Gast
Hello everyone!
There are still a few things I’m not quite clear on regarding the efke 25:
1. The term ‘double speed’ (Impex catalogue) and how this compares with newer (‘Western’) emulsions: I exposed my first efke 25 rolls at 50 ASA and developed them with Neofin Blaue, but ended up with rather flat negatives. Is this typical for Efke 25 / Neofin?
Mirko once mentioned that the film comes out very nicely in R09 1+80. What development time? Agitation? Exposure at 50 or 25 ISO? Perhaps someone could give me a few figures to go by – that would be great.
2. On those first two rolls of Efke I developed, I apparently had air bubbles. In any case, I had tiny circular dots on the negatives. As I’ve never had problems with this before: could it be that the Efke is more sensitive in this regard? Has anyone had similar experiences?
Bernd
rherz
Hi Bernd,
True speed means: other manufacturers quote ASA figures that are too high. In other words: with Efke 25, the 25 ASA printed on the film is exactly what it says – so you’ve experienced underexposure by one stop. I can’t say whether Efke works well with Neofin – but it’s simply brilliant with A49! <_<
As for the little bubbles: did you use a stop bath? Efke films really don’t like that. With some developers, there’s a reaction that produces gas and causes the emulsion to peel off (maybe Franz knows more about this). Just stop it with water and the problems will disappear. :P
Best regards,
Robert
Gast
efke25 and R09 – I started out using Mirko’s development times, but I was never really happy with them. I then gradually worked my way up to 16 seconds at 1+80. Since I started using Rodinal, I’ve fallen in love all over again!
Micha
zensusa
Hello,
As I’ve been using Efke films for years, I’d recommend the following exposure times and settings. All these settings apply to the roll films and the two sheet films (25 and 100), as I don’t use 35mm films. All settings are optimised for exposure on an LPL 4x5-inch enlarger with a split-grade screen and adapted for Classic Art PW matt and chamois papers.
In plain terms, the negatives achieve a gamma value that is therefore suitable for mixed-light enlargement (the achieved gamma value lies between approx. 0.62 and 0.65; I haven’t measured it precisely). If you have a condenser enlarger, you must adjust the data to a gamma value of approximately 0.55, i.e. lower negative ‘contrast’. This is very simple: divide the development time by the existing gamma value (here 0.62) and then multiply by the desired gamma value (0.55). And there you have the desired, approximate value! Of course, this also works the other way round, i.e. if you want to convert from condenser to mixed light!
My development takes place at 24°C in a Jobo processor; that is, rotary development (Jobo setting ‘P’). If you don’t have this option and want to or have to tilt/develop by hand, then you’ll need to convert the times to your temperature. I’ll also give you the time data below. You then need to add 10% to the converted time to compensate for the difference between rotary and agitation development. The agitation rhythm should then be as follows: continuously for the first 30 seconds, then 4 times per minute.
So now the development times at 24°C with R09 at 1:40 and 1:80. Both ratios produce very well-defined negatives!
Efke R 25 1:40 equals 4.00 minutes / 1:80 equals 8.00 minutes
Efke R 50 1:40 equals 6.15 minutes-seconds / 1:80 equals 12.30 minutes-seconds
Efke R 100 1:40 equals 9.00 minutes / 1:80 equals 18.00 minutes
Temperature/time conversion:
4.00 minutes/24 ° equals 5.30 minutes/21 ° equals 6.00 minutes/20 °
6.15 minutes/24 ° equals 8.00 minutes/21 ° equals 9.00 minutes/20 °
9.00 minutes/24 ° equals 11.45 minutes/21 ° equals 13 minutes/20 °
Bear in mind that conversions naturally only produce theoretical values! What I mean is that these values are certainly only approximate, as personal differences in working style, hardware and chemical inconsistencies, etc., will always result in variations. However, the more precisely you work with these values, the closer you’ll get to a perfect result!
As for processing Efke film, I proceed as follows and, apart from my initial test phase with Efke, have never had any problems with peeling or scratches etc. For all steps, the water temperature corresponds to the temperature of the developer bath!!!
1. 1 minute pre-rinse (constant agitation)
2. Develop with R09 according to the specified time/rhythm
3. 1 minute in stop bath (mix 60% vinegar in a 1:30 ratio or LP Citrodur)
4. 3 minutes in fixer (Calbe Unifix Liquid + Tetenal hardener – add according to the instructions)
5. 1 minute rinsing (tempered water) with constant agitation
6. 2 minutes washing with Lavaquick (ratio 1:20, constant agitation)
7. Final wash under running water: fill the container, leave to stand briefly, then empty. Repeat 10 times. That’s enough.
8. 1 minute in the wetting agent bath (LP Proofmaster, best suited for polyester films!)
9. Hang up in the drying cabinet using a weight clip, dry with cold air (never warm!)
10. Done! Enjoy your fantastic negatives!
So, that’s it. Have fun and good luck, and
Best regards, Zensusa / Lothar van de Renne
zensusa
Hi Bernd,
I’ve just realised that I’ve left out a few details in my instructions, but everything should be complete.
1. Prepare the fixative (Unifix Liquid) in a ratio of 1:7!
2. Prepare the LP wetting agent in a ratio of 1:100. Be sure to use distilled water! Distilled water is available at any DIY store. A 5-litre canister costs around €1.30.
3. After treating the film with the wetting agent, simply let it drain well but hang it up to dry without wiping it.
Finally, a general tip: as tap water can be very high in chlorine or iron, etc., depending on the region, you should definitely prepare your chemicals using distilled water if you want to prevent any negative effects on the film emulsion caused by the water used during development. Incidentally, under unfavourable conditions, water with a high mineral content can also lead to the formation of specks, circular spots or tears, etc., in film emulsions.
Good luck
Zensusa / Lo van de Renne
MatthiasS
What is the ideal gamma for contact prints?
And surface protectants – can they be used without a stop bath, or do they need an acidic environment to work? How do protectants actually work?
Best regards,
Matthias
zensusa
Hello Matthias,
There is a simple answer and a complicated answer to your question: "What is the ideal gamma for contact prints?"
1. The simple answer:
The “normal, correct” development (e.g. standard time as per the package inserts, etc.) results in a gamma value that allows the enlarger (lighting system) used to reproduce a captured subject (scene) with a normal contrast range (around 5 stops) on paper with a normal gradient (gradation 2 to 3). In other words, you therefore need an “ideal” gamma of 0.55 for hard-working enlargers or a gamma of 0.62 to 0.70 for soft-working enlargers/lighting systems (here, a gamma of 0.65 is usually considered ideal) to reproduce your correctly exposed, normal scenes on paper with a gradient of 2 to 3!
This gamma value is therefore also ideal if you are making a contact print on these very papers (the same applies when using multigrade papers or exposure systems, etc.)
A practical observation:
When I make a contact print of one of my 4 x 5 inch negatives using an LPL-Jobo enlarger and split-grade on Classic Arts paper (matt), I do so using the same negative (with a gamma value adjusted for this enlarger) that I would also use to make a print/enlargement beyond the negative format! However, if a certain enlargement factor is exceeded (4x, in my opinion), the shadows become weak and one usually tries to compensate for this with a higher gradient. The print then does not remain in the range of 2 to 3, but may reach as high as gradient 4. However, this has nothing to do with the gamma value, but rather falls into a different category of issues. In my opinion, if you wish to retain your tonal range and grey-scale gradations to some extent, you should not exceed a 4x enlargement, as a visible loss of quality occurs beyond that point. With contact printing, there is practically no loss, as it is 1:1.
2. The difficult answer:
- I cannot give you that, as it relates to specialised contact paper, which is constructed somewhat differently (and reacts differently, even depending on the brand) than normal photographic paper, because I do not work with contact paper. I therefore do not know what speed contact paper has. The latter would certainly be important, however, for appropriately adjusted negative development – including the gamma value.
A brief note on the fixer:
I am not a chemist, so I cannot answer that question. Suffice it to say that Tetenal explicitly describes its fixer as a fixative. Since it is not strictly necessary to precede the fixing stage with a stop bath, I could imagine that the retarder works even without a stop bath.
Labor Partner (LP) offers a very good retarder stop bath in the form of LP-Citrodur. Furthermore, if you want to be absolutely sure, you can also use LP-Geladur. This is a fixing developer additive and therefore takes effect from the very first ‘bath’. As far as my practical work is concerned, I am not aware of any disadvantages with either Citrodur or Geladur, nor have I noticed any.
Best regards
Zensusa / Lo van de Renne
MatthiasS
Hi Lo,
Thanks for the informative reply – it confirms my view that there’s nothing better than a correctly exposed negative.
As for my problem, I’m just thinking a bit ahead: it’s about Efke, which – according to this forum – doesn’t like being stopped (or rather slowed down) with anything other than water. I’m wondering if I can get it to develop properly without having to use a stop bath.
Also, I’m toying with the idea of mixing up some Pyro at some point – though a curing agent is explicitly advised against in that case, as the film goes back into the same bath to get more ‘stain’, which it would then no longer accept. The only question remaining is: when does a curing agent need to be used?
‘Fixative’ curing agent; Does that mean the fixer is added to the fixer? Or better still, could one, for example, mix a fixing agent as a separate bath and simply fix again before the final wash? Ever since my first attempts with Efke in 8x10”, I’ve had a hell of a lot of respect for the stuff; the emulsion is really soft once it’s wet. I develop in a Jobo Expert drum, so not much can go wrong in itself, unless a stone somehow ends up in the can for whatever reason, but by then it’s too late anyway – it’s just that I’m worried about getting the negatives hung up without damaging them.
Regards
Matthias
zensusa
Hello Matthias,
Just a quick note this time about Efke films and caps.
1. Efke films do have a sensitive emulsion, but they can withstand more than some people on the forum claim. I’ve been working with Efke films for years – both roll films and sheet films – and there are no unusual incidents as long as you treat the films as you should treat film in general!
2. Which brings me straight to the second point: the ‘speed’ when it comes to stop baths, or the idea that ‘you should only stop the film in a water bath’. That’s all myth, prejudice – a self-perpetuating myth that doesn’t become any ‘truer’ through constant repetition: - Of course you can treat Efke films with a stop bath; either with a vinegar stop bath (60% vinegar in a 1:30 ratio) or with Citrodur (lemon-based), which already contains a fixer. So, stop and fix in one go! I’ve had no problems with either method!
3. Tetenal Hüter (“Fixativ Hüter”) is added to the fixer and therefore certainly works even without a preceding stop bath. Just give it a go!
4. For those who are really worried about layer separation, scratches and other concerns, I can only advise: add LP Geladur to the developer and stop with LP Citrodur. That’s definitely enough! By the way, I don’t have an advertising contract with Labor Partner :-)
4. I can’t say anything about “Pyro”; it’s too time-consuming and fiddly for me, so I don’t use it. R09, when used with correctly exposed films, provides everything you need for both roll and sheet films!
5. As for hanging the films, I can only say: be mindful and patient! In plain English, you’ll just have to practise and come up with a method so you don’t ruin the films whilst hanging them up. And importantly, don’t forget the “Proofmaster” wetting agent bath – after all, it also has a few “protective functions” for the health of the film.
Right, that’s it for now. Have fun taking photos and developing them.
Best regards,
Zensusa / Lo van de Renne
