I'm ready to image my Peace Dollars. So I started with a test on my 1921. Here's the results so far: They are coming out too dark. Although the coin is not PL it does have a nice Mint shine. As you can see that is definitely NOT apparent in the image. One possibility is that the coin is in an NGC holder and the white insert is overwhelming the light from the coin. I can test that by making a dark mask that will block out most of the white insert. Another test would be to image a coin in a PCGS holder on a dark background. Since the holder is translucent there will be much less light coming from the areas around the coin so the light coming from the coin should dominate. Plus I have Photoshop Elements and can play with Brightness and Contrast. But that's so hard to manage I would leave it as a last resort. Any other suggestions?
I would suggest that you don't use the '21 as your test piece to set up your lighting. The high relief will surely look different than the lower relief.
Your lights aren't high enough. You have too much light coming at a lowish angle from 11:00 to 1:00. Look at the T in TRVST. The top edge of the crossbar is white, the bottom edge is black. This tells me that the light is reflecting off the upper edge of the T into the camera, and not the surface. The O in GOD is another one that really shows where the light is coming from, especially because it's round. Once you've fixed that, you'll probably still have lighting issues under the chin and on the top of the obverse, since this is a high relief coin. Hold a white piece of paper at 6:00 to use as a fill reflector, and it will help fill in the shadows a little (you don't want a lot) and pull out some detail. I do this now and then on Mercury dimes obverses, Buffalo nickel reverses, and obverses of earlier Jefferson nickels and Washington quarters.
Yeah, I'm not sure you need more light/brightness, because the highlights on the coin already look like they're saturated. The white holder will drive an ordinary digital camera to make the whole image darker. You can get around that by using the "exposure compensation" setting on the camera, increasing it to get a longer exposure/wider aperture, which will produce an overall brighter image. But like I said above, I'm not sure that's what you want to do, because then the highlights will be overexposed. I like @messydesk's suggestion to use fill light, partly because it should bring up the rest of the coin to match the highlights, but mostly because he's got tons more knowledge and experience imaging coins than I do.
Agreed. Flat surfaces of features should be brighter than their edges. If the lights you're using are large, sometimes you can mask them so they only shine from the highest part of the light. For sure you want to be at 60-deg or higher vs horizontal. Here's a demo I did a few years ago to show what lighting from different angles looks like: https://www.coincommunity.com/forum/topic.asp?TOPIC_ID=145975&SearchTerms=angle
Thanks for the comments/suggestions. I'm using a single tube bulb (white OTT-LITE). I'm shooting at about 70-80° and from about 11:00 o'clock. I'm going to try doing changes one at a time. That'll give me an idea of what works. First I'll try a PCGS slab and see how the absence of the white insert affects the image. IF PCGS slabs work better then I'll construct some sort of mask for the NGC slabs. Later I'll try a second equal light source in the 4:00-6:00 area at a lower angle and further away so that it puts less light on the coin but softly "fills in" the darker areas. I do have one other option that I would dread using more than Photoshop Elements. That would be axial lighting. I've got the setup but it's a real pain to use.
The test with a PCGS coin has DEFINITELY demonstrated what is probably the major problem. I need more light and from a different location. The PCGS coin turned out to be as dark as the NGC coin. Okay, on to test 2, a second light source. If that doesn't produce much better results I'll have to buttonhole (digitally) rmpsrpms and see what he did to my original image.
I highly recommend the "smile directors" I developed a few years ago, or similar concept, to light slabs, and raw coins as well. Before you make any changes, now that we know what you're using, you can try one thing first... The problem you may be having is too much light coming from around 12:00. You can see that especially in the image after my adjustments, as the region around 12:00 is a bit brighter and lower contrast than the rest of the coin. Since you're using a single OTT light, I'd recommend you take some duct tape and "split" the light into two by taping over the center of the light. Your light is a "line" source, so the middle of the light is at a higher angle than the rest of it. This makes the center more vulnerable to direct-reflection glare, and also at higher intensity. This is what I think I'm seeing with your image. By taping over that area of the light, you'll better balance the overall illumination, reduce the glare and level shining on the top of the coin, and allow you to get even more vertical with the overall light before glare occurs.
Okay, considerable improvement. I am now using a second light source. One is at about 11:00 and the other about 3:00. Plus I'm using a mask to eliminate much of the light coming from outside of the coin. I still am not getting the Mint shine from the coin but for now I can live with that.
After doing a bit more testing I find that I'll have to work with the lighting some more. I've got one area around 11:00 that is coming out with a contrast problem making the details sort of get lost.
And the search for a solution goes on. My problem appears to be the shape of my light(s), not their brightness, location, etc. And coupled with that is the nature of my coins; surfaces and size. Old copper works well with my original setup. MS silver does not. The shiny surfaces reflect TOO well and are creating hot spots. I need to either: -- diffuse my light sources, or -- use axial lighting. I don't have anything on hand to use as a diffusion device. And axial lighting takes up a LOT of space which I don't have much of. But I'm going to clear out a space and give axial a try.
Axial lighting works well for raw coins but not so well for slabs due to the glare created from direct reflection from the slab surface. I would still recommend a lens-mounted diffuser or Smile Directors.
