Round Marks on Negatives

[IanBarber]

Occasionally, not every time, I get these round marks on my 4x5 negatives which appear to be more noticeable in bright skies.

Has anyone else experienced this ?

Film: Fomapan 100
Developed in HC110
Ilford Stop bath
Ilford Fixer
Kodak Photoflo
Tap Water

I am wondering if it's either something to do with the Photoflo or tap water ?

[Bruce Watson]

Occasionally, not every time, I get these round marks on my 4x5 negatives which appear to be more noticeable in bright skies.

Has anyone else experienced this?

Is the attached image the entire film, or just a piece of it? IOW, how big are the spots?

Is the image a positive or a negative of the film? IOW, are the spots slightly lower density on a high density area, or are they slightly more density in a low density area? Since you talk about skies, and skies tend to be high density areas on B&W negative film, I'm thinking you're showing a negative of the film, so the spots are slightly lower density in a high density area.

If the spots are small, and are slightly lower density than their surroundings, I'm thinking they might be out of focus dust. When was the last time you cleaned out the inside of the camera bellows? The fact that it doesn't occur every sheet might just be that it only occurs when you've stirred up the dust, or not given it sufficient time to settle.

Without more information...

[IanBarber]

The attached image is a 100% scanned positive crop of the offending area.

Dust in the bellows is something I haven't thought about to be honest and will now make this a priority to clean them.

[Willie]

Air bubbles on the negative?
Do you use a good pre-soak?

[Drew Wiley]

Looks like typical air bell marks to me. How are you developing, in trays? If so, you need to practice your shuffling technique. The importance of the pre-wet
step has already been mentioned. Can you be more specific about your method?

[Ken Lee]

Air bells can appear if you use a developing tank.

When no darkroom is available, even a small bathroom can work for tray development. Infra red goggles make it easier to work in the dark.

[Bob Salomon]

Air bells can appear if you use a developing tank.

When no darkroom is available, even a small bathroom can work for tray development. Infra red goggles make it easier to work in the dark.

If you use a tank, even a tank with holders, you must rap the edge of the tank, after filling it or rap the hangers against the tank after putting the hangers in the tank to dislodge air bells.

[IanG]

Like others that's air bells. Get a Britta or similar water filter jug (UK brand) it uses a small ion exchange cartridge to soften the water that should eliminate the problem.

Ian

[IanBarber]

Thanks for the suggestions.

I always use a paterson tank to develop in.

I never pre-soak (how long do you suggest)

On this occasion, I know I did not rap the tank after pouring in the developer

Like others that's air bells. Get a Britta or similar water filter jug (UK brand) it uses a small ion exchange cartridge to soften the water that should eliminate the problem.

I like this idea and will invest in one

[Bob Salomon]

Thanks for the suggestions.

I always use a paterson tank to develop in.

I never pre-soak (how long do you suggest)

On this occasion, I know I did not rap the tank after pouring in the developer


I like this idea and will invest in one

Don't spend money, just make sure that you always rap the tank on the table and you will not get anymore air bells.