Digital enlargement of 4x5 negatives

[sanking]

I have seen many contact prints made from both enlarged negatives and original in-camera negatives and I am personally working at this time with both methods. Within the past several months I have made quite a number of carbon, kallitype and palladium prints from digitally enlarged 5X7" original in-camera negatives, and 7X17, 12X20 and 20X24 prints from original in-camera negatives.

Based on what I have seen and the results of my own work I am in partial disagreement with Carl Weese. I agree that if one is making enlarged negatives by projection with traditional wet processing there is no way three results can match an in-camera original. However, with enlarged digital negatives I am of the opinion that one can not only match, but also in many cases exceed, the quality of an in-camera original. However, both methods leave their own artifacts and depending on viewing criteria an individual viewer might prefer one or the other.

My comments assume that the same level of meticulous craftsmanship is applied to scanning, working on the image in Photoshop, and making the final print when working with a digital negative as when working with in-camera originals. They also assume that the original negative used for the scan is of high quality and that enlargement is relatively moderate, say up to about 3X or 4X. and that the quality of the scan be such that it allows a minimum of about 400 dpi at the printing size. That means that if you want to make high quality 16X20 prints from 4X5 negatives you need to be able to scan with an optical resolution of at least 4X400, or 1600dpi.

[Julian_3496]

Sandy, I'm very interested in your experiments. Having got used to the benefits of PS over the years I'm trying very hard to make enlarged digital negs for contact printing. I'm having negs drum-scanned at full optical resolution (4000ppi), doing the work in 16 bit in PS and then outputting via an Epson 7600 or 9600. My problem comes in getting what I have on the digital file onto the paper. In order to 'calibrate' the process, I output a 25 step wedge to the neg, make a test strip and expose to paper giving just enough exposure to turn the 100% black wedge black. I then dry the print and scan it into PS on flatbed using levels to nail the black to 100%. Using the densitometer I then make a correction curve to bring all the other steps of the wedge into line. I then apply that new curve before outputting my image files, but I still can't get the tones falling in the right place and am having to dodge and burn which negates much of the digital part of the process. Am I doing something stupid here?

[sanking]

Julian,

What process are you printing with? There might be a ready-made curve on the CD that accompanies Burkholder's book that you could use. There is definitely one for the Epson 2200 for Pt/Pd printing and that one might work with the 7600 or 9600 since they use the same pigmented ink system.

If not there is a fellow in Chicago named Mark Nelson who has developed a real nifty system for developing a curve for Photoshop, and it works with any process and any negative output device. The process is very simple but requires some initial testing, as follows.

1. You print a file with your process of a step wedge that has 100 steps, from Photoshop 0% density to 100% density.

2. You read the printed values of the step wedge with a reflection densitometer. (I think it is also possible to do this with a scanner but I don't know the details)

3. You enter these values into an Excel spreadsheet and calculate the input/output values at 16 points for the Photoshop curve.

4. Then, when you get your image finished you go to Curve, enter the input/output values, and then save the curve before pressing OK.

5. Next time around you just load the curve from the saved file.

I beta tested the method with a couple of different processes and it works like a charm. Mark has been putting together a package to market the method and it should be available soon. If interested contact him directly at Ender100@aol.com

[Julian_3496]

Sandy, thanks for that. I'm using my local pro-dealers setup of 7600 9600 loaded with MIS ultratone inks and studioprint rip. I helped them set it up and linearise the inks etc so I get free use and the loan of some lf gear! The inks are good because they don't smear on the film, and using the rip I've made sure I'm not laying down too much ink. To do this successfully yo have to really have your printing and digital chops in order, but even doing that you end up with a neg that has more tones on it than the silver paper (ilford warmtone) can bear, so then you work a curve which compresses the tonal values to match the paper values and it is tricky stuff! I'll try the process you mention. Thanks!

[Brian Ellis]

I was told by someone who attended the APIS conference earlier this year that there supposedly is some brand new method of making enlarged digital negatives that makes Burkholder's book obsolete. Perhaps Sandy could elaborate on this (or correct it if it's wrong), I think he attended.

[sanking]

Hi Brian,

The negative making method discussed at APIS is the one by Mark Nelson that I mentioned in a previous message.

But as good as Mark's method is, and it is really outstanding, it does not make Dan Burkholde's book obsolete. Dan's book is an extremely valuable reference that anyone interested in making digital negatives should have, unless of course they already understand all of the issue involved.

I first started to make negatives for alternative processing following the instructions in Dan's book, and using the curves provided on the CD that accompanies the book, and at his website. Mark Nelson's system for developing the curve is a refinement that allows better representation of tonal values for a specific process and negative output device, but it does not replace all of the instructional information in Dan's book.