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Is it important to use acetic-stoper for rodinal

cameralover

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Sorry if I ask stupid question. I will start my first film-development in this weeken. I already have important reagents such as parodinol (very clear one), fotospeed fx30 and tetenal mirasol 2000 (wetting agent). But I still have no idea do i have to use stop solution after parodinol-developer. I already have gracial acetic acid and ready to dilute it immediately if you suggest that it's really important. Thank you all.
 

bdial

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A stop bath of some sort is important. Using an acid stop will help an acid fixer last a bit longer. However, I generally use plain water for film.
Alkaline fixers do best with a water stop rather than acid.

Opinions vary, this might be a long thread.
 

Jerevan

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Plain water with citric acid in it, that's what I use, and after that Ilford Hypam as fixer.
 

Murray Kelly

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Um .... I hate to say it and it may sound picky, but if the paRodinal is colorless there may be something wrong with it. Most people making/using it describe it as pink initially going to light brown and so on down to black like the real stuff!
Don't be discouraged if you don't get what you expect with the first roll. It could be the developer. Look for the numbers on the edge of the film. If they're not there the paRodinal is not quite right.
Try again. That first roll of black negatives is one of the events in your life you'll never forget.
Murray
 

df cardwell

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Rodinal just needs water.
 

Mahler_one

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With Formulary TF4 fixer a water stop bath is suggested for both film and prints.

Ed
 

Nicholas Lindan

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if the paRodinal is colorless there may be something wrong with it.

Before developing the roll, put the snip of cut-off film leader in the beaker of developer and make sure it turns black.

I have found Rodinal requires steam distilled water for formulation and dilution as the tap water in my part of the world is variable and often very cruddy.
 

Murray Kelly

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Yes, I would hate for him to get discouraged by the very first film he processed to not turn out and he didn't know why. I can remember my first film in 1948 with the developer, quite litterally, in a soup bowl.
I had my parents call out when the time was up to switch to the fixer - no nonsense about stop baths for a 12 year old in them days!
Seeing that 1st film come up in ordinary light is something quite magical. I can still describe the pantry where I worked with blankets over the doors.

Oh yes - I use deionised water when I homw brew, which I get from the auto supply shop. The other chems have to get by with filtered or plain ol' tap water. Most big house suppliers make allowance for water variability by including chems to soften, chelate, or whatever, the tap supply.

Murray

 

Ian C

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I’ve used water with vinegar as a cheap stop bath for both films and papers for years. It’s cheap, readily available, and seems to work. Vinegar is about 5% acetic acid, which is the principle ingredient of commercial stop baths. So it has the correct acid to quickly neutralize the developer. It certainly stops development quickly and more thoroughly than plain water.
 

Murray Kelly

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I agree in principle. But if your'e using Rodinal (paRodinal) at 1:100 or more plain water works just fine. We are talking development times in the order of 15-25 mins here, and the odd 15 secs or so of stopping development is almost inconsequential, surely? If one requires more exactitude than that then incorporate it into your developer/fixer cycle timings. Always keep it simple.
Most manufacurers advise against using an acid stop because it can affect, badly, the final result. It causes blistering and so forth of the gelatine.

 
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cameralover

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Opps sorry, may be cause of my bad English. My parodinol is pink at first and then slightly transform to straw and untill now it a bit darker. The word "clear" for me is mean nothing floatin in the solution. I use magnetic stirer , deionized water (18 ohm), and filter it again in the end. I am a scientist, actually, so i tried everything untill I've got a satisfied one. However, Thanks all

I plan to use 1:50 dilution so it should be fine if I use just water, isn't it?
 
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Murray Kelly

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Sounds good to me, you have the basics well in control, it seems.
I just didn't want you to get despondent over a film that didn't turn out quite right.
I know what you mean by 'clear' now and it sounds like you have a good 'brew'.
Good luck and happy landings. I'm sure you will soon be an avid B&W afficionado and contributor to APUG.
Murray

 

df cardwell

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Rodinal needs a very high pH to function.. Water is more than sufficient to stop the development.
 

nworth

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A water rinse works fine with Rodinal, but an acetic acid stop does no harm. I generally rinse twice with water. Most alkaline fixers are sufficiently buffered that the very small residual of acid after draining the stop bath from the film will not affect them, and it has no noticeable effect on acid fixers, which are moore common.
 
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cameralover

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One more question, how long does the develop time with 1:50 dilution. I use 120 of neopan 400 and shoot it at ISO400. I read from this link: Dead Link Removed and it showed that 11 min but the ISO is 320?? what does it mean actually? Someone help me please.
 

John Irvine

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Be Careful with Glacial Acetic Acid

Glacial acetic acid is a strong acid and should be handled carefully. It is nothing to be afraid of, just respected. Rinse it off right away if you get some on you.

It is essentially 100% acetic acid. Never use it straight. Dilute it to 28% by carefully adding 3 parts acid to 8 parts stirred water. That is your working solution to keep on hand. To use as a stop for film or paper, dilute it further by adding 1.5 oz of 28% acid to a quart of water.

There is no concensus whether to use an acid stop or not. I use it for both film and paper because I like to apply the brakes rather than roll to a stop. Outside of a PhD dissertation, I doubt you could find any difference between the two in your picture.
 

clayne

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Glacial acetic acid is a strong acid and should be handled carefully. It is nothing to be afraid of, just respected. Rinse it off right away if you get some on you.

However, it does go great with salad!
 

PHOTOTONE

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However, it does go great with salad!

Just a safety note: If you are going to use Glacial acetic acid on a salad, be sure to dilute it to the strength of common vinegar (about 5% solution) or you will risk your health and burn your insides. When diluted to a 5% solution it should be identical to distilled grain vinegar.
 

nworth

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Make that about 1 percent. The usual stop bath is a bit less than 2 percent.
 
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cameralover

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Thanks all, the 1st experiment will be performed tomorrow. So excite!
 

gainer

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White vinegar as used in canning is, according to the label, is 5% acetic acid. It has less other stuff in it than ordinary cooking and salad vinegar.
 

Ed Sukach

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White vinegar is usually marked as "5% Acidity". Most stop baths are 1% acetic acid; so the proper dilution would be 1 part white vinegar to 4 parts water.
The only place I consider "stop" to be necessary is in color printing, between color developer and bleach-fix. In film developing, I've experienced "pinholes" from excessively acidic stop bath. 1% seems to be affective and safe enough.