Ok, I'm a bit lost...

Hi, I'm new here.
Question; I want to do the following; make a digital photograph (B&W), take the photograph in photoshop, do the retouch, etc., and then, somehow 'project' the final image on a surface (aluminum or copper plate) treated with liquid emulsion (Rollei Black Magic). So, I thought I had it all figured out, and simply buy an enlarger and go to a lab to put my digital photo's on negative (or should it be a positive slide for liquid emulsion...?) Well.. hardly any lab in my city is still doing this, and if so, the price is sky-high. What could be an alternative. Printing my own pos/neg and then put it under an enlarger? If I print the size of a middle format film, how good is the quality compared to a negative or a slide? How good or sharp will the final output be if the final image will be enlarged 3 or 4 times from this print, say the final image would be around 7 inches.. Will it be as good, as sharp, or will I see print dots? (the horror)
-What is a better idea? Digital file to liquid emulsion, please help me out.

You want to create a negative. In most US cities where they make digital negs or slides it is done with a film recorder and will cost as little as $10.00 for a 35mm or 150.00 for a 4x5. You can also get 8x10 and 11x14 negs made but I'm not sure of the prices of those off of the top of my head.

Depending upon what they use to make the neg the results can be very good.

You can make your own neg with an inkjet or even laser printer on overhead projection material, but it will not be good enough to enlarge from. It can be good enough to do a contact print. Contact printing (placing the neg on top of the "paper's" emulsion) is the easiest way to make a print and doesn't require an enlarger.

Search through the forum for Digital negs for more information.

Thank you for your response. I finally found a lab that makes 35mm slides from digital files, 11 euros a piece. They told me the file should be RGB, even if my image is in B&W. So, as I understood from you, I need a negative to use in the enlarger on the liquid emulsion. I assume that I finish my B&W image in photoshop, and then simply 'invert' the image and send this to the lab, right?
Will a 35mm slide have enough crisp details for, say 7 by 7 inch (or larger) enlargements? As a digital illustrator I most, if not always work in 300dpi resolution, what resolution is best for 35mm slides?

About contact printing; So, I print a full-size negative on a transparent sheet, and place this on top of my liquid emulsion support. Then I simply need a strong light source for the exposure? I work with a Bowens cool lite, with 8 100 Watt Fluorescent Softbox Lights, as well as a 3 lights version. Are these light sources useful in the contact printing process, and how long does an exposure approximately have to take?

The file should be positive and you need to ask them to image it to negative film. The file size will depend upon the device. In 35mm the best device I am aware of was the solitaire 16. As I recall it would image an 8k file on a 35mm. 8k being the number of samples along the long edge. The lab will give you the exact pixel size. To them it won't matter if it is 300dpi or 8000 dpi per inch as long the total pixels are correct. although they will probably tell you to give them an image that is 8"x12 x 600 dpi or something similar.

Getting the neg made appears to be your first hurdle -- the next hurdle will be figuring out how to properly enlarge and or contact the image. I've always used a contacting machine (I don't know the proper name) or an enlarger for printing. Others here use plate burners, the sun and god knows what else and may be able to help you with your specific lights.

The bottom line is that for either process you will need to do tests to determine the best exposure time. one way to do this quickly is to use an opaque card to cover all but an inch or so of the emulsion area being covered by the neg or the neg's projection from the enlarger. Using the card you will want to make a series of 2, 3, or 5 second exposures. after each exposure you will expose a bit more of the emulsion. In the end you will wind up with (if you use 3 sec's) a print with a 3sec, 6sec, 9sec... (and on and on) exposure stripes. You may find that after the first print that you need to use far larger or smaller timing increments, but eventually will have nailed the time. I have never used liquid emulsion, I have no idea how powerful your lights are or how dense your neg will be so I can't help you too much on the starting time.

Good luck ask more questions.

I think I'll skip the 35mm idea, and keep full control over the process by making digital negatives and going the contact printing way. Excellent tip about testing exposure times, thank you, I very much appreciate it.

Some of the most knowledgeable people regarding digital negs post on this forum. You may wish to read the digital neg forum or ask more questions in that forum.

Good luck and have fun.