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Overlapping exposures...

R

roguegeek

New Member
Alright, so I got my first two rolls processed from my 500CM and I'm disappointed. There were a lot of overlapped exposures, like the film didn't wind to problem spots each time. Both rolls were taken with the same A12 back and both had around 6 exposures that overlapped each other, although it wasn't consistent between the two rolls.

What do you guys think? Common problem? Not common? What kind of actions should I take?

FYI, the body was fully serviced back to factory spec AFTER I shot these two rolls, but I never serviced the A12 back.
 
You did properly load the back did you? In particular I mean winding until the counter snaps to 0. I once forgot and it definitely produces overlapping images.

Wilko
 
Spacing depends on correct alignment of the arrows on the film to the triangle on the insert.

Move the arrows further than the triangle means the spacing becomes larger.
If you are sure you loaded the film correctly there is only one conclusion:
Your A12 back needs to be serviced.
 
Positive I loaded the back properly. Looks like I'm going to be getting them serviced. Will probably do Steve's Camera here in LA since that's where I got the body serviced. Anyone know ballpark figures for getting an A12 back serviced?
 
Ha! I never knew this? is this the case? when you load a film in....you mean if you dont stop the arrows directly beside the red arrow on the filmmagazine you get bigger spaces?

polypal said:
Spacing depends on correct alignment of the arrows on the film to the triangle on the insert.

Move the arrows further than the triangle means the spacing becomes larger.
If you are sure you loaded the film correctly there is only one conclusion:
Your A12 back needs to be serviced.
Click to expand...
 
Back needs servicing for sure

roguegeek said:
Positive I loaded the back properly. Looks like I'm going to be getting them serviced. Will probably do Steve's Camera here in LA since that's where I got the body serviced. Anyone know ballpark figures for getting an A12 back serviced?
Click to expand...
 
sperera said:
Ha! I never knew this? is this the case? when you load a film in....you mean if you dont stop the arrows directly beside the red arrow on the filmmagazine you get bigger spaces?
Click to expand...

Sure, a trick often used by shooters of trannies to increase the spacing.
Move the arrows 10 mm past the mark on the insert and watch what happens.
 
polypal said:
Sure, a trick often used by shooters of trannies to increase the spacing.
Move the arrows 10 mm past the mark on the insert and watch what happens.
Click to expand...

Not only trannies, a bit more spacing is very useful when cutting negatives too. Films a typically quite a bit longer than the bare minimum, so no worries about running out of film that way.
 
Alright, I did a little test today with the bad A12 back against one that I know works properly. I threw some rolls of film through some magazines and marked where each crank advanced to on the film with corner markers and the frame number. Took a picture of the results and that's what you see below. It might be hard to see so you can find a larger version of the image here.

The two rolls on the left have been advanced through the bad back. The one on the right went through a good back. As you can see on the first roll, shots 1 and 2 overlapped. Shot 6 didn't advance very much at all. The second roll didn't have any overlap but the spacing was very inconsistent. The third roll which went through the good back, had no overlaps and consistent spacing.

I'm sure I went overkill on this, but I wanted to be sure I could recreate the problem and also prove to myself that the body was fine and the service I just did to it wasn't a waste of time and money.

Thoughts?
 

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Film backs are the part of the system that wears most.
They are also the most vulnerable part.

A film back that is dropped is almost certain out of alignment.
Backs that have been used for a couple of years and were treated with care could do with a tune up.
 
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