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David Aimone
9-Nov-2010, 07:41
Ok, I spent some time searching first but didn't find an answer (I did find an old controversy though), so here goes with a new thread...

I'm looking to try Pyrocat-MC in a Jobo tank, mainly with Fomapan 100 and Efke 25. The web site doesn't list development times for these, and the Massive Dev Chart only lists times for HD and M.

What is the difference between MC and M?

Are there reference starting points for development times for MC with these films? I'll eventually do my own tests, but a reference point would be nice.

Still a newbie (just processed my first films in my new home darkroom this weekend using D76 with success). Learning one heck of a lot!

Jay DeFehr
9-Nov-2010, 11:46
MC refers to Metol and ascorbic acid (vitamin C), and M omits the ascorbic acid. I think they are similarly active for similar development times. There should be a lot of information on these excellent and very popular developers on this forum and others, including:

http://www.pyrocat-hd.com/

Good luck, and enjoy!

David Aimone
9-Nov-2010, 12:38
Thanks for the info and the links. I will read more.

mdm
9-Nov-2010, 13:48
MC is mixed in Glycol to extend its shelf life and M is not. They can be treated the same when developing film. I use M because it is very easy and cheap to mix up at home. I cant help with times for those films in a Jobo but you could look into divided development and then the time is the same irrespective of film. I use minimal agitation and develop all of my film for 36 minutes, with 4 agitation cycles, most of the time. 1:1:150 is usually the dilution used for minimal agitation. They always seem to scan fine unless they were severely overexposed. Pyrocat is a nice developer but it might be best to stick with what you are using untill you have finished it, no point in chasing a silver bullet.

David

David Aimone
26-Dec-2010, 18:13
Ok, I might be missing the obvious here, but I purchased some Pyrocat-MC in glycol. It comes in two bottles of liquid (part A and part B). But the mixing directions on the paper don't seem to match up. These are the directions that came in the package, the same as on the digital truth website:

http://www.digitaltruth.com/products/formulary_tech/01-5095.pdf

For Stock Solution A, I am assuming I have to mix a certain volume of the bottled liquid with distilled water and glycol, but it lists four separate specific substances by grams. How do these correspond to the pre-mixed part A in ml?

Same for Solution B, distilled water, water and 75g of potassium carbonate. How does this relate to the liquid in bottle B?

Do I have the wrong directions, or am I not looking at this correctly?

Jan Pedersen
26-Dec-2010, 18:34
It sounds like you have purchased the already mixed solution A and B so disregard the mixing instructions, they are for those mixing A and B solution from scratch.

One thing that is a bit vaque is the instructions on mixing the stock solution.
Do NOT mix solution A and B together but first mix part A 1/100 of your final amount of Developer and then part B 1/100 of your final amount of developer.

You can mix part A into the distiled water ahead of time but do not ad part B until right before you are ready to pour in the developer. The mixed developer will start to oxidize quickly so you want it to be as fresh and active as possible.

David Aimone
26-Dec-2010, 18:38
Jan,

Do I need to mix part A 1:100 with distilled water or glycol? Same question with part B? I searched high and low for glycol, but are you saying it's already in the premixed bottles, just add water?

I'm still confused!

David


It sounds like you have purchased the already mixed solution A and B so disregard the mixing instructions, they are for those mixing A and B solution from scratch.

One thing that is a bit vaque is the instructions on mixing the stock solution.
Do NOT mix solution A and B together but first mix part A 1/100 of your final amount of Developer and then part B 1/100 of your final amount of developer.

You can mix part A into the distiled water ahead of time but do not ad part B until right before you are ready to pour in the developer. The mixed developer will start to oxidize quickly so you want it to be as fresh and active as possible.

Jan Pedersen
26-Dec-2010, 18:43
Did you receive two 100ml bottles with liquid labeled Part A and B?
Or, did you receive various small packages with the dry ingredients and the Glycol?

If you just received the two bottles filled with Part A and B and nothing else all you have to do is to mix what you got 1+1+100 (A+B+ water)
Just do not mix A and B together first.

David Aimone
26-Dec-2010, 19:06
two bottles...so, no need to make a solution out of each first, just add the two together with water right before using, right?

Jan Pedersen
26-Dec-2010, 19:16
Yes, what you got is the final solution, no more dilution until you are ready to develop film.
But as i said do not mix part A with part B.
Mix part A with water first and then part B just before you are ready to pour in the developer.

John Bowen
26-Dec-2010, 19:17
Yes

David Aimone
26-Dec-2010, 19:27
Thank you all!

David Aimone
27-Dec-2010, 06:52
So, one last thing. In 16 ounces of developer I'm looking at about 1 teaspoon from each bottle, if my calculations are correct and 1 ounce=6 teaspoons?

Jan Pedersen
27-Dec-2010, 07:38
You really need to be much more accurate with measurements than what you will achieve with a teaspon.
Buy some 10ml syringes at the pharmacy and two beakers, 500 and 1000ml will do for most processing.
Pyrocat is a very diluted developer, if you want consistency in your procesing accuracy is key.
If you need 500ml to process your film you only need 5ml of each A and B, there's no way you can measure that with a teaspoon.
Good luck.

Jay DeFehr
27-Dec-2010, 08:27
I have an assortment of measuring syringes, and use the one closest in capacity to the volume I want to measure. A 3ml syringe is perfect for making 300ml of 1:100 dilution developer, for instance, and 5ml for 500ml, etc., but a 10ml syringe is infinitely better than using a teaspoon. And be sure to use dedicated syringes for each stock solution. Contamination is one of the biggest potential problems (along with miscalculation the ratios and dilutions) in using a two part developer like Pyrocat.

David Aimone
27-Dec-2010, 17:56
Well, here's a sample from my first use of Pyrocat-MC. Pardon the fact that it's a medium format, but now onto 4x5! Only a 1200dpi scan also. Thanks for your help. I think I like the stuff! There is something about it...

http://www.davidaimone.com/img/s3/v24/p882504343-4.jpg

Jay DeFehr
27-Dec-2010, 18:37
Very nice! Congratulations!

onnect17
29-Dec-2010, 08:40
So, one last thing. In 16 ounces of developer I'm looking at about 1 teaspoon from each bottle, if my calculations are correct and 1 ounce=6 teaspoons?
There's a book titled "The Darkroom Cookbook" 3rd ed. In page 333 the author offer a table with typical measurements for most used chemicals. If you do not own the book please send an PM with your email and I will send you the information.
Armando

David Aimone
29-Dec-2010, 15:41
Actually, Santa just bought it. I will refer!.....


There's a book titled "The Darkroom Cookbook" 3rd ed. In page 333 the author offer a table with typical measurements for most used chemicals. If you do not own the book please send an PM with your email and I will send you the information.
Armando

Jay DeFehr
29-Dec-2010, 17:55
David,

Out of curiosity, what was the film and development?

David Aimone
29-Dec-2010, 18:33
Jay, it was Delta 100, Pyrocat-MC for 7:15. I now realize I was supposed to increase time for rotary processing...but I still like it.

Jay DeFehr
29-Dec-2010, 18:36
I think people usually decrease time for rotary processing. Well done!

David Aimone
29-Dec-2010, 19:44
Sorry, meant decrease! Thanks!