35mm DOF adapter optical idea

dbarak

dbarak

Well-known member
I was trying to think of alternatives for spinning ground glass used in DOF adapters, and I thought about using fiber optic plates. They're nearly grainless, which would help eliminate any inconsistencies in grinding, and they can enlarge, reduce or invert images depending on how they're manufactured. Has anyone given any thought to this? I may look into it if I get the time.

Dave
 
Fiber optic faceplates offer no diffusion and have a 'chickenwire' structure to them which is visible when magnified (from the spaces between the fibers).
By themselves they wouldn't work, unfortunately.
 
I only took a quick look online (I'm at work), but I did a Google search for "fiber optic plate" and came up with a bunch of links. I only checked out two links for about a minute. One was Schlotzky or Schotzky or something like that (Schotz?).

As far as the chickenwire pattern, I'm sure that fiber optic plates are available without the chickenwire pattern, though. There was a company that used to make Polaroid backs for 35mm SLRs (we had one at the newspaper I worked for) and they had a fiber optic plate to convey the image to the Polaroid film. Some small company out of New York City. I may try to check around more this weekend. My guess is that they're fairly expensive, but I can imagine a MiniDV camera with something like this built-in that would fairly easily allow 35mm DOF and interchangeable lenses, all conveyed down to the 1/3 inch CCDs.

I have a couple of natural mineral fiber optic toys that were ground to round shapes. One is just a cylinder and it appears to bring the image to the surface of the cylinder -- in other words, what you see through it (placed on the object being viewed) has no effect of being away from the viewing surface. I also have one that's cone-shaped, but with both ends ground flat. If you put the small end on the object, it appears to enlarge it when viewed through the large end, and if you put the large end on the object, it looks small through the small end (or is it vice versa?). And after my very brief look at them online, it appears they can be made to invert images, which would eliminate the need for flipping circuitry, magnets, upside-down monitors, etc.

Just food for thought.

Addition: I just noticed the "diffusion" part of your post, Luis. I guess you're right. Maybe they could be used in combination with ground glass, in order to flip the image? Still seems like there might be some potential.
 
ReneH said:
One more option in our quest for the holy ground glass!
Click to expand...

Actually, I'm thinking about trying a photochemical process to simulate 35mm DOF. Basically, I would mount my 100A onto the viewfinder of a Panavision Platinum and record video that way. I'd run film through the Panny as a backup, of course. :laugh:
 
This thing is certainly evolving, I was looking at some of the light bulbs around my house and some of them have that frosty white finish to them. Makes me wanna experiment! LOL!
 
Actually, something like that could work too -- a very thin translucent coating of some sort.

Seems like it would be fairly easy to build all we want into a MiniDV body -- DOF converter, interchangeable lenses (manual!), all that stuff. Dream on...
 
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