[alt-photo] Re: Ziatype questions

[Loris Medici]

  A last remark (just noticed the technical part of the very last part 
of your entry):

- FWIW, my exposure time with a bank of 40W UVBL bulbs was something 
around 6:30...


05.08.2010 23:02, Loris Medici yazmış:
>  I'm reading your blog(?) entry right now, some remarks:
>
> - You should get something like 27 to 29 steps (w/ the 31-step tablet, 
> which means log 2.9 DR at max - including pure black and pure white) 
> with straight LiPd + AFO sensitizer, whereas your step tablet print (I 
> think it's a 21-step tablet) shows too little step count, should be 
> something around 19 steps, if it's indeed a 21-step tablet... (Read 
> as, you really need strong negatives!) Normally you should be able to 
> see tonal separation at the 20s and 30s. (No tonal separation before 
> 40s is a property of high contrast processes like cyanotype, not soft 
> processes like palladiotype...)
>
> - The curve looks very drastic; Ziatype was giving me the smoothest 
> and mildest curve I've ever designed with any of the alt processes I 
> worked with...
>
> - The transfer to acetate suggests (to me) that the sensitizer isn't 
> well absorbed into the paper and stays on top. (Not that I've seen 
> anything like this before!)
>
> In short; there's definitely something going wrong there, and my gut 
> feeling is that the paper is causing the problem(s), not something 
> else...
>
> BTW, how does 16 drops translate into ml's with your pipettes / 
> droppers? (8+8 drops doesn't say something to me...)
>
> Regards,
> Loris.
>
>
> 05.08.2010 22:48, Vedos yazmış:
>> Thanks Loris,
>> OK, I'll dry the paper longer... another try tomorrow.
>>
>> About the EDTA, I don't really know which variety... maybe I better 
>> forget about it and use sod. sulfite (or citric acid as you suggest).
>> The paper is Guarro Casas (from Spain), like it a lot... I made small 
>> tests today, used 8 + 8 drops for a 12x16 cm area.