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Calbe 49
#1
Is this developer the same as rodinoll!!

If not what is the difference??

Niall
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#2
Hi Niall,



Calbe A49 is completely different from Agfa Rodinal. A49 is a fine grain powder developer. Rodinal is a liquid, highly concentrated acutance developer.



To make it easier for you to understand, A49 will produce finer grain, lower acutance (sharpness).

Rodinal will produce noticeable grain with high speed films and high acutance. Rodinal concentrate will keep almost forever in air tight containers, A49 stock solution about 6-12 months.



Calbe R09 is similar to Rodinal, hence it is the old recipe and lower concentrated.



Hope this helps.



best regards



Michael
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#3
In addition to Michael's comments I would like to add that Calbe A49 is also great for pushing films (very much unlike Rodinal, which loses some film speed); I like it a lot for portraits, or for pushing TMax 3200 up to EI 3200 (the real speed is around 1000 to 1250) - works well with A49 1+1, 20 min.

If diluted, A49 still is not as sharp as Rodinal (which I prefer for landscapes or architecture, though I recently switched to a homebrew recipe by Barry Thornton, which gives more film speed and less grain).

Also, if used at 1+2 or higher dilutions, you won't reach very high negative contrast levels even with longer developing times, for me 1+1 is the ideal compromise; I don't know which film you use generally, but I love Fuji Neopan 400 (shot at 320) in A49 1+1, 13 min., for portraits (and Neopan 400 at EI 250 in Rodinal 1+50, 9 min., for landscapes).



Roman
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#4
I'm using Neopan 400 at the moment Trying it out as it were and I

Develope it in rodal standard dilution!

gives good results but, would like to try A49!!

Now tell me why does one push or pull a film!!

And what effect does it give prints!!!

Niall
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#5
...Come to think of it why do you people change the film speed!!

Niall
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#6
Pushing the film: not a good thing for picture quality, you will get more grain, extreme contrast, and might get blocked high-lights or undefined shadows, or both at the same time... Why do we do it anyway? Well, sometimes there is simply not enough light to expose a film at it's real speed, and sometimes a tripod adn long exposure times are not the solution (e.g. when shooting people - movement would be visible).

Pushing is mainly used in for taking pictures of people in low light, when the subject matter is more important than the picture quality...



Pulling film: This is used to reduce negative contrast in scenes with very contrasty lights (e.g. bright sun at noon).

Lowering the exposure index of your film (i.e. shooting 400 ASA film at EI 250) is not always pulling film - most manufacturers are simply a bit overenthusiastic when it comes to rating their films' speeds...

Shooting at the 'real' film speed (which, depending on the whole chain of shooting a picture - camera shutter, lightmeter, development - different developers give different film speeds with the same film type, type of light source of the enlarger, contrast range of the printing paper, print developer used) will give you more easily printable negatives with more open shadows that will show finer detail.

There are methods to establish the 'real' film speed using a densitometer and a lot of math, or you could one of the two following methods:

go to <htttp://www.barrythornton.com> and click 'Unzone';

or go here:

<http://www.halfhill.com/speed1.html> and

<http://www.halfhill.com/speed2.html>

.. or you simply rate your film a bit lower than what is printed on the box (64 to 80 for a 100 film, 250 to 320 for 400), and reduce your development times for about 15%.



Roman
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#7
Dear Niall,



A49 is a developer like Agfa Atomal, it delivers very fine graine, also a good solution for highspeed-films with 27 DIN and more.

But on the other hand, you must expose and develop a little more precisely, I take A 49 only for films with higher speed.

If you want to have a developer between Rodinal and a49 I would recommend ILFORD ID 11, thats my developer for Films between 15 and 21 DIN.

In addition do not take the undiluted developer, because the times are not very precisly given, to make same results after some films.

Take better dilution 1+1 or 1+2.

Finally, I would not push or pull films because they delivers the best results with the onprinted speed (good there are some developers that change speed about+- 3 DIN for best results)



Werner
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#8
Niall,



why do we push and pull films? Well, first of all the ISO rates do not have to be accurate for your equipment and taste. Therefore many people do calibrate their processes to achieve the desired result. Besides that you usually push films when the contrast of scene is low. By pushing you extend the density range on the negative for a given exposure. Let's say the contrast of scene is 3 EV steps then you increase the ISO setting (underexpose) and prolong the development so that the negative density range will be 1.2 (Dmax - Dmin) which equals 4 EV steps. Pulling would be exactly opposite.

Pushing provokes grain, pulling is a very common way of adjusting to standard needs and still be safe on bright scenes. It is usually better to development shorter and print harder instead of doing the opposite.



br



Michael
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