Enlarging cyanotype?

[brummelisa]

Hi,

First I should say that I have never done a cyanotype, but will as soon as the chemistry is in my mail.

I use 4x5" and maybe feel that it may be a bit to small for cyanotype.
I wonder if anyone have used the enlarger but changed the bulb to a UV-bulb?
Does it work? Do you have a link to the bulb?

I should add that I use my camera as an enlarger so I have no problem changing the bulb.

/ Marcus

 

[gandolfi]

won't work as far as I know - the lenses in the lens prevents the UV light to go through them..

maybe if you get a lens made with crystal glasses.... ($$$$$$$!!!)

make a new larger negative in stead.

(4x5 is actually fine for cyanotype!)

 

[brummelisa]

hmm. When I think about it I never gets tanned inside.
So now I have a new question.

Can't I use any type of glass when contact-printing the cyanotype then?

/ Marcus

 

[Colin Graham]

I was really surprised how much I like 4x5 contacts prints. You may be too.

 

[brummelisa]

I think that I will like 4x5 contacts (since one may have that good looking strokes from the brush and that "enlarge" the image.

But I just wondered if I could enlarge it (in case I want to do a really big one sometime).

/ Marcus

 

[DBP]

Yes, the glass in the lenses will block UV, as will glass in some contact printing frames. 4x5 looks pretty good as a cyanotype, depending on the subject. If you want something bigger, you'll need to create an enlarged negative, either in the darkroom or via the hybrid route (or by buying a bigger camera). I've had success with the hybrid approach, and with getting a bigger camera.

I doubt a paper negative would work, but someone around here may actually know.

 

[Vaughn]

Contact printing with glass will be no problem -- just don't use that special and expensive glass used for framing photographs that has a UV-blocking layer.

There is a new cyanotype process (Cyanotype Rex or something like that) that was developed by Terri King of England. One is suppose to be able to use it inside cameras, so one could probably enlarge with it also.

He sells info on the process, so I really don't know about it much about it. It is something like coating the paper with the Ferric ammonium citrate, then after exposure, developing it in the Potassium dichromate. Probably more to it than just that to.

Have fun!

Vaughn

PS -- printing several 4x5's together is fun, too!


http://www.hands-on-pictures.com/html/rexhow.html

 

[Akki14]

I've not had good success with the one paper negative I used. Enlarged negatives are the way to go. Once you figure out what you're doing, it goes pretty quickly. I did one tonight from scratch because the first interpositive I did wasn't dark enough or contrasty enough. Paper developer instead of Diafine or Rodinal worked well for the higher contrast (with Fomapan 4x5 film, enlarging from a 35mm neg).
Freestyle seemed pretty cheap for lith film, at least compared to UK prices (even when you factor in all the customs and VAT charges).

 

[walter23]

I'd rather enlarge onto ortho paper than try to enlarge to cyanotype (which probably wouldn't work). Even with a blacklight UV light source a couple of inches away from the paper it takes a fairly long time to exposure.

 

[keithwms]

Actually the UV transmission through some enlarger lenses and also some process lenses is not terrible. But in addition to those losses, if you did install a specialized UV bulb, then when you enlarged, you'd looking at very long exposure times due to inverse square losses. Notice how bright ordinary enlarger bulbs have to be in order to overcome this, just with visible light; getting that kind of luminosity in the UV is expensive, I guess you might be forced to use a mercury or deuterium lamp with Uv mirror to focus the light down, or such. Anyway, notice that in a UV exposure system the neg and paper are held very close to the light sources- it is for this reason. So probably only for really small enlargement factors would this be practical.

If 4x5 strikes you as too small then you could enlarge to another negative, or scan to a digital neg, or scan to an LVT. Either way you will be able to get a contact-printable negative.

 

[Jim Noel]

Paper negatives work wel when made correctly. The tendency is to make them too contrasty. Use a single weight paper, Slavich from Freestyle is the only one I know is currently available. develop in a soft working developer. exposure times with cyanotype will be up to twice as long as for a negative, depending on the quality of the paper negative. My class of 20 student used made these and used them for slat prints just a few weeks ago with very goo success. It is important to have the shadow areas with just enough density to show slight tonality. Since salt prints have a much longer scale than cyanotype, the negaties had to have much more density in the highlights.