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12-11-2009, 04:24 AM   #1
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Is This Right, please help

Hi, just received my first 35mm slr and have a couple of questions.

Externally this looks very good. But the inside has something strange. The black sheet which i presume obscures the film untill the shutter is flicked has several small lines accross it. Are these normal? will they leak light?

Similarly there is a small amount of play in the rear cover not a huge amount but i assume there should be none?

here is a phone pic of the lines i am concerned about:


any help or advice would be greatly appreciated

Thanks

12-11-2009, 04:58 AM   #2
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this is normal

12-11-2009, 06:05 AM   #3
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what you see is the shutter.
12-11-2009, 06:19 AM   #4
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Thanks for the quick replies.
Am completely new to film so its all very exciting

thanks

12-11-2009, 06:54 AM   #5
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There arebasically 2 types of shutters in Pentax SLRs
_ vertical travel shutter (like the one here)
- horizontal travel shutter (older models)

See the explanation here:
Focal-plane shutter - Wikipedia, the free encyclopedia
12-11-2009, 09:22 AM   #6
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That black sheet would, indeed, be the shutter.

Those faint, vertical-running lines I see? I'm guessing someone's dragged their finger lightly across when loading film, and that's either skin oil or perhaps scratching from a fingernail.

It's fine. But it's a good time to warn you to not touch it anyway, as your finger can easily go through the blades (THIS IS BAD.)
12-11-2009, 09:52 AM   #7
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One of the most fun I had was actually buying a broken MZ camera, and taking it completely apart. It was neat to see how everything went together, and how everything (when it was working in the past) related to each other in the camera.

Luckly, I knew enough about electronics to stay the heck away from the on-board capacitor for the flash. As soon as I found it, it got cut out. I don't need to know how much fun it is to get an electric shock.

Oh, and thanks to my taking apart the camera, it is really THAT easy to put your finger through a shutter. The metal is very, very thin. It has to be, as at the speeds the shutter goes at, it can't weigh that much, or it'll be harder to control.
12-11-2009, 11:41 AM   #8
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QuoteOriginally posted by VF-19 Quote
Luckly, I knew enough about electronics to stay the heck away from the on-board capacitor for the flash. As soon as I found it, it got cut out. I don't need to know how much fun it is to get an electric shock.
I'll tell you, it's not pleasant It didn't burn my skin or anything like that, it just shuts down your brain for a second.

Reason I know this was taking film out of one time use cameras in the dark. The caps are in different places in each

12-11-2009, 03:19 PM   #9
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QuoteOriginally posted by lithos Quote
That black sheet would, indeed, be the shutter.

Those faint, vertical-running lines I see? I'm guessing someone's dragged their finger lightly across when loading film, and that's either skin oil or perhaps scratching from a fingernail.

It's fine. But it's a good time to warn you to not touch it anyway, as your finger can easily go through the blades (THIS IS BAD.)

I don't see any vertical running lines in that photo. The diagonal lines are the shutter blades. On cameras with metal, vertical-travel focal plane shutters, like this one, the shutter is not a single piece of metal. It is made up of several pieces, similar to the aperture leaves in the lens. When the shutter moves, those pieces collapse to fit in the limited space above or below the frame opening.

Actually, (for the benefit of the OP) there are two shutters. Only one is visible at a time. One shutter is closed before the exposure. When you make the exposure, this shutter opens, allowing light to reach the film. When the camera mechanism deterines that the time is up, another shutter closes, cutting off the light. These are called the leading and trailing (or opening and closing) shutters. When you advance the film, both shutters are reset to their original positions, in preparation for the next exposure. Since both are moving in unison, there is no light getting through. You can see this if you open the camera back and watch during a long exposure, such as one second. Turn the film advance lever slowly and you should be able to see the shutters resetting.

This also explains why electronic flash sync is limited in shutter speed. On my Pentax K10D, for example, the fastest flash sync is 1/180 second. This is because, at speeds faster than that, the trailing shutter begins closing, before the leading shutter has completed its travel. This results in a slit moving across the film/sensor. Since the flash duration is so short, it would not expose the entire frame.

This is basically the same as the shutters used on most dslrs. If you have a good external flash, you may notice that the flash and camera have an option to fire on the trailing shutter. It is these same two shutters that they are talking about. Since the flash duration is very, very short (1/1000 to 1/50,000 second), you can wait through most of the exposure and fire the flash just before the trailing shutter closes. When used with a slow shutter speed, such as 1/30 or 1/15 second, you can get the effect of the person or object moving in a ghost image, as if they are stepping into the bright light of the flash.

Older cameras, like the Spotmatic, used rubberized fabric shutters, that rolled up onto rollers at each end of the frame.

You're absolutely right about being careful not to damage the shutter.
12-11-2009, 03:47 PM   #10
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+1 for 'you're OK.'

This is just a little surface wear on the finish of the shutter blades. They fit tightly, so this is normal to see.

Oh, and as for the play in the film door, this is also common, and isn't necessarily a problem: what it probably means is that your seals are wearing out, as happens with time. They are easily-replaced, and are usually one of the things done when you send a camera in for 'CLA,' (clean, lube, adjust.) Which is not a bad idea for cameras this old, but you can go ahead and shoot some film. Probably near anyone here could tell how urgent the need might be, in person, but it's probably not going to be an immediate worry. Shoot a roll, see what you get. If you like the camera, you may want service done anyway: that way, you'll be good for another however-old that camera is. But, those seals often get a bit soft or show deterioration for a while before they ever mess up your film. If you see pieces of black specks in the film area that smear when you moosh them between your fingers, it's urgent. If not, try your camera.

Last edited by Ratmagiclady; 12-11-2009 at 03:54 PM.
12-15-2009, 04:16 AM   #11
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Just loaded in some film and waiting for some batteries to arrive! Thanks for all the help
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