I always ask stupid quetions again and agian here.
As you know,I am a Chinese guy.Almost all the Chinese people have black hair.I am shoting some dags for them.
From the first day when I can make a visible dag,I found it was really hard to let the black area no any tiny mercury spots left(I do not know how to call it in English,maybe I can call this as mercury frost).
These days,I made lots of experiments.I made about 30 images on receycled 4 plates.I found an interesting thing:
I devoloped the plates from 3 minutes to 17 minutes(70C and 100C).The room temprature is about 20C-22C.The latent image bacame to be visible from 4 minutes in my pot(I made my pot too big,it is really a big mistake,so my dags need to be devoloped much more slowly than others).
70C:
4 minutes-10minutes develop:very faint,and just like mercury frost on everywhere,especilly in the black area.
11minutes-13minutes:more better,no mercury frost excepet totally black area.
15 minutes:good,still mercury frost in black area.
100C:
5 minutes-7 minutes:faint image,no mercury frost except black area.
8-9 minutes:better,still mercury frost except black area.
11 minutes:good,black area mercury frost.
15 minutes:like fog on the whole plate
I think the mercury develop the latent image: very very tiny spots cover and accumulate and let the latent image visible.At fist,the whole plate just like to be sprayed and somewhere have no any mecury elements;then,mecury cover all over the plate;after that,mecury covered too thick and let the image can not be visible.Am I right?
OK,there is my stupid question:
Why the totally black area always has mercury frost?even nonengough develop time?In my dag images,Chinese people’s hair always have so many tiny black spots.
Some of d’typists let there subject before black velvet,why they have not problems which I have?
Looking forward for your reply,
Best,
Li