Enlarged B&W Negatives
Okay I have just been reading "Enlarged negatives using ...." from www.unblinkingeye.com as I have noticed a few discussions about a need for this. After reading and re-reading, I have to say I already do this but for a different purpose, and I have been using enlarged paper positives rather than contact internegatives. It is an old printing trick which I use for aerial mosaics. Now airplanes do not stay perfect in relationship to the ground so when mosaicing I have to impose corrections on to the images as they are being spliced together. so what we do is used enlarged enlargements, bigger than the enlarged negative by 300% to 600%. We check accuracy,and at this size even tonal adjustments can be made with the appropriate emulsion stains.
Since my mosaicing requires a sewing technique as well, called darts, my next step is to let this dry of corrections, clean it with film cleaner to remove any residuals, and apply it to a vacuum or pressure press for 24 hours to re-flatten it. But I could easily see the advantage of using film if re-construction isn't necessary. Also my cameras are made for flatwork (pre-press or newspaper negatives if you will) and are trammed to .001mm corner to corner, with pressured copy board and vacuum negative carrier which can take negatives up to 24"X36". I have a full size selection of ortho halftone films and the screens too, BUT why stop there, I can get fully continuous tone film with grain even to about a 200asa film up to 42 inches wide I believe, but you won't need it that wide. And wow, I have been able to successfully enlarge one of these negatives up to 600% flawlessly, and up to 1000% reasonably (usually I only enlarge negatives to 10 x 10 as my enlarger doesn't need me to consider contact size.)
The only concern I have is that I don't have access to enlargers and printers like you all have. And my light deck is completely foreign to anything I have read about here. So it may take me a while to determine the correct amount of fog or mask layer to be suitable for you. I believe one of our fellow posters is sending me a test negative, but I think this will be pretty straight forward. Start telling me now, though, what I should be looking for and at when I am doing this. Remember I am not a photographer and the engineering types I deal with probably have different requirements than you. So I will need lessons in "seeing" and I hope I can get the vision to see what is important to you all.
I have also been playing recently with doing this with color. Necessity I am afraid as this years mosaic will be in color. So before long I should have a possibility of this concept in color; six months maybe depending on busy I am with "real" work.