Vito CLR rf mirror cleaning

[fidget]

Is there a neat way to get at the rf mirror/lens to clean?
With the top off the camera, it's easy to see that it's quite tight in there, the mirror is directly behind a small lens and is almost impossible to get at...

Regards, Dave

 

[titrisol]

Check Roick Oleson's site and the KYPhoto classic camera forums
You may find the answers there

Is there a neat way to get at the rf mirror/lens to clean?
With the top off the camera, it's easy to see that it's quite tight in there, the mirror is directly behind a small lens and is almost impossible to get at...

Regards, Dave

 

[pvdhaar]

I'd be very careful cleaning RF mirrors. The silvered surfaces are extremely fragile. Besides, the spots on them are most often not dust but oxidation that can't be removed anyway.

The question is whether you'd gain anything by cleaning it any way. The RF on my CLR was as clean as a whistle, but the RF image in the finder still isn't anything to write home about. This isn't a Leica.

Another thing to be aware of, is that the RF lens that sits in front of the mirror is kept there with screws that affect alignment/travel. Horizontal travel is the screw on the left of the RF lens, vertical alignment is the axle with the square head that's on the top.. Much easier to take apart than to put together again, what with all the springs in there..

 

[fidget]

The question is whether you'd gain anything by cleaning it any way. The RF on my CLR was as clean as a whistle, but the RF image in the finder still isn't anything to write home about. This isn't a Leica.

This is what I was concerned about, whether it could be improved. The brightness of the rf patch must have degraded, they couldn't have sold many with dim rf patches like mine.

Thanks............Dave..

 

[Bill58]

Everything I've ever heard was NEVER clean a camera mirror--they are silvered on the front side rather than the back side like your home mirror. What do you do if you've "drooled" on your new/ old RF/ SLR? I'd take it to a pro repairperson.

 

[pvdhaar]

This is what I was concerned about, whether it could be improved. The brightness of the rf patch must have degraded, they couldn't have sold many with dim rf patches like mine.

Thanks............Dave..

Well, they probably could..

In 1961, the Vito CLR was priced at 259,= DM.

A Leica M3 would set you back 720,= DM, and you wouldn't even have a lens.. that would raise the price to 879,= DM with the addition of the 2.8 Elmar. Of course, you could shave ca. 100,= DM off of the price by combining that Elmar with an M2 instead, but still you could get 3 Vito's for that money..

That price difference is reflected in the choice of materials and construction. The way the RF spot is masked (the middle window in the attached picture) and the transparent plastics used in that window take a lot of light and definition away from the finder and patch.. Still, it's not too bad outdoors under decent light..

 

[titrisol]

Well, you can always put a small square of tape in the center of the viewfinder "incoming" window to make the RF image brighter

 

[fidget]

I'm so surprised that they could have cost so much! Or maybe Leicas cheaper then.
Suggesting a patch on the VF window reminds me of more than one I have seen on the Bay with what looked like a small sticker in the centre of the window, guess they had a dim rf as well.
Thanks...

 

[titrisol]

That way of correcting dim Vf works well, you can also use a sharpie marker (red or blue) and apply several dots in the RF area of the viewfinder front window
I did that for a Petri 7s I had and worked great.

 

[fidget]

What's a sharpie marker, just a fine permanent marker pen? Black OK?

 

[FallisPhoto]

Only really effective way of getting a clean and bright rangefinder mirror is to replace it. Edmund Scientific sells "beam-splitter" mirrors, for lasers, that can be cut up and the silvering on those is not particularly fragile, so you can clean and handle it while you are cutting them up and installing them. Alternatively, some of the old Polaroid cameras used large semi-transparent mirrors that can be cut up; those would be more traditional though, and you have to be very careful about handling them (sometimes the silvering sticks to your fingers better than it does to the glass).

 

[titrisol]

Xactly!
I use a staedtler overhead permanent marker.
I prefer red or blue

What's a sharpie marker, just a fine permanent marker pen? Black OK?

 

[fidget]

Well, I've been inside my CLR again, this time to try a replacement light cell (didn't work, back to the drawing board on that). Whilst the top was off I had another look at the bit of the RF that I can see is dirty. It's behind the moving lens. It struck me that this is the face of the optical block and not a mirror, that is a surface inside the block. Sorry, I may have mis-lead you all.
It's really tight in there, but I found that I could bend the end of a strip of soft cardboard and winkle it in there from the back of the camera. Then I soaked the cardboard (lightly) in windex type cleaner and gently teased the strip out. A couple of dry strips to clean up and....it's much better. Very useable I would say, more than I can say for my light meter repair trial...

 

[FallisPhoto]

Well, I've been inside my CLR again, this time to try a replacement light cell (didn't work, back to the drawing board on that). Whilst the top was off I had another look at the bit of the RF that I can see is dirty. It's behind the moving lens. It struck me that this is the face of the optical block and not a mirror, that is a surface inside the block. Sorry, I may have mis-lead you all.
It's really tight in there, but I found that I could bend the end of a strip of soft cardboard and winkle it in there from the back of the camera. Then I soaked the cardboard (lightly) in windex type cleaner and gently teased the strip out. A couple of dry strips to clean up and....it's much better. Very useable I would say, more than I can say for my light meter repair trial...

I ran across a website a while back where there is some guy who works on russian rangefinders. He says he replaces the dead selenium cells with modern solar cells, like from a cheap solar powered calculator. To do this, you temporarily wire the cell in series with a potentiometer and adjust the resistance until you get the right meter readings, measure the resistance, and then replace the potentiometer with the appropriate value resistor. You could try that.

 

[fidget]

I ran across a website a while back where there is some guy who works on russian rangefinders. He says he replaces the dead selenium cells with modern solar cells, like from a cheap solar powered calculator. To do this, you temporarily wire the cell in series with a potentiometer and adjust the resistance until you get the right meter readings, measure the resistance, and then replace the potentiometer with the appropriate value resistor. You could try that.

Yes, this is what I tried. Solar powered calculators are as cheap as chips and have a nice solar cell. As far as I can determine, the cell in the FSU cams I've loooked at and the cell in the VITO is a single element cell. This has a fairly high output. The cell from calulators is a mutliple cell unit, you can see the cell divisions on the light side, they normally have 4 elements. The cell must be loaded to get it to operate in a linear mode. This puts the output too low at low light levels and may still be too high at high levels (not loaded or divided enough, but loading/dividing further will reduce the low light output, game over....).
What it needs is a modern cell which has a single element and is as large as the original cell.
I'll keep looking....

 

[FallisPhoto]

Yes, this is what I tried. Solar powered calculators are as cheap as chips and have a nice solar cell. As far as I can determine, the cell in the FSU cams I've loooked at and the cell in the VITO is a single element cell. This has a fairly high output. The cell from calulators is a mutliple cell unit, you can see the cell divisions on the light side, they normally have 4 elements. The cell must be loaded to get it to operate in a linear mode. This puts the output too low at low light levels and may still be too high at high levels (not loaded or divided enough, but loading/dividing further will reduce the low light output, game over....).
What it needs is a modern cell which has a single element and is as large as the original cell.
I'll keep looking....

It can be smaller than the original, just not bigger. You can always make an insert to make it bigger. This should get you started: http://www.solarbuzz.com/solarindex/CellManufacturers.htm