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Purple/Violet base color on Kentmere Pan 400

Aidan Gravelle

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Jul 27, 2023
Messages
13
Location
Tucson, Arizona
Format
35mm
Hi everyone, I have noticed as of recently that the newer rolls of Kentmere Pan 400 I have developed are coming out with a slightly more purple/violet base. I recall the base normally coming out with a grey maybe slightly violet tint (as my past negatives prove this). My process is as follows:

Everything done at 20 Degrees C

Developing: 11:30-13:00 min time for 400 (Depending on shooting conditions) in Sprint Standard 1+9

Stop: Sprint Bloc Stop Bath 30 Seconds

Fixer: Sprint Record Speed Fixer 2+8 5:00 min

Wash: Fill tank with water and invert 10 times, then empty tank.

Archival Wash: Sprint Archive Fixer Removal 1+9 3:00 min

Ilford Wash method: 5-10-20

Final Rinse: Distilled water soak for 3 min

This processing method usually gives me negatives that are free of any unusual tint, including a grey base with TMAX and Delta film. Ive found that refixing for another 3 min and washing again clears most of the purple hue into a very light violet. I've also used fresh Ilford Rapid fix with the same issue.

I'm just wondering if anybody else has been having a similar experience with Kentmere Pan 400. I'm wondering if Ilford has reformulated this film stock to include less silver and more dye sensitizers?
 
I happen to have some Kentmere 400 negatives in 35mm right in front of me right now. I developed the roll yesterday. Batch number FF739/01, exp 12/2026.

The negatives have a very dark base but I see no violet. It's a darkish grey.

I fixed with freshly made Fomafix for 7 minutes. You mention you fixed for 3 minutes. I'd try at least double that.
 
Make sure you aren't overusing your fixer. Keep track of the number of rolls/sheets you fix in a given volume and increase the fixing time appropriately using the manufacturer's recommendation or by doing a clearing test.

Alternately, since the film base does not absorb fixer, you can simply fix for longer. Do a clearing test with the film in question and fresh fixer. Note the clearing time and multiply it by four instead of the usual two. This gives you the fixing time for the fixer at the very end of its useful life, i.e., just as it reaches capacity. You can then just use this time as a standard. You still have to keep track of capacity, either by throughput (x number of film per liter) or by doing a clearing test as the fixer ages and discarding it before the clearing time in the used fix reaches 2x that in fresh fixer.

If you are using fresh fixer and fixing longer and still having the stubborn pink/magenta base stain, a soak in a weak alkaline solution such as sodium bicarbonate, borax, sodium metaborate or even sodium carbonate will usually remove the stain. This step should come before the wash.

Best,

Doremus
 

Washaids like Kodak Hypo Clearing Agent - essentially sulfite plus something to adjust the pH - seem to also make a difference.
There is an entire Sticky thread about pink/magenta/purple film: https://www.photrio.com/forum/threa...which-is-a-different-issue.69462/#post-975950
And on the subject of purple ......
 

Rapid fixers (like Ilford Rapid Fix) can fail almost overnight, you need to keep checking them by putting a drop onto a cut off piece of film leader and checking how long the spot takes to clear, then double it. Anything over six minutes is too long, five minutes is best.
 
250swb said:
Anything over six minutes is too long, five minutes is best.
Click to expand...

Too long for what? In general, you can't overfix. You might get some bleaching with old emulsions if you leave the film in the fixer overnight.

There is no 'best'. There is the time given by a film leader test. If you over-run it a little, that's absolutely fine.
 
Last edited:
Thanks for the input everyone. Just to clarify I was using fresh fixer and it’s got a bit before it expires. Perhaps I’ll increase my washing time.
 

There's no point in saying you can't over fix and then immediately qualify it. Rules are meant to communicate sound principles, not introduce further answers. And I agree you can over fix, Adox CMS20 II is forty five seconds before the fix starts bleaching the image, but that is written in the instructions. 'Best' is the point where there should be no further point in carrying on.
 
250swb said:
Adox CMS20 II is forty five seconds before the fix starts bleaching the image, but that is written in the instructions.
Click to expand...

This is what the datasheet for that film says:
Fixing and inal rinse: The fixing time is only 30 to 60 seconds in any rapid fixer due to the small silver grains.
Click to expand...
It doesn't say anything about overfixing. Just that it fixes rapidly, which makes sense given the explanation they give.

250swb said:
Rules
Click to expand...

There's no 'rule' about fixing. Anyone can do as they please. Overfixing is not a real risk within any reasonable amount of time, let's say anything up to an hour or so.
 
I've noticed lately a similar experience with HP5. The base seems to retain a more bluish/purple tone than usual and doesn't seem like it can be washed out.
 
Todd Niccole said:
I've noticed lately a similar experience with HP5. The base seems to retain a more bluish/purple tone than usual and doesn't seem like it can be washed out.
Click to expand...

The HP5+ is bluish grey. Moreover, the sensitizing and/or anti-halation dyes in Harman/Ilford films are magenta. These usually don't wash out entirely; a little bit remains. Ilford has confirmed this.

Since Kentmere is also a Harman film, it's logical it shares much of the same technology - and therefore, behaviors.
 
This could be related to the disruption seen recently in the supply channels for acetate base, and/or from the increase in film stocks switching to new polyester base.
Change of various sorts has been nearly constant lately.
 
The OP indicated he was using a wash aid, which apparently doesn't help with the issue (three minutes if I remember - possibly extending the time would help some).

Still, I've found that some stubborn magenta stains just need a slightly alkaline bath to wash out. This does the job quickly and effectively.

I posted here some years ago about a problem with TMY. The retained dye was so much that the negatives were almost opaque; dense dark blue. In the alkaline bath they quickly cleared and the solution turned bright magenta. This still happens from time to time and appears to be batch-specific. Some batches of TMY process just fine, with only a hint of magenta, some have retain so much dye as to be nearly opaque. I have no real idea why this is, but the alkaline bath fixes the problem. FWIW, my processing is rather neutral-to-acidic: PMK very dilute, acid stop and Ilford Rapid fixer. It could be that the dye requires a more alkaline environment than the developer is providing to dissolve well. If that isn't happening during processing, then an after-bath does the job. This may be the OP's problem as well; I'm not familiar with the Sprint developer pH.

Best,

Doremus
 
I generally use two bath fixing for black & white films processed in a Jobo rotary machine. In my experience this approach has been sufficient to get rid of magenta from T-Max film base, alongside reasonable washing, most commonly an extension of the ILFORD method.
 
koraks said:
There's no 'rule' about fixing. Anyone can do as they please. Overfixing is not a real risk within any reasonable amount of time, let's say anything up to an hour or so.
Click to expand...

I kind of did say in specific terms some films such as Adox CMS20 II suggest a very different scenario.
{Moderator deletion}
But you raise a good question, why it's ok to fix films for an hour if they only need five minutes {Moderator deletion}?
 
Last edited by a moderator:
Moderator hat on:
Please avoid personalized, intemperate arguments.
Differences of opinion are fine..
Hat off
 
Update: I just processed two rolls of Kentmere Pan 400. The only thing that I changed in my process was increasing the fixing time from 5 to 8 minutes. Seems to clear up more and leaves a greyish/slightly violet base (Similar to HP5). Just to clear up any assumptions that my fixer was exhausted , I made fresh fixer for all the rolls of K400 I've processed recently. the Sprint fixer was recently opened and expires next year.
 
Aidan Gravelle said:
Ilford Wash method: 5-10-20
Click to expand...

This is the fill, invert X times and dump method, right? I won't comment on the efficiency and archival quality of this method, but I'm certainly sure that it won't remove any dyes remaining after fixing to the same extent as prolonged soaking would. I do a fill, invert, soak for 2', dump, repeat wash and I can collect the dumped water, which obviously enables me to judge the amount of dyes removed. The results can be striking with some films.

So, assuming that 5' is adequate fixing time in fresh fixer (and it most probably is), prolonging it to 8' isn't bad, but a longer soaking period would probably work just as well, if not better.

One last thing that I'd like to mention is a method to determine the minimum fixing time, the one with the drop of fixer... Start by putting a drop of fixer on a piece of film and let it sit there for 30" or so, it's not critical, you need to give it a good headstart. Then you drop this piece of film in your fixer and count the time it takes for the spot that had formed to disappear. This time should be at least doubled, but I usually triple it, just to make me feel better. And I never fix for less than 5'.

Hope this helps.
 
Clearing test for Kentmere Pan 400 is around 1:15-1:30 in Sprint Fixer, I always do 4-5 min minimum fix time regardless. I haven’t done one in the last 2-3 months with K400 I may have to try it again.

Relating to your comment about the archival quality with the Ilford wash method, The Naked Photographer proved that there is minimal to no fixer residue when this method is done. I’ll attach a link to that video below. I also put my film through a 3:00 min archival wash with continuous agitation.

I’ve done this method with other Ilford film stocks with no issues and I get normal looking base colors.


The Naked Photographers Video
 

Next time I process K400, I’ll give this wash method a try just to see if there’s a major difference. Thanks!
 
Obviously nobody is going to choose a developer just to deal with the purple/violet base color. But I do find that with an extended time (typically 12 minutes) in Rodinal 1:50, a 3 minute fix in Ilford Rapid Fix for cubic grain films or 5 minutes for Delta films, and a plain 5+10+20 three step Ilford wash I have no residual color in my negatives. And the negatives as far back as 2010 when I started using the Ilford washing method are still in perfect condition.

Disclaimer: I do use distilled water for everything including the wash, and I do not use T-grain films.
 
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