Strange speck on BW film

Hi all,

 

I've been processing my BW film for about a year now, but only recently have started working at home and managing my own chemicals (had access to a public darkroom before). On the last few rolls I developed, there were 1 or 2 frames that came out with a small mark on them (photo attached). Any idea what could cause this?

 

I'm using HC-110, dilution H, Ilford stop, Hypo clear, Ilford rapid fixer, doing Ilford's archival wash then photo flo. I've processed about 35 rolls of 35mm and maybe 15 of 120 and have replenished the fixer once. Could it be a deposit from the fixer? I'm using distilled water to mix all my chemicals and for the last wash.

 

Thanks,

 

It may be mechanical damage to the emulsion before it was developed. Was the film bumped or treated a little roughly while inserting in the camera, in the change bag or developing spiral?

If the color of your scan is accurate, you need a longer fixing time or to replace your fixer more often--B&W film should have a clearer base than what you're showing. As for the mark, have you cleaned your reels recently? There could be deposits left on them from previous processing runs.

It may be mechanical damage to the emulsion before it was developed. Was the film bumped or treated a little roughly while inserting in the camera, in the change bag or developing spiral?

 

Hm, I don't think so, I've become pretty efficient at loading the steel reels.

 

If the color of your scan is accurate, you need a longer fixing time or to replace your fixer more often--B&W film should have a clearer base than what you're showing. As for the mark, have you cleaned your reels recently? There could be deposits left on them from previous processing runs.

 

I clean my reels after every session by soaking them in water, washing them as I would film, then drying them with a rag pretty thoroughly, so I don't think that is the issue. The color of the film base is not accurate, this was taken with my phone using a loupe. There is a very slight purple tint, but I've been told this has no effect on printing or scanning.

On the last few rolls I developed, there were 1 or 2 frames that came out with a small mark on them

 

Were the marks on the same frames on each film, or on different frames?

 

Have you checked to see if the "mark" is a piece of foreign material by running a toothpick gently over it?

 

Alternatively, if you can't find the fault, you should have no trouble cloning them out in Photoshop

It does look like some sort of physical emulsion damage amplified by the development process.

Were the marks on the same frames on each film, or on different frames?

 

Have you checked to see if the "mark" is a piece of foreign material by running a toothpick gently over it?

 

Alternatively, if you can't find the fault, you should have no trouble cloning them out in Photoshop

I did very gently run my fingernail over it but couldn't really feel anything. Luckily this isn't a photo I really care about printing, just worried about it happening in the future.

It does look like some sort of physical emulsion damage amplified by the development process.

That's what I'm thinking. I'm thinking maybe my changing bag has collected some dust/debris and maybe something fell on it while putting it on the reel. I'm not sure what else could have happened.

UFO.

"...then drying them with a rag pretty thoroughly,"

 

- I would never do that. You don't know what kind of fluff and other contaminants you're rubbing onto your reels. SS reels and tanks should only be heat dried, blow-dried, or left to dry naturally. Plastic tanks the same, except the drying temperature needs to be kept lower.

 

The blob was probably introduced before or during development. Copper, iron, aluminium and other metals are known to react with developer to form staining by-products.