Light leak on film? New seals maybe?


cardiffgareth

Link Posted 22/03/2021 - 14:50
So ran a roll of film through the Program A and disaster! I have some light leaks. It's starts off between the frames so I think that rules out an issue with the shutter and then progresses into the frame.

Having not used film for a while I hope it's just the light seals but what worries me is that it isn't a constant leak that effects the whole film area through the exposures?







Any thoughts?
Gareth
Welsh Photographer

My outfit: K1 gripped - Pentax D FA 24-70mm - Sigma 70-200mm OS HSM - Pentax modified DA* 60-250mm f4 - Irix 15mm Firefly - Sigma 50-500mm - FA 50mm f1.4 - Tamron SP 90mm macro - Pentax AF 540 FGZ Ii

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MHOL190246

Link Posted 22/03/2021 - 15:49
If you Google 'Causes of fogging top of 35mm film' there is some interesting discussion on Photo Net which might be food for thought. My immediate thought with your query was, are you processing at home or using a lab?

Michael

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johnriley

Link Posted 22/03/2021 - 16:12
You can test if it's a light leak by taping up the joins with black tape. See if it cures it. Light leaks may vary anyway, depending on where the light strikes from.
Best regards, John

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Flan

Link Posted 22/03/2021 - 17:02
The top right hand corner (under the winder) is where I got the most sticky mush. So I would take johnrileys advice and electrical insulation tape that area first and chance another roll . If it works you might be able to do a small repair your self. Well that’s what I’ll be doing with mine when I shoot a bit of film this summer. Best of luck

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Jonathan-Mac

Link Posted 23/03/2021 - 09:17
I would change the light seals and try that as it's the most likely cause.
Pentax hybrid user - Digital K3 & K200D, film 645 and 35mm SLR and Pentax (&other) lenses adapted to Fuji X digital
Fan of DA limited and old manual lenses

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cardiffgareth

Link Posted 23/03/2021 - 12:24
Jonathan-Mac wrote:
I would change the light seals and try that as it's the most likely cause.

That's my plan. I see there are 3 different thicknesses of light seal foam? Any idea what's the best thickness?

Also tips for getting the old stuff out? I've got 99.9% isopropyl alcohol here and some cocktail sticks?!
Gareth
Welsh Photographer

My outfit: K1 gripped - Pentax D FA 24-70mm - Sigma 70-200mm OS HSM - Pentax modified DA* 60-250mm f4 - Irix 15mm Firefly - Sigma 50-500mm - FA 50mm f1.4 - Tamron SP 90mm macro - Pentax AF 540 FGZ Ii

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davidstorm

Link Posted 23/03/2021 - 12:38
cardiffgareth wrote:
Jonathan-Mac wrote:
I would change the light seals and try that as it's the most likely cause.

That's my plan. I see there are 3 different thicknesses of light seal foam? Any idea what's the best thickness?

Also tips for getting the old stuff out? I've got 99.9% isopropyl alcohol here and some cocktail sticks?!

Hi Gareth

Noticed this post as it's right up my street and I think I can help you. I wouldn't use foam at all for your rear seals. I've replaced hundreds of rear seals in a variety of film cameras and I use 100% wool yarn (black), bedded in with clear silicone sealant. This has many advantages over the foam seals:

- It doesn't compress like foam does, it has more natural 'spring', so forms a tighter seal around the rear door
- You don't have to be careful to remove all of the old seal material, just ensure there's a channel to take the wool yarn
- It is much easier to install than foam seals, just put the silicone into the channel and then guide the yarn in, using something like a cocktail stick, stretching the yarn as you go. It will seat easily in the channel
- Make sure the ends are firmly pressed into the channel so it doesn't pop out
- Leave to cure for 1 day before shutting the rear door

The wool yarn seal will not degrade like foam does, so should retain its light-tight properties for a lifetime. It also provides some resistance when closing the rear door, which demonstrates that it is sealing against the door edge. Be careful not to cover the gap where the frame counter pin is, otherwise the frame counter will stop working.

Hope this helps, send me a PM if you need any advice.

Regards
Davied
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Some cameras, some lenses, some bits 'n' bobs

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Peter Elgar

Link Posted 23/03/2021 - 16:09
Davied -- I tried to get that 100% Wool Yarn -- there was a 'Sewing Shop' here in Brentwood ( now gone BROKE!) and I asked the Lady but she didn't know what it was -- from WHERE do you GET it I use Foam Sheet from Hobby Crafts, ROMFORD ( Havering) 85 p a sheet. I looked at the NEGATIVES shown and they are all DREADFULLY THIN -- Under-Exposed -- probably a Pentax Program- A fault - I WON one in the Pentax Club of Great Britain years ago and it was OK for a few years then developed exposure fault and Camera Repair Bloke says " Pentax NO Longer Supply PARTS for Program-A" so I sold body only to an Un-suspecting member of my Club. Brentwood & District Photographic Club at our Annual Club 'Auction' for a few quid ---
been a member of Pentax Club since the Ron Spillman era! Got COMPUTERISED at last - DIGITISED? Taken the PLUNGE - BUT FILM STILL RULES !!!

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womble

Link Posted 23/03/2021 - 16:27
A well-known camera tech in the US always uses yarn for door seals, so it gets a big thumbs-up.
Kris Lockyear
It is an illusion that photos are made with the camera… they are made with the eye, heart and head. Henri Cartier-Bresson
Lots of film bodies, a couple of digital ones, too many lenses (mainly older glass) and a Horseman LE 5x4.

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cardiffgareth

Link Posted 23/03/2021 - 17:21
Thanks all. Yup, that yarn looks like it might be the solution to my issues fingers crossed!

Peter Elgar wrote:
...I looked at the NEGATIVES shown and they are all DREADFULLY THIN -- Under-Exposed -- probably a Pentax Program- A fault ...

It probably didn't help the film I used to try the camera out was expired in 2004! I wanted to check for light leaks and the wind on so used a cheap roll I bought locally to try it out before committing a good roll through it
Gareth
Welsh Photographer

My outfit: K1 gripped - Pentax D FA 24-70mm - Sigma 70-200mm OS HSM - Pentax modified DA* 60-250mm f4 - Irix 15mm Firefly - Sigma 50-500mm - FA 50mm f1.4 - Tamron SP 90mm macro - Pentax AF 540 FGZ Ii

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davidstorm

Link Posted 23/03/2021 - 20:07
Peter Elgar wrote:
Davied -- I tried to get that 100% Wool Yarn -- there was a 'Sewing Shop' here in Brentwood ( now gone BROKE!) and I asked the Lady but she didn't know what it was -- from WHERE do you GET it I use Foam Sheet from Hobby Crafts, ROMFORD ( Havering) 85 p a sheet. I looked at the NEGATIVES shown and they are all DREADFULLY THIN -- Under-Exposed -- probably a Pentax Program- A fault - I WON one in the Pentax Club of Great Britain years ago and it was OK for a few years then developed exposure fault and Camera Repair Bloke says " Pentax NO Longer Supply PARTS for Program-A" so I sold body only to an Un-suspecting member of my Club. Brentwood & District Photographic Club at our Annual Club 'Auction' for a few quid ---

Hi Peter

I ordered the wool yarn from ebay, see link below for one example, there are other sellers that may be selling it cheaper:

link

Regards
David
Flickr

Some cameras, some lenses, some bits 'n' bobs

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cardiffgareth

Link Posted 29/03/2021 - 09:46
I've updated the other thread in the general area. Found my light leak! Turns out a screw was missing on the back door that holds the rear grip on and allowing light into the film chamber. I've stuffed a screw into it and glued it in place and that's sorted that out.

Cleaned the channels out ready. On another forum someone pointed me to a website that sells precut foam seals. A pack of 3 sets so room to make errors was under £15 delivered. They're for the Me Super but I reckon the Program A is the same shape or pretty near to it and if not, as there's 3 sets, I can bodge one working set from the 3!
Gareth
Welsh Photographer

My outfit: K1 gripped - Pentax D FA 24-70mm - Sigma 70-200mm OS HSM - Pentax modified DA* 60-250mm f4 - Irix 15mm Firefly - Sigma 50-500mm - FA 50mm f1.4 - Tamron SP 90mm macro - Pentax AF 540 FGZ Ii

My Flickr
My PPG
My 500px

womble

Link Posted 29/03/2021 - 16:37
Don't forget the mirror bumper. When that goes the mirror starts flinging sticky bits of foam all over the inside of your camera and they are a pain to get rid of, especially on the focusing screen.
Kris Lockyear
It is an illusion that photos are made with the camera… they are made with the eye, heart and head. Henri Cartier-Bresson
Lots of film bodies, a couple of digital ones, too many lenses (mainly older glass) and a Horseman LE 5x4.

My website

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bjolester

Link Posted 15/04/2021 - 22:26
I have installed new light seals on several film cameras (Spotmatic, MX, FE2, FE, XA1 i.e,) using pre-cut kits made by Jon Goodman. Mr. Goodman sold his kits on eBay under the name "Interslice" for many years. His kits also include meticulous descriptions of how to go about installing new seals and mirror bumper. Jon Goodman can be contacted via email:

jgood21967@aol.com
Bjørn

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womble

Link Posted 15/04/2021 - 22:49
I've used his kits in the past and they are great.

K.
Kris Lockyear
It is an illusion that photos are made with the camera… they are made with the eye, heart and head. Henri Cartier-Bresson
Lots of film bodies, a couple of digital ones, too many lenses (mainly older glass) and a Horseman LE 5x4.

My website
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