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Paper Inkjet/Digital Negatives

Fragomeni

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Hi all. I've been a long time ghost reader here (although very active over on APUG).

I've searched the forum and read everything I could find so I apologize if I'm asking questions that have been answered. I'm very much interested in printing paper negatives and contact printing them on silver-gel paper. I've had mixed results with this and I'm hoping that someone will be able to give me some insight to help me streamline my process.

As I understand it, a negative which has a 3.5 stop range will print well on grade 2 paper. Hence, we would want a relatively low contrast paper negative (containing no more then 3.5 stops). Is there a way that I can produce my negative in Photoshop and make sure that is is within the appropriate contrast range before I print it? I understand the contrast range that I need but I am at a loss as to how to produce that from a RAW file. When I make a digital paper neg my workflow looks like the following: 1) Open RAW file 2) convert to B&W 3) invert to negative 4) tweak here or there to get a contrast that looks reasonable 5) print it on Epson Presentation Paper Matte and go try to print it in the darkroom

I am looking for a way to properly produce a negative of appropriate contrast in a repeatable and confident manner to make the process more efficient and predictable.

Just to put it out there, I've read everything of Burkholder's and Mark Nelson's and I'm familiar with QTR and some of the other rips. I do not find that any of those are effective for me and how I work. I have no need to make the perfect digital negative and I'm not interested in extensive calibrating. I just want to produce a negative of the appropriate contrast range so that I can go into the darkroom and print it as I would print one of my 8x10 film negs.

I've been reading posts for a long time and you all amaze me with what you can do with a digital workflow so I know someone out there can help me. Thanks so much for any help!
 
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Fragomeni

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I think I was a little long winded. I guess what I'm asking is simply if there is a way to measure contrast range/ negative density in photoshop so I can produce paper negs of the appropriate contrast range for wet printing? Thanks!?
 

pschwart

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If you are looking for efficient and predictable, then you need to calibrate and test, but this doesn't need to be hugely complicated. The general approach is: determine your base exposure (minimum exposure through the OHP for dmax); print a step wedge negative; print the negative using your targeted process; measure the step densities of the dry print; create/tweak a Photoshop correction curve that will provide a printed step wedge with a linear progression of tones. I think you can get this done in a couple of hours using colorized negatives. QTR will take longer but it will get you there, too. Epson ABW can make suitable negatives without much fuss. However you choose to calibrate, you will get a big return for the up front investment. Once you have a good curve, all you need to do is proof your image in Photoshop, then invert, apply the curve, and print the negative.

 
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Fragomeni

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Thanks for the reply Phillip. I'm familiar with the process you describe. I have PDN and I'm familiar with some of the other processes as I mentioned. I'm trying to avoid all of that if there is a way to simply control the contrast of what Im printing out, hence my question. I might just go back and use PDN to calibrate the process but I'd really like to avoid that so I'm looking for a contrast control method other then calibration.

Im wondering if I can just use a 31-step tablet to measure the density of a paper neg i.e. count steps between black and white and divide by .30 which will give me the number of stops and I can tweak according to that simply by reducing contrast in Photoshop? If I can do this, what is the best way to use a Stouffer 31-step tablet to measure the density of a paper neg? Could I place the paper neg on a light box and move the step tablet over it to match the tones (i.e. see which steps the lightest and darkest tones on the paper neg blend into) and use that to count the number of steps in the printed negative? If anyone can clarify this it would be very helpful.
 

Green Rhino

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Using silver gelatin paper and a hair dryer I can calibrate in under an hour. I think it would be worth your time to just do it that way. The other thing you could try is to make a range of thumbnails of an image varying the contrast, make a print and pick your favorite. You'll be missing out on the linearization curve by doing it this way but you'll get in the ball park for the contrast control you are looking for.
 

Bob Carnie

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From my experience over the last 8 years making silver prints form digital files I think I may be able to help you on some issues. It must be noted that I do not make inkjet negatives, but rather direct to fiber paper exposure or I use black white negative material and develop in a darkroom.
I am not addressing making inkjet negatives here Ron Reeder, or Mark Nelson or a host of others are much more qualified to talk about that process than I.

so
Each process has its unique characteristics and you will need to find what they are.
With using a Lambda(digital laser enlarger) before any process is started the material must be calibrated, so that the RGB lasers will out put a 21 step wedge and each step will be equal or neutral in the RGB curves and each step goes from white to black in equal density's.
Once the wedge looks good the printer is good to go.

So now all I have to do is send over a file with information. With the Info Pallette open and using LAB numbers, you can use RGB if you are more comfortable, we have found for the different materials we print on the end point numbers where we want to show significant detail in the shadows and the highlights. By knowing these numbers then for any process it is just a matter of placing the end points.
for example.... significant detail for shadow is L-3/4 for silver prints, for inkjets it is L 6/7, luster RA4 paper L 5/6
significant detail for highlight is L- 94 for silver prints, for inkjets it is L 91, luster RA4 paper L 92

anything below or above will go to dead black or pure white specular
The in between areas are how you want the image to look and you can put any curve shape you want between the endpoints.

So by knowing your process is first calibrated then knowing what your end points are using the Info Pallete in PS , you have all the info you need.

I know this sounds really simple , and after a lot of work it is, but IMO there is the calibration stage, then there is the artistic stage.
I use L channel rather than the RGB numbers because for me the numbers fall within 0 and 100, 10 basic tones or values, and we all know who wrote many books on this and have followed faithfully to place information on film and then translate to paper.
 

pschwart

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There is no escape -- you will need to calibrate, the only question is how detailed you want to get. You will still need to determine your base exposure and then evaluate a step tablet to see if you can achieve paper white. If you can't get a clean highlight, you are going to need to fix this by colorizing, or increasing ink laydown, and that's where most of the calibration is required. If you really want SIMPLE, just print the step tablet, then evaluate by eye and create the correction curve.
The easisest way to measure step tablet densities is using a reflection densitometer. You can do this with a scanner, but I find this to be a PITA -- I also like to keep calibration quick and simple

 

R Shaffer

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+1

There is just no avoiding some minimal amount calibration and I think Phillip has it stripped down to about as bare as it can get.

I might modify it slightly that you could print a 21 step wedge ( or 100 step ) on your paper of choice. Adjust your exposure until you get barely visible tone @ 90 or 95% K step. Then hope it is a long enough exposure to get a good black.

Really easy calibration - go with Chartthrob and use all black ink. You'll have a curve & exposure time in short order.
 

pschwart

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I think there is a significant craft component to making a fine print -- actually any artistic endeavor. One can use a hit-or-miss approach and make beautiful prints, but one can make *consistently* fine prints, with less effort and frustration, if one develops even basic techniques for better control.
 

donbga

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You are asking for a simplistic answer and there isn't one. You have to take the time and EFFORT to calibrate your system. What more do you want? It's really never been so easy as it is today.

Frankly, at the risk of sounding like an asshole, you come across as a SLACKER who is unwilling to invest their time into learning the craft and technique to print digital negatives.

Since you have PDN, learn to use it. Ask questions on Mark's forum or here. It takes elbow grease to make it work.

Don Bryant
 

clay

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I'm going to throw a curve ball out here. No one is a bigger advocate of getting a nailed-down and calibrated negative workflow than I am.

That said, there are some cheats if you are in a hurry.

First establish a minimum exposure time to get a solid black through your substrate material (paper in this case, I gather). Then use either Michael-Koch Schulte's color wedges or my much more simplistic ternary diagram (that is still lurking around on alternativephotography.com) to find a blocking color that just gives you paper white when you exposed at that time. These all work by adding a colorized layer over your image with the blend mode set to screen.

Now cheat the curve calibration process by using levels adjustment and the gamma slider. This means dropping the middle (gamma) slider to something less than 1.0 on the flipped (negative) image. A super quick way would to be to get a 21 step test tablet (at QuadToneRIP, for example) and then copying it 4 times across your canvas.

Invert the whole mess of them, and then select each tablet in turn and apply a levels adjustment with gamma values of 0.8, 0.6, 0.3, and 0.15 to the different tablets. Print the thing, and pick the one that is closest. It won't be perfect, or maybe any good at all, but it just might give you a starting point.

Gamma curves and process adjustment curves look remarkably similar when you plot them, and the main problem areas you are likely to find are in the extreme highlight and shadow areas. Print like Paul Strand and avoid any solid whites or blacks and it might just work.
 

gmikol

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Gamma curves and process adjustment curves look remarkably similar when you plot them

When talking about many alt-processes, this may be the case.

But keep in mind that many silver-gelatin papers tend to have a very strong S-shaped curve, and when I played around with using digital negatives for silver-gelatin printing, no simple gamma adjustment curve would have gotten me even close. I had to implement an inverse S-curve in QTR, which was very steep in the low-ink and high-ink areas, and relatively flat in the midtones. The prints looked fantastic on Arista Private Reserve.

--Greg
 

clay

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Greg, you are absolutely right about the need to carefully calibrate for the best results in any process. I was just throwing out a method that will give you quick (and decidedly sub-optimum) results. The gamma trick only works *sort of* if you get very close on your negative highlight density from the start. Any significant adjustments will require a process curve.

Realistically, if you are going to spend the time required to do the cheat, it really should not take a lot more time to just get it completely right. In the QTR workshop we did at Basho last weekend, we zeroed in on a pretty good pt/pd curve for the 3880 in two iterations.