I’ve been interested in macro photography for a while; in a past life I collected insects and flowers for an ecology degree. Most of the science and art in natural sciences focuses on the small or very small. Recently I was inspired by an article over at petapixel and have been looking for a low cost, low play worm gear driven macro rail to create high quality focus stacked images. In the past I’ve used the focus on the camera itself, but this can lead to alignment errors that need software correction.
Enter the Desmond MRA-1 Macro Rail. I have other plates aluminum mounting plates arca-swiss compatible plates that I really like from Desmond so I figured I would give it a shot. The rail is billed on Amazon like this: Wormdrive Macro Rail Fine Focus Focusing Arca / RRS Lever Clamp Compatible 100% Metal
I used the rail for a few shots and found there was a lot of play if it was not setup with weight on the screw. Here is my first, and most likely last, image taken with the rail and a 65mm Canon 1-5x macro lens. I used focus stacking at f/2.8 to get maximum sharpness over the entire object. I could stop down a bit, but there was already substantial noise from shutter speeds being longer than 1/10th of a second on the 5d mkIII. I focused at 5x life size on a flower of dried lavender
I think the screw operated well enough once you took the play out of the knob. You can turn the knob about a quarter of the way before it picks up unless the camera is pointed down, effectively lowering with the worm screw. The other problem with the design is that the screw does not attach to the other end of the housing box, causing a large amount of wiggle play at the 0 mark. Near the 50mm mark there is no play in the carriage/rail body, so it is usable through that part of its range. The play was easily corrected in software, but I became too frustrated with the amount of play to compromise. I know the play would be a constant source of frustration. Every tripod/head/rail/ I’ve ever used has a certain amount of play, but as long as it settles back in the same place it’s not an issue. Here it did not. It’s really frustrating to have your image shift that much, when micrometers count. So, back it goes!
If you need a low cost rail this is much better than the cheap ebay rails. The additional expenses is warranted, as it seems like the next step up is $300, or $500 for a computer controlled version. I’m looking at the Kirk FR-2 or the Stackshot Macro Rail as alternatives. The other option is a DIY build from printer parts, which could work well but is a major commitment.