Purple negs

[Tim Gray]

So, I finally got around to doing some B&W developing at home. I've done it before a couple years ago in a college darkroom, but I can't say that I was as on top of things then - I wasn't taking a class or anything.

Anyway, I did a roll last week. It was 135 Tri-X EI 400. I mixed up my brand new chemicals and followed the directions. I used D-76 1:1, Kodak Fixer (came in a powder) and PhotoFlo. Following the directions found here and elsewhere, this was my procedure:

D-76 for time on sheet (7-8mins for my temp, around 72 degrees)
wash - ilford method 10-15-20
Fix - 10 mins with 5 sec agitation every 30 sec
wash - ilford method 10-15-20 plus some extra running water for 5 mins
photoflo for 30 secs
hang to dry

Anyway, they seemed to turn out ok, except there is a slight purplish tint to the neg. The funny thing is that that the second roll I did does not have the tint. That roll was 135 Tri-X EI 1250 developed in a new set of Diafine:

Diafine A 5 mins with 2 agitations
Diafine B 5 mins with 2 agitations
wash 30 secs
Fix - 10 mins with 5 sec agitation every 30 sec
wash - ilford method 10-15-20 plus some extra running water for 5 mins
photoflo for 30 secs
hang to dry

These guys were fine. Is the purplish tint due to under fixing even though I fixed with new fixer for 10 mins? Is this bad for my negatives? In the future if this happens again, should I just put them back in and fix some more?

On a side note, the 2nd roll was both my first roll in Diafine and my first roll on a rangefinder! I must say that I think I will be happy with both of these 🙂

 

[Nachkebia]

Where is the stop fix? :O

 

[kaiyen]

Nachkebia - I assume you mean the stop, not stop fix? He clearly did fix tnhe film.

An actual chemical stop is not necesary, and has no realy impact on purple negatives. I should add this to the wiki (FAQ section?), but you're seeing some risidual antihalation layer after development. Diafine might be better on its own to strip some of that out, which is why the second batch came out fine.

My method is to either fix with more agitation (10 min is more than long enough), or go to a 2 bath fix. Or, add the hypo-clear step to it and that'll help with the washing.

btw - you only need the ilford wash method at the end. after development, just a couple changes of water with a few quick agitations will be enough to effectively stop development.

allan

 

[jano]

I get the purple tint on some negatives as well, depending on film and developer combo. It's come up before, and I've chosen to ignore it as the purple eventually fades away, and doesn't appear to affect scanning (I don't darkroom). When/if I use hypo-clear after the fix step, there is no purple in any combo. I think some people do a presoak before beginning development, but read up on it as some don't like to do it. My head is spinning 😛

 

[Tim Gray]

Yeah, after some more research on the topic, it does sound like a fix issue. The reason I posted is that the D76 roll exhibited the purple cast and the Diafine roll didn't.

I just want to clarify that the purple cast was pretty slight. To be honest, I didn't really notice it until I looked at the second roll.

Wash after dev: Thanks. That's good to know.

Stop Bath: after a lot of poking around here, I figured it's not worth my time and effort to use a stop. It sounds like a lot of you don't, so that works for me 🙂

Thanks for the answers. I can't wait to try some push processing with D76. Weeee!!!!

 

[Stu :)]

Stop is good, but not needed. Three quick water changes in the tank do the trick, or just use watered acetic or citric acid, cheaper than that bottled stuff the camera store will sell you.

From my understanding and based on the fact you fixed for ten minutes; purples negs means they need more washing, with or without a hypo-clearing agent. Whenever I check the negs (Kodak and Fuji Neopan) after fixing they always appear purple. Half an hour later after a good wash, glorious blacks and clear gelatin.

I'll strongly second a pre-wash/soak. A two minute pre-soak in water at 20ºc warms the film and tank up just nicely for the developer. Also don't freak out when you see the colour of the pre-soak when you pour it down the drain.

Stu 🙂

 

[markinlondon]

I've found new Tri-x (it's been 3 years now, how long are we going to keep saying that?) gives purple negs, it seems to fade after a few weeks storage. I think it might be related to the alkalinity of the developer, rolls souped in Rodinal have less purple colour 😕

Mark

 

[Tim Gray]

I've found new Tri-x (it's been 3 years now, how long are we going to keep saying that?) gives purple negs, it seems to fade after a few weeks storage. I think it might be related to the alkalinity of the developer, rolls souped in Rodinal have less purple colour 😕

Mark

I didn't even realize that a new Tri-X had been out for 3 years. The only B&W I've shot and developed was whatever my girlfriend was using in college (4 years ago), but I think it was TMax. That was pre digital. Then I shot DSLR for 3 years and am just now getting into film fo' real.

 

[oscroft]

Don't know if it's of any use, but I've never used a stop bath (or hypo-clear, and I use my fixer right until exhaustion) and I've never had purple negatives. But I'm obsessive about washing - I do a number of rapid "wash and pour" washes, then about 5 changes of water several minutes apart, then I additionally wash in gently running water for at least 30 minutes. And I can happily report that the negatives I developed 30 years ago look just as good as the ones I did last week.

 

[phototone]

The only b/w film I have used that seemed to have some "issue" with purple tint retention has been the T-max films. Sometimes they seem to have a bit of purple left.

 

[Jamie123]

I also get purple negs from time to time.

I'm guessing it's because I don't wash them long enough. At the moment I use the 5-10-20 method and add another 20 and 20+Ilfotol. I would like to wash them under running water but the problem is that in the basement where I do my development there are seperate water taps for hot and cold water so I can't adjust the temperature.
How important is it the temperature of the water used for washing the negs?

 

[Simon Larbalestier]

I'm sure this is well known already but you can pre-saok the films prior to developing @20 degrees for 2 mins
I find that when I empty the tank a lot of the anti-halation dye present in some brands of film, washes out with this pre-soak Certainly helps when processing in PMK Pyro.
The purplish cast sounds like the fix is getting exhausted - 4 mins should be enough time. The stop will help prolong the life of the fixer as it prevents excess developer being carried over.
I use the Agfa colour fix FX Universal @1:4 (it's much cheaper than the Ilford and Kodak B/W fixers) agitate continuously for the 1st min then every 30's. Works every time 🙂

 

[Bryce]

Here's what I have been told about "new" tri-x. I don't remember the source, and this could be misinformation...
About 3 years ago, Kodak decided to eliminate a separate film base for Plus X and Tri X for cost control purposes and began putting these emulsions on the base developed for the T-max series films. Hence the fixing troubles, if they are truly a problem.
My "solution" has been to use Ilford's HP5.

 

[Tim Gray]

The purplish cast sounds like the fix is getting exhausted - 4 mins should be enough time.

It was newly mixed fix that had never been used before. Was just following the directions with the 10 mins. Ultimately sounds like something not to worry about, I'll just be a bit more thorough with washing next time.

Thanks for the info on the changes Tri-X went through.

 

[Simon Larbalestier]

Here's what I have been told about "new" tri-x. I don't remember the source, and this could be misinformation...
About 3 years ago, Kodak decided to eliminate a separate film base for Plus X and Tri X for cost control purposes and began putting these emulsions on the base developed for the T-max series films. Hence the fixing troubles, if they are truly a problem.
My "solution" has been to use Ilford's HP5.

I use TX all the time and have not had the purple stain even when i've had it lab processed in Bangkok.


Tim: strange then all i can think of is the dilutiion was too much usually it's 1:4 for films and 1:7-9 for paper - as 10 mins is a good standard time for fixing papers.

 

[Dougg]

You definitely do not want to pre-soak when using Diafine, but a reasonable practice with other developers.

I tend to agree with those who suggest your purple tint could be related to the final wash. I like to use a hypo-clearing agent after a brief rinse following the fixer. The HCA neutralizes the fixer and speeds the washing.

 

[Tim Gray]

Summary: Could be the fix, could be the final wash, could be the lack of HCA, could be the new formulation of Tri-X. Also, pre-soaking is good except when it's bad.

Seriously though, I do think presoaking is a bad thing for Diafine. I agree with you there. I'm guessing I just didn't wash thoroughly enough on that first roll. It is a really light tint though.

 

[Dougg]

Seriously though, I do think presoaking is a bad thing for Diafine. I agree with you there. I'm guessing I just didn't wash thoroughly enough on that first roll. It is a really light tint though.

That's my guess, yeah... On the pre-soak, the Diafine instructions do say not to do it. And it makes sense for this product, given the different way Diafine works. It relies on enough of Part A developing agent to soak into the emulsion to do a sufficient job of development once it hits the activator in Part B. What is soaked into (and coating the surface of) the emulsion is the only developer present at that point. If there's water already soaked into the emulsion from a pre-bath, that would hinder the Part A process. Sure, over time there's an exchange of fluids there, but in the time available the solution soaked in would still be somewhat diluted with the pre-soak water. I expect the visual result would be thin negs, especially in the maximum density areas (highlights)

 

[jim0266]

Kaiyen in a post above had the correct answer: two-bath fixing. The only way to go with modern emulsions like the new Tri-X.

 

[kaiyen]

Plus, you get 40 rolls out of a liter of fix rather than 20. 🙂

FWIW, I do notice with Delta 100 and TMX that the vast majority of the pink sensitizing dyes (_different_ than the AH layer with TXT) comes out during the permawash. So, personally, I think it makes a difference to have that step. Doesn't hurt, anyway, for the price, and it gives me a few minutes to clean up my workstation.

allan