I suggest determining how close of a pic you want to take being first.
That will drive the type of device to consider.
Then LIGHTING plays a HUGE part in all of this.
For overall grades, a nice Digital Camera may be enough, if that is all your looking to do....
I personally use an
AmScope stereo microscope which is the trinocular (3 eyepiece) version. Stereo microscopes are best for taking pics of coins, and a magnification of anywhere from 3.5X to 80X is good, with say 3.5X to 40x
range being used the most.
The 3rd eyepiece allows me to use that area for the
AmScope microscope camera, which is a 5 Megapixel camera. I think the 9-10 MP camera would have been a better choice, but those can be pricey.
I occasionally struggle with lighting to this day. It depends on the coins condition and tone / luster.
I do shoot full pics of the coin with a digital camera.
The Digital Camera should have a MACRO setting on it. if your shopping for one, try setting the Macro setting and then zoom in on a penny, nickel or dime and have a look. Take a hard look at the clarity and make sure you can see the coin details as good or better wih the camera than what your eyes see. If your at a store looking to purchase or trying one hands on you'll have plenty choose from.
I suggest taking a pencil and paper or have means to take notes on a few you may be interested in. You can write down the mdels, do some research on the camera and also look to see if it is sold lower some where else.
I am sure there are marketplaces that might sell them cheaper than a department store, just depends if there is a sale, promo code, free shipping or wide enough selection online or in store for you to get what you want.