I’ve been looking for way to extend the macro capability of my digital camera for a while. I had tried other methods, including shooting through photographic loupes, and magnifiers, but the quality I got wasn’t great, and it was difficult to control. Recently I remembered that photographic enlarging lenses are often used as macro lenses by reversing them on a camera. I’m using a Sony Mavica FD7 digital camera (this is an older model with max resolution of only 640 x 480), coupled with enlarging lenses off a photographic enlarger. The enlarging lenses are much smaller and lighter than normal camera lenses, and are mounted on the Mavica reversed (ie, the front of the enlarging lens goes against the Mavica). I used a Nikon El-Nikkor 50mm f2.8 and a Minolta E. Rokkor 75mm f4.5 (pictured above). The longer the focal length of the enlarging lens, the less the magnifying effect.
These lenses have diameters around the 42mm mark, which fits very nicely onto the Mavica lens housing. My camera does not have a filter thread, and so I simply tape the lens onto the camera (see pic at left). Other cameras, and later Mavicas, have a filter thread, and so the reversed enlarger lenses may be able to be mounted onto those cameras using mating rings. Normal camera lenses can be reversed to give macro capability also, however, they are normally too heavy and too large to be used practically (smaller rangefinder camera lenses, such as Leicas, may be OK though). Also, enlarger lens optics are designed specifically to produce good results over a flat plane (as in their primary function of photographic printing), and therefore are likely to give better edge to edge sharpness than comparable quality camera lenses. I set the camera on manual focus, as the auto focus system “hunts” a bit with only small movements and makes focusing harder. Magnification is controlled by the use of the Mavicas 10x optical zoom. I find that I need to use about 5x zoom to avoid vignetting (cutting off of edges of frame) with both lenses. Full zoom gives approx 10x magnification using the 50mm enlarging lens. I have generally been using the enlarger lenses at their full aperture, or maybe 1 stop down. Stopping them down gives an increase in the depth of field, but also increases vignetting, and requires more light. Depth of field is minuscule! I have also been handholding the camera for these shots. I generally use a tripod, but focusing with this arrangement is a matter of moving the whole camera/lens assembly in & out in very small increments, and that is clumsy when on a tripod. Handholding allows normal freedom of movement to frame the shot, and the Mavica seems to supply fast enough shutter speeds (given enough lighting) to avoid shake from my jittery hands (I believe the Mavica will give up to 1/4000sec shutter speed, which ain’t too bad).
The lighting I used for these shots is very simple, consisting of an overhead fluorescent strip light though a sheet of diffusion material (greaseproof paper!), approx 10-15cm from the subject. The diffused lighting avoids harsh reflections, and angling the lighting correctly brings out the surface texture. Small alterations make major changes in the end result.
Here are some example pics…
Copyright 2000 Paul Delury