Hi Celtic33, grading is a codified but imprecise (i.e. somewhat subjective) measurement using the Sheldon scale. You can check out more about them here:
https://en.m.wikipedia.org/wiki/She...rading_scalehttp://www.PCGS.com/grades/The PCGS link has images for reference so you can get a better visual sense of the differences between grades. They also offer an app called Photograde that has images for each coin type in a similar fashion.
Coin photography can be a little tough to get right. There is a subforum here dedicated to it if you'd like to browse through that.
http://goccf.com/f/81The main goals will be making sure your picture is in focus directly above the coin or area of interest, avoiding glare, and cropping your photograph to eliminate irrelevant context. A darker background may be worth a try, and you can try diffusing or bouncing your light source, though the folks in the photography forum should have much better advice than what I can give.
Hope this helps and welcome to the forum.
Edited by Oijogja
04/21/2017 09:59 am