The recent posts from @Denis Richard and the responses from some very talented photographers have been fascinating to follow. However, as someone new to DSLR photography, I have a basic question. I read often in related posts about "focal depth" and similar, but how do I determine the optimum distance from coin to camera? I have a Sony a330 with lens SAL 1855. On the lens casing is 3.5-5.6/18-55 SAM and between that and the focusing ring is 18, 24, 28,35 and 55. And a switch for changing between AF and MF. There is a measuring mark on the body of the camera as identified in the manual, but from there how far away should the coin be? (Obviously depends on the subject but I am interested solely regarding coins as the subject). I couldn't find this in the manual or on the Sony website but, admittedly, it might have gone over my head.
It all depends on how many MP the camera has . The more the MP(s) the further you can stay away from the coin ..
My skill as a photographer is a bit shaky but it would seem to me that the distance to the coin should be a function of: -- how close you can get and still see the whole coin -- how close you can get and still be able to focus the whole coin -- how close you can get and still get adequate light on the coin.
This is perfectly correct. Especially with a zoom lens. I have an adjustable copy stand, and for small coins I often put the camera closer to the coin so that it takes up more of the image, and back it off for larger coins. If you're too far away for a small coin, you'll be taking an image of a lot of wasted space that you're just going to crop out. So, there is no "correct" distance for everything - there is a right distance for each coin.
Thank you. So I adopt the same basics as I was doing with my phone. Coin filling as much of the viewing screen while still in focus
My iPad and my iPhone have a square in the LED. Optimally, if you can get the whole coin to the edges of the square, you'd accomplish the 3 objectives (no pun intended) as kanga posts...
OK, I will look through the manual for the camera again and try to find how to show the borders on the live view screen
The best way to learn a new camera is to practice. Play with the camera. Take notes of the settings used for each image. I would not use auto focus. Start with the zoom setting. Shoot several images at different settings. You have from 18 to 55 to play with. You will probably find that something in the middle is best for your lens. Don't use the zoom to fill the frame. Move the camera up and down to fill the frame. With good notes you will find the sweet spot that works best for coins.