Higher dilution Perceptol ? 1+5?

[jarodfwh]

hi all,

i had recently just got myself a pack of Perceptol to try with Ilford Pan F for min grain, currently shooting 6x4.5 in a Fuji GA645Zi rangefinder medium format.

The problem is my current tank (AP) need 590ml of solution (~ 600 ml) to cover one roll of 120 film.

so when i am using dilution of 1+3 , i need roughly 150ml of stock solution (+450ml of water) for each roll, thus 1 litre of stock developer can last me only 6 rolls which is relatively low number compare to the possible of minimum 10 roll of film(135/120) per 1l of stock solution as stated in one of the fact sheet i read.

now come the question, is it ok to use 100ml of stock solution (since 1 litre can last for 10 roll) + 500 ml of water which is 1+5 for one roll of 120?

if yes, what are the changes in the development process that i need to do? more inversion? longer development time ( how long ) ?

lastly what effect can i expect with the change in dilution? higher contrast? more grain? etc

thanks

 

[Fotohuis]

The best compromize for Perceptol for fine grain and reasonable sharpness is 1+1 for PAN F+ and most films. By diluting more you are also diluting the amount of Sodiumsulfite which gives you the extra fine grain so here you make the choice between grain and sharpness. Further you need a minimum amount of concentrate of the developer for each 135-36 or 120 roll film area.

Even better in sharpness and still fine grain is CG-512 a recept of Udo Raffay, sold under Rollei Low Speed developer but it is working on 24C. Theoretically the finest grain you will get will Ortho- or Para- Phenylene Diamine. I am talking now for developers like W665 (Windisch) or MCM100. With all these Ultra Fine Grain type developers you will loose 1F stop of film speed.

Here an example of W665 (stock) with Fomapan 200 film (35mm), E.I. 80-100.


W665_Fomapan_200_iso100_web by Fotohuis (Robert), on Flickr

 

[jarodfwh]

The best compromize for Perceptol for fine grain and reasonable sharpness is 1+1 for PAN F+ and most films. By diluting more you are also diluting the amount of Sodiumsulfite which gives you the extra fine grain so here you make the choice between grain and sharpness. Further you need a minimum amount of concentrate of the developer for each 135-36 or 120 roll film area.

Even better in sharpness and still fine grain is CG-512 a recept of Udo Raffay, sold under Rollei Low Speed developer but it is working on 24C. Theoretically the finest grain you will get will Ortho- or Para- Phenylene Diamine. I am talking now for developers like W665 (Windisch) or MCM100. With all these Ultra Fine Grain type developers you will loose 1F stop of film speed.

Here an example of W665 (stock) with Fomapan 200 film (35mm), E.I. 80-100.


W665_Fomapan_200_iso100_web by Fotohuis (Robert), on Flickr

thanks you so much for the response.
actually my confusion is are we able to compensate for the dilution if we prolong the developing time?

for example, for a litre of perceptol stock solution, its suppose to be able to develop 10 roll of 135/120 film, thus it mean 100ml of stock solution should provide adequate chemical including Sodiumsulfite to produce the said sharpness and fine grain regardless of the dilution.

So theoretically, even at 1+5 ratio, if i leave it long enough to fully utilise the chemical( i.e. Stand development process theory ) , it should produce similar final product comparing to 1+3.

( p/s: i am not looking at finest grain but relatively fine grain compare to RO9/D76/ID11)

thank you again for your response and hope to hear more from you

cheers

 

[Fotohuis]

If your volume of the developing tank is big enough, yes you can do this. But Stand development in a high dilution will cause bromide drag.

And why would you like to dilute Perceptol in this way. Perceptol is especially used to suppress the grain.

Then it would be a better choice for another type developer.