Prolongation factor d76 Stem length

wschwetz · 2018-05-19T15:46:14+00:00

Weder auf der Packung noch bei Bedienungsanleitungen für D76 finden sich Hinweise für Verlängerungsfaktoren der Stammlösung. Auch in Forenbeiträgen finde ich...

wschwetz

There are no instructions regarding dilution factors for the stock solution on the D76 packaging or in the user manuals. I can’t find anything in forum posts either. I do, of course, know that you can develop at a 1:1 ratio. However, I would like a specific answer regarding the following procedure: ? I want to prepare half a litre of D76 and develop two films in a suitable tank. That’s enough for five films. ? Film 1+2: Time x Film 3+4: Time x plus how much? Film 5: Time x plus how much? ? In the past, the rule was always: add 1 minute for each additional film, sometimes also 10% ? Does anyone have any experience with this?

MirkoBoeddecker

At ATOMAL, we have the following rule of thumb: No extension up to film 5, and one minute longer from film 6 onwards. However, this formula is very rough. It would be better to regenerate the solution or to start with a percentage series earlier on. All specifications are, however, for a 1-litre batch and also assume that the working solution is remixed each time. I cannot recommend a partial batch of 500ml, as D76 does not homogenise. It cannot therefore be assumed that the components in the bag are mixed evenly, which is also unnecessary with a full batch. Leaving that problem aside, the conversion would look something like this, approximately: Films 1 and 2: No extension Films 3 and 4: Plus one minute Film 5: Plus 2 minutes Best regards, Mirko

wschwetz

Thanks, Mirko ? I would have assumed 2 minutes for films 3 and 4. ? I tried the partial batch method a few times a while back. I put the 3.8-litre bag into a large yoghurt pot with a lid, added the Barmann, and gave it a good shake for about 5 minutes. I then divided it between film canisters, one for each film. You do need a suitable set of scales, of course. It was a bit of work, naturally (though I’m sure it could be streamlined by marking the film tins with calibration lines). But it worked without a hitch! I’ve had far more films go wrong because the developer wasn’t working properly. However, I stir the powder into relatively hot water (hotter than specified on the packet) and then let it cool down.

Rolf-Werner

Somehow I must have come across a table of extension factors at some point, perhaps on the Kodak website. The results weren’t great, though; I basically ruined a few rolls of film using it – they just weren’t developed properly and are very difficult to print. € Since then, I’ve been developing a maximum of three rolls of film per 500 ml, after which I use fresh chemicals. That said, I do have several rolls of film in one tank. For that, I have a Paterson tank that holds 2 rolls of film, and a Jobo with space for 3. € I always mix the D76 in full and then divide it into black plastic bottles that used to contain disinfectant. They have a sturdy lid with a thick rubber seal inside, which keeps them well sealed. When I take some out (a bottle holds 1 litre, and I usually take 500 ml), I add some Protektan and put it back. € The stuff is still perfectly clear after months and works just as well as on day one. € Regards Rolf

Wolf_XL

...it’s almost impossible to achieve a homogeneous mixture of powdered substances – you can shake it as much as you like – at some point, the ingredients will separate again. So you should make batches... You can read up on the theory behind this here... € http://www.mvt.ovgu.de/mvt_media/Vorlesungen/VO_MVT/MVT_e_8.pdf € Have fun! ;-)

Photux

I simply use this stuff as a single-use developer. Diluted at a ratio of 1:1, it works out so cheaply per roll of film that I don’t want to bother with extension factors. Besides, my throughput isn’t that high, so I’m glad if I don’t have to throw any residues away. With Protectan, shelf lives of 6–12 months are easily achievable, but be warned: D76 ‘dies’ quite suddenly and then stops developing altogether. As soon as it turns visibly yellowish, things get critical; however, this alone is not a reliable way to determine whether it is still usable. If it has been standing for a long time, it is therefore advisable to develop a short test strip first.

Wolf_XL

...that’s pretty much how I do it too – stock solutions are a pain... ;-) Wait – there is one exception – namely TMax developer. But the extension factors are specified there: after the 4th film + 1 min and after the 8th film + 2 min... I’d use that as a guide for D-76 as well...

Rolf-Werner

Thanks, Photux, for the tip. I’ll bear it in mind and be careful :) ? Best regards, Rolf

Gast

The instructions for Ilford ID-11 (which is virtually identical to D-76) state that 10 films can be developed per litre of developer. The development time should be increased by 10% after each film: … https://www.ilfordphoto.com/amfile/file/download/file_id/2008/product_id/708/ … Personally, I always use D-76 as a single-use developer (usually 1+1). … Regards Wolfgang

Otto

Just have a look at the data sheet: http://imaging.kodakalaris.com/sites/uat/files/wysiwyg/pro/chemistry/j78.pdf It’s on page 5 below the last table, or here in German: http://www.fotofachversand.at/pdf/Kodak_D-76_Entwickler_Datenblatt_Anleitung.pdf on page 7 below the table. The professional solution is to use the refill solution (regeneration). If the processing time is extended, the used developer is usually poured back into the residue of the stock solution after development. Do not make a partial batch. Good luck. Best regards, Otto!