Strange Looking Frames - Mamiya 1000s

[pixelrandy]

Hello all,

I hope you're having a great Friday. I noticed a few weeks back that I had four or so frames on a Portra 160 roll that a horizontal exposure line going across. It looks like a light leak, but it's very inconsistent. The battery was also low, as it died on the following roll. With a fresh battery in the body I did have a few additional frames out of six rolls (so not bad) with the same line. It's making me a little gun shy now and I'm leaning more heavily on my Pentax 67.

Here are a few examples. The color shots were busts, so excuse the lousy scans. The B&W shot was taken with the fresh battery. The problem is more subtle, but you can still see it.



Just about the same location on each frame. Sure looks like a double-exposure in that one spot, though I don't recall either the preceding or following frames having problems.

I'd love to hear your theories!

Thanks in advance,

Randy

 

[Tom1956]

I would check for light leaks in the camera/film holder and pinhole in the shutter. Are your foam rubber seals deteriorating?

 

[Jaf-Photo]

I think that's a lazy shutter from weak batteries.

Get a new silver oxide battery, for instance Energizer 544 , and you should be alright.

(It never hurts to replace the light seals either but it most likely isn't the problem here).

 

[pixelrandy]

I should probably replace the seals. They're greasy and leave a grease mark if you tough them. Not sure what that's all about.

I'll try the Energizer 544. I've been using Duracell PX28AB, which is a alkaline battery of course.

Thanks! I'll report my findings in week or so. About to start processing my own film. I'll use a bright light on a long exposure to hunt down leaks before replacing seals. I'd like to find out for certain what's causing this.

Randy

 

[anikin]

It's a light leak without a question. This camera relies on good seals for light tightness. Some cameras can be ok with bad seals, this one is not one of them. Replace the seals and you'll be fine. Pay special attention around bottom of the door and around the latch. With bad foam light leaks are almost guaranteed.

 

[DWThomas]

Drawing parallels with my Bronica gear, I would say that looks as though the seal at the opening end (opposite the hinge) of the back cover is degraded. There is a relatively sharp and straight demarcation across one part of the band, whereas the opposite edge is just a sort of fade. In such leaks, the light is hitting the film between the supply (or take-up) spool and the film gate; not in the masked film gate area. The resulting damage depends on the intensity of ambient light, the direction of the ambient light, and how quickly the film is wound between frames. That's the reason for the variations or apparent intermittent nature of the problem.

I know the Bronica foam seals revert to goop after about 15 or 20 years, and since Mamiya is from the same country and time period, I suspect it could share a similar problem.

 

[Jaf-Photo]

My Mamiyas work fine with little or no light sealing at the back, but I got negatives that looked exactly like that when I ran alkaline batteries instead ox silver oxide.

That said, it's never wrong to put in a fresh light seal along with the right batteries.

 

[mr rusty]

I agree. Its 100% a light leak. I have had identical leaks on my Mamiya 645. The light will be coming in around the catch. If you replace the seals make sure you get some foam underneath the back-lock pin - you can't stop it either side - voice of experience.

The reason it only appears on some frames is because it depends on how the camera back is oriented and how long it is presented to the strong light source. When I refoamed my 645 the first roll was fine. The second roll, where I was carrying around the camera in sunlight had the light leak on most frames. If you look at the negs you will most likely see the light leak extending beyond the exposed frame area which proves it is a leak and not a shutter issue.


I'll just add, when refoaming and using self-adhesive foam, wet the adhesive with a little water with some wetting agent or detergent in - not soaked, just enough to wet the surface. You can now slide the foam around into the correct position easily, and the glue will grab as soon as the water evaporates. This makes positioning mirror foams much easier as well!

 

[John Koehrer]

With a bit of hesitation for fear of redundancy.
Seals would be my bet, They degrade over time and leaving a residue is never a good thing.

The seals should be absolutely dry,

 

[Nige]

If you look at the negs you will most likely see the light leak extending beyond the exposed frame area

yep, check the negs for this, that will tell you if it's the back (light leak will show outside the image area)

 

[pixelrandy]

Light leak, per the negatives. Good thinking!

I really appreciate the recommendations about fitting the foam using a wetting agent, etc. I'm starting to feel like an information mooch, but where can one find the right foam? Neoprene? Closed or open cell? Lots of options!

Thanks,

Randy

 

[MattKing]

email jon goodman for a kit with instructions: JGood21967 at aol.com

Satisfied customer

 

[pixelrandy]

Thanks,

I'll shoot an email off to him now.

Cheers,

 

[wblynch]

I have two M645s that do that and I'm pretty sure it isn't light leaks.

The line seems to move with shutter speed which would indicate a shutter problem to me. As if the second curtain was dragging.

I have not heard a definitive answer in three years of reading these same reports but the Silver Oxide battery might be the answer. I will also try new ones and see if the problem goes away.

 

[pixelrandy]

I've contacted Jon Goodman (JGood21967 at aol.com) and seals are on the way. I had plenty of rolls that worked just fine on the alkaline batteries. My seals are gooey and have lost all sponginess.

 

[mr rusty]

. The line seems to move with shutter speed which would indicate a shutter problem to me. As if the second curtain was dragging

It's easy to tell. When I had a light leak the fogging on the neg extended beyond the image area and out to the edge of the film. If it does this it's a light leak.

 

[pixelrandy]

It's easy to tell. When I had a light leak the fogging on the neg extended beyond the image area and out to the edge of the film. If it does this it's a light leak.

That's right. So here's the proof that it's a light leak and not a lazy shutter. I should have looked at the negs earlier, but this is my first run in with a light leak. Lesson learned.

Here's one of the negatives. Pretty obvious now!

Thanks everyone.

 

[wblynch]

Thanks Randy. I shall reexamine my own negatives.

 

[Jaf-Photo]

I'm not going to argue against changing the light seals. It's always a good idea with vintage cameras.

But I would like to make two points based on my experience with 1000s.

(1) Alkalines can't deliver as much current as silver oxides. They can weaken during a shooting session which may cause the shutter to lag or freeze, as it needs power to operate.

(2) Sometimes the shutter will stick halfway closed for a while. This excessive exposure can leak outside the borders of the frame, especially along the raised edgde of the shutter as there is a small gap there.

So,in coclusion, do change the light seals, but also use the proper batteries. It's more important than you would think.

By the way, for light seals i use mouse mats made of foam which I cut into thin strips with a scalpel. Very convenient and efficient.

 

[anikin]

(1) Alkalines can't deliver as much current as silver oxides. They can weaken during a shooting session which may cause the shutter to lag or freeze, as it needs power to operate.

I agree. Bad batteries in this camera can cause a lagging shutter, i.e. shutter that is slower than needed. I also agree that bad batteries can cause the shutter to freeze, i.e. not close after opening.

(2) Sometimes the shutter will stick halfway closed for a while. This excessive exposure can leak outside the borders of the frame, especially along the raised edgde of the shutter as there is a small gap there.

Agree. If the tracks are dirty or mechanically bent, or if the curtain is imbalanced, the curtain can stick mid-way and cause a problem like that.

However, bad batteries cannot create the OP's symptoms. I'm looking at the service manual of this camera right now. The shutter is almost fully mechanical. The curtains are driven by mechanical springs. The only time where battery comes into play is to activate the solenoid that releases a catch for the closing curtain. It is simply impossible for a bad battery to cause a hanging curtain.

 

[alexfoto]

-I have the same symptoms with my 645 and is light leak, the problem come from the hinge of the door because the seals is off.

 

[pixelrandy]

I had no idea this thread continued on. I've received the seals but haven't had a moment to swap them out yet. Great info on the shutter. Yes, it's almost fully mechanical. The Pro bodies are electronic IIRC.