Tiny clear spots on latest roll of film

logan2z · Feb 26, 2020

It seems that I've finally got the light leak in my Hasselblad fixed and now my most recent roll of film has some tiny clear spots on some of the frames that are showing up as dark spots on scans . The roll was developed at a lab I recently started using that has been working out well so far. I don't know if this is caused by a development problem or another problem with my camera. It has only affected about 4 out of 12 of the frames so I would think that if it was a camera fault it would show up consistently. The spots are really tiny and I can only see them with an 8x loupe when looking at the negatives and I have to zoom in on scans to see them, but a couple of them are in sky areas of landscape photos so I suspect they will ruin prints.

Could these be caused by some debris that attached itself to the film during developing? Dust in the film plane of the camera (although, again, the issue is only seen on a handful of frames and I've recently shot some other rolls of film with this camera and have not seen this)? A defective roll of film? This is the first time I've ever seen this on any roll of film I've shot.

I've attached a section of a scan (zoomed way in) to illustrate the problem.

BradS · Feb 26, 2020

Black spots on the print are clear spots on the negative...where the film was not exposed to light...usually caused by something on the film or very close to it at the time it was exposed.

removedacct1 · Feb 26, 2020

Look up "air bells"

logan2z · Feb 27, 2020

paulbarden said:
Look up "air bells"

Is that likely with a dip-and-dunk machine at a pro lab?

kevs · Feb 27, 2020

Could be. It looks like 'pinholes' caused by tiny bubbles of air adhering to the film during development. It happens.

Nodda Duma · Feb 27, 2020

What film was it?

Ian C · Feb 27, 2020

When air bubbles stick to film, they usually only stay in place until the tank is agitated. The result isn’t a clear spot. Rather, it leaves a well-defined area of low density compared to its surrounding area. That’s because once agitation clears the bubble, the delayed development begins. The fact that the bubble struck in place for a time means that little or no development occurred while the bubble clung to the film, since the developer couldn’t reach the emulsion through the air bubble.

Films spoiled by air bubbles adhering to the emulsion print as well-defined dark “blobs” where the air bubble clung to the film and insulated the emulsion from the developer until agitation swept the bubble away, allowing development to begin later than in the adjacent area. The development of the affected area can never “catch up” with the density of the surrounding area. Air bubbles stuck to film don’t result in pure black spots on the print or positive image. Rather, they produce small areas that are distinctly darker than the immediate surrounding area.

When you get tiny areas of NO DENSITY—perfectly-clear film—two possible causes are likely:

1. An opaque object clinging to the emulsion side of the film during exposure casting its shadow onto the film, preventing exposure. No exposure—no density. This results in a sharply-defined clear spot upon development.

2. A true “pinhole”. These are quite rare in modern films, especially from major makers.

A “pinhole” is a misnomer. It is an air bubble or small void in the emulsion, an area that cannot record light and, therefore, remains clear upon development. This is a coating defect during film manufacture. I was plagued with these in a 20-roll batch of Ilford Delta 100 in 120 size purchased about 2013. The problem didn’t affect every roll, but did occur in about 6 or 7 rolls in this batch. Some rolls had 1, 2, 3, or 4 frames spoiled per roll with pinholes.

The only other time I’d encountered true “pinholes” was with a batch of Fortepan 100 (from Hungary), about 2005 – 2006 in 35 mm size. On the affected films I examined, the surface of the emulsion over the pinhole was smooth and continuous, suggesting that the gelatin overcoat covered the defect. Only 1, 2, or 3 frames per roll were so affected, and only about 20% of the rolls had the defect.

When printed, the zero-density pinhole makes a tiny sharply-defined pure-black spot on the print, or positive of the scan, if you realize your images that way.

Thus far, I’ve never observed a pinhole in Kodak or Fuji films.

logan2z · Feb 27, 2020

Nodda Duma said:
What film was it?

Tri-X 400.

logan2z · Feb 27, 2020

Ian C said:
When air bubbles stick to film, they usually only stay in place until the tank is agitated. The result isn’t a clear spot. Rather, it leaves a well-defined area of low density compared to its surrounding area. That’s because once agitation clears the bubble, the delayed development begins. The fact that the bubble struck in place for a time means that little or no development occurred while the bubble clung to the film, since the developer couldn’t reach the emulsion through the air bubble.

Films spoiled by air bubbles adhering to the emulsion print as well-defined dark “blobs” where the air bubble clung to the film and insulated the emulsion from the developer until agitation swept the bubble away, allowing development to begin later than in the adjacent area. The development of the affected area can never “catch up” with the density of the surrounding area. Air bubbles stuck to film don’t result in pure black spots on the print or positive image. Rather, they produce small areas that are distinctly darker than the immediate surrounding area.

When you get tiny areas of NO DENSITY—perfectly-clear film—two possible causes are likely:

1. An opaque object clinging to the emulsion side of the film during exposure casting its shadow onto the film, preventing exposure. No exposure—no density. This results in a sharply-defined clear spot upon development.

2. A true “pinhole”. These are quite rare in modern films, especially from major makers.

A “pinhole” is a misnomer. It is an air bubble or small void in the emulsion, an area that cannot record light and, therefore, remains clear upon development. This is a coating defect during film manufacture. I was plagued with these in a 20-roll batch of Ilford Delta 100 in 120 size purchased about 2013. The problem didn’t affect every roll, but did occur in about 6 or 7 rolls in this batch. Some rolls had 1, 2, 3, or 4 frames spoiled per roll with pinholes.

The only other time I’d encountered true “pinholes” was with a batch of Fortepan 100 (from Hungary), about 2005 – 2006 in 35 mm size. On the affected films I examined, the surface of the emulsion over the pinhole was smooth and continuous, suggesting that the gelatin overcoat covered the defect. Only 1, 2, or 3 frames per roll were so affected, and only about 20% of the rolls had the defect.

When printed, the zero-density pinhole makes a tiny sharply-defined pure-black spot on the print, or positive of the scan, if you realize your images that way.

Thus far, I’ve never observed a pinhole in Kodak or Fuji films.

Thanks for the reply. If it happened during exposure, I'm curious what could have adhered to the film at that time and how it could have come into contact with the film surface inside the camera. As I mentioned, I've shot several rolls with this camera recently but this is the first time I've experienced this.

Ian C · Feb 27, 2020

A spec of dust, flake of dandruff, a small scale of dead skin from your hand or arm, fibers or tufts of lint that might have been on clothing, windblown particles if films are changed outdoors, especially if there is any wind, any of theses could stick to film. Photobooks by Kodak and others have long recommended puffing out the film & mirror chambers of cameras with a squeeze-bulb blower just before changing film to remove particles that could stick to film.

With SLR cameras, it’s also important to remove the lens and puff out the mirror box as well, because it too can harbor loose particles. This is more likely with an SLR because the abrupt upward snap of the mirror creates air turbulence that can transport particles to the emulsion. Lens changes, done outdoors are another possible route of particles into the mirror box of SLRs or the space between the lens and film on any camera.

logan2z · Feb 27, 2020

Ian C said:
A spec of dust, flake of dandruff, a small scale of dead skin from your hand or arm, fibers or tufts of lint that might have been on clothing, windblown particles if films are changed outdoors, especially if there is any wind, any of theses could stick to film. Photobooks by Kodak and others have long recommended puffing out the film & mirror chambers of cameras with a squeeze-bulb blower just before changing film to remove particles that could stick to film.

With SLR cameras, it’s also important to remove the lens and puff out the mirror box as well, because it too can harbor loose particles. This is more likely with an SLR because the abrupt upward snap of the mirror creates air turbulence that can transport particles to the emulsion. Lens changes, done outdoors are another possible route of particles into the mirror box of SLRs or the space between the lens and film on any camera.

I suppose any of these are theoretically possible. I loaded the film indoors, it's 120 film so the film emulsion isn't exposed during loading, and there are some frames with several clear spots, so this wasn't one dust or other such particle.

I recently finished another roll so I guess I'll have it developed and see if the problem occurs again.

logan2z · Feb 27, 2020

It's buried down in the dark grass, so maybe it won't be visible on a print. I'd still love to know how the spots formed, during development or from dust on the surface of the emulsion at exposure time. I suppose I may never know.

BradS · Feb 27, 2020

Embrace the uncertainty. This ain’t digital. Imperfections are beautiful.

logan2z · Feb 27, 2020

BradS said:
Embrace the uncertainty. This ain’t digital. Imperfections are beautiful.

Brad, I need to find some of the laid-back juice you're drinking. I think a couple of bottles would do wonders for me

Doremus Scudder · Feb 28, 2020

logan2z,

Check the film carefully under a magnifying loupe to see if there is any actual physical damage to the emulsion. Check both sides of the film. If there are no flaked-off spots, bubbles or scratches, then almost certainly the problem was dust, etc. on the film at the time of exposure.

Pinholes/emulsion damage can be caused by using a highly-alkaline developer and a too-strong stop bath, which causes gas bubbles in the emulsion and subsequent damage. This is extremely rare with modern films and chemistry and occurs over the entire surface of the emulsion, not just in a spot or two.

Stuff on the film is way more likely. I once had a negative with a nice shadow image of a gnat or mosquito or whatever that had got inside the camera and decided to sit on the film during exposure...

Best,

Doremus

logan2z · Feb 28, 2020

Doremus Scudder said:
logan2z,

Check the film carefully under a magnifying loupe to see if there is any actual physical damage to the emulsion. Check both sides of the film. If there are no flaked-off spots, bubbles or scratches, then almost certainly the problem was dust, etc. on the film at the time of exposure.

Pinholes/emulsion damage can be caused by using a highly-alkaline developer and a too-strong stop bath, which causes gas bubbles in the emulsion and subsequent damage. This is extremely rare with modern films and chemistry and occurs over the entire surface of the emulsion, not just in a spot or two.

Stuff on the film is way more likely. I once had a negative with a nice shadow image of a gnat or mosquito or whatever that had got inside the camera and decided to sit on the film during exposure...

Best,

Doremus

Interesting timing of your post. I just heard back from the lab that processed the film and they also asked me to closely examine the emulsion. They suggested that the backing paper may have stuck to the film and small bits of the emulsion may have been pulled off the film base when the backing paper was removed prior to processing. I have to claim ignorance here but I didn't realize there was paper backing on the emulsion side of 120 film.

If this is the case, does that imply a film defect? I'm wondering if there's anything I can do to prevent this from happening in the future.

BradS · Feb 28, 2020

The backing paper for this frame touches the emulsion side of some other frame when the roll is all rolled up...

logan2z · Feb 28, 2020

BradS said:
The backing paper for this frame touches the emulsion side of some other frame when the roll is all rolled up...

Of course. I'm an idiot.

logan2z · Feb 29, 2020

Just out of curiosity, has anyone ever had the backing paper from 120 film stick to parts of the emulsion and pull bits of emulsion from the base when the paper was removed?

I've been looking at the emulsion with a loupe but I can't tell if bits are actually missing where there are clear spots. I guess I need something with more magnification.

MattKing · Feb 29, 2020

logan2z said:
Just out of curiosity, has anyone ever had the backing paper from 120 film stick to parts of the emulsion and pull bits of emulsion from the base when the paper was removed?

Yes - with 70 year old film.

logan2z · Feb 29, 2020

MattKing said:
Yes - with 70 year old film.

I guess I should have been more specific with modern film.

Doremus Scudder · Mar 1, 2020

Humidity could cause the backing paper to stick to the emulsion. Also, any grit accidentally introduced into the roll can abrade the emulsion when rolled up with the film (think sand in the camera...). However, there are other causes of emulsion damage besides backing paper. Still, the most likely cause of clear areas in the negative is dust, etc. on the film emulsion during exposure blocking the light. I imagine you'll not find emulsion damage and confirm that this is the problem. If not, then we'll try to find the cause of the damage.

Best,

Doremus

logan2z · Mar 1, 2020

Doremus Scudder said:
Humidity could cause the backing paper to stick to the emulsion. Also, any grit accidentally introduced into the roll can abrade the emulsion when rolled up with the film (think sand in the camera...). However, there are other causes of emulsion damage besides backing paper. Still, the most likely cause of clear areas in the negative is dust, etc. on the film emulsion during exposure blocking the light. I imagine you'll not find emulsion damage and confirm that this is the problem. If not, then we'll try to find the cause of the damage.

Best,

Doremus

You may be right. I did just have the light seal replaced in the camera. I'm wondering if some small bits of debris were introduced at that time. This is the first roll I've shot since having the seal replaced.

Doremus Scudder · Mar 2, 2020

logan2z said:
You may be right. I did just have the light seal replaced in the camera. I'm wondering if some small bits of debris were introduced at that time. This is the first roll I've shot since having the seal replaced.

Aha! The plot thickens! Do do a thorough camera cleaning.

Best,

Doremus

logan2z · Mar 2, 2020

Doremus Scudder said:
Aha! The plot thickens! Do do a thorough camera cleaning.

Best,

Doremus

I will. Unfortunately I already shot another full roll and have a partially shot roll in the camera. Once the current roll is done I'll do some cleaning.

Tiny clear spots on latest roll of film

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