Dust on 4x5 negs, grrrrr!

I've been struggling with ++++ dust on 4x5 negs. Some of them have so much they feel like fine sandpaper . I thought it was my Photoflo. Mixed up fresh batch, same problem. Another new batch from new bottle of stock - still a dust magnet. The curious thing is that medium format negatives, developed in the same darkroom, stopped in same stop, fixed in same fix, washed with same water, dipped in same photoflo, hung with same clothespegs in same spot, do NOT have dust problems :confused: . Could it be something about the film itself? I've been using Ilford HP5 4x5, while using Kodak and Rollei medium format. Have just bought some Rollei 4x5, and will try that, but I still have some HP5 left, which I'd like to finish up. Any thoughts from anyone out there? Thanks, Sly

Hi Sly, can you give a complete detail of your processing from the start including opening the box and loading the film to pre wash though drying? What water quality and drying condition exist there? The environment is important too.

Curt

Dear Sly,

From your post, it seems that the source of the dust is not your chemicals. Are you using different cameras for the MF vs 4x5? Do you process both in the same type of tank? How about the condition of the film holders?

Neal Wydra

I wouldn't consider this to be a big mystery. Roll film - both 35mm and MF -comes in a rather sterile package, and the only time it is exposed to dust in the environment is while it is in the camera or being processed.

LF film, by contrast, has to be loaded into holders which are then carried around in some kind of container until the film is exposed, and again until it is taken out of the holders for processing. That additional exposure to the environment means that it is has lots of opportunity to pick up more dust.

LF photography requires an almost anal approach to the disciplines required to achieve the quality that the process is capable of. Care has to be taken to assure that the humidity is right when holders are loaded and unloaded - if the air is too dry, dust will be attracted to the holders. Holders must be impeccably clean. Always brush out (and preferably vacuum) holders before loading. And just before putting a loaded holder into the camera to make an exposure, use a small brush to remove any dust that might be clinging to the outside of the holder. Careful workers (and I admit that I don't do this) put their holders into zip-lock bags to protect them from dust as soon as they are loaded, and again immediately after exposure. If a changing bag is used in the field for loading or unloading holders, care has to be taken to assure that it does not become the source for dust getting into holders.

I mix my hypo clearing agent by hand. I use 1 tablespoon per 'cup' of water, sometimes more or less. If I don't skip the bottom part of the cup with all the sludge, I get undissolved hypo on my negs. Feels like sandpaper!
Just a thought.
I keep my holders in ziplocks. Vacuum out your camera/bellows.
Tap you holders on a table. The bottom part with the flap, you want to dislodge any junk so you can vacuum it out. Vacuum your holders before loading too. Vacuum the flaps. Vacuum everything The good part is that once you get your holders and camera clean, you just need to keep it clean.
I get a speck or two, it's normal. But usually it's no more than that.

Sly,

There is another possibility that hasn't been mentioned. I use one particular Yankee tank for photoflo and hypoclear. I rinse it before and after each use. The other day, I noticed that there was something on some 4x5 negatives. After rewetting and photoflowing it was still there. I finally looked at the tank in the light and found a precipitate on the inside walls. At this point I washed the tank with hot water, detergent and a scrubby and then after a thorough rinse, I re-photoflowed the negatives in distilled water. At that point the problem disappeared.

This is the first time that I've had such a problem in 3 years in that darkroom and I think some of the issue may be water related.

Mike

precipitate

Thank you all for your input. I am pretty sure it isn't enviornmental dust from film loading and handling. I'd have to be working in a dust storm to get that much on the negs. Precipitate from the fix or hypo-clear makes sense. I use a 1.5 liter tank for 4x5, and would pour all of the contents of the bottle in to have enough depth, while the medium format would just use a 1/2 liter, and any precipitate would likely stay in the bottle. My water is another possibility. We have a new well and the water is alkaline (8 on the pH scale). (This is better than very hard water, high in iron, and hardly any water from August to October.)
I'll dump what I have, wash the bottles, and mix up fresh chemicals with boughten water. I'll let you know how it goes. Sly

I've had problems with crud in my well water getting on my negatives. I installed a whole house filter on the line from the well, and another filter on the hot side of my darkroom water which has taken care of the problem.
Even with the filters, just to be sure, I mix the developer and photo-flo with distilled.

Since you are on a well, the quality of the water in terms of stuff in it can vary.