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Elmariachi
Tinkerer
Username: Elmariachi
Post Number: 1
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 28, 2010 - 10:05 am: | 
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Recently bought one in ebay and it came with a Carl Zeiss Jena 2.8/50
Everything seems to be in working order but I can't get a sharp image in the viewfinder, except when I'm focusing for infinity. The images combine together, but at the wrong distance (an object 1meter away is combined in the split-image vf with the lens at 1,5meters), and the image is never crisp.
What can cause this? Don't even know what to start doing. |
Djamorpheus
Tinkerer
Username: Djamorpheus
Post Number: 6
Registered: 10-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 28, 2010 - 11:50 am: |
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Well, there could be a couple of reasons for this, or a combination of them.
Could be a misalligned focusing screen in the viewfinder.
The mirror could be misalligned as well.
Could be the helical threads on the lens, try putting the lens on another m42 body if you could. Or you could get another cheap lens and see if it focuses correctly. |
Elmariachi
Tinkerer
Username: Elmariachi
Post Number: 2
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 28, 2010 - 12:48 pm: |
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how can I test for a misaligned mirror?
thank you for the leads ;) |
Djamorpheus
Tinkerer
Username: Djamorpheus
Post Number: 7
Registered: 10-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 28, 2010 - 01:51 pm: |
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well, you have to have a working lens that you know for sure is working, and then if its off at infinity that means the mirror is too high or too low im not sure which, theres a screw behind the mirror which raises it or lowers it, its really tight and virtually impossible to turn it unless you make your own special tool. or force it on the side with a flat screwdriver. The fresnel glass(the split rangefinder) could be misalligned, or the whole viewfinder block. Try taking the top off see if anything looks odd. This should help you, http://www.flickr.com/photos/zedworks/sets/72157619754247133/with/3324792347/ |
Elmariachi
Tinkerer
Username: Elmariachi
Post Number: 3
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 28, 2010 - 03:44 pm: |
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can you tell me if the focusing screen is supposed to convex or concave and if there is a way to flip it? Thank you! |
Djamorpheus
Tinkerer
Username: Djamorpheus
Post Number: 9
Registered: 10-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 01, 2010 - 05:25 am: |
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Are you speaking about the viewfinder glass? the one you put your eye to?
If you take off the lens and look at the fresnel glass, where the rangefinder is, it should be going from left to right diagonally, and it should be coming out towards the right side. |
Elmariachi
Tinkerer
Username: Elmariachi
Post Number: 4
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 03, 2010 - 11:46 am: |
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I guess it's correct then. That only leaves out the mirror.. I can't find any information on how to align the mirror correctly |
Elmariachi
Tinkerer
Username: Elmariachi
Post Number: 5
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 03, 2010 - 01:48 pm: |
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I've found a type of screw that sets the mirror's resting angle but it's very sensitive (it's not tight at all!)... is there a method to align it? |
Leesobing
Tinkerer
Username: Leesobing
Post Number: 55
Registered: 01-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 27, 2010 - 02:08 am: |
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http://www.ydo.abelgratis.co.uk/praktica_mirror_adjustment.html
MIRROR ADJUST
Thank you Steve Sheppard. |
