Lens: Nikon 28 mm f/2.8 AIS reversed
Vintage: Current.
Lens Mount: Nikon F-Mount.
Preferred Mounting: Reversed.
Filter Thread: 52 mm.
Needed Adapters: 52 mm reversing ring, easily found for all camera mounts.
Street Price: From about $125 low-end used to $500 new.
Controls: Focus and aperture settings.
Aperture: 7 blades.
Basic Function: Requires a bellows to set focus and magnification
| Extension | Magnification | Working Distance |
| adapters | 2.16 | 45 mm |
| 25 mm | 3.08 | 41 mm |
| 5 cm | 3.70 | 37 mm |
| 9 cm | 5.10 | 34 mm |
| 13 cm | 6.52 | 32 mm |
| 19 cm | 8.68 | 31 mm |
| Est. Focal Length: 28.2 mm | ||
Focus Setting: What focus setting should a reversed lens be at? There are a couple of issues involved. First, this lens has a floating internal element that allows the lens to perform better at close focus. The second issue is that when a reversed lens is focused, the lens elements tend to move farther back into the lens housing as the lens is focused close. That means less working distance. These two issues must be weighed against each other.
The table below shows that the main differences in the lens when focused near or far while reversed on a bellows are related to corner performance and working distance. When focused close, the corner performance is better with a small loss of working distance. The working distance loss isn't enough to make a big difference, so I tested the lens at a close focus setting. I tested at bellows 5 cm (minimum) and at bellows 13 cm (only showed the numbers at bellows 50 mm as they were similar).
| Focus Setting | Sharpness | Corner Perf | CA | Working Dist |
| Close | 703 | 16% | 1.5 | 37 mm |
| 25 mm | 705 | 34% | 1.3 | 44 mm |
Appearance:
Resolution vs. Aperture:
This lens is at its sharpest at f/5.6. This lens has the most resolution at f/4.
I would suggest using this lens at f/5.6 for the improved sharpness. Shooting at f/5.6 is Ok in the lower part of the magnification, but is kinda high for the upper magnification range due to the effects of diffraction (compared to other comparable lenses).
Corner Sharpness vs. Aperture:
The corner sharpness is OK at f/2.8 and improves to good/very good at f/5.6 and above.
This testing was performed at the minimum bellows extension and a magnification of 3.7:1.
Sharpness and Resolution vs. Magnification:
text.
This lens shows good resolution and sharpness although not as good as specialty lenses in this magnification range. Other lenses tend to have larger working apertures allowing improved performance.
The corner sharpness is OK to good when directly mounted to the camera and good to very good on the bellows.
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 reversed Nikon 28mm varies from very good sharpness at the low end to fair at the high end of magnification.
A lens that performs in the fair/poor range doesn't mean that the lens is fair/poor, just that there are other lenses out there that will significantly out-perform that lens in that 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.
The Nikon 28 mm shows resolution performance that varies from very good at the low-end to ppor at the high-end of its magnification range. The poor perofmance at high magnification is related to its relatively small f/5.6 aperture.
A lens that performs in the fair/poor range doesn't mean that the lens is fair/poor, just that there are other lenses out there that will significantly out-perform that lens in that magnification range.
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 reoslution, although you can likely gain a little resolution by shooting at f/4 at the expense of some sharpness.
Chromatic Aberration:
This lens show mild to moderate color fringing in the center (about 0.50 - 2.60 pixel) and mild to moderate on the periphery (0.040 - 0.100%). Anything below 0.040% is not considered significant. Above 0.08% is considered moderately visible. There is mild axial CA on out-of focus details (see image below) as shown by a magenta fringe on the right and a green fringe on the left of the image.
Longitudinal CA:
Image Contrast: Image contrast is good.
Flare: This lens shows no significant flare during testing.
Distortion: This lens shows no significant distortion during testing.
Image Samples:
About 2.1:1 magnification, f/5.6, focus stack of 15 images, resized:
Pixel level crop from the image above:
There is very good pixel level detail, no problems.
About 6.5:1 magnification, f/5.6, stack of 30 images, resized:
Pixel level crop from the image above:
There is OK pixel level detail, limited by the f/5.6 aperture.
Conclusion:
This is a lens that performs well as a macro lens. It spans the range of magnification from about 2:1 to 8:1 on a typical bellows. This lens needs to be used in reversed configuration for macro. When it is normally mounted the working distance goes to 0 fairly quickly related to its retrofocus design. This lens is easily available for a bargain price and is easy to adapt to a bellows, just needing a reversing ring. I also found that the lens works a little better when the focus is set to the closest setting. You will lose a little working distance, but the corners will be sharper.
The resolution and sharpness are good, but not quite up the standard of specialty lenses. It has good to very good corner sharpness on a bellows and OK corner sharpness when directly mounted to the camera. There is mild to moderate CA fringing across the magnification, but not enough to be terribly obvious. Working distance is good.
So, I wouldn't suggest that you go out and buy this lens for macro use. There are other lenses out there that do a better job for a similar amount of money. If you do already have this wide angle lens for your regular photography use, this lens can do double duty as a bellows lens.