Canon P Rangefinder Alignment

[jordanstarr]

I had a bad fall on my bike and my camera was in my bag at the time and I landed right on it, causing a dent in the top near the film advance lever. Now, my vertical alignment is way off. I heard that the glass in the round rangefinder part fixes that by rotating it. I've been rotating and looking in the camera for the last hour and nothing is changing.

I've rotated the two notches and checked ever 1/4 turn until it came out completely. I looked through it at some text and rotated it and watched the text move in a circular motion as it should. But for some reason, it's not working the way I anticipate or from what I've read.

Any suggestions?

 

[Mablo]

I had the same problem recently with my other Canon P. I tried to readjust it by myself but couldn't get it right so I took the camera to a repair shop. The repair person told me that if the viewfinder alignment is really out of whack the top deck must be removed for the repair. That is a job for professionals so I think you should consider taking your P to a good repair shop.

 

[paolo]

Here http://www.photoethnography.com/ClassicCameras/index-frameset.html?CanonP.html~mainFrame the procedure of rangefinder adjustment is described

 

[alexnotalex]

Here http://www.photoethnography.com/ClassicCameras/index-frameset.html?CanonP.html~mainFrame the procedure of rangefinder adjustment is described

I got good results following this instructions. Start with the round prism till it's aligned vertically then the screw for horizontal. Check at 1 or 2m and at infinity.

Good luck!
Alex

 

[jordanstarr]

I read those instructions too. I still can't get it to work.

 

[alexnotalex]

This is my rangefinder alignment routine wiyh my P
1. make a big X with a black marker on a yellow post-it
2. put it 2m away. Shine a light on it if i'm indoors or it's midnight
3. set the lens distance to 2m
4. look through the rangefinder window at the X, curse at the poor alignment.
5. adjust the round one till the vertical alignment looks good (a minute or two)
6. adjust the horizontal one till the images line up (five minutes fiddling) remembering to be gentle feeling around inside the camera with a metal object.
7. re-measure the 2m distance accurately and check it is really ok. Repeat 5 and 6 if necessary.
8. go outside, set lens to infinity, look at a distant tv aerial, test the alignment. Repeat steps 5 and 6 till done.
9. put screws back in, sigh in relief, thinking how much it would have cost if you had dented a Leica and had to get a pro to realign it.

hope this helps. If not, best go to shop.

Alex

 

[jordanstarr]

Alex...

I appreciate the response. Since my last post I did everything I could to adjust without opening. It was clearly too out of wack without taking the top off. So, I took the top off and there's 3 main, larger screws that allow you to lift and tilt the RF. After some adjusting (by that I mean A LOT) of adjusting, I was able to get it to the right spot vertically. Then when that was done, I tightened everything up, but on the cover again and adjusted the horizontal alignment. Good as new and I didn't need a shop. Took me a good 75 minutes though. I bet I could cut that time in a quarter though the next time around (hopefully that won't happen).

If anyone wants some instruction if they have the same problem, feel free to PM me with questions.

 

[alexnotalex]

Alex...

I appreciate the response. Since my last post I did everything I could to adjust without opening. It was clearly too out of wack without taking the top off. So, I took the top off and there's 3 main, larger screws that allow you to lift and tilt the RF. After some adjusting (by that I mean A LOT) of adjusting, I was able to get it to the right spot vertically. Then when that was done, I tightened everything up, but on the cover again and adjusted the horizontal alignment. Good as new and I didn't need a shop. Took me a good 75 minutes though. I bet I could cut that time in a quarter though the next time around (hopefully that won't happen).

If anyone wants some instruction if they have the same problem, feel free to PM me with questions.

Well done! you've inspired me to take the top off mine to clean out the gunk that's making my patch dim. Now... where did I put that screwdriver....

 

[alexnotalex]

Oh well, I managed to take the round prism out and clean the back but there's more in there I can't get to.

Didn't manage to get the top off, couldn't work out how to take the rewind crank out, and I think there's another screw near the rewind I can't see.

It's much cleaner, but still needs more TLC. Any tips for taking the rewind crank out?

thanks
Alex

 

[alexnotalex]

Full technical diagrams here:
http://www.pentax-manuals.com/manuals/service/canon_p_repair.pdf
http://www.pentax-manuals.com/manuals/service/canon_p_repair.pdf

Did it, cleaned it, better !
Alex

 

[Brian Legge]

Alex...
So, I took the top off and there's 3 main, larger screws that allow you to lift and tilt the RF. After some adjusting (by that I mean A LOT) of adjusting, I was able to get it to the right spot vertically.

What screws are these?

My Canon P can be aligned at either infinity or near focus but not both at the same time. If I adjust focus so that the alignment is correct for a distance object in the center of the patch, the near focus is correct (according to ground glass) when at the very far right edge of the rangefinder patch.

It sounds like there is a very slight problem with the range - possibly solvable with the adjustment above - but I don't see any screws which obviously effect the rangefinder alignment with the top off. Lots of screws but they seem to be simply securing things, not adjustments.

 

[John Shriver]

Sounds like you need to adjust what I call the "gain". You need to adjust how fast the mirror moves as you focus the lens.

I only have a Canon P parts diagram. Perhaps the roller on the end of the coupling arm is on an eccentric that allows changing the effective length. Or perhaps the location of the swivel point is adjustable. I don't see any screws under the cover that would affect the gain.

Also, you need to be certain that the flange-to-film distance is the correct 28.80mm. If it isn't, you shouldn't be messing with the rangefinder yet.

Also, I presume you are checking with a Leica, Canon, or Nikkor LTM lens, not an FSU one. Also, that you know that the lens is correctly collimated as well.

 

[John Shriver]

OK, I looked at Canon 7 service manual. (Available free online.) There is an eccentric at the end of the roller arm on the Canon 7, probably is as well on Canon P. You would probably need to custom-make a very thin wrench.

But, as I noted before, you MUST know that everything else is collimated. Also, does your ground glass have the right shim between it and the film rails? Many cameras plan on a certain amount of film curl, and when you use a ground glass to collimate (or a mirror for an autocollimator), a shim is required. (Definitely the case for my Topcon Super D.)

 

[thereabouts]

I hope this isn't a stupid question, but does anyone know if I can align the rangefinder with film in the camera, or should I wait until it is empty?

 

[thereabouts]

Well, waited until I'd used up the film.

I used some of those 'watchmakers' screwdrivers, which fitted really well. Although they don't give you a lot of 'purchase', so it was quite hard to turn the screw. Only intended for precision screws which don't give much resistence, I suppose.

Anyway, horizonal rangefinder is as closely aligned as I could be bothered, at infinity. Hopefully, that's all good.

Good news is that the vertical didn't need any adjustment afterwards.

 

[mikyor1]

I dont understand how to adjust the vertical alignment, is it the little round washer thing between the rangefinder circle and the housing ? (with the two little spots to turn it with?)

So confused.