Like I said I'm not sure what I'm after yet, so I'm researching a few options. If I didn't live in the Pacific northwest I'd probably just use the sun. There's a lot of info about bl units here but not so much about HID or short filament light sources, hence the initial questions. Thanks for your input.
I'll 2nd 9circles suggestion of a Phillips facial solarium especially if you are just starting out. I have been using one for a few years for Cyanotypes, Kallitypes and Salt Prints with no problems. Exposures range from 5 to 30 mins. They are reasonably cheap off of ebay in UK (not sure about US) or you can pick them up from local boot sales/ yard sales.
I have mine in a homemade frame which holds the unit about 25cm off the table. The unit is fine for A4 or smaller prints
It is not tradition that secures the survival of our craft, its the craft that secures the survival of our traditions.
If print sharpness is one of your main considerations, one thing that can help when using a non-collimated light source (such as tubes or multiple light sources), is a vacumn frame. But it will also depend on the alt processes you are using.
I make carbon prints using a relatively thick layer of pigmented gelatin. Using a good contact printing frame, I can not get a razor sharp print using a bank of BL tubes. With the same contact printing frame, I get much sharper results from a set-up of two 175W merc lamps. I am planning on replacing this with a single 450W lamp eventually, as there are still some sharpness issues with using two bulbs if I move the print around under them to even out the exposure. This is the bulb I am thinking of:
Talking with others (such as Sandy King), it appears that a vacumn frame would increase my sharpness also. I have a vacumn easel that I might try to convert into a vacumn frame. I have a vacumn pump that I thought I could use, but appearently it is more for liquids rather than air.
Thanks for the second on the facial solarium Phill, I very much enjoy the kallitypes you've been posting, so that speaks volumes. Ian, started looking through your gallery too, very nice.
Vaughn that's very interesting about the carbon prints being unsharp. Does it have something to do with the relief, if you use a thinner tissue does it help with sharpness? I really want to try carbon printing soon so that could be a factor. Although, it could very well be that I might not care so much about razor sharp prints when I actually get going, hard to say. So much to experiment with! Can't wait to start. Thanks again everyone for the great advice.
Last edited by Colin Graham; 05-08-2007 at 12:53 AM. Click to view previous post history.
It has to do with the relief indirectly. To get relief, one must have a thick tissue and be able to expose a good way down through it. If one imagines a black speck of something on top of the tissue, and light hitting it from all directions (diffuse), then one can imagine that the speck would create a shadow below it, but because the light is diffuse, the shadow is not sharp.
Originally Posted by Colin Graham
The same thing happen when there is not good contact between the negative and the photopaper, or when one tries to contact print a negative upside down (emulsion up) with a diffuse light source. There is too much distance between the emulsion and the paper, and the shadows cast by the light gets diffused in that space. But in a thick carbon tissue, the spreading out of the light happens within the emulsion itself
Thinner tissues might give one sharper prints than thick tissue with a diffused light source. It should not make much difference with a point light source.
I feel that I am being as clear as mud...sorry. Just as I started this post, one of my boys arrived home with a (most likely) broken arm...they just left for the ER. So my brain is a bit scrambled.
For my carbon images, I prefer sharpness -- and the raised relief seems to greatly increase the appearent sharpness. Your results may differ.
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Vaughn, I hope your son is ok. Thanks for the explanation, it's quite clear in fact.
Here is a carbon image for ya!
From a 5x7 camera negative...
"Indian Rhubarb, Tamarack Creek, Yosemite Nat Park"
Last edited by Vaughn; 05-08-2007 at 06:05 PM. Click to view previous post history.
Reason: title added
And what the heck, here is another.
From an 8x10 negative.
"Crowning Glory, Yosemite National Park"
Name comes from the interpretive sign you see on the left -- readable in the print (but backwards!)
Great stuff, Vaughn. Would love to see them in person. Thanks for posting them.
I have two UV sources - one is a bank of fluorescent tubes, the other is a 1000 watt metal halide bulb which is a point light source.
The fluorescent tubes are one stop slower than the sun in summer in southern California, the point light is about 1/2 stop faster than the same sun.
As far as sharpness,I detect little if any difference.
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