Sigh Spots on Negatives

logan2z · Aug 7, 2022

pentaxuser said:
but it raises questions as to how likely his marks are in fact airballs if, as appears to be the case, he filled the tank with enough liquid to cover the film and then at the end of his inversions tapped the bottom of the tank sharply.

I didn't necessarily conclude that the marks on my film were caused by air bells, but that seemed to be the general consensus in this thread.

I should note that I have been using 500ml of working solution developer in the 1520 tank, so more than enough to completely cover the reel. And the marks on my film aren't confined to the edge of the film as seems to be common with air bells. But I don't know how else to explain these circular marks so air bells seemed to be a logical explanation. I'd think if I was doing something to create air bells they'd show up on 35mm film as well as 120, but I've only seen these circular marks on 120 film thus far.

My use of rotary processing for my latest roll was two-fold - firstly, I wanted to see that if these were air bells from inverting the tank that they'd disappear once I used rotary processing. And secondly, I wanted to see what the effect of rotary processing would be on large areas of empty sky that are common in my landscape photos. Aside from the two banded images out of the 12 I shot on my Hasselblad, I'm really pleased with the absence of circular negative density marks and the smoothness of the skies in this latest set of photos. If I could figure out what caused the banding (assuming it's really there on the negatives), then I see no reason not to continue with rotary processing.

logan2z · Aug 7, 2022

OK, I have a wild theory that I'll throw out here:

At first glance I thought the problem areas of these bands were the darker/negative density areas. But looking closely at the tones in the upper and lower parts of the sky, it is the areas of positive density that seem out of place to me. Now, when I developed this roll of film, I used the 1530 extension to my 1520 tank to allow the tank to balance more evenly on the Jobo roller. This is the first time I've used the tank extension. I'm wondering if the locking ring that joins the two tanks together wasn't completely seated and that allowed light to leak into the tank during development.

Looking at the inner edge of the black locking ring, there are alternating vertical rectangular-shaped 'gaps' in the plastic. Is it possible that an improperly seated ring could allow a bit of light to leak into these gaps and leave rectangular high-density areas on the film?

The fact that the bands are perfectly perpendicular to the edges of the film and that only two frames on the innermost part of the reel were affected seems counter to this theory, but just thinking 'out loud' here...

logan2z · Aug 7, 2022

Backlit images of negatives (emulsion side up to avoid reflections)

MattKing · Aug 7, 2022

If it was due to a light leak in the tank, you would see it between the frames too.

logan2z · Aug 7, 2022

MattKing said:
If it was due to a light leak in the tank, you would see it between the frames too.

Yeah, true.

No clue, then. Yet another film developing mystery on what seems like my inevitable march to digital photography

MattKing · Aug 7, 2022

I think those bands originate at the camera stage.

logan2z · Aug 7, 2022

MattKing said:
I think those bands originate at the camera stage.

What makes you think that?

MattKing · Aug 7, 2022

logan2z said:
What makes you think that?

The location and direction of the banding - parallel to the film edge and only within the frame.
Development artifacts don't stop between frames on 120 film.
It could possibly be related to film and backing paper interaction, but it doesn't look like tat to me.

Sirius Glass · Aug 7, 2022

logan2z said:
I didn't necessarily conclude that the marks on my film were caused by air bells, but that seemed to be the general consensus in this thread.

I should note that I have been using 500ml of working solution developer in the 1520 tank, so more than enough to completely cover the reel. And the marks on my film aren't confined to the edge of the film as seems to be common with air bells. But I don't know how else to explain these circular marks so air bells seemed to be a logical explanation. I'd think if I was doing something to create air bells they'd show up on 35mm film as well as 120, but I've only seen these circular marks on 120 film thus far.

My use of rotary processing for my latest roll was two-fold - firstly, I wanted to see that if these were air bells from inverting the tank that they'd disappear once I used rotary processing. And secondly, I wanted to see what the effect of rotary processing would be on large areas of empty sky that are common in my landscape photos. Aside from the two banded images out of the 12 I shot on my Hasselblad, I'm really pleased with the absence of circular negative density marks and the smoothness of the skies in this latest set of photos. If I could figure out what caused the banding (assuming it's really there on the negatives), then I see no reason not to continue with rotary processing.

500ml should be enough chemistry.

logan2z · Aug 8, 2022

MattKing said:
The location and direction of the banding - parallel to the film edge and only within the frame.
Development artifacts don't stop between frames on 120 film.
It could possibly be related to film and backing paper interaction, but it doesn't look like tat to me.

I haven't seen this issue when using my Hasselblad or the 50mm Distagon lens before, but I guess it's possible. At this point I'd actually rather this be a camera fault than a development issue. Probably easier to track down.

I developed a roll of 35mm using the Jobo roller tonight so we'll see what happens when I scan the negatives tomorrow.

During a recent interview with Aperture, Robert Adams said it took him three years to nail his development technique. Maybe I'm not doing too badly after all

pentaxuser · Aug 8, 2022

Thanks for the detailed reply, logan. I do wonder whether the only way to get nearer the cause is to have a print done. There does appear to be faint marks on the negatives but are they on the negative or due to some other cause in the process of neg to scan?

pentxuser

xtol121 · Aug 8, 2022

Re: the original negative density marks - have you ever processed c-41 film with your equipment? I have had similar marks on my bw negatives when sharing a final rinse bath with c-41 negatives that were poorly processed and not realized until after I hung them up to dry. A touch of bleach somewhere could lead to negative density spots.

Re: the banding, I have a feeling it’s a shutter problem from your camera. I get similar banding with my M6 in the top left corner if I use high shutter speeds. 1/500 and 1/1000 will give horizontal negative density bands. I’m not familiar with your camera or how that would translate from a 35mm frame to 120. Would be pretty simple to test, just shoot half a roll of sky exposures with 1/30 shutter speed and the other half of the roll with highest shutter speeds.

Picture attached has the banding visible in the top left. It’s faint but enough to make me frown.

MattKing · Aug 8, 2022

This is unlikely, but is there any chance that you are using the same backlight for both visual inspection of, and digitization of your negatives?
If so, try another light source and see if you see any changes.
Sort of like struggling to clone out a dust spot in a scan, only to realize that there is some dirt on my monitor screen!

logan2z · Aug 8, 2022

xtol121 said:
Re: the original negative density marks - have you ever processed c-41 film with your equipment? I have had similar marks on my bw negatives when sharing a final rinse bath with c-41 negatives that were poorly processed and not realized until after I hung them up to dry. A touch of bleach somewhere could lead to negative density spots.

Re: the banding, I have a feeling it’s a shutter problem from your camera. I get similar banding with my M6 in the top left corner if I use high shutter speeds. 1/500 and 1/1000 will give horizontal negative density bands. I’m not familiar with your camera or how that would translate from a 35mm frame to 120. Would be pretty simple to test, just shoot half a roll of sky exposures with 1/30 shutter speed and the other half of the roll with highest shutter speeds.

Picture attached has the banding visible in the top left. It’s faint but enough to make me frown.

Thanks for the reply. I've only processed B&W film to date.

I'm starting to think it is, in fact a problem with the shutter in my Hasselblad lens. I have another roll to develop shot with the same lens and I'll see if the problem affects that roll as well.

logan2z · Aug 8, 2022

MattKing said:
This is unlikely, but is there any chance that you are using the same backlight for both visual inspection of, and digitization of your negatives?
If so, try another light source and see if you see any changes.
Sort of like struggling to clone out a dust spot in a scan, only to realize that there is some dirt on my monitor screen!

No, I'm using a flatbed scanner for digitizing my negatives and a lightpad for inspection of the negatives. But I've had similar experiences to your cloning experience. I've also discovered 'defects' in my negatives when inspecting them, only to find that there's a piece of dirt on my lightpad or a small hair inside the Printfile sleeve

Sirius Glass · Aug 8, 2022

logan2z said:
Thanks for the reply. I've only processed B&W film to date.

I'm starting to think it is, in fact a problem with the shutter in my Hasselblad lens. I have another roll to develop shot with the same lens and I'll see if the problem affects that roll as well.

Banding can occur in focal plane shutters not lens leaf shutters.

honerich · Aug 11, 2022

Just an idea:
Banding can be caused by bromide drags. A certain kind of bromide drag can occur with rotational development. If rotation always takes place in the same direction, potassium bromide can concentrate - following the film winding - on the inner turns of the reel and hinder development there. It is therefore important to change the direction of rotation regularly during rotational development.

logan2z · Aug 11, 2022

honerich said:
Just an idea:
Banding can be caused by bromide drags. A certain kind of bromide drag can occur with rotational development. If rotation always takes place in the same direction, potassium bromide can concentrate - following the film winding - on the inner turns of the reel and hinder development there. It is therefore important to change the direction of rotation regularly during rotational development.

Thanks. I mentioned early on in this thread that I changed the direction of rotation every two rotations.

Interestingly, when I asked Jobo USA about usage guidelines for the Jobo roller, I was told that there's no need to change directions. I did so anyway.

FWIW, I just scanned a roll of 35mm film that I developed using the exact same technique and there was no banding on that roll.

cliveh · Aug 11, 2022

Don't use photflo.

logan2z · Aug 11, 2022

cliveh said:
Don't use photflo.

You think that photoflo could cause such banding? Do you use anything instead? Ilfotol, LFN, etc?

cliveh · Aug 11, 2022

logan2z said:
You think that photoflo could cause such banding? Do you use anything instead? Ilfotol, LFN, etc?

De-ionised water.

Sirius Glass · Aug 11, 2022

cliveh said:
Don't use photflo.

Based on? Only your personal experience? What you read on the internet? Scientific data? R&D by Kodak, Ilford and other photographic producers had much more research and evidence to the contrary than you could ever conduct.

albada · Aug 12, 2022

Here's a long-shot idea about your original problem of low-contrast spots: Were either the tank or reel wet when you put film into them? Or did you cough or sneeze when loading them? If so, a few droplets of water might have gotten onto the film, causing a slight difference in density because developer would take a slightly different amount of time to diffuse into the gelatin.

logan2z · Aug 12, 2022

albada said:
Here's a long-shot idea about your original problem of low-contrast spots: Were either the tank or reel wet when you put film into them? Or did you cough or sneeze when loading them? If so, a few droplets of water might have gotten onto the film, causing a slight difference in density because developer would take a slightly different amount of time to diffuse into the gelatin.

I don't think the tank/reel were wet when I loaded them with film, they had been sitting out drying for a couple of days. And I loaded the film in a changing bag, so I couldn't have coughed/sneezed onto the film/tank/reels during the loading process. Interesting theory, though...

Bayliss · Aug 12, 2022

I use Ilford Ilfotol Wetting Agent with distilled water and still get water spots (only on 35mm film though for some reason). Haven't been able to solve the problem yet.

I live in London so possibly the issue is very hard tap water.

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