Schneider Componon 28mm f2.8 Lens test

Schneider Kreuznach Componon 2.8/28 machine vision lens

This is the latest 28mm Componon design from Schneider intended for industrial machine vision applications like OLED inspection and quality control. This lens is just a little more expensive than the older 4/28 enlarger lens model, but the faster maximum aperture and all-metal v-mount body are worth the extra cost. The image quality of this lens in a stacked configuration is truly excellent but the Componon 2.8/28 is unknown in the macro photography world. At 3.2x magnification and at f3.1 the image quality of this lens is extremely clean and pristine from edge to edge, be sure to take a look at the 2500 pixel image sample below to see what I mean. At 4x this lens can outperform all, but just a few of the best microscope objectives. See the test below against the Mitutoyo 5x M Plan APO pushed down to 4.3x for a good example.

This lens was purchased at the full price and I did not receive any discount or commission for this post which does not contain any affiliate links, ads or visitor tracking.

Update on December 28th 2018: The Schneider Kreuznach 2.8/28 Componon lens and Mejiro 5.6/90 scan lens at 3.2x will cover the Nikon D850 full frame sensor body. See the image sample below under Full Frame Sensor Coverage at 3.2x.

QUICK REVIEW

  • Excellent image quality and extremely consistent corner performance

  • Better performance than any non-HR objective from 3-4x

  • Better than the Mitutoyo 5x M plan at 4.3x

  • Sharpest at f2.8 - f3.1

  • Very good CA correction

  • Perfect APS-C sensor coverage

  • Full frame sensor coverage is very good

  • All metal barrel, no plastic

  • V38 mount

  • Excellent prices on the used market

  • Vibration and dust resistant design, cells are locked in place with thread locking compound.

Stacking vs extension

Stacking lenses, also called coupling lenses is a technique where you mount a lens in reverse on a second lens, usually a telephoto lens mounted normally, that can deliver excellent results. With the rear lens set to infinity focus and with the front lens reverse mounted there is no loss of light due to extension so you have the potential to resolve more than a since a wider aperture has the potential for higher resolution. Certain pairs of lenses when stacked can eliminate or greatly reduce chromatic aberrations. Stacking also can increase the coverage of a lens.

Twice before I’ve tested lenses of this type setup using only extension, and in both cases the results were very disappointing mostly due to soft corners. The earlier 4x test of 28mm enlarger lenses is available here on Closeuphotography.com: https://www.closeuphotography.com/4x-lens-test-part-3. Because of the disappointing results of the first two tests I sold all of the lenses from the first two groups except for the Schneider Componon 2.8/28 lens, which never received a single bid after sitting on eBay for months. Thanks to the encouragement of a friend I rediscovered stacking or coupling lenses in 2018 and I decided to try that 2.8/28 Componon lens. In a stacked configuration the 2.8/28 produces sharp corner to corner results wide open from and is currently one of the best lenses I have ever tested since starting this site in 2017. See this test of 28mm lenses, including the 2.8/28 Componon here on Closeuphotography.com: https://www.closeuphotography.com/28mm-componon-test

Image sample at 3.2x

The image below is at 3.2x magnification, click on the image below to open a Lightbox viewer and if your screen/window is large enough you can see the full size image, to check just look up at the URL window at the top of the browser, the URL should have 2500w at the end. If the image size is anything smaller you can easily change the number to 2500 manually and press enter to bring up the largest image.

The Papilio palinurus or emerald swallowtail butterfly wing scales at 3.2x

Below are the center and corner crops at 100% view in Photoshop.

To see a larger of the crop image just click the image, right click, or two-finger press, and select Open in a New Tab or New Window from the menu. You can also right click, or two-finger press, and select  Save Image As to save and view the image full size.

For best results I use this lens in a stacked configuration. Stacking lenses, also called coupling lenses, is a technique where you mount a lens in reverse, or face-to-face, on a second lens, usually a telephoto lens. With the rear lens set to infinity focus and with the front lens reverse mounted there is no loss of light due to extension. Together the combination has the potential to resolve more than either of the lenses setup for close-focus with extension. You can predict the maximum possible resolution from a certain lens by using the simple fact that a wider aperture = higher potential resolution.

A f2.8 lens focused at 3x magnification by extension would have an effective aperture of f/11 using the simple formula, effective aperture = nominal aperture * ( Magnification + 1 ). With the same lens setup in a stacked configuration the effective aperture would be only f/8.4 using the formula effective aperture = nominal aperture * Magnification.

Schneider Kreuznach Componon 2.8/28 machine vision lens

Schneider Componon 2.8/28 Technical Details

Schneider Kreuznach Componon 2.8/28 - 0001
Other official names
:
Componon 2.8/28 Machine Vision Lens
28mm f/2.8 Componon Makro Iris
MACRO COMPONON 2.8/28MM    
Schneider Optics part number: 
14794
Filter threads: 37mm x 0.75 standard for the V38 line scan lens line up
Barrel type: B-V barrel also known as Makro-Iris mount
Mount: V38 V-mount
Type: Industrial Machine Vision
Iris: 5 blades
NA: 0.18
Nominal Aperture
: f/2.8 forward mount, f/2.6 reverse mount
The iris on the lens does not open 100% but the aperture size does measure f/2.8 forwards and slightly faster in reverse.
Sensor pixel size: to 3.65μm (micron)
Magnification range: 0.12x The latest data sheet from Schneider has the optimized magnification at 0.5x.
Coverage: On extension in forward mount the official image circle is 30mm, but only 11mm at f2.8. In practice, when reverse mounted, the lens can easily cover APS-C with an edge to edge sharp image.
Forward or Reverse Mount: Reverse and stacked on a telephoto lens.
Current Retail Price: $714 USD Schneider Optics USA
Typical used price: $250-300 USD used. New in factory packaging units are available on eBay in December 2018 for $350 with free Fedex delivery.

RATING

What I Like: 
f/2.8 maximum aperture
Image quality when stacked
All metal body and V-mount interface
Surplus factory packaged units are available on eBay
Locking iris ring

What I Don’t Like: 
Non-circular aperture shape of the 5 blade iris

Componon 2.8/28 Image sample; butterfly scales at 3.2x

Click on the image below to view a larger version in a Lightbox viewer, but this will only be the largest size image if your screen/window is large enough, so check the size of the image you are looking at, look up at the URL window at the top of the browser, the URL should have 2500w at the end. If the image size is anything smaller you can easily change the number to 2500 manually and press enter to bring up the largest image.

The apilio ulysses or Blue emperor butterfly wing scales at 3.2x

The crops below, one from dead center and the other from the extreme upper left corner, show that the image quality is very consistent across the frame without any image quality drop off at all even in the far corners.

To see an images in a new browser tab, right click, or two-finger press, and select Open in a New Tab or New Window from the menu. You can also right click, or two-finger press, and select  Save Image As to save and view the image full size.

SETTING UP THE COMPONON 28 FOR best results

At higher magnifications from about 3x - 5x, this lens performances best in a stacked configuration with the lens reversed on the front of a telephoto lens at infinity focus. In the image above the Componon 2.8/28 is reversed and mounted on the rear lens in the stack, a Schneider Makro-Symmar 120 that is mounted out of sight inside the SM2-52mm extension tube and focused on infinity. The Componon lens is reversed in the above image with the lens hood mounted on the rear of the lens.

The Schneider Makro-Symmar 120 is mounted inside a SM2-52mm extension tube using a V38 to 42mm x 1.0mm adapter attached to a Thorlabs SM2 to 42mm to 1.0mm adapter. Another 42mm x 1.0mm adapter goes on the front of the 2.8/28 and that mounts to the Thorlabs SM2 to 42mm to 1.0mm adapter and the lens also mounts inside the 52mm extension tube directly in front of the Makro-Symmar lens.

The advantages of mounting both lenses inside a SM2-52mm tubes is that each lens can be positioned exactly as needed; either touching or leaving room for a threaded iris or aperture disk. It’s possible to leave the front barrel and aperture protruding from the tube to allow easy access to change apertures.

Schneider Componon 2.8/28 reversed and Schneider Makro-Symmar 5.6/120. The 2.8/28 hood is mounted on the rear of the lens.

Componon 28 test at 3.2x

In the last months I have tested more than a dozen telephoto lenses as a rear lens in a stacked set-up. Out of the 18 or so lenses that I’ve tried, two are exceptional. The Schneider Makro-Symmar 120 line scan lens and the Mejiro 90/5.6 line scan lens. You can see test results made with the Componon 2.8/28 + Mejiro 5.6/90 below. The results are very sharp, very consistent and clean from edge to edge. Be sure to check out the full size 2500 pixel sample below.

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 α6300, model # ILCE-6300, also known as: 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.

2500 PIXEL IMAGE SAMPLE

Click on the image below to view a larger version in a Lightbox viewer, but this will only be the largest size image if your screen/window is large enough. The size of the image sent to your device is based on the screen size. The below is 2500 pixels across. To check the size of the image you are looking at, look up at the URL window at the top of the browser, the address should have 2500w at the end. If the image size is anything smaller you can easily change the number to 2500 manually and press enter to bring up the largest image.

To see an image in a new browser tab, right click, or two-finger press, and select Open in a New Tab or New Window from the menu. You can also right click, or two-finger press, and select  Save Image As to save and view the image full size.

Schneider Kreuznach 2.8/28 Componon lens + Mejiro 5.6/90 scan lens at 3.2x on Sony A6300 APS-C body.

This un-cropped image is flawless from edge to edge with excellent sharpness and no signs of chromatic aberrations.

100% View Crop Image Samples

100% view center crop

100% view corner crop.

The performance from this pair of lenses is very consistent; I don’t see any difference between the center and corner crops. Microscope objectives will not give you this type of consistency in my experience.

3.2x Test Results

After testing dozens of lens pairs over the last few months the image quality from this combination is at a level that you won’t see very often. This is the kind of image quality I would expect to see from a HR (high resolution) objectives and something like a Nikon Rayfact 3.5x OFM35162MN, but those two are at least 10 - 20X more expensive and are only made to order so you won’t be seeing these in factory packing on eBay at any point in the future. The 2.8/28 Componon is an awesome value and easy to find, I paid $200 for my first unit used and my second copy was bought as new and in the box still sealed in plastic for $350, an excellent bargain of a lens.

Full Frame Sensor Coverage at 3.2x

The Schneider Kreuznach 2.8/28 Componon lens and Mejiro 5.6/90 scan lens at 3.2x will cover the Nikon D850 full frame sensor body. Center and the edge are just about perfect. There was a slight drop in sharpness at the far corners, but it’s hardy noticeable and nothing close to the type of drop off in quality you would see with a microscope objective.

2500 pixel image sample with the D850

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

4.3x Test: the Componon 2.8/28 vs Mitutoyo 5x M Plan APO

The Componon 2.8/28 is excellent at 3.2x, but higher magnifications are going to be very difficult since this is where microscope objectives almost always have a sharpness advantage due to a larger effective apertures. The Mitutoyo 5x M Plan APO was chosen for this test since it’s one of the most popular and best performing objectives at this magnification beating almost all comparable objectives. FYI Nikon and Olympus objective’s are designed to cover a smaller field than the Mitutoyos. as a matter of fact, with a much smaller FN or field number, and most don’t even cover the manufacturers specifications for the lens. So comparing the Schneider Makro-Symmar 5.6/120 + Componon 2.8/28 lens to a Nikon or Olympus 5x objective’s would be a waste of time in my experience since the sharpness consistency from center to corner is pretty weak even on a small APS-C sensor.

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 α6300, model # ILCE-6300, also known as: 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

A stack of images in 2 micron steps was made for this test, 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 and 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.

To see an images in a new browser tab, right click, or two-finger press, and select Open in a New Tab or New Window from the menu. You can also right click, or two-finger press, and select  Save Image As to save and view the image full size.

Crop areas outlined in white.

100% View Center Crops

The differences are very small. In some areas the Componon is sharper and in some the Mitutoyo has an advantage. Its the same case with CAs, some areas the M Plan is better, some areas its not.

100% View Below Center Crops

The Componon seems to have slightly better sharpness but the Mituyoto has slightly better CA control. The performance from both lenses where is great.

100% View Edge Crops

Now there is a large difference in IQ at the edge. The Componon is much sharper with better contrast, the Mitutoyo is softer but has less red fringing. For both of these lenses a specific frame was selected for the edge crops and processed identically and at the same time.

100% View Corner Crops

At the corner, the Componon has quite an advantage over the Mitutoyo in sharpness, resolution and CA control, see the arrow at the far upper left corner, the Componon is CA free.

4.3x Test Results

The Componon 2.8/28 and Mitutoyo M Plan are in the same price range new and used and both have similar performance here around 4x. The Mitutoyo would probable beat the Componon at 5x and higher but the Componon has an iris and is much larger and more flexible range from 1/20 to 4x.

I would easily recommend either one, I’m just glad I already own both!

Longitudinal Chromatic Aberration test

No problems with LoCAs at 3.2x with the Componon 2.8/28.

Componon 28 Price and Availability

The price of the 2.8/28 lens new is about $700 so is not too expensive even direct from Schneider Optics but there are 2.8/28 units in the factory packaging available on eBay for $350 USD now. The seller had about 10 in stock as I am writing this post. New-in-the-box old-stock lenses on eBay are always a safer bet than used.

For a little less money the f4 28mm Componons can be found eBay, the range of prices is ludicrous, today on eBay the range for a 4/28 Componon is $50 to $250. Personally I don’t see any reason to for with the f4 lens and I would rather spend the extra money for the latest f/2.8 version. New 4/28 units can still listed on the Schneider Optics USA for $500 USD.

Componon 28 Notes

The 2.8/28 is the only Componon and the only SK lens that I have seen with a thread locked rear cell. The retainer ring on the back of the lens that holds the cell in place has thread-locker and has red paint applied as part of the quality control process. Most SK lenses in my experience have only hand tightened lens cells that can sometimes loosen in your hand if you do not handle them carefully.

The 2.8/28 is also the only Schneider lens that I know of that comes with a inspection supplied sheet in the box. Is this lens model special or is this something that was done for all Componons at one time? Its interesting that this lens was made in 2011 and sold as-new by a surplus dealer in 2018.

Other Componon Lenses

Schneider 2.8/28 Componon on the left and the 2.8/35 Componon on the right.

Another super performer from Schneider is the 2.8/35 Componon. A detailed review is available here on Closeuphotography.com: https://www.closeuphotography.com/schneider-componon-35mm/

Componon 28 Iris Types

There are basically three iris types between the 7 or 8 versions of the Componon 28. The 5 blade which is the most common, the older 15 blade and a preset iris type. The 15 blade iris with the nearly perfect circular aperture is more desirable since it produces much more natural looking bokeh. But beware, some of the 15 blade lenses have single or are non-coated, and will be more prone to flare and have less contrast than later versions. Some f/4 lenses, the one in the center of the above, have an iris that has been reset to open all the way to f/2.8.. The performance was nothing special at f/2.8 so I soon sold the lens in the image above. You can also remove the rear lens cell and re-set the aperture ring to open the iris fully with any of the lenses above except for the f2.8 where you will find thread locker applied so proceed at your own risk.
 

Componon 28 versions

Schneider has been selling the Componon 28 design since the 1960s for work with subminiature film formats that are smaller than 35mm like 12 x 18 and 18 x 24mm. Its amazing that the design has been around so long and is still sold today by Schneider. The first enlarger lens I ever owned was a Componon 4/28 and since then I’ve owned at least 12 of these over the years in 6 different versions. There are at least 8 versions of the Componon 28 that I have seen and there are probably more out there.

Above are the four most common versions of the The Schneider-Kreuznach 28mm f4 Componon that you will see. L-R, there are at least 4 other types not pictured above.

S-K 28mm f4 Componon in Chrome barrel with 15 blade iris 30.5mm x 0.5 filter threads
S-K 28mm f4 Componon in metal B00 barrel with 5 blade iris 30.5mm x 0.5 filter threads
S-K 28mm f4 Componon in plastic BKV-L barrel with 5 blade iris 40.5mm x 0.5mm filter threads
S-K 28mm f2.8 Componon Makro-Iris in metal B-V barrel with 5 blade iris with reversable center barrel section

All of these are still available new from Schneider Optics in the US except for the older chrome barrel version on the far left. They are all almost exactly the same optically, even the 29.3mm focal length but the Componon 2.8/28 industrial version on the far right is optimized for for slightly closer focus than the others. The early versions of the lens before 1980 or so are single coated or some are even uncoated so be careful. These older lenses tend to flare a lot easier than the never coated versions.

Schneider Kreuznach 28mm f/4 Componon in B00 barrel
4/28 black metal barrel lens model with the white split circle aperture indicator
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

Schneider Kreuznach 28mm f/4 Componon in BKV-L barrel
4/28 all plastic barrel green aperture window model
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 28mm f/2.8 Componon in B-V barrel
2.8/28 in Makro-Iris all-metal 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: 249-350

Schneider Kreuznach 28mm f/4 Componon
Chrome all-metal barrel model

Filter threads: 30.5mm x 0.5
Mount: 25mm x 0.5mm
Iris: 15 blade
Image Circle Coverage: Corners are poor on APS-C in reverse
Note: Chrome 15 blade version. Some of these early lenses are non-coated or single coated.
Price as new: 1963 retail price was $53 in 25mm mount and $58 for the leica mount, the 50mm f4 lens was $59 in 25mm and $65 in Leica mount.
Typical used price: $25-250 USD

Schneider Kreuznach 28mm f/4 Componon
Black all-metal barrel model with 15 blade iris

Filter threads: 30.5mm x 0.5
Mount: 25mm x 0.5mm
Iris: 15 blade
Image Circle Coverage: Corners are poor on APS-C in reverse
Note: Chrome 15 blade version. Some of these early lenses are non-coated or single coated.
Price as new: 1963 retail price was $53 in 25mm mount and $58 for the leica mount, the 50mm f4 lens was $59 in 25mm and $65 in Leica mount.
Typical used price: $25-250 USD

Schneider Kreuznach 28mm f/4 Componon
Larger Black metal barrel 
with the split circle aperture indicator painted on the barrel
Filter threads: 30.5mm x 0.5
Mount: 39mm x 26 TPI ( turns-per-inch or threads-per-inch, approximately 0.977mm pitch)
Iris: 5 blade
Image Circle Coverage: 30mm diameter but far corners are poor
Note: This is black metal barrel 5 blade version
Typical used price: $25-250 USD

Schneider Kreuznach 28mm f/4 Componon
B00 smaller black metal barrel 
with the split circle aperture indicator painted on the 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
Iris: 5 blade
Image Circle Coverage: 30mm diameter but far corners are poor
Notes: Small black metal barrel with 5 blade iris. 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

Schneider Kreuznach 28mm f/4 Componon Cylinder body
4/28 Componon preset Cylinder body

Schneider Optics part number: unkown
Filter threads: 30.5mm x 0.5
Mount: cylinder mount
Iris: none
Image Circle Coverage: same
Notes: Very rare find on the used market. These were made to be used in lens turret for a printing machine with other pre-set focal length SK lenses like the 4/40. All the Cylinder body SK lenses share interchangeable center sections with waterhouse stops.
Current Retail Price: Unknown
Typical used price: Purchased two new-old-stock in the factory-packaging for $40 from a seller in Israel in Oct. 2018.

Schneider Kreuznach 28mm f/4 Componon preset heavy duty barrel body
4/28 Componon preset heavy Cylinder body

Schneider Optics part number: unkown
Filter threads: none
Mount: heavy cylinder mount
Iris: none
Image Circle Coverage: same
Notes: rarely seen on the used market.
Current Retail Price: Unknown
Typical used price: $40+

Componon 28 Data


LINKS FOR MORE INFO:

The 2.8/28 Componon on the Schneider USA site:

https://www.schneideroptics.com/Ecommerce/CatalogItemDetail.aspx?CID=1347&IID=6006

The Line Scan line up on the Schneider USA site:

https://www.schneideroptics.com/Ecommerce/CatalogSubCategoryDisplay.aspx?CID=1347

V38 Line Scan lens lineup on the Schneider Kreuznach site:

https://schneiderkreuznach.com/en/industrial-optics/lenses-v38-line-scan-macro-system

2.8/28 CPN data-sheet on the Schneider Kreuznach site:

https://schneiderkreuznach.com/application/files/1215/0839/7424/Componon-2.8-28.pdf

V38 machine vision lenses on the Schneider Optics site:

https://www.schneideroptics.com/Ecommerce/CatalogSubCategoryDisplay.aspx?CID=1347

Line Scan PDF from Schneider:

https://www.schneideroptics.com/pdfs/Large_Format_Lenses_with_Technical_Info.pdf

The 2.8/28 on the Edmunds site where its $150 more expensive than direct from Schneider:

https://www.edmundoptics.com/p/componon-f28-28mm-focal-length/17668/

Machine vision lens page on the Schneider USA site with an image of an out of place enlarger lens for some reason and some links are broken.

https://www.schneideroptics.com/industrial/unifoc/lenses.htm