Geló Tutorial 16 - Back to some basics... / by James Moore

Adding colour with Overlay mode

I was recently asked about the tutorials on the blog, and whether there was anything more suited to the beginner. This got me thinking that perhaps some of the terminology or subject in some of the tutorials were too focussed in a particular photographic style or effect. So going back to some basics, this quick tutorial looks at the different blend modes within Geló and the effect they have on images. The test shot is a good image to illustrate each effect - there's a range of tones, textures and solid contrast to show each effect.

[one_half] The edit controls. Showing colour sliders (top), Colour/Mono mode, Contrast mode and reset colour editing. [/one_half]

[one_half_last] The 'Over' (short for overlay) blend mode above adds a coloured gel having effect on the lighter colours within the image. Generally stronger colours like reds, greens and blues will override any other colours.

Yellows, brighter tone colours like Cyan will appear 'thinner' over the image and some of the underlying colour will still show through. You can cancel this out by converting to monochrome, shown in the edit panel (shown) in the left-most pair of toggle buttons.

Additionally the right set of toggle buttons contrast to normal or high. The mini swatch, resets any current colour edits. [/one_half_last]

The colour effect can be quite strong dependent on the subject, so contrast boost can help brighten the underlying image to make the overlay more vibrant.

Moving on to 'Tint' mode (below) will add colour to existing tonal values, mainly in mid tones. This is a great way to enhance the colour of skies in daylight or at dusk. You can see below that the overall tone of the sky is still there, as is the texture of the clouds but it has an added colour quality. The original image is shown to illustrate the difference at the footer of this post.

Example of the Tint Blend Mode

And to finish, the 'Add' mode (additive) colours the entire image, with most of its impact on the darkest parts of the image. This is particularly evident in strong shadows, and contrasty graphic shapes. Using contrast boost, can give a high key 'screenprint' effect as shown in this previous tutorial in the blog.

Example of the Add Blend Mode

To get to grips with the blend modes, start by using an image with the sky in the background. This gives a good range of tones to show how each effect works. The best thing to do is experiment. Once you get the gist of this try making the sky pop in this tutorial

Original image with the other blend modes applied.And I'd love to see your images so make sure to tag them #geló on Instagram or on Flickr. I look on there regularly and if you need some inspiration do a search as there are some great examples out there in the iPhoneography community. I've found the images folks are creating to be really inspiring, and surprising in what they can wrench out of the apps features!

If you're on Flipboard, be sure to check out Gelóscope - where I post some of my fave images I have found make use of Geló in their processing.

Next up I'll take another look at the types of overlay shapes and gradients currently available in Geló.