Sunday, March 9, 2014

ChartThrob Results

Second Round Results - Success! I think...
Okay, I think I got it! If you don't want to read the whole post and just want the curve, here it is. Remember to make your image look good as a black and white image, then apply the curve, then Flatten the image, then Invert the image, then print it. Simple!
This whole process took quite a bit work to get it down. I had hope and expected it would be easier, but in reality I was also working on getting my emulsion application and exposure times dialed in at the same time, so that likely slowed the process down.You can see how much better the chart looks this time.
The thing that turned out to be the trickiest was to insure that the samples that the script 'found' where not in the right place. I had to crop several times then run the script then check to see if it sampled the right places. Lots of trial and error. Finally, I got it to sample the correct patches though and it generated a curve that seems appropriate. I read somewhere they they smooth out the curve before using it. I will try it as is and see what I get. Will update the blog once I have a time to make some prints using it.

Here is what the resulting Curve looks like.

 Here is ChartThrob message.
 Here is the chart:
This shows the sample areas lined up with the corresponding patches. 
 This shows the sample areas lined up with the wrong patches. The samples would result in two patches being averaged together.  

First Round Results - 
Here is the Photoshop Curve Preset that I generated via ChartThrob for use with Cyanotypes. Below is the dialog box that I got during while using ChartThrob to generate the curve. So, I will do as it suggests and make another print of the chart but expose it for less time. I will also give this curve a try to see what the results are.
I printed the chart twice. I wasn't happy with the first chart as the emulsion hadn't been applied very well and resulted in the paper being torn. So I did it again. The curve is very similar from both.
A nice write up on how to use ChartThrob

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