Sunday, November 3, 2013

SnapFocus from Midas Mount - First Impressions

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I just received my SnapFocus late last week. I had fulfillment number 40, if that info helps anyone else waiting.

First impressions are mixed. The build quality is good, not great. The rack and pinion housing seems well-built, but is mounted atop two ugly, unfinished stamped-metal pieces that form the slide for positioning the drive gear against your lens gear, and they’re held in place by a single ¼-20 screw that you adjust by hand (I’d recommend against really cranking on this one, as it will mar the pieces forming the slide). Other than the slide, all the components are nicely black anodized. The rail mount is from SmallRig, with their logo on the locking handles.

Mounting it up presents some challenges if your lens has larger-diameter sections near the focus gear (e.g. a Rokinon Cine 14mm). Raising the camera farther above the 15mm rods helps a lot.

The bicycle levers are pretty simple, and mounted up very easily on my Redrock Micro handles (by removing the grips and attaching the bicycle handles to the core rod). The drive gear is natural-colored plastic and looks to be 3D-printed.

The rack and pinion system is capable of about 4 inches of rack travel, but (and this is my biggest beef with the unit right now), the bicycle levers only allow about 1 inch of that travel – severely limiting the range of lens focus throw you can use. The drive gear rotates about 90 degrees maximum, which is WAY too short to use the full focus of most lenses.



Yes, I know drive gear rotation doesn’t correlate 1:1 to lens focus throw, but the bottom line is the same: The SnapFocus only uses a very short range of the focus throw of the lens. I have some cine lenses with 200 degrees of throw, and with the SnapFocus I can use very little of it.

The limitation is the short pull radius of the bicycle levers – it’s about 1 inch. As the lever travels, the net cable travel lessens even further as the cable stretches between two points of the arc – geometrically forming a segment rather than a sector (yes, I’m an engineer).



To me, this is a very significant shortcoming of the system, and I’m eager to hear from others who have received their units and had time to play with them. Short of completely changing the bicycle levers (to ones with more pull) or rigging a planetary gear, I’m puzzling over how to get the full linear travel of the rack to get the most focus pull range from the SnapFocus.