Recent content by vasya1945

I'm necroposting a bit, but is op's recipe doing someting like this? I recently realized that even photograms are interesting, and with positive chemistry there is even more room for experiments...

I think your curve comes from amalgama heating inside the cfls. I'd give it a couple of minutes for mecrury concentration to stabilize. The led units I posted are pretty bad inside. There is like 5cm blob of glue for 20x25 board. That the only spot of contact with casing. But still fan seems to...

I wonder if it is practical to make positive cyanotype from your negative...

I was mounting them on a plate and cooling with external fans. My experiments were not progressing and I was only printing test strips. So I assembled the fixture back. Now I use it in it's original shape but still keep external fans on. Inside the led pcb is only touching metal surface in some...

I only have two. I was thinkig of having 4, but with 4 there will be a gap (bezels are thick on short side) and then I'll have to move them a bit away and some light will be lost. For other procecess it's not a problem, but cuprotypes exposure can get too long. And I couldn't make cuprotypes...

If you do 4x5 than you can get one of these chinese ligh sources. Led assembly size is 16x22cm, so you can put it pretty close to the negative so no light is lost. In my experiments it gave around 20mins exposure (to the point where uncovered paper and film covered part burn to the same...

Do you mean that with iron toner prussian blue is produced? If so the colors I get is what you'd expect from mixing blue and brown . That's good news, we have reasonably stable brown prints. I'd rather make theese than VDB's. And what about citric acid toner? What does it do?

What exactly do you mean? I mix soulutions by volume like 1:2:3 but the solutions themselves are prepared by wieght. All relatively fresh. The variation I get is pretty wild. Here is the same paper that I tried during the las couple of weeks. If that's the normal sensitivity of the process to...

I think it is the coating-exposure step. After exposed sheet comes out it is either lighter or darker mustard. Then it is mostly consistent. Darker yellow images tone to darker brown and lighter to more washed out brown. At this stage I don't even have to do the first toning step to tell how it...

That's what's I am following, yes. I use your concentrations with various papers. I observe inconsistency in depth of brown between coats and I can't figure out the soure. I tried single/double coats, different papers, different tween concentrations, different dilutions of chemicals etc. This...

What are your concentrations of chemacals and coating process? I am looking at hypo-cuprotypes but somehow coating does not work for met.

Some more tests are needed, but it is highly likely that it's the film and not the printer. I turned off the profiles but tinting was still there. In the meantime I came across a blog post with examples of grayscale tables that also showed tinting. And the author ised Epson P600 rather than a...

Do you measure it with some instrument?

What process are you talking about? I don't know what these density 2 and 1.5 mean. Like you can measure it with some instrument? I also used cheap hp with printing head inside cartriges but only for cyanotypes. Density was enough with cmyk black, so I could choose a color that requires less...

Well results are not repeatable enought to finetune the curve to that level of precision. I does not remove the tints completely. Paper profiles seem to have more impact in this particular case. I can probably find a reasonably good combination of paper profile and negative color. But this is...