Experiments In Olympus 4/3 Photography For Coins

Just eyeball it. If the coin fills about half the sensor (vertically), it's taking up about 1350 pixels.

When we use the term "1:1" in photography, we're talking about specific sizes of what leaves the back of the lens, towards the camera sensor. 1:1 with a Morgan dollar would mean that a 38.1mm coin goes through the lens and comes out the back as a 38.1mm image on the sensor of the camera.

The sensor of your Olympus is 17.2mm wide x 13mm high. So, filling that sensor with a Morgan dollar is a magnification of 0.34:1 - the coin is 34% of its' actual size, on the sensor. 1:1 with a Morgan would mean you can only get 1/3 of the coin onto the sensor. You can only actually ever achieve "1:1" with a coin 13mm or smaller, using your specific camera.

This is the major reason we always advise larger-sensor cameras for high-end coin photography.

So, keeping in mind that you're rarely going to achieve true 1:1 when shooting full-face images of coins, the best lens for such photography will be as good at 0.35:1 as it is at 1:1. Longer lenses (say, 75mm and up) are advised because of the additional relief they offer, giving you more room for light.

The sensor in my camera is only 16mm, not much different from your 13mm, so a new camera won't change much. Just eyeball it and take pics! ...Ray

Lobby, that's beautiful. What did you use for lights? Very nice!

What works for nickel doesn't work for copper, and silver is different from both, as is gold. A circulated coin needs different lighting than a Mint State one. Heck, the obverse and reverse of a Morgan require different exposures under identical lighting.

Your latest Morgan is a wonderful shot.

Having managed that Morgan so elegantly, you will find just about anything else different, but easier.

So, "devices flat to the sensor" means, for example, that the eagle on the reverse isn't straight up and down? Is there just a compositional thing, or is there some technical reason that affects image quality?

I did no post processing. Just a jpg import into iMac PS Elements 9, and crop. The only "tweak" was the color setting on the camera (a little bluer than daylight, IIRC).

Oh, I see what you're after.

I just cropped excess. The background I used was sorta fugly, so I chose to crop in a circle instead of the squares we generally do. There was no downsizing of the picture.

Until I uploaded to my photo sharing site. Smugmug. I suspect Smuggy resizes automatically, else they have to address exponential storage growth. I think there may be options on that site that I can select to change this... Not sure.