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Part 5/7 – The digital negative.

Introduction.

When people involved in alternative processes started printing with digital negatives, at first I totally ignored the new ‘trend’, being then focused on sensitometry tests, densitometers, pyro staining and so on. Although learning all that has proved to be extremely useful in the computer age too, working digitally gives us more consistency and better results in less time (plus other advantages). I now print from digital files only (except old work of course), directly from a digital cameras. Ditching heavy view cameras altogether (of which I was an avid user for many years) has also improved dramatically the quality of my work and made easier to capture the images that I want, when I want. When I have to print an old image (I have a large archive of 8×10″ in-camera negatives) I generally contact print from the original negative, unless it is an important image, which I feel I will be printing again in the future. In that case I prefer to scan it (I use a Microtek full bed scanner) and prepare a digital negative anyway.

I do not care whether working traditionally, or digitally, or both. I am interested in producing the best possible, long lasting images and to me, a mix of digital and traditional is what works.

That said, let see how to produce a digital negative that can compete with a traditional one. First, the raw file has to be good. If you shoot digitally, this means a top-notch digital camera (i.e. a full frame sensor Canon Eos 5d would be the very minimum), or if you scan traditional negatives, a good quality scanner and software. I use Vuescan in 16bit mode. If the file from your digital camera or scanned negative does not have the resolution required to produce a good negative, and you really want to make the print, I would recommend to blow it up with specialist software, such as onOne Genuine Fractals PrintPro (Benvista Photozoom Pro is also good). Keep in mind that of course this is a compromise, yet I have managed to produce good prints from relatively small files. Many of my customers do not own ultra professional digital cameras or scanners and often supply me with medium if not low resolution files. Speaking of software useful for working with digital files, I would like to mention Alien Skin’s Exposure. This neat Photoshop plug-in “emulates” the look of many traditional films (HP5, Tri-X etc.), includes complete control on grain and also has a nice channel mixer to convert to B&W, plus many other features. I am the first to admit that moving from traditional film to digital and then using a filter to emulate… film may seem absurd, but as said at the end of the day the results count. I do not think one needs to invest in more software to do a good job, although Viveza 2 (NIK Software), is terrific for localized contrast tweaking (and the new Structure slider is worth the purchase of this filter alone).

The last “software” of course is your own skill to use Photoshop to make your images look great. This goes well beyond the scope of this article, just keep in mind that you need an image with at the very least a good histogram (without gaps between sample values) and plenty of details in the shadows (I feel to say this because almost always, when I get digital files from my customers, the shadows are too thin). Here is an old little Photoshop trick to give your images more “presence” in the mid tones and shadows. Load a picture. Duplicate the layer. Gaussian blur the new layer until it is out of focus (not too much e.g. about 10/15 pixels for an 8×10″ 400dpi image). Double click the blurred layer to get the Layer Style window. Select Blend Mode: Multiply. Opacity around 60% (you will play with this setting later). Go to the first of the two grey gradient lines at the bottom of the window. Alt-click (on a PC, I do not know on a Mac) the left white pointer to detach it from the right one and slide it to the left, to your taste. Now slide a bit to the left the other white pointer too keeping an eye on the highlights. What we are doing here is having the blurred image multiplied on the background layer in the mid tones and shadows only. Now click OK and in the layers window you can play around that 60% Opacity that we set earlier. Slide around it to see the difference. Use this technique with the greatest moderation because of course we are introducing some blurring in the image.

Two last things about working digitally, before we talk about the platinum curves. First, with digital negatives we have the opportunity to improve the original image, with cropping, dodging, burning and so on, but we can also enhance it a bit with some special effects. I would recommend, however, to use special digital techniques carefully and with moderation, i.e. without making drastic changes to the original image. After all, we are working with an almost two centuries old process which certainly deserves all our respect!

Second thing, in platinum you can print everything, not necessarily photographs. For example, because of its extraordinary permanency, I have often being asked to print even important documents. Or you can print painting reproductions, completely computer generated landscapes such as those made with Vue or Terragen and so on. Endless possibilities and fun.

Photoshop and curves.

You need to make a step wedge. In Photoshop, create a new image 4×5″ at 360 dpi (this resolution is the recommended resolution to print all our digital files). Marking six columns and nine rows will create 54 squares. Number them from 00, 02, 04… to…98, 100 (you will leave three squares unused). Then fill each square with black in the respective density, i.e. 0% (white), 2% (very light grey) up to full black (100%). Please check with the eyedropper in Photoshop that the numbers truly reflect the indicated density, then, invert and flip the image. Now insert a sheet of 8,5×11″ Pictorico OHP in your printer to print the wedge. Make a new larger Letter size image same resolution as the wedge and paste the wedge in the top left corner as a new layer, so not to print it in the dead center of the Pictorico sheet, this way you will save some space for further tests.

For years the printer I used to print my negatives was an Epson R1800 with ultrachrome inks, so your settings may vary depending on the printer you have, but if you use any Epson with ultrachrome inks they should be very similar to mine. I have recently switched to an Epson Stylus Pro 3880 without any change in my curve. With Epson printers and Windows Vista, this is the procedure: choose Edit/Color settings and notice the settings. In my case Gray gamma is 2.2, please note that if you make your test with a gamma and then change it in the future it will make a difference. Click File/Print with Preview and make sure that your settings match mine, in particular Color Management > Print > Document > Profile Gray Gamma 2.2 (every time that you print a negative check that this setting is the same that you used when printing the wedge). To print Pictorico I am using the Epson profile PhotoRPM for Premium Glossy paper (download your Epson profiles if you do not have them yet). Note: some people print digital negatives with a color cast (i.e. orange, brown etc.) to take advantage of the actinic qualities of UV light, i.e. to obtain more density. This to me is NOT necessary and only complicates things just the same as developing negatives in Pyro.

Click OK and in the Epson panel make sure that everything matches, i.e. Premium photo paper glossy, Photo RPM quality, etc. If you do not use an Epson, try the best photo quality settings on glossy paper for your printer. Also make sure that the color management is obviously ICM. After printing the first wedge you can duplicate the layer, shift it to another quadrant in the Letter size image, delete the first layer which you have already printed, and re-insert the same sheet of film in order to print the wedge again changing the printer settings, for example I have different glossy paper profiles in my computer and I have tested them all with different setting such as Photo, PhotoRPM etc. Our goal is to obtain the maximum density your printer is capable of. If you have a densitometer and a calibrated wedge you can check the density. In my case, printing pure black on Pictorico gives me the same density as wedge #14 on my 21-step calibrated Stouffer wedge. Step#14 is a 2.00 density which is plenty. If you do not own a densitometer you can make a quick visual test: in normal lighting conditions, lay down the wedge on some black text written on the back of a Pictorico envelope, you should not be able to see the text at all under squares # 00-10, and very faintly through square #12.

After printing the same wedge – if you want – up to four times (of course you should take note of the settings maybe writing them down on the Pictorico sheet itself with a marker) we are going to coat some paper and make our first print.

If you have built your UV unit similar to mine, your printing time should be around 4 minutes. Coat the paper with pure palladium and one drop of 2.5% Na2 and expose the sheet for this time (as said earlier if you want to standardize your printing with one drop of 5% Na2 you can, just do it now and do not change it anymore). Develop, clear, wash and dry and you are ready to assess your first “print”. The procedure is quite straightforward: notice on the print the first square that is not pure white and write down its number, the same for the first one which is not pure black. These are our limits when preparing out images, or in Zone system terms, these are your Zone IX and I. These two zones as said are the limits but please keep in mind that you have to shift the zones one stop to get useful details in the print (e.g. Zone VIII and Zone II, the lightest and the darkest zones in the texture range). To easily find these zones, I usually cut a corner from the print and punch two holes, one in the black brush strokes and the other in the clear paper. I then pass over the squares to compare the densities. Please do this in normal lighting conditions, not under a strong light to see better.

In my case, and hopefully in a similar way in your tests, I got Zone IX = ~8/9% and Zone I=~78% with a 4 minutes exposure. Why I am happy with these results. Because I have several pure white and pure black squares above and below this range, which means that my time is correct as well as my contrast. If you do not, for example if the 0% square is not white but slightly darker than the paper outside the brushed area it means (assuming that the print has cleared well) that your time is too long (or there is a problem printing your negative i.e. not enough density). Conversely, if none of your blackest squares are not as black as the brushed borders your time is too short. Especially with pure palladium the brush strokes should be real black, like ink. Lower the light panel if they are not. If you have built the exposure unit as suggested, you can raise or lower the light panel to correct the timing, being careful to stay around four minutes (remember that if you double the distance, the light received will be four times less). Only one stop more is already eight minutes, two stops are 16 and so on, and this is not convenient when printing for business. Conversely keeping the UV tubes too close to the paper would give unpractical short times (for dodging etc.) and probably would show light stripes from the tubes on the print.

I would stick to this test in pure palladium for now. Of course, should you decide to go for a classic 50/50 solution with platinum, for example, you will have to repeat the test with this mixture (same thing if you plan to print with different papers).

Now back to Photoshop to create your own printing curve. Load your favourite grey scale image, a landscape, a portrait etc. with good tonality, plenty of detail in shadows and highlight, like my lake in the next page for example. Go over the image with the eyedropper, for example on shadows where you still want good details. Photoshop will probably indicate a value of 80% or more. But by checking the printed wedge you can see that 80% will print almost pure black, so this value needs to be tweaked. Likewise pass over well detailed highlights, the reading will be too low, such as 30%, while you know that your Zone VII is around 10%. So the next thing to do is to apply a curve to the image to match the palladium curve in the darkroom. Create a new Curve Adjustment Layer. Basically as a starting point you just grab the central part of the curve, which of course is a flat line (from top right, shadows, to bottom left, highlights) to start with, and pull to the right, adding control points to keep it smooth. Keep the Curves window open and click over the same highlights as before and notice the two values in the Curves window, Input and Output. As you can see the 30% reading has now become probably a 15%, similar change has happened with the shadows.

The curve will resemble a sort of an S (do not move the control points at the two vertices). The curve is obviously only a starting point. To tweak your own curve you just keep an eye on the wedge and another on the image, and slightly shift the points on the curve to match the wedge. Basically if, for example, you have a photo of a beach and the sand falls on Zone V, you can first check you reference (the printed wedge) and see that, let’s say, your Zone V is 30%. You click the eyedropper on the sand (be sure to right-click the eyedropper and pick the 5×5 pt average reading) and check that Output is around 30% in the Curves windows. If it is not, shift the curve’s points accordingly. Of course, if you have chosen a well balanced image, you do not have to do this with every image that you will be printing. This is done only once and that will be your own curve. You should repeat the procedure for different mixtures of platinum and palladium, or when changing paper, or printer, or with another contact printing process – but I prefer this approach rather than giving you different curves for pt, for pd, or for different printers on the market (I could not anyway). This way you will have to spend some time working at your own curve(s), but just think of the power in you hands: Ansel Adams was limited to place the shadows on Zone III or IV and develop to get a decent Zone VIII or IX. You, up to a certain limit, can place all the ten zones almost wherever you want! I usually re-print my wedge (both negative and in pt-pd) every six month, to make sure that my procedures are still correct. For example my wedge is now slightly darker than the first I printed years ago, probably because of the UV lamps aging.

Now when you are happy with your curve, click OK, then click again the fourth icon in the Layers window and pick Invert. Finally, click Flip Canvas Horizontally to mirror the image and print on Pictorico in the very same way as you printed the wedge. You can now print the negative as before and, if everything has been done correctly, almost certainly you will get a print that will look very similar to the one on the screen. As said earlier, from now on all your prints in palladium will print with the same time and the same contrast, provided that you spend some time at the computer to get a good negative. Sometimes, you may get a print that is not what you wanted because it does not look similar to the computer image, for example because the shadows are too thin. In this case it is easy to go back to the computer and tweak the curve a bit to give more details to the shadows. Then print the negative again. Since there is little control in the darkroom (because we are printing with as little contrast agent as possible), making a new negative is almost always more convenient. Of course, please always keep in mind that you are trying to match a transmitted light image on the PC with a reflected light subject, a print on watercolor paper which is obviously 100% matte. As said earlier, if you are coming to pt-pd from an high contrast printing process such as silver for example, please consider that here the contrast will be lower, the darkest shadows will be lighter, the tonal scale will be longer. If you like very contrasty and punchy images I think that platinum-palladium is not an appropriate medium.

Assuming that your first print satisfies you, after drying and flattening it, it is time to pass to the final part of the process, spotting and mounting, which will be discussed in Part 6/7.