Canon LTM Canon P bouncing RF alignment

Canon M39 M39 screw mount bodies/lenses
kb244

kb244

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I had my Canon P sent into the local repair guy some time ago, just got it back today while everything else seemed fine and at first the RF spot seemed to be perfectly vertically and horizontally aligned it wasn't even two minutes before the vertical alignment changed.

Apparently if I look thru it and tap the top of the chasis the RF alignment will snap out of alignment, mostly vertically, and sometimes horizontally. You can tap it a few more times and it would snap back into the 'perfect' area but doesnt last for long. I was so hoping that it would actually come back repaired, whats up with the 'bouncing' alignment... Basically right now I have an extreme mistrust of the actual RF accuracy.

I really would not want to pay 90$ for a repair job that actually didn't repair the camera.

Kinda like how if I point the RF to a flat wall with lines, it shows on the lens roughly past 6ft, but if I focus with my SLR with a split prism, just shy of 7ft.
 
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Agreed. My P had the same, or v. similar, problem, but the problem appeared about 8 months after I got the camera back from a CLA, so I can't say that it wasn't me that caused it. I'm getting the impression that the rangefinders on Ps can be a little finicky, which is a bummer if true b/c the camera is otherwise incredibly solid. My P is now w/ DAG for repair (someone else did the CLA last year). It may be that a fitting or an optic came loose inside the camera.
 
Bingley said:
Agreed. My P had the same, or v. similar, problem, but the problem appeared about 8 months after I got the camera back from a CLA, so I can't say that it wasn't me that caused it. I'm getting the impression that the rangefinders on Ps can be a little finicky, which is a bummer if true b/c the camera is otherwise incredibly solid. My P is now w/ DAG for repair (someone else did the CLA last year). It may be that a fitting or an optic came loose inside the camera.
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It originally went into repair because the mirror or the RF spot 'fell' off something and as such was tiping back and forth making the accuratcy completely way off as the RF was no longer on a solid platform, that was supposed to be fixed. I just got it back today. I need to send it back and pretty much declare "job not done" , even though I didn't ask him to, he seems to have tweaked the frame advance and shutter to the point that its as smooth as a baby's bottom and the shutter sounds like a very quiet single click. Which would be superb if the rangefinder was actually deemed working.

Edit ya definitely whacked, it focused 3.5ft on something 7 ft away just now, then min later focused 6 ft.
 
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back alley said:
it's an easy diy fix.
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Then tell me how, also calibration/alignment is one thing, if that sucker is bouncing around in there, I doubt its an "Easy DIY Fix".
 
relax, i'm not the bad guy here.

the alignment is an easy fix...if the mirror is bouncing around that's another whole thing and then yes, it needs to go back.

a small screwdriver and a slow steady hand fixes the allignment/focus, i used to do it on my 3 canon p bodies.
there are detailed instructions on rff somewhere, better written than i could describe.
joe
 
Right, I knew that much, and no I'm not intending to be snippy. But if the rangefinder spot is bouncing around just from me taping the top of the camera, then thats obviously an issue thats not gona be fixed by just calibrating it.

Also if I already owe the guy money for the repair (note I just got it back this afternoon), its best principle to send the camera back to him to make him finish the job he started.
 
no argument from me.
i'd send it back if the original problem was not properly fixed.
and if it's the rf spot moving then for sure i would not try to tackle it on my own.
i should have read your o.p. more slowly as i thought you were talking about the allignment only.

joe
 
back alley said:
no argument from me.
i'd send it back if the original problem was not properly fixed.
and if it's the rf spot moving then for sure i would not try to tackle it on my own.
i should have read your o.p. more slowly as i thought you were talking about the allignment only.

joe
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Well the spot itself remains stationary, but the actual image inside the spot bounces around just from taping the top of the camera, and its not like it bounce and returns to previous position but rather set's itself in a new position. The "spot" also seems to be slightly up and to the left in overall position than when I sent it in the first time.

I mean aside from my new Olympus Pen-FT my Canon P is my favorite 35mm camera, so you can imagine I am a tad fustrated :bang: I know the camera should not generally matter but I wanted this camera to be the one I took into the operating room when my son was born prematuerly, not the Fed-2A and a Digital Rebel (which is out for repairs for the second time). I can't argue much, I was at least smart enough to pick up the Fed-2A for backup purposes, to which point it is actually serving the purpose it was originally intended.

Call me sentimental and somewhat attached to the materialistic side of things, but aside from a brighter rangefinder spot, the Canon P in it's aestetics, feel and operation is most of what I could hope from a simple and robust rangefinder, it just feels right so I want it to work as soon as I can.

This is an old picture of it so you can see what I'm moaping over, haven't had it quite a year yet.

Canon_P.jpg
 
It's some time since I last had a P apart, but from memory the large glass block which you see at the front of the camera as the viewfinder window incorporates the beam splitter of the rangefinder. This glass block is just glued to the camera chassis and with costant cleaning and the odd bump it is possible the glue has released after nearly fifty years and the block can move about. If this is the problem,and if you are used to working on cameras it is an easy fix because the P has the most easily removed top plate of any of the post IVSB2 Canons.
 
It sounds like the prism behind the Rf window is loose, (edit) or what Charles has just posted.

Bring it back in. It should be an easy fix- for the repairman once he has the top off. The worst I've seen was the frameline prism of a Canon 7 sheered off at the base. Solid glass prism. That was not an easy fix, nor was getting the glass shards out of all of the gears of the film transport. Superglue for the prism, TLC for the alignment.
 
Charles Woodhouse said:
It's some time since I last had a P apart, but from memory the large glass block which you see at the front of the camera as the viewfinder window incorporates the beam splitter of the rangefinder. This glass block is just glued to the camera chassis and with costant cleaning and the odd bump it is possible the glue has released after nearly fifty years and the block can move about. If this is the problem,and if you are used to working on cameras it is an easy fix because the P has the most easily removed top plate of any of the post IVSB2 Canons.
Click to expand...

This I think was the original problem with the P before I sent it in, to which he likely repaired because the chasis doesn't "rattle" anymore when tipped. I think the problem is now in the actual moving rangefinder mirror as possibly a post-repair 'oops'.
 
Brian Sweeney said:
It sounds like the prism behind the Rf window is loose, (edit) or what Charles has just posted.

Bring it back in. It should be an easy fix- for the repairman once he has the top off. The worst I've seen was the frameline prism of a Canon 7 sheered off at the base. Solid glass prism. That was not an easy fix, nor was getting the glass shards out of all of the gears of the film transport. Superglue for the prism, TLC for the alignment.
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I hope you mean something like Loc-Tite rather than your typical super glue, I've killed the front of least one lens (thank god it was just my ****ty 18-55 EF-S lens) because of the super glue 'vapors'.

Oh and you just sent shivers down my spine the way you described the damage of the Canon 7.

I hope he can do the fix rather quickly, he originally quoted me a 3-hour job for the initial fix, but even if it only took 3 hours, it took him close to a month and a half to get round to it, I would hope thats its not going to be a 2 months wait to fix the fix.
 
back alley said:
for old times sake...
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Where can I get one of them brackets...

I was hoping my P worked today because I was gona load up one of those Canon V film canisters (you know the ones that don't have that fetered felt and such) with some Tech Pan 25, I just got the film canister so was hoping to try it. I also already have a Canon V flash gun, I'm hoping to get almost most of the accessories of the P minus the meter (don't really care for it's aestetics).
 
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I should add to my last post that I have seen these glass blocks dislodged in 7's, but because they don't incorporate the beam splitter in the front block of the 7 or 7s etc, the rangefinder isn't affected. In earlier Canons the beam splitter block was secured to the rangefinder chassis but in the P there was probably not room for a securing strap. It is unlikely that any part of the moving prism has come adrift because in my experience the screws fixing this part of the rangefinder are as tight as hell, bit it is possible that glass block is secure and the rangefinder fixing screws are loose. You could try touching the front of the glass block and seeing if there is any detectable movement.
 
Charles Woodhouse said:
I should add to my last post that I have seen these glass blocks dislodged in 7's, but because they don't incorporate the beam splitter in the front block of the 7 or 7s etc, the rangefinder isn't affected. In earlier Canons the beam splitter block was secured to the rangefinder chassis but in the P there was probably not room for a securing strap. It is unlikely that any part of the moving prism has come adrift because in my experience the screws fixing this part of the rangefinder are as tight as hell, bit it is possible that glass block is secure and the rangefinder fixing screws are loose. You could try touching the front of the glass block and seeing if there is any detectable movement.
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Well I'll be damned... I used my fingernail to push on front of the glass window (you know the big square one) while looking thru and it's doing the problem I've been describing. Basically seems like the front sheet of glass isn't exactly permetly affixed, or 'secured' as you say. Would explain why it didn't do much at all when taping it facing down.

So um... now what?
 
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the front vf square window is the actual glass block that contains the 50/50 mirror.
Canon did not use a glass window pane like what is on the M Leica.
I guess Canon thought it would result in a more contrasty, less flare prone vf. by their method.
 
xayraa33 said:
the front vf square window is the actual glass block that contains the 50/50 mirror.
Canon did not use a glass window pane like what is on the M Leica.
I guess Canon thought it would result in a more contrasty, less flare prone vf. by their method.
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Is it something I Can just easily straighten out myself?

Just can't figure out how to get the top off, or for that matter worry if I am gona screw up the springs for the advance lever.
 
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