4X Lens Test Part 3 - Enlarging Lenses

The Test

This test of 7 enlarging lenses, is a third part of a 4 part test comparing 33 objectives and lenses at 4X magnification. 

This comparison was made to find out which lenses perform best at this magnification. The test results are only being posted to share this information. Since I own all the lenses the test, I not promoting any one lens, a sponsor, or one brand over another, the test results can speak for themselves.

The Studio Setup

42mm Extension Tube Studio Macro Photography setup with the Sony A6300 and a Schneider APO-Componon.

Camera: Sony α6300, model # ILCE-6300, also known as: A6300, ALPHA 6300, and alpha 6300. 
Flash: Godox TT350s wireless flash x 2
Wireless controller: Godox X1s 2.4G wireless flash transmitter

All of the enlarging lenses for this part of the test were mounted on my 42mm extension tube studio set-up. For more information on the 42mm studio setup, follow this  link:  https://www.closeuphotography.com/42mm-setup/

See the bottom of this post for more details on the test set-up.

The Lenses

Schneider Kreuznach 28mm f/2 Xenon in metal B00 barrel
Schneider Kreuznach 28mm f/4 Componon
in metal B00 barrel
Rodenstock 25mm f/4 Omegaron (Identical to Rodagon)
Schneider Kreuznach 28mm f/4 Componon in plastic BKV-L barrel
Schneider Kreuznach 35mm f/4 Componon
in plastic BKV-L barrel
Schneider Kreuznach 28mm f/2.8 Componon
in metal B-V barrel
Schneider Kreuznach 45mm f/4 APO-Componon
in metal B-V barrel

For a full list of information on the lenses in this test, see the bottom of this page.

Note: There is only one Rodenstock on the list since I this is the only wide-angle Rodagon enlarging lens that I now own. Before I sold the lenses I did have, Rodagon 28/2.8, 28/4, 35/4, I tested them against a Canon Macrophoto 35mm and that lens was much better at everything at 2x. The issue with the Rodenstocks was an small image circle.

 

L-R, SK Xenon 2/28, SK Componon 4/28, Rodenstock 25mm Omegaron, Componon 28 and 35mm, SK 2.8/28 and SK APO-Componon 45mm. 

The results:

All the images here are from a single file and are not from a stack. In some cases the corners improved with stopping down, but none of the lenses had better corners in a different frame, than the center image.

Schneider Kreuznach 28mm f/2 Xenon

Schneider Kreuznach 28mm f/2 Xenon at 4x and f/4.5

Schneider Kreuznach 28mm f/2 Xenon at 4x and f/2.

Schneider Kreuznach 28mm f/2 Xenon at 4x and f/2.8

Schneider Kreuznach 28mm f/2 Xenon at 4x and f/4

Schneider Kreuznach 28mm f/2 Xenon 100% center crops from f/2 to f/4.5

Schneider Kreuznach 28mm f/2 Xenon 100% center crops from f/2 to f/4.5

These center crops are interesting. At f/2 the center shows surprising resolution, and the quality improves stopping down to f/2.8, with better contrast and less CAs. Click on the image above to open a larger version in a new window.

SK 28mm f/2 Xenon 100% center crop at f/2

SK 28mm f/2 Xenon 100% center crop at f/2.8

SK 28mm f/2 Xenon 100% center crop at f/4

SK 28mm f/2 Xenon 100% center crop at f/4.5

Center crops at 100%. Click on any of the images above to open a larger version in a new window.

Schneider Kreuznach 28mm f/2 Xenon 100% corner crops from f/2 to f/4.5

Schneider Kreuznach 28mm f/2 Xenon 100% corner crops from f/2 to f/4.5

Corner crops at 100%. Click on any of the images above to open a larger version in a new window.

SK 28mm f/2 Xenon 100% corner crop at f/2

SK 28mm f/2 Xenon 100% corner crop at f/2.8

SK 28mm f/2 Xenon 100% corner crop at f/4

SK 28mm f/2 Xenon 100% corner crop at f/4.5

Schneider Kreuznach 28mm f/2 Xenon Notes

This is the small black lens on the far left, Schneider calls this mount the B00 barrel. This lens must be mounted in reverse for close-up shooting. Forward mounted at a closeup distance, the image quality was very poor.

First the bad news, the Xenon image circle is not large enough to cover an APS-C sensor at f/2, to f/2.8, but it gets better as you stop down from there. By f/4 or f/4.5 the corners are usable, not as sharp, but for an enlarging lens, they are okay. Beyond f/4.5 the corner sharpness drops.

Looking at it another way, the Xenon corners at f/4.5 are no worse than the 4/28 Componon at f4.5, maybe even a little bit better!

This lens surprised me. Having owned maybe a dozen different versions of 28mm componon over the years, I always thought these were sharp enlarging lenses, but that was only until I looked at the results from the Xenon. The best thing about the Xenon is value, I picked this lens up in mint condition for less than $50 on Ebay, for comparison, I just sold a 4/28 Componon this month on Ebay for $200. Keep a look out for the Xenon 2/35 and the 2/40mm versions on Ebay.

It looks like the Xenons were not sold as enlarging lenses, my 2/28 lens came with an industrial adapter mount, with a lock nut, so at least this lens was used in an industrial installation.

Schneider Kreuznach 28mm f/4 Componon

Schneider Kreuznach 28mm f/4 Componon lens at 4x and f/4.5

Schneider Kreuznach 28mm f/4 Componon, center crop at 100% view, f/4.5 at 4x

Schneider Kreuznach 28mm f/4 Componon, corner crop at 100% view, f/4.5 at 4x

Schneider Kreuznach 28mm f/4 Componon Notes

This is the small black lens, second from left, Schneider calls this mount the B00 barrel. Lens was mounted in reverse and the sharpest image was made at f/4.5. Don't even bother trying this lens forward mounted at macro distances.

Over the years I've probably owned a dozen 4/28 componons, and the multicoated versions always perform about the same, sharp in the center with a small image circle. Schneider still sells the componon 4/28 in 2017 and recommends them for sensors up to 18 x 24, which means it should cover APS-C, but the image quality at near the corners drops quickly! Schneider's MTF only graphs frequencies at 10-20-30 l/mm, which usually means weak resolution.  MTF link: https://www.schneideroptics.com/pdfs/photo/datasheets/componon/componon_40_28_2.pdf

The image quality at 4X peaks at f/4.5 where the sharpness are corners are slightly better than f/4. The 4/28 Componon was the first really sharp enlarging lens I ever owned and they still are sharp as long as you don't compare them to the Xenon 28mm f/2. Bellows like the Canon 20mm or 35mm will beat the the SK 4/28 with a larger image circle and better corners.

Rodenstock 25mm f/4 Omegaron

Rodenstock 25mm f/4 Omegaron lens 100% view, 4x at f/4

Rodenstock 25mm f/4 Omegaron lens 100% actual pixel view center crop. 4X at f/4. Clicking on an image will open a larger version.

Rodenstock 25mm f/4 Omegaron lens 100% actual pixel view corner crop. 4X at f/4. Clicking on an image will open a larger version.

Rodenstock 25mm f/4 Omegaron Notes

This is the third lens from the left, that strange looking adapter on the front of the lens is a 39mm adapter I epoxied to get around the lack of filter threads. This lens was mounted in reverse for this test and shot at f/4. Stopping down did not improve sharpness.

This lens was thrown in the comparison at the last minute, and honestly think it did better than I thought it would.

Performance is decent at 4X, considering that I paid something like $15 for the lens, its a solid performer and a little better, I think, than other Enlarging lenses at the same price point.

The color cast in the images with this lens is a mystery. All of the lenses in this test were shot with the same lighting and converted from RAW with the same zero'ed settings.

Schneider Kreuznach 28mm f/4 Componon

Schneider Kreuznach 28mm f/4 Componon lens at 4x

Typical standard 28mm f/4 Componon performance, sharp in the center, soft outside the center.

Schneider Kreuznach 28mm f/4 Componon lens at 4x, 100% actual pixel view center crop. 4X at f/4. Clicking on an image will open a larger version.

Schneider Kreuznach 28mm f/4 Componon lens at 4x, 100% actual pixel view center crop. 4X at f/4. Clicking on an image will open a larger version.

Schneider Kreuznach 28mm f/4 Componon Notes

This lens is in the standard late model Schneider enlarger mount with a green ring, this plastic barrel is called this mount the BKV-L barrel.

Lens was mounted in reverse and the sharpest image was made at f/4.5.

Schneider Kreuznach 35mm f/4 Componon

Schneider Kreuznach 35mm f/4 Componon at 4x and f/4.5

This should be about normal for a 35mm Componon performance, strongest in the center.

Schneider Kreuznach 35mm f/4 Componon lens at 4x, 100% actual pixel view center crop. 4X at f/4.5. Clicking on an image will open a larger version.

Schneider Kreuznach 35mm f/4 Componon lens at 4x, 100% actual pixel view center crop. 4X at f/4.5. Clicking on an image will open a larger version.

Schneider Kreuznach 35mm f/4 Componon Notes


This lens is in the standard late model Schneider enlarger mount with a green ring, this plastic barrel is called this mount the BKV-L barrel.

Lens was mounted in reverse and the sharpest image was made at f/4.5. Performance is similar to the Componon 28mm f/4.

 

Schneider Kreuznach 28mm f/2.8 Componon Makro Iris

Schneider Kreuznach 28mm f/2.8 Componon at 4x and f/4.5. Clicking on an image will open a larger version.

Schneider Kreuznach 28mm f/2.8 Componon at 4x and f/4.5, 100% actual pixel view center crop. Clicking on an image will open a larger version.

Schneider Kreuznach 28mm f/2.8 Componon at 4x and f/4.5, 100% actual pixel view corner crop. Clicking on an image will open a larger version.

Schneider Kreuznach 28mm f/2.8 Componon Makro Iris Notes

This lens is second to the right, in a metal Makro Iris, industrial mount, B-V barrel. Lens was mounted in reverse and the sharpest image was made at f/4.5.

The performance of this was a let down, wide open the image, even in the center was not sharp, and where it reaches its peak sharpness, f/4.5, the image quality was a bad match for the Sony A6300 sensor with a lack of fine detail.

Looking at the optical layout information that Schneider provides for this lens and the f/4 version and they are almost identical, except for some very slight changes. After seeing this lens, side-by-side with other lenses, it looks like they gave up center sharpness, where it is behind the older 28mm f/4 versions, for uniform performance across the field. The corners are cleaner than the 28mm f/4 version at least. 

With this lens so I ended up running three stacks with this lens at each stop, from f/2.8 to f/5.6, just to make sure the lens was really was that soft!

Schneider Kreuznach 45mm f/4 APO-Componon Makro Iris

Schneider Kreuznach 45mm f/4 Componon at 4x and f/4.5. Clicking on an image will open a larger version.

Schneider Kreuznach 45mm f/4 Componon at 4x and f/4.5, 100% actual pixel view center crop. Clicking on an image will open a larger version.

Schneider Kreuznach 45mm f/4 Componon at 4x and f/4.5, 100% actual pixel view corner crop. Clicking on an image will open a larger version.

Schneider Kreuznach 45mm f/4 APO-Componon Makro Iris Notes

This lens is on the far right in the metal, industrial mount, B-V barrel with the gold colored mount. The optics are exactly the same as the plastic enlarger mount version. Lens was mounted in reverse and the sharpest image was made at f/4.5.

The SK 45/4 does not perform well at this magnification due to the slow maximum aperture and the fact that it is not sharpest wide open. Looking at the results of this test, this lens definitely out of its range at 4X due to diffraction, see the notes below.

In case you are thinking these poor results are probably due to this lens being a bad copy, that is definitely not the case. This was the best performing lens out of the 3 of these lenses that I own! Who knows why Schneider calls this lens an APO-Componon, when it shows chromatic aberrations all over, even in the center!

Summary

At 4X magnification and higher, microscope objectives have a big advantage over lenses like these, and that's aperture.  You can predict the resolution from a certain lens by using the simple fact that a wider aperture = higher resolution. At 4X the "effective aperture" of the f/4 lens will be the nominal or marked aperture x 5 (a factor of m+1), or f/20. So the problem with most of the lenses here is sharpness loss due to diffraction. 

The diffraction problem gets worse when you stop the lens down. The Schneider 45mm APO-Componon, sharpest closed down a half-stop from maximum, at f/4.5, is operating at f/22 at 4X, and well into diffraction territory. The images from the Schneider 45mm might look okay resized for use on Facebook, but will look horrible at larger sizes, like with a 100% actual pixel view crops that you can see here.

The Schneider Xenon 28mm f/2 lens is operating at an effective f/10 when set-up with extension and wide-open. The difference in sharpness with larger aperture lenses like the Xenon will really be easily apparent at a 100% view when compared to slower lenses like the Schneider 45mm APO-Componon at an effective f/22.

The Set-up 

The Sony α6300 camera used for the test was vertically mounted on a Nikon MM-11 stand. Manual mode was used at ISO 100. Two Godox TT350s, at 1/128th to 1/4 power to avoid eliminate any vibration problems. The flashes remained in place for the entire test to avoid changes in light angle, the flash was mounted on a flash bracket bolted to an optical breadboard shooting into a 4-3/4 inch (12 cm) Godox plastic half dome diffuser placed over the target which was a 6 inch silicon wafer purchased on Ebay. For more about the flash I used in this test, follow this link: https://www.closeuphotography.com/godox

Each lens was focus bracketed and the single sharpest image for flat field lenses was chosen at 100% view in Photoshop. If a lens did not seem to be performing at its sharpest, I would run another second stack. For this test I had to run three stacks with the Componon 28/2.8,  just to make sure the performance was really that bad, and not an error on my part, like a big thumbprint on the back element. It wasn't my technique, its just not a sharp lens at 4X. 

For this test I ran all 3 copies of the Schneider 45mm APO-Componon that I own, I could not believe the performance was that bad at 4x. They were all that bad.

All images were shot as RAW ARW files and processed in PS CC 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. 

 

More Lens Information and Notes

Schneider Kreuznach 28mm f/2 Xenon in B00 barrel
Schneider Optics part number:
discontinued
Filter threads: 30.5mm x 0.5
Mount: 25mm x 0.5mm
Note: If you are lucky this lens will come with a Schneider industrial 42mm to 25mm step-down adapter.
Current Retail Price: Discontinued
Typical used price: $30-100 USD

Schneider Kreuznach 28mm f/4 Componon in B00 barrel
Schneider Optics part number:
10-010340
Other official names: 
COMPONON 28/4.0 BARREL #00
Componon 4,0/28
Filter threads: 30.5mm x 0.5
Mount: 25mm x 0.5mm
Image Circle Coverage: 30mm diameter
Note: In 1981 the 4/28 Componon retail price was $153, thats equal to $423 in 2017. This lens is still available in 2017 new at Schneider Optics USA for $523. 
Current Retail Price: $523 USD new.
Typical used price: $40-250 USD

Rodenstock 25mm f/4 Omegaron
Filter threads: None. For reverse mounting for macro photography  you can glue a 39mm or 42mm adapter to the front of the lens.
Mount: 39mm x 26 TPI ( turns-per-inch or threads-per-inch, approximately 0.977mm pitch)
Note: The Omegaron lens is identical to the Rodagon. These turn up on Ebay occasionally can be bought for almost nothing if you are patient.
Current Retail Price: Discontinued
Typical used price: $15-50 USD.

Schneider Kreuznach 28mm f/4 Componon in BKV-L barrel
Schneider Optics part number:
10-037275
Other Official names:
COMPONON 28/4.0 LEICA
Componon 4,0/28
COMPONON 28/4.0 BARREL BV-L
Filter threads: 40.5mm x 0.5mm
Mount: 39mm x 26 TPI ( turns-per-inch or threads-per-inch, approximately 0.977mm pitch)
Image Circle Coverage: 30mm diameter
Note: This is the late model plastic enlarger lens style with the green stripe. This lens is also available new from Schneider but the metal B00 model is $200 cheaper new.
Current Retail Price: $751 USD new.
Typical used price: $40-250+ USD

Schneider Kreuznach 35mm f/4 Componon in BKV-L barrel
Schneider Optics part number:
10-037277
Other Official names:
COMPONON 4/35 BARREL BV-L
COMPONON 35/4.0 LEICA  
Filter threads: 40.5mm x 0.5mm
Mount: 39mm x 26 TPI ( turns-per-inch or threads-per-inch, approximately 0.977mm pitch)
Image Circle Coverage: 32.5mm diameter
Note: This is the late model plastic enlarger lens style. This lens is also available new from Schneider but the metal B00 model about $150 cheaper new.
Current Retail Price: $705. USD new.
Typical used price: $30-150.

Schneider Kreuznach 28mm f/2.8 Componon in B-V barrel
Schneider Optics part number: 25-014794
Other official names:
Componon 2.8/28 Machine Vision Lens
28mm f/2.8 Componon Makro Iris
MACRO COMPONON 2.8/28MM    
Componon 2.8/28-0001 Macro lens
Filter threads: M37 x 0.75
Mount: V38 standard Industrial V-mount
Image Circle Coverage: 30mm diameter at f/4, only 11mm at f/2.8
Note: V-mount allows easy mounting lens and hood in normal or retro
Current Retail Price: $174. USD new.
Typical used price: $190-350

Schneider Kreuznach 45mm f/4 APO-Componon in B-V barrel
Schneider Optics part number:
25-014783
Other official names:
Apo-Componon Macro lens 4.0/45-0007
APO-Componon 4/45 Machine Vision Lenses
MACRO COMPONON 4/45MM    
Filter threads: M37 x 0.75
Mount: V38 standard Industrial V-mount
Image Circle Coverage: 32.5mm diameter
Note: V-mount allows easy mounting lens and hood in normal or retro
Current Retail Price: $807. USD new.
Typical used price: $190-350

 

The Test

To see other parts of this comparison see the links below:

1. 4X For Less Than $100: https://www.closeuphotography.com/4x-lens-test/part-one-4x-for-less-than-100-dollars
2. High-End Objectives: https://www.closeuphotography.com/4x-test-part-two-high-end-objectives
3. Enlarging Lenses Compared at 4x: https://www.closeuphotography.com/4x-lens-test-part-3/4x-lens-test-enlarging-lenses
4. High-magnification macro lenses at 4x: https://www.closeuphotography.com/4x-lens-test-part-4