Prepress service bureaus for digital negs?

In my reluctance to buy an inkjet printer I've been trying to find some other options to get digital negs printed.

Has anyone used service bureaus for this? Their prices seem MUCH cheaper than a place like Chicago Albumen Works. Here are a couple, but there are more.

http://laserweb.com/film.htm
http://laserweb.com/forms/MFI_Pricelist_04_2008.pdf

Dead Link Removed

Also, what would be the best resource to optimize files for various contact processes if I were to use one of these services?

Thanks,
Paul

Paul, try to locate David Fokos' article (somewhere, online) about making digital negatives with imagesetters. Also, there was a chapter about imagesetter negatives in the book "Coming into Focus" by J. Barnier, IIRC...

If you'll be printing more than a couple of dozen alt. process prints, purchasing a printer could prove to be a better investment. If not, you may found yourself in a position where you've spent more just for the negatives!

Regards,
Loris.

P.S. You need something a little better than 3600dpi for a truly decent / smooth tonality. Been there, done that... (Minimum 3840dpi w/ a 240lpi screen, ideally 4800dpi w/ a 300lpi screen.)

I used a service bureau about ten years ago to make digital negatives. I gave up on them because the quality just wasn't there for me. To get really good digital negatives you will want to create files at about 300 dpi. This is about double the resolution most service bureaus normally produce and at the outer edge of the mechanical capabilities of the machines.

Most of this business is going away because many printers are now going directly from computer files to printing plates. The printers using service bureaus are on the lower end of the quality scale.

The good news for me was that I had to learn to use photoshop, Pagemaker (before InDesign) and Acrobat in order to put 4 - 8 x 10 images on a 20 x 24 sheet of film to meet the requirements of that particular service bureau. That got me thinking about combining text and images, using InDesign to make folios and making my final product more than just a photograph in a frame on a wall.

Joe's right. Most of these shops "calibrate" their devices for much lower screen resolutions. (Usually around 130lpi "max.") They'll need to re-calibrate their imagesetter for higher screen resolutions. (Exposure / development ect...) Also, outputting at high resolution takes too much memory and time. You'll have hard times in finding someone who's willing to co-operate with you in that aspect, and if you manage to find one, they won't be cheap for sure... (Unless they're friends ect.!) And the imagesetters are more prone to do errors (e.g. strange lines etc. where you don't want them) at extra-high resolutions. (Outer edge of capability indeed, as Joe have put right above...)

Regards,
Loris.

Thanks for the thoughts. I hear what you're saying about these services. I'm sort of indecisive on the printer issue -- the Epson 2880 is more than I really want to be spending right now, and I generally don't trust the used market for things like printers and scanners.

Prepress is the term used in the printing and publishing industries for the processes and procedures that occur between the creation of a print layout and the final printing. The prepress procedure includes the manufacture of a printing plate, image carrier or form, ready for mounting on a printing press, as well as the adjustment of images and texts or the creation of a high-quality print file. In today's prepress shop, the form of delivery from the customer is usually electronic, either a PDF or application files created from such programs as Adobe InDesign or QuarkXPress.

Informatics Outsourcing is a offshore Prepress Service Company.

Elevator will be considering making digital negatives on silver film .
We will use a Lambda outputting device and output negatives at 400 ppi.

Currently we are doing this for our own work with great results... we have made images up to 20 x28 inches films for silver lith contact prints and we are making 16 x20 negs for gum over pt pd and multiple colour carbon.
We will be testing the Harmon/ Ilford Ortho pan for this process as we have been using Rollie. Problem is we need to order minimum $4 k worth of stock to test and we are finishing up our
stock of Rollie before we switch.
Rollie sold us film , but now refuses to produce any more as our needs are small potatoes., I hope the Ilford product will work... If so we will start working for clients to make alt negs.

Can someone help out a wayward digital newb...

How does 300 or 400 DPI/PPI (is the difference between D & P key?) result in an acceptable print. When I'm scanning negatives, I know that 300 DPI will get me an unbelievably small file.

I know I'm missing something here... but a primer of sorts would be most useful.

Thanks

Chris--

It's a forehead-slapper once it gets explained to you.

300 PPI (in the print) has become a rule-of-thumb for print output because it relates to the smallest features the typical human eye can resolve at a certain distance (something like viewing an 8x10 at arm's length) to get an "acceptable" print. Some people claim that differences can bee seen up to 600-800 PPI in output. A gigantic print viewed from a significant distance does not need that high of an output resolution, but a 16x20 viewed from 2 feet might need even more in order to not look soft. Like I said, the 300 PPI is a rule-of-thumb, but the true answer is "it depends".

The second half of your question relates to why you should think in terms of "pixels" (PPI) instead of arbitrary "dots". If you want to make an 8x12" print, using the 300 PPI rule-of-thumb, then your digital file needs to be 2400 x 3600 pixels. If your source is a 35mm frame, then you need to scan in excess of 2400 PPI (since the frame is slightly less than 1" in height). If you're scanning from a 6x9 frame (2.25" x 3.25"), then you only need to scan that frame between 1000 and 1200 PPI to get the digital data you need. Now, there's nothing stopping you from scanning at a higher resolution and down-sampling for the print, but it sets a minimum for what you should scan at to get good quality in your print.

There's an additional complication/confusion when it comes to imagesetter negatives like the OP asks about, since they are not continuous-tone, just dots or not-dots. But I don't think I can explain that adequately. Hopefully, someone else will chime in and do so.

Hope that helps.

--Greg

*slaps forehead*

Greg, thanks very much. That makes perfect sense now.