How to make digital negatives

An easy way to make interesting negatives with the help of a computer. If you think Photoshop is too expensive – The Gimp is a cheaper program – it’s actually free.

Writer and illustrations / Jim Read

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The programs are not difficult to use, and once you get the hang of them, they soon become second nature.

Instead of having to do all the work in camera, in development and under the enlarger you can sit at your computer and prepare a negative to your own taste. Personally I have found it the best thing that has ever happened to my photography. I am free to create what I want when I want it and to suit the mood I am in.

I wanted to help as many people as I could with this technique and searched the web for a suitable windows freeware program that I could hang the article on, Photoshop being very expensive is not available to everyone. The only free program that I could find, that will resize an image and change the dots per inch at the same time is The Gimp, the ability to do this is paramount and decent negatives cannot be made without it. Malin suggested that I write out the technique to cover both programs, so I’ll start with The Gimp.

The original article for those who’ve been here before was written for The Gimp Version 1, this worked on Win95, 98 and ME. The Gimp Version 2 is out now for Win 2000 and XP and will not work with the older operating systems, I tried it! So, after much arm twisting I went out and bought Win XP and found a version of The Gimp on a magazine cover, this can be freely distributed, so anyone who has trouble with the download is welcome to contact me, pay me for the blank CD and the postage and I’ll send it to them.

The Gimp – version 2

This section will cover the steps in the Gimp, which starts with downloading the program.

• Download the first two files on the page
• GTK+ 2 for Windows (version 2.6.9) and run it through ‘setup’ first.’
• The Gimp for Windows (version 2.2.8) and run it to complete the setup

The setup asks a few simple questions but is not overly complicated and you should have the program up and ready in a few minutes. Unlike other programs there isn’t a desktop, only windows that float on top of whatever else you’ve got underneath, in my case this article. In the left window you will see the usual ‘File’ and under that ‘Dialogs’ from here you can control the displayed windows, I have the ‘undo history’ one minimised because I use 800 x 600 screen resolution.

Starting work on your image

I’ll assume that you are going to use a scanner to input an image (if not got to ‘File’ and ‘Open’), go to ‘File’ and ‘Acquire’ and ‘TWAIN’ and click on the device that appears in the little window. Your scanner software will appear and when scanned the image transfers to The Gimp and the scanner window closes. The screen shot below was taken just after I’d saved the scanned image, do the same so that you don’t lose it.

My image needs cropping so I use the top left rectangular selection tool to define the area I want to keep and then go to ‘Image’ and ‘Crop image’, after this two quick conversions, go to ‘Image’ to ‘Mode’ and click on RGB to convert it to colour from grayscale and then to ‘Layer’ and ‘Colors’ and from there to ‘Invert’ to convert the image to a positive.

It looks a bit wishy washy so I’m going to tweak the contrast, go to ‘Layer’ to ‘Color’ and to ‘Brightness-Contrast’ a little window will appear, I altered this image to 55 Brightness and +77 Contrast.

Altering the size of the image

I want to make my image 5″ x 7″ and this must be done in two stages, at the moment the image is 34″ x 22″ at 72dpi, go to ‘Image’ and ‘Scale image’, in this window go to ‘Print Size & Display Unit’ and change the height to 5″ and click on the chain symbol, now we have an image 5″ x 7.5″ at 328dpi, click OK

This is still half an inch too wide, go to ‘Image’ and this time to ‘Canvas size’ in this window change the width to 7″ and then click the ‘Center’ button and them ‘OK’.

This takes a bit off each end of the image, you can set it to take from one end or the other. Finally go to ‘Image’ and ‘Flatten image’ this sets the crop and allows you to save the image.

Ready to make the negative

Go to ‘Layer’ to ‘Colors’ and to ‘Invert’ to turn the image to a negative, then back to ‘Colors’ and to ‘Levels’, in this window alter the ‘Output levels’ to 20ish on the left and 200ish on the right.

This compresses the tonal range to allow for the limited tonal range that the Cyanotype process will print. Nearly there now, you could use this negative ‘as is’ try it and see how you get on.

I found by using a coloured negative you get slightly better results so the very last step is to change the colour to a pleasant reddish hue, go to ‘layer’† to ‘Colors’ and to ‘Colorize’ in the little widow change ‘Hue’ to 15, ‘Saturation’ to 100 and ‘Lightness’ to 30 and there we are, a negative ready to print out onto a transparency.

You might like to have some idea of what your cyanotype will look like by inverting the image again. If you want to have the ’emulsion’ side of your negative up against the coated paper you can flip the image horizontally.

Wreaking

The Gimp has got lots of filters, play with them you can wreak all sorts of wonderful effects onto your images. Use the layers function to put one image on top of another and then blend them. With colour images some of the effects are really impressive.

Used with delicacy and a light touch the effects are very suitable for altering Cyanotype negatives making them easier to print, try using some of the ‘Noise’ filters to begin with, add a bit of Tri-X grittiness to your images.

 

Photoshop

Doing this in Photoshop is very easy indeed so I’ve not done any screen shots, the method is very similar to The Gimp anyway.

I used Photoshop 4 to do this, which is a very old version, but the principle is the same with all versions. Open the image you want from File/Open. If you do need to alter the size go to Image/Image Size uncheck the Constrain Proportions and Resample Image boxes, this locks all three together and altering any one will alter the others, resize your picture to the negative size you need.

Go to Image/Adjust/Desaturate and then to turn it into a negative use Image/Adjust/Invert and to lower the contrast Image/Adjust/Levels. Now adjust the Output with the bottom sliders from 0 to 255 to about 24 to 200. At this point you could print the negative and use it, but for most printers the image needs to be denserthan this.

On the left of the window is a Toolbox and at the bottom the Foreground and Background colours, a mouseover will tell you which is which. Click on the foreground colour and in the window that comes up you will see on the right C.M.Y.K. change these to C=0, M=50, Y=50, K=0 this will produce a nice orange colour in the Foreground box. This colour adjustment can be made using anything from 0-40-40-0 through to 0-70-70-0 conduct your own experiments with these settings.

The next step is to go to Edit/Fill, another window will open, in the Mode box choose Color and OK and the image will change to an orange colour. The last step, if you want to print the negative in contact with the emulsion is to reverse the image, go to Image/Rotate Canvas/Flip Horizontal and you are finished.

Conclusion

Like most instructions they look complicated but the steps are a lot harder to describe than to actually do. I print my negatives onto Overhead Projection Film and use the photo paper setting to do it, this setting puts more ink on the film. Handle the negative carefully and hang it up to dry away from dust, some of the ones I make take up to 12 hours to harden.

I am more interested in the content of the image, in making a print that is suitable for the process and the paper I am using rather than making pin sharp pictures.

For those who have downloaded and got used to The Gimp but think nevertheless they should get Photoshop, please don’t bother, whilst writing this I have experimented a lot more with the program and find it just as good just as easy and just as intuitive. I said that last bit about The Gimp Version 1, Version 2 is even better.

And finally… the print

10 minutes exposure in front of my UV exposure unit, a facial solarium bought at a car boot sale. The paper is some heavyweight cartridge variety.

 

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Here is a technical note on installation from Michael Blum:

In order to do a first time install of any version of GIMP a version of GTK (run time environment) must be installed first. There are two versions of GTK depending on the OS you are using.

1) GTK+ 2 Runtime Environment (version 2.10.6, for Windows 2000 and newer) 5539 kB
This package is required to run The GIMP on Windows 2000 and newer. If you have older version of Windows, install GTK+ 2.6 instead.

2) GTK+ 2 Runtime Environment (version 2.6.10-20050823, for Windows 98/ME and NT4) 3557 kB

This package is required if you want to run The GIMP on Windows 98, ME or NT4.

Next is the actual GIMP download and install.

If you need/want the Help file (GIMP Help 2 (version 0.11)) It is on the same web page as the above. You can download as a single @38meg file or as 5 separate files. With a high speed access the single is much faster to download.

Web site for all of the above:
https://www.gimp.org/

There is quite a bit of documentation available for GIMP and there is a book you can download and print if you desire. Web page for this is:
http://www.gimp.org/tutorials/

Gimp is also available for MAC, UNIX/LINUX, and source is available if you want to tinker. several user groups are available also: GIMP Usergroup (GUG). Meet fellow-GIMP-users here and see what they created using GIMP. There are other links available which you can access from the tutorial page.

For the price, you can’t beat it.

Jim Read is a UK based photographer.