Strange white circle on print

[mark]

I have a strange perfectly white circle on a print. I know this can be cause by dust on the neg but there was no dust on the neg. This is a contact print on POP. The dark spot is definatley in the negative but what would cause a perfectly 1mm round dot in the silver. The photo was taken on a cloudy day in rushing water with no specular highlights anywhere.

Could this be an anomoly in the film? BPF 200 is what the film is. The spot is not very seeable as it is in the rushing water but I am curious. It is like this perfect circle is over exposed by a hell of a lot with no bleeding into the surrounding silver.

 

[colrehogan]

Perhaps a bubble in your developer? I have a 4x5 negative that has some bubble marks on it, they are very small, but they showed up on an 8x10 enlargement.

 

[rbarker]

Air bubbles would reduce the density of the neg, often with a distinct edge and some increase in density toward the center of the bubble (but still less dense than the surrounding area. A dark spot, I would think, would have to be caused by greater development of that area, perhaps due to an undissolved developer crystal attaching itself to the film?

 

[fhovie]

Sounds like a nasty waterspot - happens to me when I am not careful with photoflow

 

[mark]

This is no water spot. That I do know. It is plain weird.

 

[Ole]

Could it be an air bubble in the emulsion? That sometims gives increased density in a thin ring around a clear (or at least thin) centre.

I have seen it on EFKE R17, the old name for R50 some years ago.

 

[mark]

It looks like someone aimed a 1mm pinpoint of light at the unexposed negative. It is not a ring it is a solid dot. Like I said no big deal, just strange.

 

[glbeas]

Most likely its an actual object that was in the water, seeing how there was no sun out to make a highlighht.

 

[Donald Qualls]

Perhaps a mark from pressure on the film in handling, or from a static spark? I started to suggest it might be a pinhole image of the sun cast by a light leak in the bellows, but to be that small, it would have to be cast from a point very close to the film -- within a couple inches, in fact -- and in any case would require the sun be shining on the bellows in a direction that could reach the film, while the dark slide was out. Alternately, a drop of some fogging chemical that landed on the emulsion, either before or after exposure, would give the same effect -- brown or selenium toner could do it, badly decomposed fixer might (sulfur is a strong foggant), and there are a few other chemicals around that could. A droplet of developer could do it, if you tray process your sheet film, causing gross overdevelopment of a very small region.

 

[mark]

Good thoughts donald but none of them fit. It was painfully cloudy, I process in a Unicolor drum so nothing sits on the emulsion. I never have my selenium anywhere near my negs. Who knows. Just some mystery that will never get solved I guess.

 

[Donald Qualls]

I process in a Unicolor drum so nothing sits on the emulsion.

Actually, it seems to me a Unicolor is a good candidate for my "developer droplet" theory -- if, while filling the drum, a drop(let) of developer escaped the interior trough before you started rolling or put the drum on the motor base, it could cause local overdevelopment; especially so if, for some reason, the negative sat in the drum with developer loaded for a couple minutes before starting the actual processing.