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Raradek
Tinkerer Username: Raradek
Post Number: 1 Registered: 06-2013
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, June 02, 2013 - 11:02 am: |
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Hello, my Praktica MTL5 got stucked so i had to open it and unblock some slider.. doing this i accidentally (more than that just from not knowing what i was doing) turned the cogwheel of the light-meter's variable resistor. Now i can't figure out how to put it back to its position that matches the selected shutter speed/ ASA(DIN) value on the knob. What i would really appreciate is if someone could just open his Praktica's bottom, set up some ASA(DIN) value and try to see how the resistor's contact moves while changing the shutter speed - e.g. at which point the contact comes out of the plastic as it is on the image bellow, so that i can adjust mine.. http://static.photo.net/attachments/bboard/00Q/00QVJL-64169584.jpg Thank you so much, it's just 4 screws ;) Or if there is some guru praktica user who could tell by heart.. the resistors contact moves sometimes inside the resistor and sometimes outside, over the non conductive plastic part which i don't quite understand why and what values could use that but it might have something to do with the ones that are marked in orange (B - 15) or white (30 - 1000) on the knob.. |
Sillyconguru
Tinkerer Username: Sillyconguru
Post Number: 48 Registered: 12-2007
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, June 02, 2013 - 11:43 am: |
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IIRC; at 100ASA the meter works from 1/1000 to 1/2, so (reasonable thinking says) the contact should be insulated from the resistor at 1" and B. |
Waynemel
Tinkerer Username: Waynemel
Post Number: 457 Registered: 08-2009
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, June 02, 2013 - 12:29 pm: |
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This link may help... http://cameracollector.proboards.com/thread/5289 |
Prasanna
Tinkerer Username: Prasanna
Post Number: 98 Registered: 10-2009
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, June 02, 2013 - 08:03 pm: |
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Hi! Please look up Chris Dzombak in CMC Forum on Photo.net. I had given full instructions in that thread for tuning the PCB pots in the Praktica Meter. Steve Shepherd provided the adjustment for the cog-wheel you refer to. These were later relayed in the "Camera Collector" mentioned above. I hope this helps. |
Prasanna
Tinkerer Username: Prasanna
Post Number: 99 Registered: 10-2009
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, June 02, 2013 - 08:10 pm: |
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Here is the link with all details. Look at Steve Shepherd's notes. Good luck. Buying Praktica MTL 5 - what to look for? - Photo.net Classic ... http://photo.net/classic-cameras-forum/00QTcl Photo.net Home ... Popular Articles: Three Tips to Blend Photography and Positive Change Sigma 18-250mm ... Chris Dzombak , Aug 11, 2008; 07:36 p.m. ... |
Raradek
Tinkerer Username: Raradek
Post Number: 2 Registered: 06-2013
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, June 03, 2013 - 04:00 pm: |
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Thank you all for replies! I will paste Steve Sheppard's post from the link mentioned above, which seems to be in accord with Sillyconguru's answer too (but Steve's seems to be more precise): "With the bottom cover removed, set the film speed to 20 DIN/80 ASA. At this setting (and only this setting) the metering should function over the whole range of shutter speeds 1 sec to 1/1000 sec. Check that at the 1 sec and 1/1000 sec speeds, the potentiometer slider is symmetrically placed at opposite extremities of the track. There should only be about 1/32" of carbon track visible beyond the slider at each end (the track is mainly hidden below the "roof" of the component). If it's wrong, lift the potentiometer again and reposition its gear linkage until you get it right." The only little unclarity for me is the 80ASA /20DIN value that's mentioned but isn't marked on the scale.. there are 100/21 and 50/18, but that's normal right? I just set the little window in a third of distance in between those values.. |
Ronnies
Tinkerer Username: Ronnies
Post Number: 43 Registered: 09-2009
Rating: N/A Votes: 0 (Vote!) | Posted on Tuesday, June 04, 2013 - 08:14 am: |
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Correct. The two tick marks between 100 and 50 indicate 80 and 64 ASA. Ronnie |