Bolex REX 4/5 16mm - Light Leaks

[Daniel Meier]

I've aquired this camera about two years ago. Shot two rolls of 100ft and everything looked fine.
Last fall I started shooting my 3rd roll of film. This time I went for 500T stock.
When I got it back from the lab and scanning, it had these really nasty light leaks. (Starting at 0:53 in the YT link)

https://youtu.be/3_QMzjQ5GLs

I shot the first third of the roll in Paris. Then went back to my home (Germany) and that first shot I took there had this light leak thing going on.
I took it some days after I came back from Paris.

Now I am wondering about the cause and the root of the issues. Did the camera got damaged during transportation?
Is it just a regular light leak happening because the camera wasn't sealed good enough?
Did any of you experience similar effects? 
And what about those 10 frames of white happening every 5 frames after a new shot.

I didn't change anything on the camera, except for lenses. Always kept the slide filter in with some 85B filter. To balance the 500T for daylight.

The only other thing that changed is how I store the camera, when not shooting with it (but film still being loaded in it)
The shelf where the camera sits now has a decent amount of top-light (LED). 
But I also made sure that there is no light coming in from the top compartment of the camera, where a 400ft mag could be installed.

I spent about 210€ for developing and scanning only.
Can't afford this to happen again ?

Would be very pleased to hear your experiences.

Edited July 12, 2022 by Daniel Meier
providing additional information

[Dom Jaeger]

The leak seems to be coming from the lid side, could the lid have been damaged, or not properly closed? I’d be looking where the lid seats near the gate or just above it. Check that the lid secures ok with the three clamps that extend when you lock the latch. Also check there are no holes from missing screws. 

Has the camera ever been serviced or checked by a technician?

[Doug Palmer]

If there's fogging near start of a new shot it does indicate a leak near the top of the camera.  But you say the top mag hole is securely covered.  And presumably the door is on properly ?  Perhaps if you have a small light you could place it inside, close the camera and observe the effect in a dark room.  If it's a superficial problem maybe it can be cured with a good helping of black tape. 

[Simon Wyss]

I suspect the film stock to be overdue. Hast du altes Material zusammengekauft?

[Mark Dunn]

Additionally, the white blob on the right of frame from about 00:50 on appears to be some sort of obstruction in the optical path. It's not flare or a leak because it doesn't vary.

Edited July 13, 2022 by Mark Dunn

[Daniel Meier]

Sorry for the late response. I was on vacation.
Thank you for all your replies. It helped a lot.

I did a test with a mini LED flashlight. And I quickly found out that a missing screw caused the light leak to happen.
I remember that the turret lock screw broke. So I decided to get rid of the mechanism at all, since I would still use the Turret Plug to keep the turret from spinning.

Now I screwed everything back in - except for the silver part that is supposed to lock the turret. This one can't be tightened anymore due to the missing screw (which is broken and half of it got stuck inside the thread).

The attached image should help grasping.

[Daniel Meier]

On 7/13/2022 at 11:37 AM, Simon Wyss said:

I suspect the film stock to be overdue. Hast du altes Material zusammengekauft?

I don't know the exact expiration date of the film stocks. I purchased a bunch of stocks along with the camera, back when I got it from an ebay seller. But I think it should be fine, since the copyright says "2017".

Maybe you can tell better from the photos I made? 

[Dom Jaeger]

3 hours ago, Daniel Meier said:

I did a test with a mini LED flashlight. And I quickly found out that a missing screw caused the light leak to happen.

Thanks for getting back with an answer, many times we never find out what the issue was.

Glad you sorted it out.

[Simon Wyss]

Of course I can’t, there’s none on the boxes. It wasn’t the film anyway.

[Mark Dunn]

Professional stocks don't have an expiry date- they're expected to be used fresh. But 2017 ought to be OK if the film was frozen, or even refrigerated.

3 hours ago, Simon Wyss said:

there’s none on the boxes

There's a copyright notice in very small print. Probably accurate to a year or so. But I'm not sure that Kodak has always done that so it may not be reliable for older stocks.

When I got some sheet Tri-X with an old Mamiya Press in about 1982, the dealer had torn off the expiry date. It was OK.

 

[Simon Wyss]

So sheet film isn’t professional stock? Now you can laugh at me.

[David Sekanina]

let's go for a beer Simon, I'm buying, you've been a bit grumpy these days ?

[Mark Dunn]

45 minutes ago, Simon Wyss said:

So sheet film isn’t professional stock? Now you can laugh at me.

The Tri-X I was referring to expired 50 years ago, but I meant MP stock, as that's what the thread was about. I think stills film always had an expiry date- I haven't used film for 18 years- but it's quite a bit shorter than for an amateur stock for the reason I stated. An amateur film may spend some time on the shop shelf. Ours goes straight in the freezer.

The last film I used - Agfachrome- was about 5 years out of date, but bought fresh. I didn't take 5000 photographs a year then.

Edited August 3, 2022 by Mark Dunn

[Doug Palmer]

On 8/3/2022 at 12:40 AM, Daniel Meier said:

Sorry for the late response. I was on vacation.
Thank you for all your replies. It helped a lot.

I did a test with a mini LED flashlight. And I quickly found out that a missing screw caused the light leak to happen.
I remember that the turret lock screw broke. So I decided to get rid of the mechanism at all, since I would still use the Turret Plug to keep the turret from spinning.

Now I screwed everything back in - except for the silver part that is supposed to lock the turret. This one can't be tightened anymore due to the missing screw (which is broken and half of it got stuck inside the thread).

The attached image should help grasping.

Thanks for this.  It's something all us Bolex users should be aware of.