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Message |
    
Greem
Tinkerer
Username: Greem
Post Number: 1
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 31, 2012 - 02:33 am: | 
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Hi,
as the title says the coincident focusing area is weak. It is impossible to focus as the double image is not visible.
I've heard that one can place a filter inside the tinged green finder thus trying to restore the missing coupling image by heightening the contrast. What are the real choices I have? I want to fix it my self. I'll try to be careful. Please focus on the solution towards restoring the coupled image, not on how easy or difficult it is doing this. |
Ivanku
Tinkerer
Username: Ivanku
Post Number: 2
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 31, 2012 - 06:21 am: |
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Hi Greem,
Try to use golden colour window glass reflection foil, it works well. |
Greem
Tinkerer
Username: Greem
Post Number: 2
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 31, 2012 - 07:46 am: |
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Hi Invaku,
I am afraid this is my first time dealing with the inside of a camera. It would be helpful if you explained what is needed and where this is to take place, in the camera. Thanks. |
Ivanku
Tinkerer
Username: Ivanku
Post Number: 3
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 31, 2012 - 09:48 am: |
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Hi Greem,
I forgot one point, that is dust on the splitted image glass. If so, it is easy.
First you remove the screw on top cover, (one at the the left side), then remove the film rewind knob. There are two more screws after remove the file rewinder, take them out then the top cover can be taken out.
You will see a black paper on top of rangefinder (see photo 1, peel off the black cover carefully you will see the splitted image glass (see photo 2 the one sitting at 45 angle), use cotton swap to clean both side, but take care the one facing to eyepiece side, this side has reflection coating. Do not use any solvent just dip clear water cleaning will be OK. Try this first.  |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1193
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 31, 2012 - 10:18 am: |
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if all you want to do is be able to use the rangefinder, here's the EASY (lazy) way:
http://rick_oleson.tripod.com/index-165.html |
Greem
Tinkerer
Username: Greem
Post Number: 3
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 31, 2012 - 12:46 pm: |
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Thank you Ivanku, Rick.
You've been really helpful. I will try cleaning the other side of the glass. I want to find out what are the colors that coincide inside the rangefinder, yellow on pink perhaps, and will experiment with dark hues first rather than jumping directly to black. It may take some time but I will let you know asap. |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1195
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 31, 2012 - 01:17 pm: |
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I haven't worked on the Petri. The most common approach was to use pure gold as the reflective surface on the transparent mirror: with gold, the central reflected image has a yellow/pink color, and the light passing through the gold (the outer area of the viewfinder) looks blue/green. |
Greem
Tinkerer
Username: Greem
Post Number: 4
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 01, 2012 - 05:07 am: |
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OK,
I opened it up. Followed directions. Unfortunately the coating on the inner side of the rf glass has deteriorated. I did clean the other side and very lightly the coated one, but it ain't cleaning that's needed. It needs a new coated rf glass. You know where can I get one ? Having said that I'll look on ebay, but just incase there isn't one there, you are more than welcome to put in your know where and how. I did mark the front of the glass on the outside and does the trick, but the image becomes triple, and it ain't what exactly I would call an easy focusing task. However it needs something opaque, simply a marker mark won't do the job. I've used a thick opaque piece of semi-transparent masking red tape, marked it with a permanent black marker and coated this with a few layers of shellac. Image in the rf is not easy to deal with but it's there and focusing is a possibility.
If the rf inner side of the glass was coated with a gold leaf it wouldn't do it cause coating needs to be semi-transparent, where as gold is opaque. |
