Cloudy/Muddy/Foggy Rangefinder finder

afrank · Sep 24, 2012

Hi all!
I just got myself a canonet QL17 and was using it and read somewhere that almost all rangefinders need their finders cleaned.
How do you recognize and see the difference between a Cloudy/Muddy/Foggy finder and a "clean" one? How does it hurt the image taking process?

Thanks in advance for your input!

cliveh · Sep 24, 2012

afrank said:
Hi all!
I just got myself a canonet QL17 and was using it and read somewhere that almost all rangefinders need their finders cleaned.
How do you recognize and see the difference between a Cloudy/Muddy/Foggy finder and a "clean" one? How does it hurt the image taking process?

Thanks in advance for your input!

Because when you look through it, it looks Cloudy/Muddy/Foggy. It is not the taking lens which maybe ok, but hinders clarity of vision and your decision as to if/when you press the shutter.

darinwc · Sep 24, 2012

It pretty easy to remove the top cover of the Canon QL17. Then a cotton swab and a dab of alcohol will clean it right up.
-When clean, the QL-17 has one of the brightest viewfinders of the compact-fixed-lens-rangefinder class.

kozesluk · Sep 25, 2012

just don't try to clean the 45° mirror in the viewfinder from the back side - it is a surface mirror and you will damage the silver coating thus rendering the rangefinder useless or at least hard-to-use.

afrank · Sep 25, 2012

ty all for the info and Specially Lukas for that word of warning! I heard eople put a blue plastic to increase contrast. Any comments on that? and if I were to do it, does it go on the main window or the above lens one?

elekm · Sep 25, 2012

Right -- the mirror that sits at a 45-degree angle has a semi-reflective coating. That coating often is delicate and should be touched as little as possible.

What are usually dirty are the front and rear glass elements, whether they be lens elements or simply pieces of flat glass.

kozesluk · Sep 26, 2012

the blue plastic should be placed in the main window in front of the semi-reflective mirror so that the direct optical path will be coloured blue and the rangefinder image (which is usually yellow) will be more contrasty against that. however I've never tried that.

sometimes black marker pen can do little magic when you precisely make a small mark/patch on the main window plastic cover (from the front side of the camera) - it helps to tame the direct image so the rangefinder image is better visible. it's especially useful in cases you have a camera that has been inadequately serviced - like someone cleaned the semitransparent mirror before

afrank · Sep 26, 2012

Lukas_87 said:
sometimes black marker pen can do little magic when you precisely make a small mark/patch on the main window plastic cover (from the front side of the camera) - it helps to tame the direct image so the rangefinder image is better visible.

Tried the marker, and it does help in contrast, by making the rf image more visible, but also makes the direct image blurry as hell.
Blue, red or black film what should I use now hmmm.

David Lyga · Oct 1, 2012

OK, I have done this several times. And it is easier than you think. First remove the top: remove screws and turn the round nut on the film advance lever normally (ie, counterclockwise to loosen). After the top is off you CAREFULLY wipe all the glass surfaces with a soft, clean tissue impregnated with water with a bit of dish liquid. Contrary to caveats (elekm) about not wiping the sliver coated mirror, you can wipe it with this solution. Do not use alcohol on that mirror, however. The solution for this cleaning has to have enough dish liquid to create a non static environment but not so much that it leaves a residue.

Of course, you are having to get into tiny crevices here. Take your time. What I do is cut small pieces of tissue beforehand and fold a few times. Then grasp into a tweezer and carefully wipe the surfaces. Immediately thereafter, before fully dried, I use a new tissue, again in tweezers, to fully dry what I have just washed. CAREFUL is the byword here. It really is as easy as I just described. - David Lyga

afrank · Oct 1, 2012

Lukas_87 said:
just don't try to clean the 45° mirror in the viewfinder from the back side - it is a surface mirror and you will damage the silver coating thus rendering the rangefinder useless or at least hard-to-use.

How do i know if I screwed the 45degree mirror?

kozesluk · Oct 1, 2012

afrank said:
How do i know if I screwed the 45degree mirror?

The superimposed rangefinder image will be very dim or gone at all.

David Lyga · Oct 2, 2012

AFRANK: It is rigid if you mean you might move it.

That is why I said to use care. Take your time. You will not screw up anything if you are gentle and take your time. Again, the mirror is rigid and fits into a slot. As far as removing the reflective silver surface: mere water with a tiny bit of soap will not ruin the silver surface of the mirror. Alcohol or, perhaps, lighter fluid, will.

Lukas_87 is correct in that removal of the silver would remove the shadow image which confirms focus. - David Lyga

afrank · Oct 2, 2012

I used a non alcohol liquid used to clean the digital sensors of cameras. I wasn't sure if it had alcohol and all it says is that us made of bio materials :/. The cleaning went well and its more clear now, but was worried I had damaged something I wasn't able to detect. The only issue i have is with the viewfinder frame. It seems to be tipped on one side. instead of looking like this:
http://www.flickr.com/photos/mnmleung/7320083890/

it seems like crooked frame on a wall, tipped to one side. It was like that before but I could not fix it :/

kozesluk · Oct 3, 2012

isn't that a vented lens hood?

Cloudy/Muddy/Foggy Rangefinder finder

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