GUS

Well, it's meant to be a temporary superimposition for the purpose of quickly counting the inner circles comprising whatever surface feature you want to measure, to get a faster measurement than you would with Guy Buhry's original, precisely because the circles cover the whole photo, so no centralized twisting is required, the whole point of an alternative version - facilitating and speeding up measurements.

Thanks everyone for the feedback! Taking into account Steve's observation, I made two slightly more minimalist versions, in black and in white lines for a less obstructive view depending on the wavelength to be superimposed on. And thanks to James responding to Steve, I discovered google sites from where you can download the originals! (They're at the bottom of the default page which I haven't yet bothered modifying). I attach two examples although personally I think black works better in all cases. Everything was done in Paint. Cheers!

Hi, I would like to share with everyone a solar ruler 'mod' I made. Cheers!