Re: Request how to
Hi UserInterface and welcome!
It looks to me like that was done using Photoshop's "Color Halftone" filter (under Filter>Pixelate). Basically, for each channel, the filter divides the image into rectangles and replaces each rectangle with a circle. The size of the circles will depend on the lightness of the rectangles. So if you were to use a gradient where the lightness varied, so would the circle size vary. With your orange colored example, the background was probably orange and the gradient (on a new layer above the background) was a lighter orange or maybe a yellowish color. The gradient layer had the color halftone filter applied (all channels set to about 45 deg.) and then was probably set to the soft light blending mode.
Probably the best thing for you to do is search the web for tutorials on using the color halftone filter. Once you get the general idea, you'll have no problem recreating that effect.
Hope this is helpful.
