Review: Minolta MC Macro ROKKOR-X 100mm f/3.5

Minolta MC Macro ROKKOR-X 100mm f/3.5

This is an equipment review of a somewhat different nature.
I’ve found working with conventional lenses converted for macro photography using extension tubes, macro reverse rings and closeup lenses quite rewarding. However, since I do posses a dedicated manual-focus macro lens, it also makes sense to use that as well. The only problem is, it’s not a Nikon macro lens, but a Minolta.

So, having already invested in a Fotodiox FD-Nikon adapter, the purchase of the MD-Nikon version seemed the logical solution. Even if the quality of the corrective optics were not up to par, they could be removed, as the macro function of the lens does not require infinity focus. Without the optics, the adapter would then behave as an extension tube that would work with any Minolta MC or MD lens.

The Minolta MC Macro 100mm lens is of the old school; solid, all-metal construction, silky-smooth damped focusing, positive, half-stop aperture ring (predictably only a full stop between f/3.5 and f/5.6). One of the key features of this lens is the magnification and exposure compensation factors engraved right into the lens barrel, for both the lens and lens/extension tube combination, which gives a magnification of 1:2 (.5x) and 1:1 (1x) respectively. However,  these figures change to 1.05x and 2.1x on an APS-C camera with the corrective optics factored in. Simply multiply the numbers on the scale by 2.1 to see the true magnification.

Fotodiox MD-Nikon Lens Mount Adapter with corrective optics

Mounted on the Nikon D90 using the Fotodiox MD-Nikon Lens Mount Adapter, this lens has a minimum focus distance of approximately 10.38" or 26.4cm, reduced from its normal 18" distance. But with the corrective elements in the adapter removed, this changes to 8.69"or 22.07cm. Either of these distances still provide adequate working distance for natural lighting. The focus ring makes nearly a full revolution from the minimum distance to infinity making fine adjustment easy. The lens barrel extends just shy of 2" at closest focus. The filter threads remain stationary during focusing, so the use of a macro flash such as the Sigma EM-140 DG is a feasible option.

As with any manual focus lens, the Minolta MC Macro 100mm takes skill to use, mainly in the form of a steady hand when used hand-held. Under bright conditions, it’s easy enough to gauge focus by using the matte screen. Under darker conditions or with smaller apertures, zooming in with Live View can be beneficial, and is one of my favorite applications of this feature. If you can find a specular highlight, you can tweak the distance between the camera and the subject to achieve sharp focus.

This lens focuses slightly past infinity, due to no fault of the Fotodiox adapter, as I have tested it with other Minolta lenses. As a user of Nikon AF-S lenses which by design do not have a hard stop at infinity, I am familiar with this situation, which might be able to be corrected through adjustment. However, since infinity focus is possible, it’s not a major problem.

So how did it perform? Well, these two exposures were taken at 1/100, f/5.6, ISO 1600, the first in each pair with the optics in place, and the second with them removed. These images came directly from the camera, with no post-processing (except for the crop in the second and third examples).

Full frame, corrective elements in place.

Full frame, corrective elements removed.

Viewing the entire frame, aside from the exposure loss and the slight change in scale, the difference is negligible. But when we zoom in, the differences become much more apparent.

Center, 200% crop, corrective elements in place.

Center, 200% crop, corrective elements removed.

There is definitely a slight but noticeable improvement at the center of the image. But all in all, the quality isn’t bad at all. But, this is the center of the image. If we move to the extreme borders, we get a different story entirely.

Border, 200% crop, corrective elements in place.

Border, 200% crop, corrective elements removed.

The corners without the optical elements are significantly sharper and less prone to chromatic aberration than those with. So, the verdict is, I can definitely use this Minolta ROKKOR-X macro lens with my Nikon D90 and realize its full optical quality, while enjoying the conveniences of using a dedicated macro lens. The only real down side is that due to the loss of infinity focus, the range of scale that I can achieve is reduced. However, I wouldn’t really need a macro lens to achieve that scale anyway, I could do it with any close-focusing lens.

With the optics installed, I can enjoy these same capabilities at a slightly increased magnification level, with a slight loss of speed and image quality, which could easily be corrected in post-processing.

Border, 200% crop, corrective elements in place, post-processed.

It’s not perfect, but it’s definitely an improvement. With a little more effort, it could have been made to look even better that the version with the corrective optics removed.

As a 210mm telephoto lens (100mm x 1.5 x 1.4 = 210mm), the MC Macro performed quite well at f/5.6, with moderate veiling at f/3.5. At f/8 and beyond the images were very sharp indeed. It was more practical to use the Nikon D90’s matte focus screen than the focus confirmation lamp, and the long focus ring travel made fine adjustment easy.

Build Quality ★★★★★

Solid, all-metal construction, weighing in at a whopping 21.3 oz (604g). Three-color, engraved, paint filled markings.

Compatibility ★★

In terms of use with a Nikon body, and when used with the Fotodiox adapter, manual exposure is the only mode that can be used, and even then stopped-down metering cannot be used on consumer and some prosumer bodies. Since this is not an autofocus lens, it would be pointless to mention that autofocus would not work either. Also, there is no auto diaphragm coupling, so the aperture must be stopped-down just before exposure. However, optically speaking, the lens performs quite well when mounted to a Nikon DSLR body, and the exposure is easily determined through histogram chimping.

Focusing ★★★★★

Buttery-smooth and perfectly damped. Long-travel (almost 360°) for fine focus control. Rudimentary hyperfocal scale with f/8 and f/22 markings. Six-step magnification scale for lens alone, and with its dedicated extension tube. Infrared index.

Optical Quality ★★★★

Very sharp, even at its widest aperture.

Value ★★★★★

As this lens sells for about $133.00 on the used market, it’s an inexpensive option with superior quality for those interested in exploring manual macro photography.

Diaphragm

6 curved blades. Apertures of f/3.5-f/22 with half-stop increments between f/5.6 and f/22.

Filters

Accepts 55mm filters in its metal, non-rotating filter threads. The Hoya Pro1 Digital MC UV(0) is highly recommended.

Hood

No provisions for a bayonet or snap-in hood are provided, but the recessed front optic may reduce the need for one. Otherwise, the Hoya 55mm Screw-in Rubber Zoom Lens Hood is an excellent option.