Review: Fotodiox Minolta MD-Nikon Lens Mount Adapter

Fotodiox Minolta MD-Nikon Lens Mount Adapter

My primary reason for acquiring this was to use the Minolta MC Macro ROKKOR-X 100mm f/3.5 lens that I had acquired from its previous owner. Being in good condition, and at the time the only dedicated macro lens I owned, it seemed worthwhile to put it to good use in the digital realm.

While it works perfectly with my Minolta SR-T 201 body I wanted to try it on my Nikon D90, to test a theory. That theory was that for the purposes of macro photography, you can convert lenses with shorter flange-focal requirements to Nikon bodies, and do so without optical degradation.

In recent years, Fotodiox has earned a reputation for offering many types of lens adapters at reasonable prices. Some of these adapters achieve what is said to be “impossible”; the adaptation of lenses with shorter flange-focal distances to bodies with longer ones. This is accomplished through the use of corrective optics.

Their build quality is reasonably good; the machining looks good enough, but the product looks as though it went a few rounds in a rock tumbler before it was anodized. The attachment to the lens and camera are straightforward, except that Minolta lenses rotate clockwise to lock, while Nikon’s rotates counterclockwise. Once mounted, there was a significant amount of play, more on the Minolta side than the Nikon side. That got me thinking, since the mount seemed to slide together tightly. On closer inspection, I discovered that that three screws securing the Minolta mount to the body of the adapter were, in fact, loose. Tightening them solved the problem.

This adapter has two coated optical elements to correct for infinity focus which also enlarge the image by a factor of 1.4x. These are easily removed by unscrewing a metal retaining ring, restoring full quality at the expense of infinity focus. This essentially turns the adapter into a 10mm extension tube. The elements must be reinstalled in their original order and orientation; with the Minolta mount facing up, the plano-convex element goes in first, convex side down, and the biconcave element goes on top.

With the elements removed, the adapter did indeed allow the Minolta MC Macro lens to be used on the Nikon D90 with excellent results. The image was slightly smaller and also significantly brighter than with the elements. The only downside is that the furthest distance that the lens could focus on changed to about 36", which limits the ability to control the scale of the subject. Other than that, all the advantages of a dedicated macro lens, such as long focus ring travel and extended working distance were realized. This then would seem to be an excellent application for these Nikon converters who’s corrective elements tend to degrade image quality.

I also tested the adapter with a 50mm normal lens, both with and without the corrective elements. Again, without the elements the lens behaves as if it’s been converted to a macro lens with a 10mm extension tube. The resulting image quality was actually better than with some of my other Nikon lenses used with the Kenko 12mm extension tube. But with the elements, it becomes an excellent 70mm soft-focus lens, which on the D90 is 105mm. At wider apertures, the image details are still sharp, but veiled with coma to the extent that it appears as if a fog filter has been used. As it’s stopped down, the image gets progressively sharper, until about f/5.6, were the veiling all but disappears. At f/8 ad beyond, the image is quite sharp. It’s 105mm equivalent focal length makes it ideal for close ups and portraits.

The Verdict
Used for macro photography and soft focus portraiture, these adapters allow you to create some unique effects with a wide variety of non-Nikon lenses. Used wisely, they can create beautiful images, but you cannot compare the results with the corrective optics installed with those of a native lens. Used with smaller apertures, the degradation is minimal, and unless you are planning on producing very large prints, or substantially cropping them image, the differences may very well go unnoticed.

Build Quality ★★

Black anodized, all brass construction is solid with good-quality machining, but the product ships with a considerable amount of blemishes. The screws that secure the Minolta mount were loose, and had to be tightened.

Compatibility ★★★★

Mounts tightly on the body and lens with only a very minor amount of rotational play.

Focus ★★★★★

Infinity focus is achievable with the supplied corrective optics.

Optical Quality ★★/★★★★★

With the corrective elements in place, there was substantial image degradation below f/4. At f/5.6 and above, the image quality improves significantly, with only minor loss. With the corrective elements removed (macro extension tube mode) the optical quality is as good as the lens itself.

Value ★★★★★

For the relatively small investment of about $40.00, you can breath new life into older, non-native lenses. There’s a lot of enjoyment to be had experimenting with alternative lenses and their special effects for a small entry fee.

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To see the test results, see the review of the Minolta MC Macro ROKKOR-X 100mm f/3.5