John,
The stain produced by Pyro developers is a UV blocker and results in
more contrast because it is greater in the highlights than the
shadows.
This is explained in some detail on p. 3 of my article on Pyro
developers. Go to http://unblinkingeye.com/Articles/PCat/pcat.html
and for the question of the impact of stain with different processes,
which is really quite complicated, see page 3.
Sandy
>Sandy,
>
>I was responding to the email below. Where you say using ABC does not
>produce a lot of stain. I am confused by your paragraph. You essentially say
>that by having more film stain you get more contrast...? I was just seeking
>clarification because I have never used Pyro in conjunction with UV
>processes.
>
>Regards,
>
>John
>
>
>> John wrote:
>>
>> Hello,
>>
>> I am bit confused with this line of questioning. Are you saying that
>> PyrocatHD has less of a staining effect, thus it exposes faster under UV
>> processes?
>>
>> Regards,
>>
>> John
>>
>>
>>
>>> I am confused by the question. I don't remember anything like that
>>> being mentioned in my exchange with Cor.
>>>
>>>
>>> Sandy
>>>
>>>> Cor
>>>>
>>>>
>>>> Yes, I have been testing with Pyrocat-HD, and also with ABC Pyro. ABC
>>>> gives much larger grain than Pyrocat-HD but develops more contrast
>>>> for blue sensitive processes like AZO and graded papers. On the other
>>>> hand ABC does not produce a lot of image stain so for UV processes
>>>> you get more contrast with Pyrocat.
>>>>
>>>> Sandy
Received on Thu Mar 4 12:10:22 2004
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