iPhoneography Apps – Bonus post: iColorama’s Blend color sliders
November 12, 2015 1 Comment
There’s a new group on Facebook called iColorama Formulas and Techniques. It’s built for users to learn this robust app from each other, and limits its posts to explanations of how effects are achieved using iColorama. Of course, some questions arise there as well. One question that came up today requires more explanation than a single screenshot or a silent video recorded in the app can give.
There are settings under the Effects>Blend option that may not be obvious in their use. There are four sliders marked Gray, Red, Green, and Blue, with handles at both ends. I’ve discussed the Gray slider before. By moving the left handle toward the middle, you can have the blacks in your photo drop out. By moving the right handle to the middle, you can make whites drop out. This means that you can make an object on a white or black background “float” over a new background. It’s a kind of quick masking – you can find a picture of an object on a white background and quickly and easily composite that image on top of a new background.
The Red, Green and Blue sliders are not so easy to describe. I put together the following image to help show how those sliders work. It’s got 50% gray, red, green and blue squares. Feel free to copy it and follow along.
I go into Effects>Blend and load the new image on top of a background using the Photo button at the bottom left. The default blend mode is Normal, and the blocks of color completely obscure the underlying image.
I bring up the Settings (Set button at bottom center) and see the Red, Green and Blue sliders. There is a different effect depending on whether you move the left or right end of the slider. When you move the left handle of the Red slider, you drop out all pixels that do not contain any Red. Pure Green and Blue don’t contain Red, so they drop out. 50% Gray contains the same amount of red, green and blue, so that remains.
Moving the right handle drops out that color. Below I’ve moved the right handle of the Red slider, and the Red drops out.
Moving the right handle just a bit further drops out the gray square. Gray contains red as well as green and blue, so it will be affected no matter which slider you use.
That’s pretty straightforward so far. You might expect these sliders to work the same no matter what the Blend Mode is, but you’d be wrong. They work a bit differently for most blend modes other than the Normal blend we’ve been using. Below I’ve changed the blend mode to Overlay.
Now when I move the right handle on the Red slider, the red square does not “drop out” – it “drops” to Normal blend. If you have experimented with the Feature slider on Effects>Blend, you’ll know that it works the same way.
Below you’ll see the effect of the Features slider moved all the way to the left. It removes the “feature” of Overlay blend and reverts to the default Normal blend. So the Red slider removes the Overlay blend mode for the red square and returns it to Normal.
Things change even more when you use one of the last four blend modes: Luminosity, Hue, Saturation, or Color. The Gray, Red, Green and Blue sliders have absolutely no affect when using one of these blend modes.
These sliders can be very useful, but I would wish that they would work consistently across all blend modes. I don’t know of any time that I would want to “drop to Normal”.
I hope that this has been useful to you. Until next time, enjoy!