You can make a selection with the eleptical marque tool. May take a few tries to see where you want it start to end up in correct spot.
Check out this link for a few hints. http://digital-photography-school.com/five-secrets-of-the-marquee-tools-in-photoshop
If you drag guides to the edges of the coin, you can then drag out the Elliptical Marquee from the intersetion of the guides, and it will be right in place.
Ok I am good with a selection VIA~ ALT key Win7 While holding SHIFT key to keep perfect cirlce... marching ants..Check. Now what? How to save just the coin not in a square? Cannot be done can it?
That may be clear on your end... Yet it is not on mine. Guides? you mean Grab bars? I have no problem cutting out the coin using the Marq tool. Yet I cannot save it just as a circle with no background it always saves or exports as a Square. Yes I could get a smidge closer on the crop, yet that leaves the 4 corners...
I think it is not possibe to save a circle in PS...Yet. Which would make for nice "clean" assets. Yes, I know how to save as a PNG etc. As my original post describes
Depends of end product. If you want a coin with transparent backgound you can save selection with Ctrl C and click on File/new and paste.
To save with transparent background you can use psd, tiff, or png. Saving as jpeg will save it with a white background as it will not save layers.
Which the sqare does show up in my video editing as a 'ghost artifact. Hence me wanting to crop that out as a round...
You should contact the maker of the video editing software and ask for help to prevent the ghosts.
FYI, in case it isn't clear...
Every image known to modern man has a rectangular format, as far as I know.
Your task is to create a rectangular image with transparent pixels around the outside of the coin and right up to the edges. Several formats can carry transparency - PSD or PNG for example.
Note that teh pixels that are right at the edge of the coin may end up partially transparent, to avoid jagged edges.