leaky exposure window

I not get any light leaks from the exposure window on my Holga, which is always

'open'. However, I get a frame ruining diagonal leak (see attached) from

briefly opening my Sputnik window to quickly advance frames?

 

I added a circle of Red #25 gel filter to beef up the overall opacity of the

window. I also added an overhang edge of flocking paper to the window cover so

that it will seal better when closed. I don't think there are leak problems

when the window is closed. When open, it is terrible. Why?

 

What is the big difference between the Holga and the Sputnik in this regard?

How can I make this problem go away? Or, are there mitigation strategies I

haven't considered?

 

I want to fix the problem, not lurk around advancing frames in deepest shadow.<div></div>

Holga cameras are EXPECTED to have light leaks. It's part of the "charm" of them. Lots of duct tape on all the seams after you load film is the solution.

My Holga does NOT leak through the exposure window. My Sputnik DOES. Why?

It might not be the exposure window, maybe the lock or back seal.

 

Light Leaks in Sputnik:

My first suggestion is to paint all shiny or metallic surfaces inside or around the doors with flat black enamel, especially the inside parts of the back lock. Next line the space between the doors with a strip of black velveteen using contact cement. Velveteen can also be used as a baffle around the inside hinge area. Attach strips on the inside door where the hinge meets. Attaching some thin black string, like crochet wool, to the inside grooves may be effective as long as there is room.

Cliff,

 

Thanks for these tips.

 

I really think it is coming from the exposure window. If I tape the developed film to the back of the camera and peek through from the shutter side (on bulb setting), the brightest center part of the streak lines up exactly with the exposure window. A minor leak will show up at the spot. A major leak will start there and radiate in NE and SW from that location. Also, if I really make sure to keep the window closed all the time, I don't get a leak.

 

How is the light going through the opaque backing paper? How opaque is it? If it was bouncing around inside the camera, why do the film edges never show leaking? ...only right in the middle of the frame.

 

I have already applied velveteen flocking to the door edges on both sides and all the other door edges and in the tiny cracks.

 

More thoughts on this are appreciated!

I think it is getting in at the edge or seam when you put the slightest pressure on the button to open the exposure window. that pressure is opening up another spot. If it is radiating from about where the window is then look at the edge in that general area. You might try taking some black tape and go around the seams, if it is still there you might start looking at the front.

Here is where I found that information. You might want to doo all the things he

 

http://www.rmm3d.com/3d.encyclopedia/repairs/sputnik.sam/sputnik.html

Cliff,

 

Thanks for your tips. I was on the wrong path. You were right. The top of the back was leaky. My test photos of when pressure was applied to the window had no leaks but everything else did. ;-) So, I flocked the parts of the door where it mates with the body. It is a tight fit but it seems to do the trick. Thanks!

 

Aaron