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Michael Roberts
17-Feb-2017, 21:00
This has been on my drawing board for a while now, and I finally managed to cobble together a prototype: a simple, wire sports finder / viewfinder similar to the ones on Speed and Crown Graphics, but without doing irreversible damage to a vintage camera.

The wire is 1/16 dia. brass tubing from a local hardware store. Bent to form a 5x7 frame. The wire is mounted on a 7" long 1/2" x 1/16th" piece of basswood, with a second piece glued just below the wire to form a shelf for the wire to pivot up and down. The wire is then covered with a strip of leather and glued in place with contact cement. Two small pieces of 1/8" x 1/2" basswood serve as corner keepers to hold the wire viewer in the up position, or swivel to allow the wire viewer to pivot down and out of the way to fold the camera up. Two pieces of adhesive-backed velcro, one on the top rear of the lens board frame and one on the wire viewfinder, hold this accessory in place and allows quick removal.

Not shown: I marked the rear of the wire with a Sharpie at the half-way points on the vertical, 5" sides to align my eye for composing and shooting when the film holder is inserted.

Focusing can be done on the gg (either in handheld mode or on tripod, before inserting the film holder) or using a distance scale affixed to the bed of the camera. Final composing and shooting handheld (or on tripod) can be done using the wire viewer.

I tried this out today while snowshoeing; worked great. Looking forward to working more with this.

Graham Patterson
18-Feb-2017, 08:51
Most variations of this I have seen - my MPP for example - have a fixed or parallax adjustable peep sight on the camera body. Even with your half-height marks, I am not sure how you keep your eye centered. But if it works, it works!

I like the use of leather on the bar, as it ties the device to the camera very well.

Randy
19-Feb-2017, 06:13
Thanks for the post Michael. I have been trying to come up with something similar for my home-made "TravelWide" but haven't gotten very far. Surely it's possible to down-size it somewhat...? As Graham mentions - I would think a peep-sight would be necessary for alignment and could also allow for scaling the front frame size down. I have a couple old 8mm movie cameras that have fold-down sports finders. I am going to see if I can modify one of those for mounting on top of my camera.

LabRat
19-Feb-2017, 07:23
You can make a wire frame or mask device much smaller, that would mount on top of the camera somehow, that could have an adjustable peep sight for parallax adjustment too... There are sportsfinders for various formats that could be adapted, or optical finders also...

I used to make various sportsfinders using wire coat hangers, bent with pliers, and the rear peep sight with a tiny washer or foil with a small hole, so my eye would not wander in and out the frame area for night or underwater use... The frame area would slightly change if I wore glasses, as there would be a slightly different eye to peepsight distance, so bear in mind...

Steve K

Michael Roberts
19-Feb-2017, 11:02
Yes...like this.

I've been playing around with this style, too.

The eyepiece folds down but is o/w stationary; the wire slides up and back for different focal length lenses.

I still need to figure out a good way to keep the wire frame in the upright position. It's just taped in the photo.

When I figure out a solution, I'll post an update.

Meanwhile, if you've got a suggestion please let me know.

Graham Patterson
19-Feb-2017, 11:35
If the wire frame is an open squared-off C shape, then the base needs a drilled pivot hole on each side. A small slot vertically above the pivot hole will let the wire frame latch into position. A similar (probably longer) slot on each side parallel to the camera top will hold it in the down position. This assumes that the frame is sprung outwards moving from horizontal to vertical. That's about the simplest mechanism I can think of, if it suits your materials.

Michael Roberts
21-Feb-2017, 10:05
The wire frame is bent into a rectangle, not a C shape.

I removed the leather I glued to cover the bottom of the frame and replaced it with a piece of wood. This seems to provided the necessary amount of resistance to hold the wire frame in any position I place it.

So, the next step is to calibrate this little wire viewer to a lens and try it out in the field.

Will post results when I have them.

barnacle
21-Feb-2017, 13:30
Ahh... the trick is to make the bottom legs only a few millimetres long, and poke them into holes either side of the slide, so that the spring of the metal keeps tension on the pivot. Then, above each pivot hole, a vertical slot. If the width of the wire square is a touch smaller than the slider, it'll drop right into the grooves and stay vertical, but will fold down easily.

Neil

Michael Roberts
22-Feb-2017, 05:57
Thanks Neil, great idea. I will try this on my next refinement. This should also work on the larger wire viewer that fits on the rear of the lens board frame and would be a simpler design.

Meanwhile, I took the camera and wire viewers out yesterday to calibrate the 5x7 camera and wire viewer with a 203 Ektar. I decided two things: 1. the 1/5th scale of the wire viewer is too small, I may try a 1/3 scale next, i.e., 1 2/3" x 2 1/3". The current 1/5th scale is just too tiny and felt confining, especially when viewing through the wooden peephole, eyepiece. I would also change the eyepiece to a more open, v-notch. 2. I like the bigger wire viewer that is attached to the back of the lens board frame much better.

The difference in the two (to me, ymmv) is like sighting through a 35mm viewer vs. looking at a 5x7 gg. I prefer the latter.