Digital Negatives

[matt_vogt]

Hey everyone, I am somewhat curious with the idea of digital

negatives and will be buying Dan Burkholders book here shortly but

was wondering if anyone here was doing the process. I searched

through previous posts and didn't find a whole lot. I was wondering

if there is a film scanner out there now a days that would do a good

enough job so one wouldn't have to pay the money to drum scan. I

shoot 4x5 and am assuming that flatbeds are not good enough, but for

6x7 work I have heard that the new Nikon scanner does a good job, but

would the resolution be high enough for the digital negative

process? Also I was curious, do you make the digital negative as big

as the final print you want, or could you make say a 4x5 digital neg

and then enlarge it under an enlarger to like 16x20? Would a home

desktop printer, say the 2400, print enough detail in the neg so you

could enlarge to 16x20 and not have noise? If anyone is doin any of

this and could let me know a little about their results and have any

advice i'd appreciate it. Thanks.

[trw]

One of us is confused about what "digital negative" means.

 

Why would you inkjet print a small image at 1440dpi (assuming a top of the line Epson), then enlarge it, instead of just printing a large image at 1440dpi? Printers have much lower resolution than scanners, and scanners have much lower resolution than slow films.

 

If you're going to use an optical enlarger, you're probably far better off using your 4x5 negative or printing to Ilfochrome if the original is a slide. Using an optical enlarger to scale up a small inkjet print, your concern should be lack of detail and pixelization, not noise.

 

For me, the CanoScan 9950F has good detail and low noise (when using multi-sampling), but I know it's not as good as a drum scan, and isn't as sharp as my Scan Dual IV (35mm only). The file sizes start to cripple my computer if I scan at over about 25Mpixel (1200dpi for 4x5, 2400dpi for 6x6).

 

Whether Canon or Epson flatbed is good enough is up to you. It won't hurt to try. Rent or borrow one for a few days, and see what results you get.

[roger hein]

Matt,

 

I make digital negs for use with 'alt' processes on Pictorico OHP with both an epson 1280

& 2200 printer. Keep in mind with most 'alt' processes the paper used is usually a matte

art or watercolour paper so the surface itself will 'mask' the imperfections in a digital neg

from an inkjet printer. I also use a flatbed scanner (4990) to scan film negs and have been

more than satisfied with the quality for enlargements up to about 3x. For a 4x5 neg that's

a 12"x20" print. For 'roll' film my feeling is that something better than a flatbed is needed

since more than likely you'll be enlarging to a higher degree. I would also recommend, as

an alternative to Dan's workflow, to try Mark Nelson's Precision Digital Neg workflow:

http://www.precisiondigitalnegatives.com/. It offers a much tighter control over the

whole process. Good luck!

[Ed_Ingold]

By "digital negative" do you mean an inkjet print on a transparent base to make a negative which can be enlarged or contact-printed in a conventional photographic process?

 

The limiting factor is definitely not the Nikon scanner from a 6x7 source. The scanned image at 4000 ppi would be about 8500x9900 pixels.

 

An inkjet print has a resolution of approximately equal to the dpi divided by 8. So if you have a 2880 dpi printer, like an Epson 2400, the resolution is approximately 360 dpi. Since 2880 dpi is produced by half-stepping, the effective resolution is between 180 and 360 dpi. The specified dpi does not represent visual resolution because an inkjet printer emulates continuous tone by dithering in an 8x8 dot matrix.

 

You would have to print the "digital negative" at least 10 times the size of the original film to retain the resolution of the scan. Even so, the dynamic range of the scan is 5 to 7 stops, depending on the source, whereas the dynamic range of an inkjet print is less than 3 stops.

 

What a splendid waste of time, unless you are interested in artsy-fartsy projects with little technical quality.

[brad_hinkel]

I find making digital negatives opens a whole vista of possibilities lost in the traditional silver darkroom.

 

First, I strongly recommend that you always contact print. The prints from an inkjet printer are not sharp enough to enlarge, and there are some great advantages to contact printing. In fact, the enlarger is the best thing we can leave behind in the traditional silver darkroom. Contact printing is extremely sharp: my silver RC prints from inkjet digital negatives are sharper than enlargements, especially for significant enlargements.

 

Second, once you have a chance to contract print, you can use almost any photographic process: platinum, silver, gold, cyanotypes, gum, albumen, Daguerreotypes, etc. And many of these processes are both beautiful and relatively easy.

 

Finally, using the computer allows for a level of precise control in image editing well beyond the enlarger.

 

I find it great fun to print in the wet darkroom from digital negatives.

 

For the specific items from the original post. I definitely recommend starting from 4x5 if possible: there are a number of scanners that do a decent job of scanning 4x5 film. For the price of a new Nikon 6x7 scanner, you could likely get a used Imacon Precision II scanner for 4x5 film. But a number of the recent flatbed scanners produce very good scans on larger film (but less so on 35mm). I have used the Epson 3200 to get good scans from 4x5 and the newer models are even better.

 

If you want to make a digital negative to contact print onto silver paper, I recommend using Pictorico White Film for the negative (not Pictorico OHP transparency film). This produces extremely sharp images, and works fine for processes that use visible light.

You will also need to create an appropriate correction curve for the particular process on which you are trying to print: otherwise the photo paper will print a good image with too much contrast. Grade 2 silver paper is a good place to start since it is relatively low contrast. Mark Nelson's has the complete steps for making curves in his book. I have provided some simpler steps for creating correction curves on my web site: http://www.bradhinkel.com/Correction%20Curves%20for%20Digital%20Negatives.htm.

 

Hope this helps, let me know if you have any success.

 

Brad

[majid]

I've seen platinum contact prints made from a digital negative, and was frankly underwhelmed by the tonality.

[beepy]

I've seen some beautiful platinums from well done digital negs. I too endorse Mark Nelson's

approach.

[roger hein]

Matt,

 

I tried replying to your email but keep getting rejected by your spam filter. If you have an

alternate email I'll be happy to reply.

[joseph_wisniewski]

Matt - you will find a decent flat bed is quite adaquate for scanning a 4x5, and that will give you better results than a 6x7 on a film scanner. A 4x5 has times 129cm2 of area, 3.5x the 37cm2 area of a 6x7. That area difference so overwhelms the scanner difference that it's no contest at all. You'll have to learn a few tricks, like multipass scanning to pull up the shadow detail. VueScan is an excellent scanning program for this kind of work, definitely worth the $59.

 

As has been pointed out, a negative made on an inkjet (even a 2400) will not enlarge well, even if you're using a process as exotic as mine (6 different black inks loaded into an Epson 2200). Also, if you're doing alternative process (platinum, gum, cyanotype, etc) you need a pretty formidable ultraviolet exposure, minutes under powerful blacklight. You can't get that kind of UV level from your enlarger, you pretty much have to print.

[almagnus]

Matt, contrarily to what Mr. Ingold says, it is not a waste of time. His opinion about densities is of no worth. You can get splendid prints with this technique. I recommend A3 printing and contact exposing, sandwiched in a sheet of heavy glass. However, the most difficult choice being in the inkjet paper. You should find enough data on this. In a few hours printing on test strips, you can get a near perfect result, without Dans' book or other external help and curves. The basic idea is that the black point is fixed by the transparency of the paper, and working the exposure to get the black point as dense as possible, without greying the white point. Then simple adjustment curves.

 

The main drawback of this technique I found is the slight blur given by fact that the ink is not directly in contact with the silver paper.

Good luck, its' worth it.

AM

[joseph_wisniewski]

Al, are you printing platinum or silver?

 

For platinum, I've found the "magic bullet" is good clamping. My old contact frame, on a 12x18 negative, just couldn't maintain good contact. The problems were lack of pressure and the glass bowing up in the center. The frame loaded pressure on the edges of the glass. I'd estimate less than 0.1 PSI (pounds/square inch) on the frame, and even less in the center.

 

I got a piece of 1/4 inch thick "low Fe" glass to reduce flex, and built a new printing frame. The back has cams and dogs and can put about 200 pounds of pressure into the frame. That's about 1 PSI into a 12x18, and gets a pretty good paper/negative contact. A vacuum frame would better this (theoretical limit up to 15 PSI) but the clamps seem to be doing OK. Maybe when I build the new 36x48 frame. I'm not getting 1 PSI from clamps on a 1728 in2 frame. One ton hydraulic dogs? 1 inch thick glass?

 

For silver, a good, columnated light source will get you up and running, with any clamping system. A simple "point source" contact printing lamp is good, as is using an enlarger as your light source. I don't think you'll get a UV point source that can do a decent job, and I don't want to be around it if you do ;)

 

Maybe a halide source at 8 feet from the frame. Or sunlight.

 

p.s. by "low Fe", I mean a low iron glass, commonly known as a "decolorized" glass. This is entirely different from "low E" glass. Low iron glass doesn't block as much UV. Starphire is a good one (in the US). Optiwhite is good in Europe.

[german]

Gentlemen,

 

I am new to this forum and find it very, very informative. (I had only checked the large format area and did not really know it had so many other forums to visit.)

 

In any event, I am also interested in making digital negatives and read that one has to read Dan Burkholders book in order to make them.

 

Is that necessarily the case? The book is like $50 or $60 and I don't have quite a lot of money to spend at this time.

 

Is it that difficult to make them? I understand is not just inverting a file in Photoshop and getting the negative, but I would not think one has to read a $60 book to do it.

 

Please advise.

[richard_curtis1]

Hi,

 

i am active with digital negatives and platinum printing.

i have some stuff detailed on my web sites

1. www.richard-curtis.net.blog (light box details)

2. www.platinumprints.co.uk

Personally i am using techniques tought by Dan Burkholder (i tried mark nelsons approach, and it didn't very well with B&S chemicals, maybe someone can advise me).

 

But generally i am getting excellent results (you have to be patient i have been at least 6 months and may $500 - $700 dollars thru trial and error).

 

It is also, very complex. but great fun.

 

i am happy to supply any info, rich@richard-curtis.net

 

Richard (UK)