Lens: Nikon 50mm f/1.8 AIS
Vintage: 1980-82.
Lens Mount: Nikon F-Mount.
Needed Adapters: 52mm reversing ring.
Preferred Mounting: Reversed.
Filter Thread: 52 mm.
Street Price: $100-$150 in good used condition. Prices vary a lot online, shop around.
Controls: Aperture and focus settings.
Aperture: 7 blades.
Basic Function: Requires a bellows to set focus and magnification.
| Extension | Magnification | Working Distance |
| adapters | 0.51 | 141 mm |
| 25 mm | 1.01 | 87 mm |
| 5 cm | 1.34 | 77 mm |
| 9 cm | 2.07 | 61 mm |
| 13 cm | 2.91 | 54 mm |
| 19 cm | 4.11 | 50 mm |
| Est. Focal Length: 50.8 mm | ||
Appearance:
Resolution vs. Aperture:
This lens is sharpest at f/5.6 with the most resolving aperture between f/4 and f/5.6. Above this, diffraction progressively limits the resolution. These numbers are typical for a 50mm lens.
Corner Sharpness vs. Aperture:
Corner sharpness is a mess at f/2 (even worse at f/1.8). I found that the sharpness in the center of the image is much better at f/2.8 than wide open. It is generally easier to get a sharp focus at f/2.8 than at f/1.8 or f/2 and I would recommend that you use that aperture for focusing.
The corner sharpness improves to reasonable levels at f/5.6 and is very good from f/8 and up. For imaging above a magnification of 2:1, f5/6 will work very well. Below 2:1 I would sacrifice a little resolution and image at f/8 if you want the corners to be reasonably sharp.
(Testing done at 1.34:1 magnification. Numbers at each aperture setting will tend to improve as the magnification is increased and worsen as the magnification is decreased.)
Sharpness and Resolution vs. Magnification:
This lens shows good sharpness and resolution, at least in the center of the field. If you are just looking at center sharpness, this lens outresolves the Nikon 105vr at 1:1. That is the advantage of a shorter focal length. It doesn't have quite as high of a resolving power as a dedicated macro lens of a similar focal length, but that should be expected given that we are using it for a purpose it wasn't designed for.
As expected, the corner sharpness at f/5.6 (green line on the graph) gets progressively better as the magnification is increased and is quite good at the higher end of the magnification range.
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 Nikon 50/1.8 AIS shows sharpness performance that varies from very good to fair across the magnification of 0.5:1 to 4:1.
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 50/1.8 AIS shows resollution performance that varies from very good to fair across the magnification of 0.5:1 to 4:1.
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 0.10 - 0.50 pixel) and moderate on the periphery (1 - 2 pixels). Anything below 1.0 pixel is good.
Image Contrast: Image contrast is good across the magnification range, not as good as a typical bellows lens, but certainly adequate.
Flare: This lens shows no significant flare during testing.
Distortion: This lens shows no significant distortion during testing.
Image Samples:
About 1.3:1 magnification, f/5.6, resized:
Pixel level crop from the image above:
There is good pixel level detail, no problems.
About 3:1 magnification, f/5.6, stack of 12 images, resized:
Pixel level crop from the image above:
There is good pixel level detail, no problems.
Conclusion:
The Nikon 50mm f/1.8 AIS works pretty well as a macro lens when used in reversed configuration. The resolution in the center of the frame is quite good at lower magnifications and reasonable at higher magnifications.
If you have the need for razor sharp corners at lower magnification, this probably isn't the lens for you. With the right choice of aperture, the corner performance at lower magnification can be significantly improved with only a small reduction in resolution.
This lens is known for being a good normal lens at a relatively inexpensive price. It's nice to know that it can be drafted into macro work if need be.