was repeated for each aperture. The sharpest frame was then chosen using Photoshop at 100% actual pixel view. Separate images were selected for center, edge, and corner if needed. Each image was processed in PS CC with identical settings with all noise reduction and lens correction turned off, all settings were zeroed out (true zero) and the same settings were used for all of the images. All of the images shown here are single files.

Crop Areas Outlined

100% View Center Crops

100% View Edge Crops

100% View Corner Crops

Componon vs Mitutoyo Test Results

These two were both excellent in the center and closer than you might expect but at the edge and corners the Componon shows a definite advantage over the Mitutoyo.

Questions and comments welcome.

Best,

Robert

ChrisR · Post by **ChrisR** » Fri Dec 28, 2018 3:44 am

It'a good.
Pros and cons? Slightly less colour fringing from the Mitty?

ray_parkhurst · Post by **ray_parkhurst** » Fri Dec 28, 2018 8:45 am

Hmm, I'm seeing some hue shifts that I can only believe are due to LoCA on the Componon shots. This may be due to small focus shifts as a result of picking the best single frames, which might result in some frames or parts of the frame being focused high or low depending on which shots are chosen. I don't see these hues at all in the Mitty images.

Can you publish a + and - focused image from one of the shots (both Componon and Mitty) to show effect of slight defocusing so LoCA can be assessed?

RobertOToole · Post by **RobertOToole** » Fri Dec 28, 2018 8:55 am

ChrisR wrote:It'a good.
Pros and cons? Slightly less colour fringing from the Mitty?

Two interesting things Chris.

There is slightly cleaner blacks with the Mitutoyo in the center but this reverses in the corners where it looks like the CPN is better.

Another thing is that the Componon 2.8/28 is really not exceptional at all without a tube lens, its not even a good lens without the tube lens, its just average maybe, similar to a 4/28 enlarger lens. Its extraordinary how it goes from average to amazing with the addition of the tube lens.

The full size image of the orange wafer is flawless. I have never seen a microscope objective that can even match that on APS-C. The S Fluor comes close though so I will look at that soon.

Robert

RobertOToole · Post by **RobertOToole** » Fri Dec 28, 2018 9:07 am

ray_parkhurst wrote:Hmm, I'm seeing some hue shifts that I can only believe are due to LoCA on the Componon shots. This may be due to small focus shifts as a result of picking the best single frames, which might result in some frames or parts of the frame being focused high or low depending on which shots are chosen. I don't see these hues at all in the Mitty images.

Can you publish a + and - focused image from one of the shots (both Componon and Mitty) to show effect of slight defocusing so LoCA can be assessed?

Yes, I do see that in the center and edge crops but with the corners if you look at the black lines, the componon looks more neutral and with the small arrow there are some CAs in the Mity crop.

Since I own both of these lenses I put a lot of time and care to make sure all the processing was exactly the same.

This image is on the full test page on my site but its not the best since there is too much space between the print lines I think. I planned to re-shoot this but I ran out of time over the holiday.

Thanks for the comments.

ray_parkhurst · Post by **ray_parkhurst** » Fri Dec 28, 2018 9:33 am

RobertOToole wrote: ...
This test image is on the full test on my site but its not the best test image since there is too much space between the print lines I think. I planned to re-shoot this but I ran out of time over the holiday
...

This is a good test image actually. The LoCA is subtle and much better controlled than with many lenses or combos. You can see slight green shift on upper half, and slight red shift at the lower half, starting at the OOF edges of the middle letters, but again not bad at all.

RobertOToole · Post by **RobertOToole** » Fri Dec 28, 2018 9:34 am

ChrisR wrote:It'a good.
Pros and cons? Slightly less colour fringing from the Mitty?

Can't help but wonder what it would take to really beat the Componon here, something faster than f2.8 that can go to 3.2x + and cover a large sensor.

This Rayfact should do the job but since it is using extension the effective f-stop would be a little slower than the stacked Componon.

This might cost a little more than the Componon

Davids · Post by **Davids** » Fri Dec 28, 2018 9:35 am

Exceptional work as always, Robert. Thank you for posting. Have you ever tested these stacked lenses with a larger sensor camera? I have a Schneider 120mm apo digitar macro and am wondering if stacking the 28mm Componon in front would cover a Fuji GFX sensor (43.8 mm x 32.9 mm). While I enjoy and appreciate your posts, my wallet and bank account groan!

Thanks again.

RobertOToole · Post by **RobertOToole** » Fri Dec 28, 2018 9:44 am

Davids wrote:Exceptional work as always, Robert. Thank you for posting. Have you ever tested these stacked lenses with a larger sensor camera? I have a Schneider 120mm apo digitar macro and am wondering if stacking the 28mm Componon in front would cover a Fuji GFX sensor (43.8 mm x 32.9 mm). While I enjoy and appreciate your posts, my wallet and bank account groan!

Thanks again.

Thanks, glad to hear you found the test interesting.

Wish I knew more about coverage limits. My plan was to run my lenses on APS-C first then run the best on my D850 to find the best coverage but then I started spending too much time experimenting with stacked lenses.

I eventually will do that, I have a few lenses here, a Rayfact 1.4x VL and a Schneider Xenon Sapphire 1.4x (loaner from a friend) that I plan to test on a larger sensor.

The Mejiro and Componon and still set up so I could try my D850 before I break the set-up down again. I might have time to run it on FF at least.

Will update the post if I can run the FF test.

Best,

Robert

RobertOToole · Post by **RobertOToole** » Fri Dec 28, 2018 4:47 pm

Davids wrote:Exceptional work as always, Robert. Thank you for posting. Have you ever tested these stacked lenses with a larger sensor camera? I have a Schneider 120mm apo digitar macro and am wondering if stacking the 28mm Componon in front would cover a Fuji GFX sensor (43.8 mm x 32.9 mm). While I enjoy and appreciate your posts, my wallet and bank account groan!

Thanks again.

Update

Good news, the stacked combo will cover the D850 with a 43mm diagonal image circle with just a slightest drop in sharpness and only at the very far corners.

Schneider Kreuznach 2.8/28 Componon lens and Mejiro 5.6/90 scan lens at 3.2x with the Nikon D850 full frame sensor body

Be sure to click on this 1000 pixel image to open a window with a larger 2500 pixel image.

Lou Jost · Post by **Lou Jost** » Fri Dec 28, 2018 5:18 pm

Amazing, excellent discovery (again). And thanks for putting in the butterfly scales! Now I need to include wafers in my tests. First I need to find a good one...

lothman · Post by **lothman** » Sat Dec 29, 2018 4:03 am

thanks for sharing if I only could understand why adding another lens with numbers of additional lens can improve thing so much?

Did you stack your result or is it a single fram sharp from Edge to Edge?

JohnyM · Post by **JohnyM** » Sat Dec 29, 2018 4:45 am

lothman wrote:thanks for sharing if I only could understand why adding another lens with numbers of additional lens can improve thing so much?

Suprizingly, like many others, Schneider enlarging lenses are optimized for infinity, despite being enlarging. Also effective aperture is improved quite a bit.

Lou Jost · Post by **Lou Jost** » Sat Dec 29, 2018 5:16 am

lothman, anyway it is a myth that more lens elements should necessarily degrade image quality. More lens elements can mean better correction. The best fast lenses today have lots of elements to better correct aberrations. No one uses a doublet for photography.

The one thing that does happen with more elements is a slight loss of light, and an attendant loss of contrast, because of the number of glass-air interfaces. Modern coatings have reduced that loss substantially.

RobertOToole · Post by **RobertOToole** » Sat Dec 29, 2018 3:11 pm

lothman wrote:thanks for sharing if I only could understand why adding another lens with numbers of additional lens can improve thing so much?

Did you stack your result or is it a single fram sharp from Edge to Edge?

Hi Lothman,

I feel the same way. With this Componon 28 the best part is I tried to sell it for over 1 year due to the average image quality. But I had no takers then when I tested it stacked I was really glad it never sold. I like it so much I picked up a second copy now.

Some images like the 2500px are stacked, the crops are all singles.

The lens isn't perfect so there is some field curvature. Some lenses like the Canon MPE or MP35 are very flat but still need a couple of frames to get everything the sharpest possible.

The only really truly flat field lenses, going from memory, are the scanner Nikkor 14 element and the MacroVaron maybe.

Robert