16 Jun 2014

Cutting masks for Fujifilm GX680

Ever since I got my Fujifilm GX680 II,  I've wanted to fit a digital back on it. What you see in the picture above is the PhaseOne H101 digital back designed for the Hasselblad H series fitted using one of Fuji's own film backs. Yeah the focusing distance is wrong right now but that is not the point. I'm working on that. The point here is that the image area on this digital back is 36x24mm.

The Fujifilm GX680 series shoots 6x8 or 6x7 negatives depending on which film back you have mounted. The focusing screen is designed for that size of negatives with the right indicators drawn on it, so you know what you are shooting. However, when you fit a digital back with a smaller image area, you will need a mask on the focusing screen in order to tell what your digital back is seeing, unless you don't mind drawing shapes on your expensive piece of ground glass and thus dropping its resale value.

In this post I will show you how I cut my cheapest effective masks for the Fujifilm GX680. I will also share a PSD file so you can print a pattern to cut your own easily. All you will need is the right kind of masking materials, and I've decided laminating film is one of the best choices, because, well, it functions like ground glass itself if you want, but when placed on ground glass, it's like a visible transparency.

The Fuji GX680 focusing screen has a mesh of 8x8 divided into square centimetres.  What I did was first to create an A4 document on Adobe Photoshop,  in which I recreated the 8x8cm mesh of squares, over which I created layers in the shapes and positions of the frames that I expect my camera to shoot. One for 40x40mm, one for 36x24mm, and one for 36x70mm, both horizontal and vertical.

Download the file and make one print for each mask that you want to cut.

On a piece of glass for cutting, put some double sided adhesive tape to hold the printed paper in place.

Then use some more double sided adhesive tape to fix a single layer of laminating folders (A3 size by the way) perfectly flat on the paper, leaving no room for bends or air bubbles.

Cut both the outer 8x8 and the inner frames with a utility knife.

You get some extra shapes that you can play with. The huge 36x70mm mask is in preparation of a 35mm mod to one of my film back. This one is going to be a bit difficult to achieve.

The mask is ready to fit on the focusing screen. Just insert it and slip it under the focusing screen's metal frame. It will be a perfect fit.

Here is an image of what my viewfinder looks like. You should now be able to see both what is inside your frame, and what is outside of it. :)

And then of course you can be cheeky and put two of them together to see both a normal 35mm frame, and an extended panoramic one.

The 40x40mm frame can be used with some ancient digital backs such as the Leaf DCB. I will be using the 36x24 mask with my Phase One H101.  You can use it with Leaf Valeo 11, 17, other Phase One H series backs, Imacon and many other digital backs that have a 35mm format full frame sensor. I will add mask shape/size to fit larger sensors later or upon request. I may be getting an 48x36mm sensor soon. ;)

Download the PSD file to print your masks here.

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