Pentax ME Super light leak

[Ste_S]

Had a Pentax ME Super serviced by Harrow Technical (now retired) in the UK a year ago. All well until a few weeks ago where it's developed a light leak. Always in the same position on the frame, but only happens occasionally. Any ideas ? Had a nose around inside the camera and all seems good, including shining a light through the camera from front to back.

 

[M-88]

I had a light leak on ME Super, here it is:

Although not exactly the same, it's somewhat similar... Turns out, the back cover was bent a little and light leak was coming from the area indicated with an arrow:

Of course your issue might be entirely different though

 

[Ste_S]

Thanks. I don't think it's coming from the back of the camera. The leak is within the frame on the neg and doesn't touch the sprockets, which I guess means it's a front leak ?

 

[M-88]

Indeed you are correct. Is that a native K mount lens, or something through an adapter, like M42? Those adapters leak on some lenses. Also, it's curved, probably the leak is coming from the lens? Have you tried another one?

 

[Ste_S]

Yup, native K mount lenses. Had it happen definitely with the SMC M 50mm f2, and the SMC M 28-50mm f3.5-4.5. Also possibly with the SMC M 28mm f2.8.
No filters used on the lenses.

 

[Billy Axeman]

Check the seals around the ground glass inside the mirror box. When the mirror is up the ground glass should be sealed all around.

 

[Joel_L]

How do the shutter blades look?

 

[Ste_S]

How do the shutter blades look?

Shutter blades look fine. There is some wear on them but nothing obvious that would cause a light leak like buckled blades.
In operation for frames that don't have the leak exposures are fine

If it is the shutter blades it's going to be something small that I've missed

Check the seals around the ground glass inside the mirror box. When the mirror is up the ground glass should be sealed all around.

Have not checked that yet, will have a look

 

[M-88]

I had two Pentaxes, one was ME, other was ME Super. Both of them had no mirror damper (which I believe also doubles as a seal of that part) and didn't leak from there. Of course I repaired the damper on both, but never investigated further, so it is a good idea to look at that, like Billy said.

 

[Joel_L]

Interesting that two pics look similar, one not so much.

Do you get something on all frames or just some?
Is it worse on one end of the roll, and change as you get to the other?

Do you process you own film?

 

[M-88]

Interesting that two pics look similar, one not so much.

The third "one not so much" is actually mine, not OP's. His photos look the same.

 

[Ste_S]

Check the seals around the ground glass inside the mirror box. When the mirror is up the ground glass should be sealed all around.

Checked this. There is fresh foam at the front and back of the ground glass, no foam to the sides. Doesn't look as though there has ever been any on the sides. When the mirror lifts up it looks as though it makes a good seal over the ground glass.

Interesting that two pics look similar, one not so much.

Do you get something on all frames or just some?
Is it worse on one end of the roll, and change as you get to the other?

Do you process you own film?

Leak happens on some frames, and is in the minority on a roll. Most frames are exposed correctly and don't have the leak.
I've had the leak happen in different parts of the roll, on 2x Natura 1600, 3x Ultramax 400 and 1x Tri-X (pushed to 1600)
I don't process my own film, these rolls have all been developed at the same lab which I've had no complaints with before.

 

[flavio81]

behind the mirror there is a cloth that blinds the light from the viewfinder from reaching the film when the mirror is up. Take a look at it.

It is present on many Pentaxes of that era.

 

[Joel_L]

Well that explains it, wonder how I put the two post together...

The third "one not so much" is actually mine, not OP's. His photos look the same.

 

[Joel_L]

It does look odd. When you look at the negs with a loop, by any chance does it look like the film has been scraped?

 

[Ste_S]

behind the mirror there is a cloth that blinds the light from the viewfinder from reaching the film when the mirror is up. Take a look at it.

It is present on many Pentaxes of that era.

On mine it doesn't have cloth, it has a piece of ribbed plastic (?) stuck on the back of the mirror. It looks intact and in place

It does look odd. When you look at the negs with a loop, by any changes does it look like the film has been scraped?

I don't have a loupe at home (i know, i know) but when we looked at the negs on the labs light box it didn't look like a scrape. I've had a look around at the film runners and the advance mechanism and there doesn't appear to be anything obvious that would damage the neg.

The weird thing is how intermittent it is. At one point I had the camera sat on a tripod with a setting sun beaming directly in it, but yet all these exposures turned out fine.

 

[Billy Axeman]

Checked this. There is fresh foam at the front and back of the ground glass, no foam to the sides. Doesn't look as though there has ever been any on the sides. When the mirror lifts up it looks as though it makes a good seal over the ground glass .....

That's OK. I checked my own ME Super and the ground glass has no seals on the sides so the black light trap is supposed to do the work. I thought the issue was that light was entering via the viewfinder, because you say the leak is not consistent.
If you are wearing spectacles the chance of sunlight directly hitting the viewfinder is much bigger and some light might pass via the sides of the ground glass or perhaps reflecting off the glass in the viewfinder and bounce around. This is a known issue with many camera's, the leak on your photo's has a weird structure though.

 

[720treker]

Inspect the felt hinge seal. If you load a test roll in camera and mark the affected area in the film gate(upper right third)then advance the film two times with the back open. You will see where the affected area lands.

Probably did not happen on a tripod because as you hold the camera, you may flex the back.