Artifact: What's the cause?

Sirius Glass · Jun 19, 2010

Worker 11811 said:
A 100ºF presoak? That sounds like you're just begging for reticulation to me! Really 100ºF?

PE is referring to the C-41 processing for color print film.

Steve

Photo Engineer · Jun 19, 2010

Worker 11811 said:
I always use 1 soak of 1 minute at whatever temperature the development is going to be. (e.g. A 68ºF soak for a 68ºF developer.)

The rationale I was taught was that it brought everything to the same temperature as the developer so that the thermal mass of the film, reels and tank would not affect the temperature of the liquid poured in.
I was also told it removes the antihalation dye if there is one.
Now, I also know that it prevents air bubbles from sticking to the film as well.

Sounds like there are more chips on the "presoak" side of the scale than there are on the "don't presoak" side, to me!

A 100ºF presoak? That sounds like you're just begging for reticulation to me! Really 100ºF?

If you are doing C41 or E6 this is reasonable. Also at that high temp, the drop in the first presoak is bad enough to need a second one. So, I use 2 30" presoaks at 100F and 1 presoak at 68F.

Reasonable?

PE

christom · Jun 20, 2010

Worker 11811 said:
Shot these two images last Saturday & developed on Sunday. Just scanned and made digital contact/previews last night so I can get ready to print them this week. (See attached.)

I noticed the same artifact in both images. I'm just wondering if anybody has an idea what the cause was.

Both images are on the same roll of film. Probably 6 or 8 exposures apart.
Both images were shot within a half hour of each other. The locations were approximately a mile apart. They were both taken facing in the same general direction. Almost due west.
The time of day was about 1:00 in the afternoon. The sun was coming from my left front quarter. Basically at the top, left of the frame in both shots.

I think the spots are from lens flare but I've never seen lens flare look quite like this. Usually, lens flare looks lighter than the rest of the image and there is more halo around the image. Could it be that the lens flare was so bright it caused the film to reverse? I've never seen lens flares that are perfectly round, either. They are usually a little bit oblong when I've seen them in the past.

Film: Ilford Pan F+ (ASA 50 - shot at ASA 40)
Processed: XTOL (Full Strength) 6 min. 30 sec.
Camera: 35mm. Pentax ME Super 50mm /1.7. (Standard lens for that camera.)
Scanned from film: Canon 8800F flatbed 2400 dpi then downscaled to present via Photoshop.
The spots are visible on the negatives with a loupe.

Is this lens flare or is it something else?
What do you think?

T.I.A!

Air bubbles wouldn't sit in the place shown on your images. It looks like fixer or acid got "flicked" on the film right before developer.

lxdude · Jun 20, 2010

One plus: you can say you have photographic proof that you were abducted by aliens and taken to another world which is an analog to this one, except that it has double black suns.

lxdude · Jun 20, 2010

christom said:
Air bubbles wouldn't sit in the place shown on your images. It looks like fixer or acid got "flicked" on the film right before developer.

Be sure to tell that to the folks at Ilford who determined that it was air bubbles.:rolleyes:

Vilk · Jun 20, 2010

I haven't had a single roll of Pan F+ without this. Yes, they're air bubbles, no need for microscope. As a result, I dropped Pan F+ altogether, despite great tonality. Killed some of my best frames. I compliment Ilford for their great customer service, no irony here, but until they publish an unequivocal confirmation that they have fixed this "feature" of Pan F+ once and for all they're not getting this (lifelong, vocal) supporter back on the Pan.

Respectfully ripping open another brick of HP5+,

Vilk

Worker 11811 · Jun 20, 2010

I appreciate your view on this but I'm not ready to give up so quickly.

First, I have received specific advice via private e-mail about how to avoid this in the future. It's all common sense stuff but it basically means I have to redouble my efforts to make sure I agitate correctly and tap the tank enough to prevent the bubbles from sticking.

Second, I have received good advice from this forum, much along the same lines as the advice I received from Ilford, which will help me prevent the problem in the future.

Third, PhotoEngineer has given some good advice about prewetting film to help prevent air bubbles from sticking to the film.

Finally, I'm not a quitter. Unless and until this becomes an insurmountable problem I will keep using whatever film gives me the images I'm looking for. Up until this incident, I have NEVER had an air bubble ruin a photograph before and, given the advice I have received, I don't expect to have another one any time soon.

Vilk, I will take your advice at face value. For some reason, Pan F is prone to air bubbles sticking to the film. Now I know that. I'll watch out for it and I'll be careful about it.

If it does turn out to be a problem, I won't be able to say you didn't warn me. Right?

Vilk · Jun 20, 2010

I wish I could say I coloured it up a bit.

Please post here when, after following all the good advice, you pull the tenth roll out of the tank and still find no bubbles. I'll go back to it in a blink. I cut my darkroom teeth on Ilford thirty years ago and I have never had a reason to look elsewhere--until this (it probably explains why it took me twenty rolls to give up and not one).

Ian Grant · Jun 20, 2010

Vilk said:
I haven't had a single roll of Pan F+ without this. Yes, they're air bubbles, no need for microscope. As a result, I dropped Pan F+ altogether, despite great tonality. Killed some of my best frames. I compliment Ilford for their great customer service, no irony here, but until they publish an unequivocal confirmation that they have fixed this "feature" of Pan F+ once and for all they're not getting this (lifelong, vocal) supporter back on the Pan.

Respectfully ripping open another brick of HP5+,

Vilk

How do you expect a company to fix an issue that's down to your techniques rather than their product ?

There are ways to solve the problem but personally I don't think a pre-soak is a magic cure in many cases, I've found my way for the water here in Turkey, but there may be other ways for you.

Ian

Worker 11811 · Jun 20, 2010

Does nine count?

I developed nine rolls of Pan F+ before that happened. If I would have made one more, it would have been ten but I can not rule out the fact that I might have gotten just a little bit sloppy when I developed that last roll of Pan F.

I do not expect to see this problem again, to be honest.
Since January, I have developed almost 50 rolls of film. Not one has had any bubbles.
In my life, I have probably developed a couple-few hundred rolls of film. That doesn't make me an expert but it does mean that my batting average for this kind of problem is less than half of one percent. Pretty low.

Given the information I have learned from this forum, I'll be on my toes and watch out for the problem. Maybe you're right. I'll just have to double check and triple check my work. But, if what you say proves to be true, I won't say you didn't warn me.

I am just not the kind of person who gives up easily. I don't intend to give up on this, either.

Vilk · Jun 20, 2010

Ian Grant said:
How do you expect a company to fix an issue that's down to your techniques rather than their product?

Before I answer I must take exception to the premise--Pan F+ is the only out of many films I have processed over many years that exhibited this behaviour with terrifying regularity. I gave up when I realized I'm taking three or four shots of the same scene anticipating the bubbles, knowing they would be there. Around my darkroom I'm a reasonably well-behaved Vilk.

It's still a mass market product and it's been around for years. Likely, hundreds of thousands of people around the world souped a roll at least once. I don't think it's just Randy and Vilk scratching their heads. Ilford knows.

To answer your question--the scientific term is "fool-proofing". It works for other films, it can work for this one, too. I have confidence in Ilford.

Now, perhaps, we may have reached the limits of physics. Maybe you cannot make an emulsion with these characteristics without leaving it prone to trapping air bubbles at the surface. Engineering is nothing but trade-offs: is it better to have that perfect curve and lose Randy and Vilk, or should we rather make the curve a bit more mundane and keep these two donkeys in the stable?

Only the company accountant can answer that.

richard ide · Jun 20, 2010

Why even think of blaming the product when it is a technique caused problem?

Vilk · Jun 20, 2010

Worker 11811 said:
Does nine count?

Well, once I spotted the first ones--like you did, against a bright, even sky--I knew what to look for. I went back and found many more, hidden in dense foliage, carpet patterns, stone textures...

I really wish it were nothing but my technique. Then I could use those few still left in my fridge.

See? I have a real incentive to find a Vilk-based solution!

Vilk · Jun 20, 2010

richard ide said:
Why even think of blaming the product when it is a technique caused problem?

Because the first twenty-nine "What did I do wrong?" bullet points checked negative?

I'm not "blaming" the product. I'm pointing out a way to make it better.

Photo Engineer · Jun 20, 2010

Well, when I learned how to develop film in tanks many years ago, I was taught to bang the tank against the palm of my hand to dislodge air bubbles. This works, but I still found that a prewet was nearly foolproof whereas banging helps to a certain extent depending on film. Now, I use a prewet and bang the tank during the prewet. (unless I am using the Jobo)

PE

nworth · Jun 20, 2010

Photo Engineer said:
I hate to say this in the face of Ilford's great record for high quality, but this looks like a DEC (Double Ended Comet) defect, caused by a bubble in a slide or curtain coater operation. I have seen nothing else like it but that or an extreme case of bromide drag on each side of an air bubble. But this is on the upper edge of that air bubble defect for size and density.

PE

An interesting possibility. I've seen these defects a number of tines with EFKE sheet film processed in a Yankee tank. I've always though they were processing problems, although they did not occur when I processed Ilford film in that tank. The Yankee tank requires you to agitate by violently shaking the tank from side to side (vertical motion and inversion are impossible due to construction). That can lead to some weird artifacts.

Photo Engineer · Jun 20, 2010

You can distinguish between a DEC and an air bubble by using a microscopic examination through the film or doing a cross section slice of the film and looking under a microscope. Either way, a DEC looks like a tiny crater with a trough running away at each side, while the air bubble looks like simply a lack of development surrounded sometimes by an edge of heavy or lighter silver depending on film.

The cross section is most definitive for a DEC as it is unequivocal. Sometimes, just looking down through the film at right angles to the support, you can be misled. In a cross section, a DEC resembles a mini volcano in the emulsion, with slight troughs off to each side.

PE

Artifact: What's the cause?

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