Re: relief

Richard Sullivan wrote:
> Halvor,
>
> I'm following your adventure with interest.
>

thanks, and let me add an extra thanks for keeping that website (and not
selling mopeds), I have been reading through your tech section several
times the last years.

> That 3 mm is a wet coat, right? How do you measure it wet?
>

yes, "wet" or gelated as in "solid" gel with water, eh.. names of tools
is a bit missing from my vocabulary in english.. right, and 5 online
dictionaries refused to translate it. basically a ruler, with a moving
part - at one end clamps measures with, other side "insides" as in screw
holes diameter, on the other end depth, precision is 0.01 mm, normal
tool for metal work. a "pushing ruler" would be a logical translation
from Norwegian.
        Clearly a case where a picture would have helped.

        (Also of course, it is a function of volume - 30x120x3 mm is about 11
ml, say 15 ml, as this is thick and a few ml sticks in the "another word
missing" - measure up/make up, a dam or mold with clay, suitable for
size of the the test, on a piece of glass, make marks in the clay for
wanted thickness and pour in the gel.)

bit tired here that got confusing..

> As for getting a high relief I think it is a function of dichromate
> concentration, pigment concentration, and tissue thickness.
>
> <Dichromate, >relief
> <Pigment, >Relief
> >Thickness, >relief
>
> I believe this was referred to as "carving depth" by latter day carbon
> folks. Too much pig and dichromate and you don't have the light
> penetrating very deep into the tissue and thus less relief.
>
big ear waving

> I've not tried to make a high relief tissue yet on my machine. It's one
> of the ideas I need to explore in the future. It may prove to be
> impractical as a machine made product. THis may be one advantage to
> making lay-down tissue.
>
> --Dick
>

would like too see that machine, but bit far away,, while I think it
could be done, it would probably be messy & slow,,,

it is still early with my tests, have had a bit of a multiple errors
situation for a while and did first today/ystrd start to get results
that looks reasonably similar to a step tablet.

are right now using that wet exposure simply to save time and avoid some
problems with dark reaction, at least one of the gelatin types I have
here is not good for long drying times. will look closer at that later,
but need to get a basic procedure up and running before optimisations.

the test mentioned yesterday; I did have a better check of the thickness
, after drying, with a micrometer, the 30 min exposure gave a 120 micron
thickness, the one hour exposure gave 330 micron, that is 0.12 mm and
0.33 mm (if I take off that white coat), now as said, my working method
is still a bit rough, but this looks like it could make sense taking
into account that the first test was dumped into cold water after dev,
although I read somewhere that this was recomended for preserving the
relief, transfering photographic gelatin products (film) from hot water
to cold water is at least in normal black and white wrong, what is the
word "cracilation" ? the swollen gel was not entierly happy about that.
got a bit wrinkled.

the second test could also maybe have stayed a bit longer in the "dev".

will try again next week, with a sequence of 30 min, 1 hour, 2, hour and
4 hours and see how it goes, if 8 hours seems like a possiblity, I can
probably just as well start drying the tests to start with, as I am not
going to save much time anymore....

One question, The Woodburytype mentions a development sequence of first
cold water until the dichromate is cleared out then increasing
temperature for development, is this neccesarily ?
        To get rid of left over dichro into one water bath would simplify the
enviormental concerns (of this school, I have none, (I do doubt that me
releasing 0.1 gram dichro a day mixed to infinity with water is that
bad, but..)) but does for a dry gel of this thickness take several
hours.. overnight seems to be the easy but slow solution...

I will be offline for some days, will try to limit the lenght of these
mails in the future, sorry.. once I start writing I tend too keep on..

but thanks for listening
Halvor
_______________________________________________
Post to the list as PLAIN TEXT only - no HTML
carbon mailing list
carbon@spitbite.org
FAQ at http://spitbite.org/carbon/list.html
Received on Wed Dec 15 06:16:11 2004