Project A720: Shooting Coin Pics With An Inexpensive Digicam

Lighting and background

Now we're going to push some limits.

I have sold the Large Cent since the last pics were taken. However, I've acquired a fairly decent Half Cent, so we're going to see what we can do with it. All of the following pics have been taken in the last couple hours. As a preliminary, here's what the hardware setup looks like for the night:



I'm roughly 4" coin-camera. Note how close I'm still able to bring those MR16 bulbs to bear; a standard bulb just wouldn't be able to do what I'm about to do. One might still work well - I haven't tried that yet - but the settings I'm going to describe would probably change greatly. I have such a light available; that'll be a post for later.

Here's my first decent shot, with the lighting as it looks above:



F/5, ISO 100, 1/500. Lighting is at about 9:00 and 3:00. Not the greatest of focus, but nothing I can't acceptably correct in postprocessing. I don't like it, though - details aren't highlighted. The curls and date aren't as bold as I want. The lighting angle isn't right. So, I play with the lighting to make it closer to 10:00 and 2:00. The result:



Better. I'm getting more contrast with the date and curls. Still ain't right, though - seems blurrier than I was getting with the Large Cent. I'm at f/5; I wonder what happens if I widen the aperture all the way?

OK, f/2.8, ISO 100, 1/1500. Remember, I'm letting a whole lot more light in with the wider aperture, so the exposure gets considerably faster. I got this:



Now we're getting somewhere. Much sharper focus, better contrast. I wonder, does my camera have problems at the tighter apertures or slower speeds? But wait - the best Large Cent I just posted above was f/5, ISO 100, 1/40.

1/40, when it took me 1/500 at the same ISO and aperture to do this Half Cent tonight? I am honestly clueless, and as I write this post I've spent the last half-hour thinking about it and comparing settings via EXIF data. I have no ideas, and will welcome anybody's theories. The Large Cent pics were taken before dark, while the Half Cent was shot after dark, and I'd expect to need an even shorter exposure for the Half Cent. The background, lighting and camera resolution were identical.

Oh, wait....No, the lighting wasn't identical. I was only using one light with the Large Cent, not two. Hmmmm. I make the change, and shoot the Half Cent:



Me likey. Much sharper focus, much better contrast. Still, though, this one was shot at 1/500 when the Large Cent was shot at 1/40, everything else identical.

OK. Now we go to a black background. I won't bore you with the details of getting there, but here's my favorite shot of the bunch. F/2.8, 1/800 at ISO 80:



Here's the same coin, shot with my dSLR. F/8, 1/125 at ISO 400:



You cannot expect to duplicate the level of detail available from a 12MP dSLR with a dedicated macro lens, and the original shot from the dSLR is over twice the size, but you know what? I like the A720 shot just as much, and I suspect you might grade the coin in the A720 shot a little higher than the coin in the dSLR shot.

There's a lesson to be learned there.

Dick, your vision may not be what it once was, but what you do with it is still sharper than most. These pictures are 5/800 pixels out of round - roughly 800 pixels by 795. The reason for that is my Ebay-bought copystand does not keep the camera exactly parallel to the base - I think it's slightly defective but it took me two years to find this model at all, so I kept it - and I am tilting the surface holding the coin to compensate. I'm eyeballing it parallel, and since I'm getting decently-focused shots, I'm not putting the time into getting it perfect. The pencil is the only tilt I'm adding.

I'm trying to decide what the easiest way to correct the copystand's error will be - it looks like I'll have to put an exact bend into a 5/8" solid aluminum rod to get it done.

Hi, Dave. So, what happened when you shot the 1/2 c at exactly the same settings as the cent (i.e., f5, i100, s40)? What kind of light bulbs are M16s? I like the little lamps cause they can get right on the subject w/o being blocked by the camera itself (my current problem). Can I find these lamps at Walmart do you know? I have a Canon, too. And two Canon video cameras, and two Canon printers and an old Canon scanner. And when I bought someone a camera for a gift what brand do you guess it was? My camera is old but still does what I need it to so I've kept it. I'm real impresssed with the specs of this A270, 6x optical with IS! I have a 10x optical with IS but it's twice as big and cost 3x as much. BTW, that was a real fine lg cent you let go. I hope you got a good price for it. Thanks for answering any questions and thanks for the step by step demo,it helps.
Ron

Despite your limitations, that's pretty amazing you picked that up. I bet you have a good eye (and mind) for "out of round" tolerances.

This is a very informative writeup--I enjoyed the read.

tights24, that is affirmative, Home Depot. That is where I bought mine.
Dick

SuperDave, I have the 2' bar, and I wonder if there are different length lights? Mine are 12".I want to "eventually make a permanent setup", so there is room for changes, if you see worthy, (4' bar vs 2'). Longer, (if available) lights, if you think it will help.
Thanks, Dave! I appreciate it,
Dick

In case you didn't know, I work for Home Depot.

We stock bars in 2, 4 and 8ft lengths, but only the one gooseneck light. There's a tradeoff involved in this setup - MR16 bulbs are only available in Halogen (LED's are out there, but like $20+ each), and they create a lot of heat and can be too bright for what you're doing, especially with lustrous silver. I'm going to grab a set of 35w bulbs (I'm using 50w) to see if that helps.

You can dim them - I have mine on a dimmer - but they get yellower as you dim, affecting white balance, and you have to alter camera settings anyways to compensate for the lesser light. That means dimming the bulb is usually a wash, photographically speaking.

My living situation isn't currently compatible with doing a lot of lighting experimentation. In the coming months, once that changes, I'll be playing with a bunch of cheap lighting solutions to see what we can come up with. R20-type screw-in bulbs are available in a few different types, and they might make a nice compromise if I can find the right fixture to put them in.

Remember, my goal here is to get direct lighting as close to vertical over the coin as possible. That's a "perfect situation" scenario for a lot of coins, and represents the most difficult solution to achieve. Angled lighting is easy, and I don't like stuff to be easy.