My Attempt At Homage To Edward Curtis

I admit it, I did have to look up the word homage to make sure that I was using it correctly. I finally managed to find a Edward Curtis goldtone which I was able to sample using the method described by Paul Butzi. Of course, I am depending on the image that I located being an accurate representation of his orotype. Assuming that was the case, I opened the Curtis image in Photoshop and using the sample tool I made a series of samples at several K values.  I tried this twice using two different sample sizes in order to see what the differences would be.  Here is a table of samples using an 11x11 pixel average:

K	20	40	60	80
R	156	120	86	44
G	84	53	31	9
B	21	4	2	1

I had thought about taking more samples, but Photoshop CS3 only allows you to set four points at a time using the sample tool.  Next, I created a new PS3 document (using the defaults) and then drew a grayscale gradient.  Using the eye dropper tool, I placed color samples that matched K values of 20, 40, 60, and 80%.  (Press the Shift key before clicking in order to add a sample point.)  Add a curves adjustment layer.  Adjust the Red, Green, and Blue color curves so that we get the desired R, G, and B values at the sampled K values on the gradient.  For example, select the Red channel curve, then using the color sampler tool, click on the sample point corresponding to the K = 20% value.  A corresponding point will appear on the Red curve.  (If you press the Command key before clicking on the sample point, a point will be added to the curve.  I understand that this is different in PS4.)  Nudge the selected point on the curve using the mouse or arrow keys until the RGB value in the sample is the same as you measured.  Look at the input/output boxes for more information.  If there are big changes, you may need to repeat this on the RGB channel, according to Paul Butzi's web site.  For this example, it seemed reasonably good.  Add points and adjust the curve for each K value point.  Repeat the process for the remaining curves.  Then save the curve.

Now that we've done this first attempt at generating a curve (or transfer function) for the orotype, I wanted to find a picture to apply it.  There are some very nice red sandstone Fountain/Lyon geological formations in some of the Jefferson County Open Space parks that I have frequently taken pictures of that would do quite nicely.  The picture had already been adjusted in Lightroom and so there wasn't much to be done in Photoshop other than adding an adjustment layer to test the effect.  When I added a curves adjustment layer and loaded the first version of my orotype curve preset I notices that it was a little too much of a red cast (perhaps a bit too orange).  So, I went back to the how the original Curtis goldtones were produced.

Applying a blend mode of darken took the image where I thought it needed to be.  The opacity was adjusted to govern the degree of effect.  The result is what you see below. 

In Honor Of Edward Curtis, originally uploaded by gcmandrake.

This was only a first attempt to see if the effect would grow on me.  Obviously it's not the same as the wonderful orotones created by Edward Curtis, but the warmth of the image is quite nice, almost golden.

As an aside, I did try out the gold presets that are available in Lightroom and the Nik Software Silver Efex software.  I'm sure that both could be tweaked to create results like this, but this method appealed to the scientist in me.  If there is interest, I will post the curve, somewhere.