Pentax 645 - light leaks?

[dugrant153]

Recently, I've been shooting with my Pentax 645 and have seen a few frames with light leaks that show up halfway through the frame. It's a bit disconcerting as it's happening to not one of my Pentax 645s but to my other one also (my backup).

Curious if you folks have run into this and ... maybe it's the insert??




*EDIT: It happens every few frames, not on every single frame...

 

[Pioneer]

Certainly sounds odd. Could it be possible that the film may have had some exposure to very bright light before loading it? As I am sure you are aware, unlike 35mm, 120 is not completely light tight, particularly if the wrap is a bit loose, before you load it or after it has been exposed.

 

[Ricardo Miranda]

Now, I don't have a 645, but I have a Spotmatic that had that same problem.
It isn't actually light leaks in the strictest sense. It is something else. On the Spotmatic it could be unwanted reflexes from the focusing screen due to a light seal deterioration.
It could also be a shutter problem if the 645 has a vertical travelling shutter. In that case it only happens at certain speeds and that's why it only occurs in some frames.
Check the light seals around the focusing screen and the shutter.
That is at least a start.

 

[dugrant153]

Certainly sounds odd. Could it be possible that the film may have had some exposure to very bright light before loading it? As I am sure you are aware, unlike 35mm, 120 is not completely light tight, particularly if the wrap is a bit loose, before you load it or after it has been exposed.

Possibly, but then I suspect that the leak wouldn't be so uniform? It's always down the middle all the time when it happens (just like in the photo).

It could also be a shutter problem if the 645 has a vertical travelling shutter. In that case it only happens at certain speeds and that's why it only occurs in some frames.
Check the light seals around the focusing screen and the shutter.

this is what I'm starting to suspect. It could be the shutter... or the light seals? Hmm....light seals seem OK. If it's the shutter, I'm thinking this might be an expensive repair... or opportunity to be a 645N or NII.

 

[Alan Gales]

If it's happening to two of your camera's then I would highly suspect a film insert.

 

[Alan Gales]

If you are looking for an excuse to buy a Pentax N or Nll then you don't need one. I have owned all three cameras and the N and Nll are both much better cameras than the original 645.

 

[polyglot]

If it's happening to two of your camera's then I would highly suspect a film insert.

This. Is there any chance the leaks correlate with a particular back?

 

[dugrant153]

Hmm... it might relate to the film insert. That being said, I switched film inserts on this camera and (just to confuse things more) also switched camera... so it's either another bad back or faulty camera ... or both. ... I will have to grab a test roll or two and just try different combinations out to narrow down the results.

I have 3 inserts and 2 P645's.

1 good insert + Good 645 (as far as I can tell - will be taking for a spin today as a wedding guest. Used on a recent shoot and it was fine)
1 leaking insert
1 questionable insert + Dodgy 645?

That being said, curious if others have ran into this issue and what the fault was?

 

[dugrant153]

If you are looking for an excuse to buy a Pentax N or Nll then you don't need one. I have owned all three cameras and the N and Nll are both much better cameras than the original 645.

Are they quieter than the original one too? (to some degree?)

 

[Pioneer]

If you are looking for an excuse to buy a Pentax N or Nll then you don't need one. I have owned all three cameras and the N and Nll are both much better cameras than the original 645.

I don't know about that. I shoot with a 645Nii and a 645 and with the exception of the controls and autofocus they are both excellent cameras. As a rule the A lenses are less expensive than the FA lenses.

 

[winger]

Are they quieter than the original one too? (to some degree?)

If the P645N is quieter than anything, I'd hate to hear how loud that is.

I haven't used an original or an NII, but I do love my N.

 

[Alan Gales]

I don't know about that. I shoot with a 645Nii and a 645 and with the exception of the controls and autofocus they are both excellent cameras. As a rule the A lenses are less expensive than the FA lenses.

I like the controls on the N and Nll much better than the original 645. You also have the choice of using the autofocus lenses or the original manual focus lenses.

The N and Nll also add Matrix metering, brighter viewfinders with more information displayed, and film edge data imprinting. The Nll also adds mirror lock up which most including me don't feel is necessary.

In my opinion the N and Nll are much improved over the original 645. Of course it all depends upon if the added features are important to you.

 

[Alan Gales]

If the P645N is quieter than anything, I'd hate to hear how loud that is.

I haven't used an original or an NII, but I do love my N.

The mirrors are so dampened on these cameras that you don't need the mirror lock up of the Nll. I did like the textured finish of the Nll better (it helps hide scratches) but of course this is purely a cosmetic thing.

 

[Pioneer]

I like the controls on the N and Nll much better than the original 645. You also have the choice of using the autofocus lenses or the original manual focus lenses.

The N and Nll also add Matrix metering, brighter viewfinders with more information displayed, and film edge data imprinting. The Nll also adds mirror lock up which most including me don't feel is necessary.

In my opinion the N and Nll are much improved over the original 645. Of course it all depends upon if the added features are important to you.

I guess I must be quite insensitive to improvements in equipment. In use I have a hard time telling any differences, with the obvious exception of focus. They feel the same to me and the photographs are equally awesome.

 

[Alan Gales]

I guess I must be quite insensitive to improvements in equipment. In use I have a hard time telling any differences, with the obvious exception of focus. They feel the same to me and the photographs are equally awesome.

Well, what's important to one person isn't important to another. I remember a friend buying a brand new Nikon FE2. He was so proud of that 1/4000 second shutter speed and thought it to be a huge improvement over the FE. To me 1/1000 second was plenty fast enough so a feature that was so important to him was no advantage to me.

Neither one of us is right or wrong about the Pentax 645 cameras. It's just our opinions.

 

[dugrant153]

All this talk has me thinking about upgrading eventually now. Darn it!!
However, I've used my Pentax 645 on many an assigment and has produced some mind-blowing results and a lot less camera shake (love that well-damped mirror).

In the next while I will be shooting a few test rolls in different cameras to see if the issue comes up again. I sure hope it's an insert or two (and not the bodies) but if it is I would like to pin down the cause so I'm not buying leaking inserts!

 

[Vrimmel]

I had light leaks issues with my 645. And I tried changing the light seals. It didn't fix the problem. But taking great care when I remove the exposed film helped.
This problem first showed up when I switched to Fomapan film (I do like the film, but not the hard, stiff backing paper). The film seems to want to unfold
when I take it out. I now open the back slowly, and press a finger on the roll as fast as I can before removing the back. I try to do this in dim light also.

To sum up, the problem was the filmchange not camera lightleaks.

 

[dugrant153]

I can see that being the case if the images had light leaks that were very random, but these appear to be uniform (a straight line plus a leakage area on top of it in the same spot on the negatives that are affected... see the attachment).
But thanks for the suggestion. You could be right.

 

[Pioneer]

The reason I mentioned this early on is that I experienced a light pattern similar to your own. It was not from my 645 but actually came from one of my folders. After a lot of unnecessary troubleshooting I found that the light leakage went away if I unloaded in the darkroom and tightened the roll after it came out of the camera. There was nothing wrong with the camera with the only exception being that it did not roll the film tight enough. The arm that exerted pressure on the feed roll did not do a good job of keeping that pressure even as I advanced the film. The film and paper were slightly loose on one side of the roll allowing light in. The light did not affect all the negatives, only a few that were on that side.

As you say, it probably has nothing to do with it. But it is pretty easy to fix. If the exposed roll feels a bit spongy when you remove it from the camera it could be loose enough to let light in at different locations on the roll.

 

[dugrant153]

Thanks, Pioneer. I'm starting to get convinced it could be my unloading the roll in broad daylight and perhaps night tightening it enough. Hmm... how does one counteract this?

 

[Vrimmel]

I believe there is 1000 answers (at least), but I can start counting:

1. That's 120 film! Not quite safe always.
2. Black plastic bag. Darkroom changing bag (I know, not a good suggestion). Hide in shadows.
3. Film backing paper and the film itself acts different. As I said in an earlier post, this problem startet when I switched to Fomapan film.
I, and many others I believe, have seen this with Shanghai film. They both uses a stiff, heavy backing paper. Sometimes not quite straight at the ends, some sort of curly, or how shall I tell it? (Sorry, my English is not as good as my Norwegian).
I have never observed this with Kodak or Ilford films, and they use a very thin, smooth plastic like backing paper.
.
.
.
and so on.

I do struggle with this type of problems still, so I have no intention of telling any solutions to this problem. But this is some of my thinking and what I have tried and continue to try.

I'm anyway still convinced my problems is the film, not the camera.

 

[Pioneer]

http://www.freestylephoto.biz/112082-120-Film-Hard-Case-Black-Holds-5-rolls-of-120-size-film

I unload in the shade. Then I put the exposed film in a case. This is what I use now. Haven't had any trouble since.

 

[Alan Gales]

http://www.freestylephoto.biz/112082-120-Film-Hard-Case-Black-Holds-5-rolls-of-120-size-film

I unload in the shade. Then I put the exposed film in a case. This is what I use now. Haven't had any trouble since.

Good idea, Dan!

I never knew about those film cases but I always loaded and unloaded my film inserts or backs indoors or in the shade outdoors.

 

[Pioneer]

I picked up a few rolls of Adox CMS 20 120 a while back and they came in a plastic case. They are very handy as well but you may not want to buy rolls of Adox film. That is what gave me the idea

 

[dugrant153]

So, based on reading this thread and all your thoughts, I took a bit more care to cover and fold up my 120 film in shaded areas and TIGHTLY winding it. Unloading takes place in a darker area.
I've used two different inserts in a camera and so far, the images have been very good. No issues.

You all may be right. Think it might be user error: mine.