Purple negatives: How to prevent?

**ChrisPlatt** · 01-25-2016, 05:57 AM

I've read much advice - some conflicting - regarding how best to prevent purple negatives
commonly associated with Kodak Tri-X and some other popular black & white films.

Presoaking, fixer type and time, HCA and rinse are some often mentioned factors.
What's your most successful method for minimizing this unpleasant effect?

TIA,
Chris

**blackcloudbrew** · 01-25-2016, 08:16 AM

I think, this may be caused by the fixer being spent. This is what I've seen in the past. If you have fresh fixer, it is possible to soak the negatives in new fixer to clear them even after you fully treated them. If you do that, you should rinse them again etc. as you would do with any negatives. Can't tell you on how much time would be required to fix them. You just have to do some trial and error.

I have done this in the past to clear purple negs.

G and T · 01-25-2016, 10:28 AM

The purple that you're seeing is the remains of the anti-halation layer being "fixed" onto the negative. A good pre-rinse, re-fix and rinse should remove it.
I always pre-soak and pre-rinse my negs.until the water emptying from my tank runs clear before I add my developer, especially with films that have this purple predisposition. I don't know why but some films even of the same type take a lot more pre-washing to remove this purple pollution.

Glenn

_Ben · 01-25-2016, 07:32 PM

I mistakenly got my stop and fix mixed up today so I only fixed for 30 seconds or so. This also meant that I dumped my fix into the used stop container and dumped my stop into the silver recovery unit after the hypo check indicated that it(the stop) was spent

A quart of used stop is cheap so it wasn't a big deal and the film was only like fifteen frames out of the bulk loader. I was really testing a new(old) camera. As soon as I looked at the film as I was putting it in the dryer I knew what happened. Dark thick purple, my instructor said I could re-fix it but I had another class so I tossed it. I was really just playing while my actual assignment was washing and drying. I think I had one to many pots on the stove. Other than this I've never had any purple aside from a little on one edge where I didn't have enough in the tank. I think the key is good chemistry and consistent technique.

**beachgardener** · 01-26-2016, 01:34 AM

Originally posted by G and T

A good pre-rinse

How long is a good pre-rinse?

**fs999** · 01-28-2016, 05:47 AM

Originally posted by beachgardener

How long is a good pre-rinse?

5 minutes is a good approach, especially if it is an old film...

**beachgardener** · 01-28-2016, 08:57 PM

Originally posted by fs999

5 minutes is a good approach, especially if it is an old film...

is it necessary to agitate through the rinse period?

**fs999** · 01-29-2016, 01:29 AM

Originally posted by beachgardener

is it necessary to agitate through the rinse period?

Yes 3 times every 30 seconds.

**beachgardener** · 01-29-2016, 02:38 AM

Originally posted by fs999

Yes 3 times every 30 seconds.

Thanks for that

At a later date can I ask you about the Cafenol process?

It has been years, decade, since I did B&W developing.

**fs999** · 01-29-2016, 05:50 AM

Originally posted by beachgardener

At a later date can I ask you about the Cafenol process?

No problemo. In the meanwhile here are some recipes :

tuco · 02-01-2016, 03:35 PM

Try a two-stage fix which Kodak has recommended for the pink with 100 T-max film. Fix normally and then fix with a fresher bottle of fixer for about another minute longer and give it a really good wash. I never seen purple with 400TX or the now discontinued in your format 320TXP (Pro Tri-X) but I have seen it with Plus-X

01-25-2016, 05:57 AM	#1
ChrisPlatt Site Supporter Join Date: Nov 2007 Location: Rockaway Beach NYC Posts: 7,692	Purple negatives: How to prevent? I've read much advice - some conflicting - regarding how best to prevent purple negatives commonly associated with Kodak Tri-X and some other popular black & white films. Presoaking, fixer type and time, HCA and rinse are some often mentioned factors. What's your most successful method for minimizing this unpleasant effect? TIA, Chris

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01-25-2016, 08:16 AM	#2
blackcloudbrew Loyal Site Supporter Join Date: Mar 2009 Location: Cotati, California USA Photos: Gallery \| Albums Posts: 4,460	I think, this may be caused by the fixer being spent. This is what I've seen in the past. If you have fresh fixer, it is possible to soak the negatives in new fixer to clear them even after you fully treated them. If you do that, you should rinse them again etc. as you would do with any negatives. Can't tell you on how much time would be required to fix them. You just have to do some trial and error. I have done this in the past to clear purple negs.

01-25-2016, 10:28 AM	#3
G and T Veteran Member Join Date: Aug 2011 Location: Langwarrin Australia Photos: Gallery Posts: 382	The purple that you're seeing is the remains of the anti-halation layer being "fixed" onto the negative. A good pre-rinse, re-fix and rinse should remove it. I always pre-soak and pre-rinse my negs.until the water emptying from my tank runs clear before I add my developer, especially with films that have this purple predisposition. I don't know why but some films even of the same type take a lot more pre-washing to remove this purple pollution. Glenn

01-25-2016, 07:32 PM	#4
_Ben Senior Member Join Date: Apr 2015 Location: Pensacola Florida Photos: Gallery Posts: 130	I mistakenly got my stop and fix mixed up today so I only fixed for 30 seconds or so. This also meant that I dumped my fix into the used stop container and dumped my stop into the silver recovery unit after the hypo check indicated that it(the stop) was spent A quart of used stop is cheap so it wasn't a big deal and the film was only like fifteen frames out of the bulk loader. I was really testing a new(old) camera. As soon as I looked at the film as I was putting it in the dryer I knew what happened. Dark thick purple, my instructor said I could re-fix it but I had another class so I tossed it. I was really just playing while my actual assignment was washing and drying. I think I had one to many pots on the stove. Other than this I've never had any purple aside from a little on one edge where I didn't have enough in the tank. I think the key is good chemistry and consistent technique.

01-26-2016, 01:34 AM	#5
beachgardener Site Supporter Join Date: Sep 2013 Location: Australia Photos: Gallery Posts: 3,842	Originally posted by G and T A good pre-rinse How long is a good pre-rinse?

01-28-2016, 05:47 AM	#6
fs999 Loyal Site Supporter Join Date: Jul 2008 Location: Luxembourg Photos: Gallery Posts: 8,636	Originally posted by beachgardener How long is a good pre-rinse? 5 minutes is a good approach, especially if it is an old film...

01-28-2016, 08:57 PM	#7
beachgardener Site Supporter Join Date: Sep 2013 Location: Australia Photos: Gallery Posts: 3,842	Originally posted by fs999 5 minutes is a good approach, especially if it is an old film... is it necessary to agitate through the rinse period?

01-29-2016, 01:29 AM	#8
fs999 Loyal Site Supporter Join Date: Jul 2008 Location: Luxembourg Photos: Gallery Posts: 8,636	Originally posted by beachgardener is it necessary to agitate through the rinse period? Yes 3 times every 30 seconds.

01-29-2016, 02:38 AM	#9
beachgardener Site Supporter Join Date: Sep 2013 Location: Australia Photos: Gallery Posts: 3,842	Originally posted by fs999 Yes 3 times every 30 seconds. Thanks for that At a later date can I ask you about the Cafenol process? It has been years, decade, since I did B&W developing.

02-01-2016, 03:35 PM	#11
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,025	Try a two-stage fix which Kodak has recommended for the pink with 100 T-max film. Fix normally and then fix with a fresher bottle of fixer for about another minute longer and give it a really good wash. I never seen purple with 400TX or the now discontinued in your format 320TXP (Pro Tri-X) but I have seen it with Plus-X