Defective Tetenal RA-4 blix

hrst · Feb 22, 2009

Hello.

I just encountered an interesting problem.

About a year ago, I tried RA-4 reversal processing. As I had problems with getting decent highlights, I now tried it again but got even worse highlights and overall gray image. I worked a few days with it and tried different kind of workarounds (adding halide solvent to first developer, etc.) as I believed in Tetenal RA-4 blix I had just made. But finally I found out that the blix was guilty to my problems. Having only a little bleaching and fixing power, it produced gray results that got even more gray in daylight. I just tried re-bleaching and fixing this time's first print. You can see the difference between re-bleach-fixed and original part:
Dead Link Removed

Seen this, I bleached and fixed again my reversal RA-4 tests from a year ago. But the blix wasn't the issue then; they were fine. So that time the poor highlights were due to too high developer dilution and/or too short dev time. Maybe I'll write about my reversal RA-4 experiments later, but now I'm troubled with the problem of defective blix.

The funny thing starts here. I also tried bleaching and fixing again normal RA-4 prints I made two weeks ago - but they were fine. The only thing I did after that was that I made a new blix - but I used exactly the same concentrate.

The blix I'm using now has quite large amount of solid matter in it. I have to rub it away when final washing the print... The previous Tetenal RA-4 kit didn't have this much crud in it.

Have I done something wrong? How is it possible that the new blix made from the same concentrate as before is not working at all?

Another problem I've found with this Tetenal blix - and maybe with the previous batch too, I'm not sure - is that the paper whites gets very yellowish and smudged if the blixing is carried on too long - 45 seconds seems to be maximum in order to get good results. Is this normal?

Should I report this problem to Tetenal and/or try different blixes?

As a workaround, I'm now using ferricyanide bleach and E6 (ammonium thiosulfate based) fixer.

- Antti Alhonen.

Photo Engineer · Feb 22, 2009

Look at the clear portion and the red portion of the blix before mixing. I would guess that the clear portion is cloudy and/or has scale on the sides of the bottle or a precipitate in the bottom. The red porion is probably clear.

If so, this indicates that your hypo is bad.

Mix up 100 - 200 ml of standard ammonium thiosulfate solution in 1 liter of water and add 10 g/l Sodium Sulfite and 10 g/l Disodium EDTA. Adjust the pH to 6.5 and add it to 1 liter of the red part and dilute to 4 liters total volume.

This should be fine.

Your photo is overexposed by several stops and needs more red filtration.

PE

nickandre · Feb 22, 2009

The blix has a poor shelf life when concentrated. Does the tetenal kit come as a blix concentrate or with two seperate bleach and fix concentrates? The blix decays and gets a strong sulfur smell with flakes/crud of god knows what and stops working well. You should not have crud/have any problem over blixing with good blix. Your blix is dead. Complain. Buy the Kodak stuff.

glaiben · Feb 22, 2009

As soon as the sink is installed in the darkroom, I'm going to try some RR4 processing. I noticed the print referenced above is blue - what is the cause of this?

Thanks...gregg

Photo Engineer · Feb 22, 2009

Thiis is an RA-4 reversal process.

There is no comparison to the neg-pos process.

This is cross processing.

PE

hrst · Feb 23, 2009

Yeah, I forgot to mention that Tetenal kit has only one concentrate for blix. It is just diluted to working solution. It indeed looks dead... What can I do to avoid this problem in the future? That is to say, I have one Tetenal RA-4 2,5 liter print kit waiting to be opened... Can the aeration of blix concentrate be the problem? I have not diluted the whole kit at a time, but to make one third at a time. Or is the problem with this Tetenal's "Mono-concentrate" -- should I buy some brand having two concentrates for blix?

Is it okay to use potassium ferricyanide bleach (40 g/l potassium ferricyanide, 25 g/l sodium bromide) and KODAK E6 fixer with RA-4? (Of course with proper washes before and in-between.) It seems to work very well.

Regarding the reversal RA-4 process, it seems very interesting, and although I wasted much time with this blix problem (trying to fix it buy changing exposure, filtering and developer ), I have quite a good results now. I've examined both Kodak and Fuji papers and different concentrations of sodium thiosulfate added to first developer. Maybe I'll start a new thread after I have some more concrete information to share about reversal RA-4. It's almost ten times cheaper than Ilfochrome! Dead Link Removed - this is not so blue as the first one ;-).

David Grenet · Feb 23, 2009

hrst said:
I have quite a good results now. I've examined both Kodak and Fuji papers and different concentrations of sodium thiosulfate added to first developer. Maybe I'll start a new thread after I have some more concrete information to share about reversal RA-4.

Please do.

Photo Engineer · Feb 23, 2009

You really cannot make a single part blix that is stable.

If your blix came as a liquid in one bottle, it is probably dead by the time you get it. You are mixing an oxidant and a reductant (Ferric EDTA + Hypo) and it self destructs.

It will take about 1 - 4 months, but how long is it sitting on the shelf?

Sorry.

PE

hrst · Feb 23, 2009

Okay, I was wondering the same. Tetenal, way to go! They advertise this as a good feature, making it more easy to mix. It would indeed be very painful to mix two liquids ;-D.....

The developer is the same, only one concentrate, whereas C-41 have three concentrates, for example. But the Tetenal ra-4 dev works very fine and seems to have long shelf life, even with one concentrate.

Next I'll buy KODAK .

AgX · Feb 23, 2009

Photo Engineer said:
You really cannot make a single part blix that is stable.

If your blix came as a liquid in one bottle, it is probably dead by the time you get it. You are mixing an oxidant and a reductant (Ferric EDTA + Hypo) and it self destructs.

It will take about 1 - 4 months, but how long is it sitting on the shelf?

Sorry.

PE

Tetenal states that this RA-4 kit has got an `optimum protection against oxidation´ (whatever that means).
Further they state that a partially emptied bottle of Blix mono-concentrate would keep 6 months.
However, they ask to use protective gas on this bottle.
This does not make much sense to me. That gas will protect the hypo from being oxidized by air, but is not that bleach the greater threat for the hypo?

Photo Engineer · Feb 23, 2009

The Ferric EDTA is an oxidant, no matter what gas is used for storage.

They may use a stabilzer, but whatever it is, it will reduce the oxidation potential of the Ferric ion and thereby slow the blix. If it slows the blix, then you have more retained silver or you must use longer fix times.

I know of several chemicals that can be added to a blix that would essentially turn it off totally! It also makes it as stable as a hypo solution of the same composition without the iron salts. And, it makes it only a fix. That can be done, and no one would notice the difference except for having retained silver. It would make it a very expensive and complex bleach bypass.

No, the bottom line is that both developer and blix should be multipart.

The developing agent begins to decompose when dissolved in alkali. Kodak and others store the developing agent in an acidic part that is neutralized when mixed with the other two parts. The Hydroxyl Amine in the developer should also be stored as an acid for best keeping, or at least in a neutral solution.

I'm afraid that Tetenal is going to run into shelf keeping problems with these single part kits. We already see an example here, and I think there have been other threads on this as well.

PE

hrst · Feb 23, 2009

I sent email to Tetenal:

Subject: Defective RA-4 blix

Hello,

I'm very disappointed in your product TETENAL RA-4 print kit 2,5l. There should be no reason to use monoconcentrate to help mixing. The blix has oxidant and reductant together and has too short shelf life in one concentrate.

I have used two kits and the blix has somehow worked only occasionally. It has crud in it and the bleaching and fixing power is not sufficient. It can die before even getting to the final user. You should use two concentrates.

I've now re-bleached and re-fixed a lot of my prints. Some of them are fine, some are not. This has caused me much work and hassle.

Kind Regards,
Antti Alhonen
Finland.

It may be true that the problem is known and accepted, because with normal RA-4 prints the problem may not be visible for an "average customer" (hobbyist) - at least when the print is examined in subtle room lighting for short periods. But the reversal process shows the problem in its full glory since all the silver is developed...

Svitantti · Feb 26, 2009

A funny thing is, I tried bleach bypass processing for some RA-4 prints using Agefix and then compared the result by using this same exhausted blix. I noticed no obvious difference in the final result and I was wondering, why the images looked almost exactly the same .

Photo Engineer · Feb 26, 2009

Bleach bypass will fix the coating and leave silver in image areas. This degrades the color, sharpness and grain. An exhausted blix which can still fix, can have the same effect, but if it cannot fix properly then the image is just like a B&W image which is unfixed.

If the fixer is not of the proper pH in bleach bypass, or when using a bad blix, then the dyes can suffer in both hue and stability.

PE

Domin · Mar 6, 2009

hrst said:
The blix I'm using now has quite large amount of solid matter in it. I have to rub it away when final washing the print... The previous Tetenal RA-4 kit didn't have this much crud in it.

I got the same problem repeatedly. It seems that it happens when the blix concentrate is not quite fresh. Unfortunately there is no way of telling before you get the kit (you don't need to mix the crud shows at the bottom of concentrate) as there is no expiry date on it.

I've been unable to clean kodak paper with E surface and its quite a chore to wipe it of F surface. Since that I've switched to minilab chemistry. If you find someone to share a bigger package or some minilab operator willing to sell some you get 5l of working solutions for the price of the amateur kit. And no crud as a bonus.

Tom Kershaw · Mar 6, 2009

Domin,

See:

(there was a url link here which no longer exists)

Tom.

Domin · Mar 8, 2009

I'd gladly use Kodak chemistry but it seems it is not available in small packages here while shipping from abroad makes it to expensive. I don't print color very often so I do not have much choice.

mts · Mar 9, 2009

If commercial chemistry isn't available, then consider using scratch-mix bleach and fix. There are many formulae available. While bleach does take a bit of rocket science to ensure archival dyes, fixers are quite standard and easy to mix from scratch. As PE has noted here before, blix one might consider blix bad when it is mixed. Separate bleach and fix is clearly the way to go.

Tom Kershaw · Mar 9, 2009

Domin,

Fujihunt produce a small RA-4 5 litre kit which might be easier for you to obtain.

Tom.

decolorante · Apr 29, 2010

From images I found on Google, I see that the Tetenal Colortec RA-4 kit has blix in two separate concentrates in the 5 liter version, but the 2.5 liter version has just one. Maybe they separated concentrates in the bigger version to allow for better splitted mixing?

I am going to get the 5 liter one.

nickandre · May 2, 2010

I tried mixing small quantities of Kodak RA4 developer concentrate and the reaction was a vigorous foaming/terrible smell. I get the feeling that the mono-concentrate idea is a poor one.

Defective Tetenal RA-4 blix

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