*Sigh* Spots on Negatives

[logan2z]

I use 500ml for my 1500 tanks and the 3010 Expert Drum and have never had your problem.

Inversion or rotation?

 

[Sirius Glass]

Inversion or rotation?

Rotation using the CPP2 processor.

 

[logan2z]

Rotation using the CPP2 processor.

Ok, I'm going to give rotation a shot and see if that helps eliminate my air bell problem - hopefully without introducing any new problems

 

[Sirius Glass]

Ok, I'm going to give rotation a shot and see if that helps eliminate my air bell problem - hopefully without introducing any new problems

Why would one not use the processor??

 

[logan2z]

Why would one not use the processor??

No real reason. I only recently started home developing my film and started with inversion agitation, so I've just been working through some rolls that way. I don't have a full-blown Jobo processor but I picked up the Jobo roller a few weeks back with a plan to try manual rotary processing. This seems like a good time to give that a shot.

 

[Andrew O'Neill]

They look like air bells. One thing that can be overlooked, is amount of developer solution covering the film. I always make sure I pour in enough solution so that it covers the film by a couple cm's. I use an agitation cycle that minimises bubbles... figure 8 pattern. No invertions.

 

[pentaxuser]

I presume that the "theory" is that constant rotation in a horizontal plane either prevents airbells forming or prevents air bells sticking as the rotation is of sufficient speed to either prevent airbells sticking or is sufficient to dislodge the airbells immediately from the film surface?

Does anyone know which of the above, if any, is correct and why the rotational movement prevents airbells or prevents sticking better than a good rap on the tank's bottom at the end of the inversion cycle?

We have had over the years several threads on airbells but I can't recall anyone saying that the one sure cure is to switch to rotary processing

pentaxuser

 

[Sirius Glass]

I presume that the "theory" is that constant rotation in a horizontal plane either prevents airbells forming or prevents air bells sticking as the rotation is of sufficient speed to either prevent airbells sticking or is sufficient to dislodge the airbells immediately from the film surface?

Does anyone know which of the above, if any, is correct and why the rotational movement prevents airbells or prevents sticking better than a good rap on the tank's bottom at the end of the inversion cycle?

We have had over the years several threads on airbells but I can't recall anyone saying that the one sure cure is to switch to rotary processing

pentaxuser

The air bells disappeared for me in the 1960's with tank thumping and have not shown up ever with rotary processing.

 

[logan2z]

I presume that the "theory" is that constant rotation in a horizontal plane either prevents airbells forming or prevents air bells sticking as the rotation is of sufficient speed to either prevent airbells sticking or is sufficient to dislodge the airbells immediately from the film surface?

Does anyone know which of the above, if any, is correct and why the rotational movement prevents airbells or prevents sticking better than a good rap on the tank's bottom at the end of the inversion cycle?

We have had over the years several threads on airbells but I can't recall anyone saying that the one sure cure is to switch to rotary processing

pentaxuser

I just did a rigorous, scientific experiment with... an empty, clear orange juice bottle and some water

I almost filled the bottle with water but left a bit of room at the top. I gently inverted the bottle 3 or 4 times and set it upright. Bubbles could be seen moving quickly towards the top of the bottle.

I let the bubbles dissipate and then turned the bottle horizontally and performed several smooth rotations. I then turned the bottle upright and - zero bubbles!

I'm convinced

 

[Sirius Glass]

I just did a rigorous, scientific experiment with... an empty, clear orange juice bottle and some water

I almost filled the bottle with water but left a bit of room at the top. I gently inverted the bottle 3 or 4 times and set it upright. Bubbles could be seen moving quickly towards the top of the bottle.

I let the bubbles dissipate and then turned the bottle horizontally and performed several smooth rotations. I then turned the bottle upright and - zero bubbles!

I'm convinced

Did you drink the orange juice.

 

[logan2z]

Did you drink the orange juice.

Of course!

 

[Sirius Glass]

Of course!

With or without Vodka?

 

[logan2z]

With or without Vodka?

Without. The only thing that could make my film developing even worse is doing it drunk. Actually, maybe that would help!

 

[pentaxuser]

I like it when a problem get solved as in this case. Mind you I'd still appreciate answers to my questions in#32 in terms of why it works

pentaxuser

 

[logan2z]

BTW, I should have added way back at the start of this thread that the air bells only seem to have affected the first one or two frames of my last two rolls. I load the Jobo reels starting with the tape end of the roll, so the first couple of frames are on the outermost part of the reel. Not sure if that area would be more susceptible to air bells or if it's just a coincidence that only the first couple of frames were affected, but thought it was worth mentioning.

 

[logan2z]

OK, so I tried the Jobo roller on my latest roll of 120 Tri-X and scanned the roll.

The good news: I don't see any sign of air bells on my negatives. Development also appears to be very even - large swaths of sky look great on nearly every negative.

Now, the bad news. The last two negatives on the roll appear to show some vertical banding in exactly the same location on both negatives. Looks like bands of negative density to me. No sign of it anywhere else on the roll. These would be the innermost frames on the reel since I'm loading the reel starting from the tape side/end of the roll.

I rolled the tank in a bidirectional fashion, switching directions every two rotations. I kept the rate of rotation as constant as possible. I did not presoak the film.

I've included scans of the two frames. I tried scanning the negatives emulsion side up, emulsion side down and flipped 180 degrees to try and eliminate a scanner fault but the bands remained.

It's really hard to visually verify whether these bands are actually on the negatives - at first glance, even with a loupe, the negatives look fine. But I believe I can see the bands if I look really, really closely with the film on a lightpad.

I'm not sure what could have caused this with 120 film (no sprocket holes) and rotary processing. The bands look to be perfectly straight and in the same location on both frames - and only those frames.

Here's the scans, darkened to emphasize banding:

The frame right before these two looks fine, as do all others on the roll:

Maybe I need to make a darkroom print to really prove that the bands are on the negatives, but I believe they are.

I'm not going to lie, I'm getting a bit frustrated...

 

[koraks]

Maybe I need to make a darkroom print to really prove that the bands are on the negatives

Yes. First prove they're actually there. My first impression is that they're a digital artifact, but there's no way I can know for sure.

 

[foc]

OK, so I tried the Jobo roller on my latest roll of 120 Tri-X and scanned the roll.

The good news: I don't see any sign of air bells on my negatives. Development also appears to be very even - large swaths of sky look great on nearly every negative.

Now, the bad news. The last two negatives on the roll appear to show some vertical banding in exactly the same location on both negatives. Looks like bands of negative density to me. No sign of it anywhere else on the roll. These would be the innermost frames on the reel since I'm loading the reel starting from the tape side/end of the roll.

I rolled the tank in a bidirectional fashion, switching directions every two rotations. I kept the rate of rotation as constant as possible. I did not presoak the film.

I've included scans of the two frames. I tried scanning the negatives emulsion side up, emulsion side down and flipped 180 degrees to try and eliminate a scanner fault but the bands remained.

It's really hard to visually verify whether these bands are actually on the negatives - at first glance, even with a loupe, the negatives look fine. But I believe I can see the bands if I look really, really closely with the film on a lightpad.

I'm not sure what could have caused this with 120 film (no sprocket holes) and rotary processing. The bands look to be perfectly straight and in the same location on both frames - and only those frames.

Here's the scans, darkened to emphasize banding:

The frame right before these two looks fine, as do all others on the roll:

Maybe I need to make a darkroom print to really prove that the bands are on the negatives, but I believe they are.

I'm not going to lie, I'm getting a bit frustrated...

Maybe I am going blind but I can't see any banding in the images.

Could you mark the banding with a red pen in Photoshop?
Also can you show a backlit image of the negatives, please?

Something like this:

 

[koraks]

On the first image they run vertically through the left half of the cloud formation. On the 2nd image they're also in the same spot, around 2/3rds from the left.

 

[pentaxuser]

I tried Logan's scientific test myself a few moments ago with a bottle of plain water. In the usual 5 inversions bubbles are created in the water but when the bottle is righted the bubbles go straight to the top and disappear without any further action such as a sharp tap.

When the bottle is rolled horizontally there are no bubbles. So I can "half produce" Logan's test but in my inversion test the bubbles do just disappear

Of course in film tank inversion there is the little matter of there being a reel there with a film wound into it which may make a difference but if the bottle test is to be relied upon and this may be doubtful, then as Andrew points out, if the tank is filled with enough liquid to slightly more than cover the film then the bubbles should rise to the surface and burst or if not, will not adhere to the film. In the event that not all do break away from the surface of the film then a sharp rap should surely achieve that

When I have taken the top cap off my Jobo tank i.e. the cap not the lid, there are always plenty of bubbles in the top of the lid's concave surface so clearly a lot of bubbles are created in inversion agitation but they leave the film's surface and yet a tap at the end of the inversions has never left me with an airbells so a reasonable conclusion would appear to be that most bubbles rise to the surface of their own accord and any that remain attached to the surface of the film are dislodged with one sharp tap. I say on tap as in my case I have never used more than one tap

I use a Durst tank occasionally as well and have never had a problem with bubbles sticking there either

I feel that the source of Logan's airbells, assuming that that is what they are, may be due to something else but I know not what

I suppose Logan might be just one of those unlucky individuals for whom whatever can go wrong does go wrong

The problem is still a "head-scratcher" for me

pentaxuser

 

[Sirius Glass]

I cannot see the banding on any of the photos.

 

[koraks]

a bottle of plain water

That might not be representative of an actual (used before) development tank, with reels, developer and film in it. Any of those can have traces or even significant amounts of surfactants or other surface-tension modifying agents in them. Not saying your experiment was worthless - to the contrary, in fact. But this sort of thing is pretty hard to troubleshoot. IF (big if) this is really a bubble thing.

I cannot see the banding on any of the photos.

It's there, clearly visible to me. Sometimes it helps to scroll your screen/window perpendicular to the direction of the bands; makes them easier to spot. Or copy the image in Photoshop and boost contrast. Neither is necessary for me to see those bands, though. They're pretty obvious.

 

[logan2z]

For those of you having trouble seeing the banding in the photos, I've outlined the areas in red below...

 

[logan2z]

I suppose Logan might be just one of those unlucky individuals for whom whatever can go wrong does go wrong

That certainly seems to be the case - at least in the film developing universe, which has been rather unkind to me so far.

At least I haven't had a hard shadow on my Hasselblad negatives, so that's something

 

[pentaxuser]

koraks I was basing my scientific experiment on logan's experiment as quoted by logan below:

"I just did a rigorous, scientific experiment with... an empty, clear orange juice bottle and some water

I almost filled the bottle with water but left a bit of room at the top. I gently inverted the bottle 3 or 4 times and set it upright. Bubbles could be seen moving quickly towards the top of the bottle.

I let the bubbles dissipate and then turned the bottle horizontally and performed several smooth rotations. I then turned the bottle upright and - zero bubbles!

I'm convinced "

As you will see from his emoji at the end, I had assumed that he made this experiment in the same vein of "science " as I did

I was just using it to show that there may be large difference between his experiment and my findings which were much the same as his and the real world of a tank, reel,film and developer

I don't think his or my experiment proves anything useful in terms of airballs on film 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.

If I in 17 years and most of us over a much longer period have never suffered from airballs on film then either most of us have been incredibly lucky or logan is extremely unlucky

If I were logan I'd have doubts about a switch to rotary processing being the solution. Maybe he does harbour doubts as well but so far his actions appear to have cured the airball problem but now he has another issue to worry about

pentaxuser