RA-4 and stop bath

[Neil Souch]

Quick question: Is a stop bath between dev and blix essential with RA-4 in a slot tank (nova) when working at 35 C with 2 litres of chems? The reason I ask is that I have started to get less than white (tending to be very light green) boarders on my prints, when the boarders should be white! I am wondering if a normal strength stop bath would do this? All chems / papers are fresh and the darkroom is light safe, and I do not use a safe light.

Any thoughts would be most welcome,

Neil.

 

[Fotohuis]

A stop bath will prolong the life time of your blix in the Nova, but it is not necessary. Do you have fresh RA-4 paper and stocked in the right way (fridge <12 degerees C).

Are there signal lights (dokatimer) or other equipment which can give a problem on your RA-4 paper. Specially Kodak Endura is very sensitive for these kind of failures.

Best regards,

Robert


www.FotohuisRoVo.nl

 

[Neil Souch]

A stop bath will prolong the life time of your blix in the Nova, but it is not necessary. Do you have fresh RA-4 paper and stocked in the right way (fridge <12 degerees C).

Are there signal lights (dokatimer) or other equipment which can give a problem on your RA-4 paper. Specially Kodak Endura is very sensitive for these kind of failures.
www.FotohuisRoVo.nl

Robert,
Many thanks for your help. The paper is fresh but not kept in a fridge, it is kept with my mono papers which all keep OK. I have trapped out all the indicator lights but I do have a fair bit of glow strip dotted about - would that be the problem? The paper in question is Supra 111. I am having another colour sess on Saturday so was wondering if it would be safe to cut the stop bath out completely. In the various instruction blurbs stop bath use doesn't seem to get much of a mention.

All the best,
Neil.

 

[Nick Zentena]

Both the prewash and the stop are "optional". OTOH I need a prewash with Supra III to avoid the green meanies. Don't know who coined that term but when I saw it I knew what they meant. I wouldn't get just green borders I'd get a whole green print.

Supra III is a fairly old paper that hasn't been made in a few years. If it hasn't been in the fridge/freezer it may have gone off.

 

[Ed Sukach]

The one place where I consider stop bath to be necessary is in RA-4 processing. I've experienced all kinds of random color shifts without it.

I sometimes wonder about all the fuss over stop bath odor. I've been using Kodak "Indicating", but only because I've had that bottle since time immemorial. When I run out, it will be 5% white vinegar diluted 1:4 with water.

Funny - it seems no is offended by a vinegar and oil salad dressing, taken internally... but put a weaker solution in a darkroom ... and WOW!! One seems to need a respirator, chemical contamination suit, goggles, emergency water bath nearby, LARGE ventilation fan...

 

[Neil Souch]

Both the prewash and the stop are "optional". OTOH I need a prewash with Supra III to avoid the green meanies. Don't know who coined that term but when I saw it I knew what they meant. I wouldn't get just green borders I'd get a whole green print.

Supra III is a fairly old paper that hasn't been made in a few years. If it hasn't been in the fridge/freezer it may have gone off.

Nick, do think it would be worth trying a pre-wash ? I have not come across the green meanies. Just the boarders looking a bit off. But I dare say the whites have been affected overall, although the imgages look OK. Do you know what gone-off Supra 111 would look like?

All the best,
Neil

 

[Nick Zentena]

Funny - it seems no is offended by a vinegar and oil salad dressing, taken internally... but put a weaker solution in a darkroom ... and WOW!! One seems to need a respirator, chemical contamination suit, goggles, emergency water bath nearby, LARGE ventilation fan...

If you ever put vinegar on a plate of hot chips you'll never find the smell of a darkroom a problem again

 

[Neil Souch]

Agree 100% about the smell of stop bath / vinegar - I am hooked on it! I must admit I would feel happier continuing using a stop with RA-4.

Neil.

 

[Tom Duffy]

I agree with Ed. A stop bath is necessary, as its own step, particularly at 35C. At closer to room temperature the acid can be mixed into the bleachfix.

 

[Neil Souch]

Hi everyone,

Many thanks for your respones to my stop bath query with RA-4 at 35 degrees C. I had another go over the weekend and I am now sure the paper has aged and that this is causing the slight colour shift with the whites - easily noticed on the borders. Agree that a stop bath is essential 100%. I have ditched the paper and will be keeping my new stock in the fridge from now on!

Many thanks again,

Neil.

 

[Nick Zentena]

Nick, do think it would be worth trying a pre-wash ? I have not come across the green meanies. Just the boarders looking a bit off. But I dare say the whites have been affected overall, although the imgages look OK. Do you know what gone-off Supra 111 would look like?

All the best,
Neil

Sorry I didn't see this. Ya try the pre-wash. It helps with so many other things that I can't see why not to do it.

I've got some allegedly "well stored" Fuji paper. It's a nice pink when processed. The best of the two rolls you won't see the pink anyplace but the white borders. The other roll looks horrid.

 

[Neil Souch]

Nick, thanks for that - will give it a go. Actually the borders looked OK until I noticed them against a pure white! Like your resuts, interestingly, although the borders were a tad off the prints looked fine.

Cheers,

Neil.

 

[inthedark]

I agree with Ed, I find stopbath for RA-4 necessary to avoid random color shifts, HOWEVER I think that I actually have figured out why I have this need in my shop. I use a safelight for color. A heavily ambered (with filters) 7wt that is waaaaay down at the other side of the shop and behind & around a corner. Perfectly safe till I get within three feet of the blix. Sooo, I have to be sure it is stopped before I get to the blix.
Ed, could this be similar to your situation? I have never tried without having the safelight on, so maybe it (the odd shaped "smudges" of discolor) would happen in spite of the safelight.

 

[Ed Sukach]

Ed, could this be similar to your situation? I have never tried without having the safelight on, so maybe it (the odd shaped "smudges" of discolor) would happen in spite of the safelight.

I *never* process RA-4 color except in total blackness - using a JOBO CPP2 processor.

Without shortstop, between color devloper and bleach-fix, random color shifts have been a problem. With it, - no problem.

 

[pentaxuser]

RA4 and stop bath

Quick question: Is a stop bath between dev and blix essential with RA-4 in a slot tank (nova) when working at 35 C with 2 litres of chems? The reason I ask is that I have started to get less than white (tending to be very light green) boarders on my prints, when the boarders should be white! I am wondering if a normal strength stop bath would do this? All chems / papers are fresh and the darkroom is light safe, and I do not use a safe light.

Any thoughts would be most welcome,

Neil.

This reply is a long time coming as I have only just joined the site. Most Nova tanks are 3 or 4 slot and using stop bath is worthwhile. It stops dev instantly and avoids contamination of blix and is cheap.

I could never understand how anyone could use the Nova slot processors in the practically non existent light provided by most colour safelights until I got a DUKA 50. It opened my eyes literally. When I hear of colour printers saying that printing in absolute darkness is the only safe way I can only assume they have never experienced a DUKA 50.

I noticed in this thread that Kodak Supra III was being blamed for problems due probably to age or storage.My experience of Kodak Supra III is totally different as well. I bought a Jobo processor secondhand and the seller gave me Kodak Supra III paper which was then quite old. I only used up the paper a few weeks ago after having it for over a year and could detect no problems with it. It had sat in my darkroom at normal room temp for about a year. The previous owner may have kept it refrigerated but I think not. So my experience is that storage may not be as critical as claimed. Likewise print dev processing time. I have never found this to be critical to the second or even several seconds, having on many occasions inadvertently allowed the Jobo processor to run on before pouring out developer.

Unless you or your print viewers are very critical or can judge prints to a degree that eludes me and my viewers then processing is less critical is supposed. The only exception to that I have found is that print exposure is quite critical but an enlarger timer and colour analyser takes care of accuracy in that area.

Pentaxuser

 

[Photo Engineer]

All color papers are quite prone to staining if the blix action is not uniform and rapid. Both Fuji and Eastman Kodak recommend the use of a stop bath to prevent this type of problem.

I have kept Supra III on the shelf unrefrigerated for a year or more and found only a slight change in red speed (prints become red as the paper ages). So far, with limited data, I find that Endura seems to keep better. I have no data on CA.

PE

 

[Neil Souch]

Pe & PU

Many thanks for what you have each added. All very useful.

Cheers,

Neil.

 

[pentaxuser]

I agree with Ed. A stop bath is necessary, as its own step, particularly at 35C. At closer to room temperature the acid can be mixed into the bleachfix.

Looking over this thread again(I do this on wet Saturday afternoons), does anyone have a formula for how many prints the stop bath can cope with before it needs changing. As far as I can see the usual indicator stop bath is useless for colour work. My stop bath which is Ilfostop and has an indicator designed for B&W work changes colour markedly due to the RA4 developer after a few prints but is presumably still working.

I have tried the "nose" test to detect when it may be exhausted but my stop bath is of the odourless variety so has little odour when fresh but quickly gains an odour which must come from the RA4 developer but may not indicate exhaustion.

For information I process via a Jobo drum and make up about 200cc's of stop, using about 80 to a 100cc's per print but re-mixing it with the stop remaining in the stop container. After processing about 15 prints which are normally 5x7 inch I then throw the stop away and re-fill the stop container with fresh stop.

This may be wasteful or may mean I am economising to a degree that means that the stop is contaminated with developer and dregs of this in the drum is then mixed with blix. I just don't know.


Pentaxuser

 

[Nick Zentena]

I thought indicator stop actually caused problems? The indicator doesn't play nice with the RA-4 process.

Personally I use white malt vinegar. I mix up 500ml every time I mix up 250ml of developer. 1% solution. I haven't had any problems.

 

[Claire Senft]

The only processing that I have done in RA4 where a stopbath was not a help was with a roller processor that uses a squegee to remove the developer before it hits the blix.

In all other cases a vinegar stopbath will prevent enough problems to be a very worthwhile investment in terms of both time and money.

 

[Ronald Moravec]

Water is ok in my Nova for about two prints. After that I get stains.

I utilize the four slots for dev, stop, water, bleach-fix . Stain problem went away.