Easy / Cheap source for mirror stock for reflex VF ?

Luddite Frank

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I just scored a nifty Premo "Cyclone" 4x5 box-type plate camera.

Looks like the biggest box-Brownie you ever saw.


It's in really good clean condition, with one exception: the reflex mirrors in the two little waist-level finders have lost their silvering.

They appear to be "normal" back-silvered glass mirrors, about 3/32" thick x 1" wide x 1-1/4" long.

Any suggestions where to look for source material to make new mirrors, and how to cut finished mirror glass to size ?

I've cut a fair amount of window-glass successfully in my time, but have never attempted cutting mirrored glass.


Am trying to keep this a DYI project, as this beast is certainly not worthy of any significant cash out-lay ( I - B simple shutter, single-element meniscus lens ); it is truly a "Box-Brownie" that shoots on 4x5 plates / Riteway sheet holders.

( Will try to post some pics later ! )

Thanks !

Luddite Frank
 

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Not as perfect as a silvered mirror but far more easy to cut to size are stainless steel polished so called "vandalism resistent" mirrors.

Another way to go is the re-silvering of the original mirror. Tips about that can be found in forums about astronomy (building mirror telescopes).

btw It's strange that the Premo's original mirror is back-silvered. Wouldn't expect that in a camera.
 
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Not as perfect as a silvered mirror but far more easy to cut to size are stainless steel polished so called "vandalism resistent" mirrors.

Another way to go is the re-silvering of the original mirror. Tips about that can be found in forums about astronomy (building mirror telescopes).

btw It's strange that the Premo's original mirror is back-silvered. Wouldn't expect that in a camera.


I'm more familiar with the "front-silvered" mirrors in TLRs and SLRs, but this super-sized box-camera is far from a precision optical instrument, even for its era (1895-1900 ). In this case, thats to my benefit, as back-silvered mirror glass is much more common and cheap ! .

I have some very nice TLR's with sick VF mirrors... ( Welta-Flex and Cirro-Flex ); that repair is probably cost-prohibitive.

Thanks for the additional suggestions, Hans ! :)
 
If you're only using it for composing your image, some hobby stores (Michael's in the U.S.) that sell front-surface mirrors. They have a plastic backing -- no big deal for certain applications. And they sell for about $3 a sheet. I have a couple of sheets for those cheapie TLRs.
 
I don't know your camera, but if it's a reflex viewing mechanism it seems to me that with a back-silvered mirror you run the risk of ghost double images. That's more of a problem when the reflex viewing is part of the focusing mechanism, i.e., which image do you focus on?

For a budget DIY fix, go to a good glass shop and ask for a first surface kaleidoscope mirror, and pay them to cut to your spec (the dimensions of the old mirror to be replaced). You'll have bright new viewing mirror for small money. The thickness shouldn't matter *unless* your camera is set up to compensate for the thickness of a back-surfaced mirror. That's most unlikely.
 
Those are only viewfinder mirrors, are not reflex mirrors (pivoting mirrors behind the taking lens), and have no effect on the photo, so I'd go to the nearest department store with a sporting goods section and look for a steel camping mirror to cut up. It's much easier to cut than glass and will work fine. In fact, lots of other box cameras used metal mirrors, like the Agfa ShurShots. All that does is show you what the camera is pointed at, and a metal mirror will fulfill that function just as well as a glass one. That said, if you really want to get a glass mirror, the makeup mirror idea from the earlier post is a good one. You score it on the silvered side, to avoid removing chips of silvering when you break it.

While you're at it, here's another tip: take a little dab of toothpaste on your finger and rub the viewfinder lens with it for a minute or two (both sides). You'll find that it brightens the image in the viewfinder considerably, even if you didn't realize it was dim before. Do NOT, however, do this to a taking lens. The viewfinder lenses are not precision optics and this treatment won't hurt them; the taking lens is though, and it will.
 
... but if it's a reflex viewing mechanism ...

The things are simple mirrors that show you what is at a right angle to the viewfinder. They have nothing at all to do with the photo and simply show you what the camera is aimed at. They are not even like the mirror in a TLR, since there is no lens in front of them -- it's just a sighting mechanism.
 
I didn't know Michaels had anything for mirrors. I will have to check the next time I take the Grandson there. Someone mentioned in a previous thread that Edmond Scientific has them. I checked and they do.

But I think FallisPhoto has your best advice on using a back silvered cheap mirror.
 
If you need a cheap source for good mirrors, get a used Polaroid for $1. Most of them have an excellent, large front-silvered mirror in them. The way most Polaroids are built requires a mirror in the light path between lens and film, so Polaroid actually used really good ones, since any defects directly impact the final image. I've used them for all sorts of purposes.

If you feel bad about gutting what would otherwise be a perfectly usable Polaroid camera, get one for which there is no film anymore. ;)
 
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