| Author |
Message |
    
Nick_om10
Tinkerer
Username: Nick_om10
Post Number: 1
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 02, 2007 - 05:05 am: | 
|
Hi,
New to these forums, followed a link from the Rangfinder forum.
I have a 35RC which is giving an exposure of f/5.6 at 1/60 sec when the lens cap is on (indoors). Taking the lens cap off and I'm getting incorrect reading too (f/22 @ 1/500th etc).
I have tried to adjust the meter by loosening the two brass screws and turning it, however this was in low light and whilst I was getting reasonable results, when it came to use in bright sunshine the calibration was obviously wrong (f/5.6 @1/250th with ISO 200 film, I would have expected f/16).
I guess I have a couple of questions :-
1. Is this an indication that the meter or cds cell is broken, or some other fault with the circuit?
2. Should I calibrate for bright conditions and let the rest take care of itself? I read somewhere that the 35RC meter is inaccurate in low light anyway (less than 7ev?)
Any help greatly appreciated.
Nick |
Wernerjb
Tinkerer
Username: Wernerjb
Post Number: 133
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 02, 2007 - 05:35 am: |
|
Hi, Nick.
#1: yes (probably short-circuit inside the LDR = no resistance at all?)
#2: no
All those built-in meters if compared to a hand-held reference meter are somehow "inaccurate" towards the limits ; the RC's slowest exposure time is 1/15 sec, its maximum aperture f 2,8, who would be using that sort of camera in low light?
The mechanical calibration facility of the meter is somewhat limited on the RC, so do not expect too much, W. |
Nick_om10
Tinkerer
Username: Nick_om10
Post Number: 2
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 02, 2007 - 07:20 am: |
|
Thanks, what is the LDR and can I find the short circuit and fix it?
Nick |
Wernerjb
Tinkerer
Username: Wernerjb
Post Number: 136
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 02, 2007 - 10:12 am: |
|
LDR stands for Light Dependant Resistor (formerly AKA CdS cell). If this resistor quits the circiut is open and the meter is dead, but if its resistance is zero (which usually is the case in very bright light) the light meter is more responsive to light.
A DIY repair is possible, as the RC 35 is fairly simple, provided everything else is fine and you have a replacement cell (I usually salvage them from junkers).
The LDR/ "EE" cell (for "electric eye") sits in the plastic nameplate ring opposite the film sensitivity selector. This ring comes off after unscrewing that two-notched black metal ring around it.
From your saying you had newly calibrated the meter I took for granted that you are quite experienced with the repair of rangefinders, but now I am not so sure any longer. In case you are repairing your first camera I suggest you take a look at some more basic information on that sort of repair and/or camera, I hope you are getting on fine with your project, W. |
Nick_om10
Tinkerer
Username: Nick_om10
Post Number: 3
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 02, 2007 - 11:51 pm: |
|
Thanks. I have another 35RC with faulty wiring I think (the meter needle twitches but does not give a proper reading).
I hope I can make one working camera out of the two broken ones.
I am not an experienced repairer, just a tinkerer!
Nick |
Nick_om10
Tinkerer
Username: Nick_om10
Post Number: 4
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 08, 2007 - 04:49 am: |
|
I am a bit happier now. I prised the battery compartment out of my other 35RC and discovered the wire was completely corroded. I re-attached it and I am getting 90% correct meter readings when compared with my e500 dSLR's meter. On occasions, in tricky situations it can be a bit out. |
