Mystery Fog

[baronvonaaron]

Sorry to make a new thread, I'm sure there's been thousands of these already.

I just pulled a batch of negative out of the darkroom this morning and all of them have similar fogging. I don't know conclusively what is causing it but I have a suspicion it's sun related. Here's the facts: Shot on an intrepid 4x5 that I've been using for 3 years without this problem. Used a film holder that I've been using for 10 years without problem. all exposed and unexposed film was stored in 3 part film boxes inside an xray bag and travelled via carry-on. This is my 3rd batch of negatives processed in an SP445 tank.


the beach shot was taken on a very sunny/clear day around noon, and the one of the house was taken around 4pm on a slightly overcast day. both of these sheets came from the same box of film.
189693

189694


this one was taken with the same holder and camera about a week later, stored in the same download box. same sunny and clear conditions as the first image, but processed in a previous batch. this sheet came from a different box of film.
189695

my question is if this looks like an error on my part, or could it possibly be an issue with the SP445 tank? it doesn't look like it to me, but is there a chance that this is a manufacturer defect? i still have a dozen sheets to process and i don't want to tray process all of them.

[Louis Pacilla]

Just glancing at your leaks I would think a combination of weak back springs & and not pinching the rear standard and spring back frame together while pulling the dark slide. That would be my guess.

Also in addition to the precaution I mentioned above I also do the prudent thing and keep the back end of the camera covered with the dark cloth particularly when the dark slide is pulled. All my cameras are in great condition w/ no light leaks as are all my holders and even when in house I do this, mostly out of habit but why not as it's a safety precaution against things like your experiencing. I have never or not very recently (10-20 years) have had this bad experience. BTW- I wrap then lightly tie my dark cloth ends around/under my tripod crown of so they can't flap around in the breeze.

[Steven Ruttenberg]

Agree with above. I had that issue a couple of times. Be sure film holders firmly seated. I started taking the gg holder off and inserting film holder while off camera. Let’s me check lens is not blocked by bellows and I can visually confirm film holder properly inserted and less chance to mess up camera after everything focused and framed. Got that idea from Steve Sherman.

[baronvonaaron]

Thanks for the input. I hope the rest of the negatives are ok.

I wonder if putting something down like duvetyne tape on the camera back would help against light leaks. has anybody ever tried that? I have a homemade pinhole cam that i used weather stripping for this need, but focal length isnt as critical there.

[Jim Noel]

Did you think to cover your camera with your darkcloth?

[Michael Kadillak]

Did you think to cover your camera with your darkcloth?

If you have standard steel spring GG back with good tension and a good groove to receive the holder and use modern holders you should not need to cover your camera back with 4x5, 5x7 or 8x10. In over 20 years I never have had a problem with these formats necessitating a dark cloth cover. The only exception I can think of would be Death Valley where the intensity of reflective light knows no bounds. That being said with ULF I always cover the camera aback with a dark cloth.

[Sal Santamaura]

If you have standard steel spring GG back with good tension...This is a three year old Intrepid. It uses elastic cords, not springs. :)

[Steven Ruttenberg]

Make sure all the seams on wood joints are good.

But, I think either the holder wasn’t in all the way or the dark slide was partially pulled at some point.

I use blue painters tape to firmly secure my dark slides in place prior to and after the shot. After pulling a couple slides partially out, I started using the tape. I don’t trust the little bent wire to not rotate. At one point, my tripod had like 50 little pieces of tape stuck to it. I looked like I knew what I was doing :)

[baronvonaaron]

This is a three year old Intrepid. It uses elastic cords, not springs. :)
This is something that I worry about going into the future. So far the elasticity has held up pretty well. I really wish they had springs on those earlier models. Gonna have to figure out some DIY mods when those start to go. Or maybe by then somebody will gift me a Wista haha


Make sure all the seams on wood joints are good.

But, I think either the holder wasn’t in all the way or the dark slide was partially pulled at some point.

I use blue painters tape to firmly secure my dark slides in place prior to and after the shot. After pulling a couple slides partially out, I started using the tape. I don’t trust the little bent wire to not rotate. At one point, my tripod had like 50 little pieces of tape stuck to it. I looked like I knew what I was doing :)

I use rubber bands to keep my slides in. i used to use painters tape too, but after a while i got tired of running out of tape on the road. Some common things are surprisingly difficult to get a hold of when you're on a rock or theatre tour.