Canon IV Sb 2- Frame Overlap

Discussion in 'Classic Manual Cameras' started by ben_hutcherson, Nov 21, 2017.

  1. I picked up one of these the other day mostly to get the nice chrome 50mm 1.8 on it.

    In any case, I ran a roll through it and MOST of the frame showed serious overlap.

    This camera has a rapid winder on it...before I waste more film, I'm wondering if the problem could be in the rapid winder and not in the film advance mechanism, per se. Specifically, is it possible that the rapid winder is advancing enough to cock the shutter, but not advancing the film I'll the way?

    If this sounds likely, I'll crank a short roll of expired HP-5 out and see what happens if I ONLY use the knob to wind. I'll also probably go hunting for a regular base plate. The rapid winder is a neat addition, but it certainly adds a lot of weight and bulk to the camera.

    It seems I can't win for losing with these cameras :) . This one seemingly has good speeds, the curtains are fine, and there's no vertical misalignment on the rangefinder. Fortunately, at least, my Leica IIIc and Canon 7 do both work perfectly, albeit with the vertical misalignment that seems all too common. I need to just box up all my LTM stuff and send it off for service.
     
  2. I would definitely try it out without that rapid winder first.

    I'm looking at my IIIa right now, which is identical to the IV SB except it does not have the flash rail. I note that the frame counter is part of the knob that you use to wind on the film. Is your frame counter staying aligned with the proper pic as you're shooting? I'm just guessing here, but it seems like if your camera is stopping short of its intended position, it might be reflected in the counter. This is really just a guess, though. Make sure that little lever with R<->A under it is set all the way to A.

    You might try doing a search on the Classic Camera Repair Forum archive and see if there's anything stored there that might help you:
    Topics - The Classic Camera Repair Forum

    I miss that forum.
     
    Last edited: Nov 23, 2017
  3. I have a Rapid Winder which I use on my IIIA. Take off the winder and look at the advance shaft. Looking down at it, you’ll see a little nub. This nub should rotate 360 degrees when you advance the film. If it’s less than that, that’s probably the cause of your frame overlap.

    As an aside, i just picked up a IV-Sb2 yesterday. I haven’t had the chance to use it yet but hope to this weekend.
     
  4. Cool. Well, now that the weekend has passed, I hope you had fun! What lenses do you have for your Canon RFs?
     
  5. My apologies, I should have read your post more closely. Perhaps you've tried it by now anyway. I just took out my IIIa again to see if the shutter would trip without the film being wound all the way. Turns out, mine does fire the shutter. But, interestingly enough, I had it set to the slow speed dial, and I had the dial set to one second. When I tripped the shutter, it went very fast. Sounded closer to 1/1000 sec. So I moved it from the slow speed dial, but I selected 1/40 so I could hear both shutter curtains. Wound it to within a couple of frames on the counter to where it should be, and fired it. Same thing again. Sounded like 1/1000. So, yeah, chances are your camera will behave similarly, but your premature exposures are limited by the fast shutter speed and available light. Also, if the winder is falling short in its winding, the frame counter should show this, plus the wind knob should still have some take-up slack left. Although the winder probably locks down that shaft.
     
  6. Thanks.

    I haven't run any more film through the camera, but the frame counter registers correctly and there's no slack left in the knob after winding with the rapid winder.

    The one roll I ran through was expired TMAX-100. It was an overcast morning and I was walking around in the front yard just to burn through the film. I pre-set it to 1/125 and f/8, and aside from the base fog all of the negatives looked to have what I'd call normal density. I think I did 7 minutes in straight D76, so there was nothing really abnormal about the developing either.

    If it had been firing at 1/1000 at f/8 and EI 100 I'm guessing the negatives would have been thin since even in full sun that would have been about 2 stops under-exposed. Although I didn't meter, with it as overcast as it was I'd be in the 4-stop under range, and with the film as foggy as it was I don't know that I'd have seen much of anything.
     
  7. Several, all Canon. A 25/3.5, 35/2.8, 50/1.5, 50/1.4, 50/1.2 and a 100/3.5. Favorites are probably the 25/3.5 and the 50/1.4. Very impressed by the IV-Sb2. The differences between that and my III-A are subtle, but meaningful. The viewfinder and shutter changes are really appreciated. A fine camera.
     
  8. I'm intrigued by this, being an x-IVsb owner, and as I mentioned above, an owner of a IIIa, which is the same as the IVsb except without the flash rail. But now I'm curious. Can you tell me what the differences are between the IVsb and the IVsb2?

    Ah, I just googled it. Apparently the IVsb2 has both bulb and x-sync? One of the things I like about my IIIa is the bulb and x-sync aftermarket installation on my camera. There's a sticker on the baseplate, explaining how to use it, from International Camera Corp in Chicago, which is still in business.

    Nice set of lenses you have. I'd love to get a 25mm some day. Having a 50/1.4 and/or a 50/1.2 would be nice, too.
     
    Last edited: Nov 28, 2017
  9. Canon slightly changed the viewfinder optics and increased the size of viewfinder itself. Not a major change by any means but the viewfinder is less "squinty" than you find on earlier Canons. The also changed to a new shutter with the main difference being that you can change fast speeds before or after advancing the film. On earlier canons you had to advance the film before the little index mark on the shutter speed dial would line up with the speed you want. The IV-Sb2 is like a modern camera, the shutter speed index is always pointing to the chosen speed (film advanced or not). Plus it uses the modern 1/30, 1/60. 1/125. 1/250, etc. shutter speed progression. Small changes, all of them, but they make the camera a pleasure to use.
     
  10. I also have a Canon ivsb2. I really like it. Often I set the finder to it's highest magnification and use an external finder for framing.
    I have the 28, 35, 50,85,100.
    All are gems but they are hard to find without internal problems.
     
  11. OK, Jim you've pretty well convinced me that I should add an IVsb2 to my collection. Hrm . . . but do I really need one? I do have a P after all . . .
     
  12. I have an L1 too, and really didn't need the IVSB2, but now that I have one, it's a keeper.

    You can always get a IIS2, which is the same camera except for the top shutter speed. 1/1000 on the IVSB2, 1/500 on the IIS2.
     
  13. For many of these cameras, the grip on the film spool can get low after a while, so it slips a little too much.

    I don't know if that is related to the rapid winder.

    Yes, these are different enough from the P that you should get one.

    I have a IID2, I believe that is what it is, which is enough different from the P (and VI).

    Though similar enough to Leica, that maybe you don't need one.
     
  14. That's always been my attitude when it comes to Canon rangefinders and their lenses.
     
  15. (snip regarding the early Canon rangefinders)

    The later Canon rangefinders, like the VI and VII, with the now common back loading, are different enough.
     

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