Lens: Schneider 80mm f/5.6 Componon
Vintage: 1960's?
Lens Mount: M25.
Needed Adapters: Reversing ring and 30.5 - 52 mm step-up ring.
Preferred Mounting: Reversed.
Filter Thread: 30.5 mm.
Street Price: Less than $100 in good used condition. Prices vary a lot online, shop around.
Controls: Aperture setting.
Aperture: 15 blades.
Basic Function: Requires a bellows to set focus and magnification.
Extension | Magnification | Working Distance |
5 cm | 0.43 | 249 mm |
9 cm | 0.93 | 152 mm |
13 cm | 1.43 | 121 mm |
19 cm | 2.19 | 102 mm |
Est. Focal Length: 80.1 mm |
Appearance:


Resolution vs. Aperture:
At a magnification of about 0.9:1, f/6.7 and f/8 have about the same sharpness. F/6.7 shows significantly higher resolution. I did a little additional testing at f/8 at lower magnification (0.4:1) and found that f/8 shows much higher sharpness with only a slight loss in resolution. For this reason, at magnifications significantly lower than 1:1, I would shoot at f/8 and switch to f/6.7 for the higher range. I will likely need to start doing aperture testing at more than one magnification because of these findings.
Corner Fuzziness vs. Aperture:
I have started to include resolution in the corners in addition to my standard sharpness testing. They don't act exactly the same way as they do in the center. Sharpness is just OK at lower magnification at f/6.7 but does improve when using f/8 and above. The resolution is pretty good at low magnification and f/6.7. This disconnect between sharpness and resolution appears to be related to more complex aberrations like astigmatism and CA acting on the periphery.
Lateral CA vs. Aperture:
This lens shows minimal lateral CA at all apertures.
Performance: Sharpness vs. Magnification:
I have 4 lines that represent levels of performance from outstanding (top) to fair (bottom). This shows where this lens fits into the hierarchy that I have created.
The sharpness performance stays generally in the very good range across the magnification range.
Performance: Resolution vs. Magnification:
I have 4 lines that represent levels of performance from outstanding (top) to fair (bottom). This shows where this lens fits into the hierarchy that I have created.
Resolution varies from very good at lower magnification to fair at the high end.
Corner Fuzziness vs. Magnification:
The corner sharpness is not so hot at lower magnification and f/6.7 but improves considerably to very good at the high end. Using f/8 at the lowest magnification would improve this considerably. The corner resolution is no worse than good at low magnification and also improves as magnification rises.
Resolving Power vs. Magnification:
This graph represents the smallest details that are able to be resolved by this lens at various magnificaitons. If the number doesn't get smaller as the magnification rises, there is little benefit to going up in magnificaiton with this lens. This situation is also called empty magnification.
Good resolution, no problems.
Chromatic Aberration:
This lens show minimal color fringing in the center (about 0.01 - 0.27 pixel) and minimal on the periphery (0.009 - 0.028%). Anything below 0.04% is not considered significant. Above 0.08% is considered moderately visible.
There is minimal axial CA on out-of focus details (see image below) as shown by a slight red fringe on the right and a slight cyan fringe on the left of the image.
Longitudinal CA:

Image Contrast: Image contrast is good, typical for an enlarging lenses.
Flare: This lens shows no significant flare during testing.
Distortion: This lens shows no significant distortion during testing.
Image Samples:
About 0.6:1 magnification, f/8, resized:

Pixel level crop from the image above:
There is very good pixel level detail, no problems.
Pixel level crop from the corner:
There is slight fuzziness in the corners, not bad.
About 2:1 magnification, f/6.7, stack of 8 images, resized:

Pixel level crop from the image above:
There is good pixel level detail, no problems.
Pixel level crop from the corner:
There is slight fuzziness in the corners, not bad.
Conclusion:
The Schneider 80/5.6 Componon is a good performer across the range of about 0.4:1 to about 2:1. It shows very good sharpness across the range and resolution compatible with the aperture. These can be found used for very little money. It has good contrast although not as high as a good macro lens. It has very little CA in the center or corners. It's corner performance is a little weak at the lowest magnifications, but that is improved by shooting at f/8. Shooting at f/8 is probably indicated at the lowest magnification anyway since the sharpness is much better than f/6.7 with only a mild loss in resolution.
This lens makes a pretty good macro lens replacement although it won't handle larger coin fully on my bellows, but it does give you a nice range up to 2:1 for close-ups. The only other real complaint I can see is the relatively small maximum aperture of f/5.6. This will make for a darkish viewfinder and maybe a little difficulty with getting the focus exactly where you want it.