Canon eos 1 i got today skipping frames

[oniongal]

i bought a canon eos 1 today, and i was really excited to develop the film i shot with it however to my sadness i saw that many of the images have been completely skipped while two have been only incredibly lightly exposed, since the side marks appear completely normally I could only conclude that its the cameras fault and the main culprit seems to be it thinking that its back is open and thus shooting at 1/8000th, is they any precautions i could take to prevent this

 

[loccdor]

the main culprit seems to be it thinking that its back is open

Why do you think that is the reason? Is the back loose?

Are you sure this might not be Canonitis where the higher shutter speeds don't work because of the mirror bumper foam degrading and messing up the shutter? Could you take a pic of the shutter?

 

[Taylor Nankervis]

Being an early pro-level EOS body, reliability is rock solid unless something seriously fails, or the camera has been damaged.

If you are a new user of the EOS 1, ensure the film is correctly loaded at the take-up clasp on the right. If it is not, the film will not wind-on even if the shutter fires at any speed. This (incorrect film loading) will be accompanied by a rapid flashing of the film-loaded line at the bottom of the top panel LCD.

As this is now a very old camera 1990, pre-dating the EOS 1n that I have owned since 1992, has it been serviced? Skipping so many frames could be indicative of a winding fault and, by association, the possibility of micro-motor failure associated with the take-up of film has to be considered.

 

[koraks]

Skipping so many frames could be indicative of a winding fault and, by association, the possibility of micro-motor failure associated with the take-up of film has to be considered.

That's easy to verify - @oniongal did you miss any photos? I.e. do you remember making photos that ended up as blank spaces on the roll, or did you get to make ca. 20 photos on a 36 exp. roll?

Personally I don't think it's that; my guess is that the mirror is stuck. The sticky shutter issue @loccdor mentions is also possible, but it's usually evidenced by capping on some frames. It's pretty easy to detect most of the time; if we could have a look at the frames that did end up being exposed OK, it might be able to tell whether there's any shutter capping going on.

If it's indeed an intermittently stuck mirror, I'd start by inspecting around its edges for any signs of degraded foam or other sticky junk that might hold it down. The mirror requires very little force to lift, and consequently only minor contamination can hold it down.

As to servicing; I think it's safe to assume nobody has bothered to service this camera in the past 25 years, even if they would have tried to locate the nonexistent entity that would be in a position to do so.

 

[oniongal]

Why do you think that is the reason? Is the back loose?

Are you sure this might not be Canonitis where the higher shutter speeds don't work because of the mirror bumper foam degrading and messing up the shutter? Could you take a pic of the shutter?

it just checks that with some flawed contacts, and when dry fireing it i also sometimes got that one way faster shutter speed although almost never after i cleaned the contacts, i was also shooting at low shutter speeds so it cant be faster speeds messing up

 

[oniongal]

That's easy to verify - @oniongal did you miss any photos? I.e. do you remember making photos that ended up as blank spaces on the roll, or did you get to make ca. 20 photos on a 36 exp. roll?

Personally I don't think it's that; my guess is that the mirror is stuck. The sticky shutter issue @loccdor mentions is also possible, but it's usually evidenced by capping on some frames. It's pretty easy to detect most of the time; if we could have a look at the frames that did end up being exposed OK, it might be able to tell whether there's any shutter capping going on.

If it's indeed an intermittently stuck mirror, I'd start by inspecting around its edges for any signs of degraded foam or other sticky junk that might hold it down. The mirror requires very little force to lift, and consequently only minor contamination can hold it down.

As to servicing; I think it's safe to assume nobody has bothered to service this camera in the past 25 years, even if they would have tried to locate the nonexistent entity that would be in a position to do so.

yeah i remember taking pictures that would have appeared in the blank spaces here are the unaltered negatives

 

[koraks]

Thanks for the quick follow-up. There's an interesting phenomenon along the top edge of some of the negatives you posted where something has evidently partly blocked the image; note the gradient:

The frame edge should be the same along all edges.

I suspect this is a problem with the mirror system as I proposed earlier, and that it manifests itself intermittently. My first guess would be sticky parts of foam that sometimes prevent the mirror from doing its full cycle.

Shutter capping is also conceivable, but most of the time I say it, it's not specifically limited to the edge of the frame.

If you open up the camera back and look at the shutter blades, is there any shiny black goo anywhere?

 

[oniongal]

Thanks for the quick follow-up. There's an interesting phenomenon along the top edge of some of the negatives you posted where something has evidently partly blocked the image; note the gradient:
View attachment 411584

View attachment 411585
The frame edge should be the same along all edges.

I suspect this is a problem with the mirror system as I proposed earlier, and that it manifests itself intermittently. My first guess would be sticky parts of foam that sometimes prevent the mirror from doing its full cycle.

Shutter capping is also conceivable, but most of the time I say it, it's not specifically limited to the edge of the frame.

If you open up the camera back and look at the shutter blades, is there any shiny black goo anywhere?

no there isnt any, this is how it looks like while exposing and, the state of the mirror ligth seals which are also not sticky, this is also my 3rd canon film camera that I've used but my first expensive one, and i never had anything similar happen on the others

 

[koraks]

Thanks; I see no major/obvious problems, but that doesn't mean there aren't any. And in fact, given the problems on your test roll, there's evidently a problem with either the shutter or the mirror. You could try doing some test exposures with the lens removed and the back open and observing the mirror and the shutter to check for any inconsistencies. If you do enough exposures, you may be spot an irregularity at some point. For the mirror you could do some slow (1-2 seconds or bulb) exposures and see if the mirror flips up entirely and to the exact same spot 100% of the time. Note that you may be looking for only a minor misalignment. If you're 'lucky' you may see it lag or even not flip up at all once in a while. If it's the shutter, try doing short exposures (1/4000 or so) with the camera pointed at a light source while looking through the back of the camera; again if you're lucky you may be able to see some variation in the light intensity or even dropped frames every so often. This should help you determine at least whether it's the shutter or the mirror.

 

[loccdor]

Sometimes, if you're lucky, minor problems with old cameras can be fixed by firing them a few hundred times.

If it were me, after trying a few things and still having the problem, I'd return the camera for a refund. I'm trying to get my Canon EF mount film camera serviced to fix a similar problem, and also looking at buying a low shutter count EOS-1V as an alternative since they aren't as old. But those are quite expensive and also heavier.