making a digital negative

In Cyanotype and Albumen printing we used digital negatives.  We also used a digital negative for Van Dyke prints but as it was the last experiment we performed we did not create new images and simply reused the ones already created.

Now a digital negative is a negative that was printed out on a transparency.  To create the negative we first picked an image that we wanted to use.  For me, and I’m not exactly sure what other programs are capable of making this digital negative, but Adobe Photoshop was the program used.  The following steps will take place within the Photoshop program however, the concepts can probably be applied to another program if you have one. 

Upload your image into Photoshop.  To do this, I saved my image to my computer and then opened it up through Photoshop’s open file link.  However, you can probably create ‘new’ and then copy paste the image into the new window. 

Now, I’ll note right now that I don’t really know much about technology and what I’m actually doing, this is just a reiteration of the instructions provided to us by our professor. 

Okay, so once you have your image open you have to tweak it.  [Most of these things you must do will be found under the Image tab].  So find the contrast/brightness, and alter the contrast and the brightness until you get the image you desire.  The image will come out clearer if you increase the contrast as the tonal ranges vary (longer).  The brightness can also be upped if you so desire.

Next, set your image mode to 16 bits… I have no idea what that really means but its something you have to do.

The next step is to upload a curve.  The curve will alter image and make it is the best for the process.  There are different curves for each process.  For instance there is one for albumen, cyanotype and Van Dyke, however we only used the albumen and the cyanotype curves thus making only two types of negatives.  You can download these curves by either buying packs or finding them on the internet.  Our curves were provided through our professor.  Go to Image, adjust, curves and it will bring up a window.  If you are using a newer edition of Photoshop there is a little box next to the drop down menu of the new window that will allow you to load the downloaded curve.  The image will be altered by the new information contained in the curve. 

The next step is to make it a negative which requires inverting the image, a gray scale image.  You then have to convert it into RGB, flatten if it asks, and convert back to 8 bits if you have to do it manually. 

Now a new layer must be applied.  The new layer will have no background and thus be clear.  We will in a sense dye or paint the layer in an image as the color filter will allow for better pictures.  Set the layer mode to screen. 

For a salt and albumen a density range of 2.5 or otherwise known as R:25 G:50 B:0 is preferred.  Just input the numbers into the color picker, which is the little box that holds a color in the tools to the side.  This will make a green tone. 

For cyanotype we want a hue of 15 and lightness of 30 or R:70 G:19 B:0.  This will make a red tone.

 You must then use the paint bucket to coat the layer.  The image will then change tint to the color you imputed and the image can printed out on transparency.  If, when you use the fill, your image is no longer seen and you only have color it is because you did not change it to a screen.  Undo the action and change the layer mode to screen and then fill.

Once you’ve printed the image out on a transparency you have your digital negative.  Other processes negatives like Van Dyke can be made this manner by simply finding the right curves and the correct color screens.

It is important that you use and save your photo at the highest quality to improve the result from your negative.  Also, use the best print out method you can find.  Office Max will print a transparency better than your computer, if your computer can print transparencies.  The quality of the image and thus the printed negative will greatly affect the outcome of your final print so use the best.  Office Max prints transparencies for around $1.50.