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Doesn't T-Max block UV?
----- Original Message -----
Sent: Monday, March 30, 2009 7:07
PM
Subject: Re: BL light box 'blues'
Let me see, 2:2:100 73C 13mins... it's Tmax-400 right? Well, I
can't say
anything other than suggesting to expose a test sheet (w/o any
negative)
in the contact printing frame, covering (or uncovering) it
gradually too
find out the minimum 'black' exposure for your emulsion /
lightsource
combination and see how that compares to others'
timings.
With my lightsource (bulbs 2" above frame glass) I would get
something
like 5:45 (no negative, 6:30 with Pictorico negatives) to achieve
a
convincing black with 2A:1B trad. cyanotype.
Hope this
helps,
Loris.
31 Mart 2009, Salı, 12:46 am tarihinde, Ken
Sinclair yazmış:
> Hi Loris...
>
> I checked out Sandy
King's article on introductio to Pyrocat-HD where
> I observed
>
his recommended 2:2:100 (distilled) water to achieve a log density
> of
.080 - .085 for
> VDB.. so the negatives received a developing time of
13 minutes at 73°
> F...
> They look OK to my eye....
although the 'stain' is not as obvious to
> the eye as the stain
>
I am used to with PMK.
>
> The negatives do not seem to be what
one might consider "bulletproof"
>
>
Ken
>
>
>
>
> On 30-Mar-09, at 3:04 PM, Loris
Medici wrote:
>
>>
>> Maybe your Pyrocat negatives are
way too dense? They can get perfectly
>> bulletproof negatives (in
case of overdevelopment) while they fake
>> like
>> being
thin; the brownish stain is a pretty strong UV light
blocker!
>>
>> What film, EI, Pyrocat dilution (A?B?H2O?)
and development time (and
>> regime) have you used for the negatives?
Maybe someone with good
>> experience with Pyrocat may evaluate this
info and tell you if you're
>> indeed overdeveloping the
negatives.
>>
>> Regards,
>>
Loris.
>>
>>
>> 30 Mart 2009, Pazartesi, 11:48 pm
tarihinde, Ken Sinclair yazmı�:
>>> Have recently
decided to intensify my interest in non-silver, I
>>> constructed
my
>>> new UV light-box using 10 BL tubes presently 5 inches above
my
>>> printing frame.
>>>
>>> So that I
could use the same negatives for both silver-gelatin,
>>> Cyanos
and VDB
>>> I switched to Pyrocat as a developer... and I must
admit, they do
>>> look "sweet".
>>>
>>> A
few years ago my southern Alberta summer sunlight exposures
for
>>> Cyanos were
>>> running around the eight
minute mark... which expanded to around two
>>> and a
half
>>> hours in the rather weak December
sun.
>>>
>>> The exposure times I expected using the
new 24" BL tubes are nowhere
>>> as short as I had
>>>
hoped... Cyanotypes seem to be requiring around 40 to 50
minutes
>>> while I have not
>>> yet reached the
'end-point' for acceptable VDB exposures, it seems as
>>> if 60
-70 minutes
>>> might be the absolute
minimum.
>>>
>>> I do not have a stouffer wedge to
assist reaching my standard
>>> exposure times, my patience
is
>>> wearing (as my frustration level
rises).
>>>
>>> I have just put a VDB out on the deck
to enjoy some natural UV rays
>>> from the sun
>>> for
a time comparison...
>>>
>>> Are my BL light-box test
exposure times "out of line" with times
>>> experienced by
others?
>>>
>>> Ken
>>>
>>>
Quando omni flunkus moritati (R.
Green)
>>>
>>>
>>
>>
>
>
Quando omni flunkus moritati (R. Green)
>
>
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