Featured A photo comparison of CFL and incandescent lighting on toned coins

I recently made the switch from incandescent lighting to compact fluorescent and I thought I'd share some of the immediate changes I've noticed, along with a side by side photo comparison of a few toned silver coins. All photos below were taken on a point-and-shoot camera with two lights. The incandescent lights were ordinary 60W bulbs, while the CFLs were natural daylight bulbs with a color temperature of 5500K.

The first difference I noticed was how much brighter CFLs are than regular bulbs. The 15W CFLs I bought were supposed to be equivalent to a 60W incandescent, but in practice I found them much brighter. Brighter isn't always better, as too much light can wash out the color on coins with more delicate toning. I currently have my CFLs in adjustable-neck lamps with metal shades, so I may experiment with using just the bare bulbs to see if that diffuses the light a bit more.

Another big difference I found was how much easier it is to achieve correct white balance with the CFLs. Previously, I had struggled immensely with white balance on toned coins. White balance options on a typical P&S camera are limited and often overcompensate, moving the image into an entirely different hue. The white balance tool on photo-editing programs is not much better—adjust the balance and you run the risk of de-saturating any toning on the coin. The CFLs seem to do a much better job of capturing the in-hand color (and color temperature) of a coin, with minimal to no required white balance adjustments.


This Peace Morgan dollar is a good example of the above. The image on the left was taken with two incandescent bulbs at 10 and 2 o'clock. The original image was much too warm (pinkish hue), so I had to adjust the white balance in my photo-editing program. Unfortunately, that also muted the toning on the upper-left. With the CFL bulbs, I did not have to make any adjustments (beyond selecting my camera's 'Daylight' white balance option), which allowed the toning to appear as it is in-hand.



As you can see here, the white balance is incorrect on the left image, resulting in a reddish hue. The colors are also deeper and more saturated. For the right image, I had to tilt the coin to get the colors to come through. The colors are slightly less vibrant and saturated, but you can see much more of the greens and blues around the bottom half of the obverse, and the overall hue is much closer to that of the coin in-hand. The contrast of the image on the right is also slightly muted compared to that of the coin on the left - part of this is due to the way I tilted the coin, but I noticed a similar effect on a few of the others below.



This is another vibrantly toned coin, with prooflike surfaces that make it somewhat difficult to photograph. Again, the colors on the left are more saturated, with an unbalanced pinkish hue for the base patina. Switching to the CFLs on this coin made getting a full color band much more difficult - what you see on the right is actually a composite of three separate images. The CFLs are very bright and seem to have a much more focused (as opposed to diffuse) beam of light, which meant I could only capture the colors on one quadrant of the prooflike obverse at a time. I'm not very satisfied with the CFL image yet, so I'll have to keep tweaking my technique and see if I can get a decent picture without resorting to a composite.



Another Maria Theresa thaler, but with slightly different results. The surfaces of this coin are less prooflike than the previous one, so that made capturing a full color band with the CFLs much easier. The image on the right is not a composite, unlike the previous one. Again, you can see more of the blues, greens, and yellows in the CFL image compared to the incandescent. There's also a much nicer contrast (in my opinion) between the gold toning on the lettering and the blue on the fields.



A typical "gun-metal" patina. Not much more to say here—the incandescent image is still warmer than the coin in-hand despite having white balance adjusted both on the camera and again in photo-editing.


An example of a coin with booming luster but non-prooflike surfaces. Compared to the MT thalers, the CFL image here shows a more complete obverse color. It's much easier to illuminate the entire surface of a half dollar than it is to illuminate the 41mm MTTs. I might try experimenting with three lights on larger coins, though positioning becomes a bigger hassle with three lights rather than just two.


I also thought this thread might serve as a good example of how coin images can be misleading. When I compared all of these images, I was honestly surprised at the massive color differences. Never assume that an eBay seller has taken the time to properly white-balance his/her images. If you see an image with a reddish hue, odds are that the colors are not balanced and are possibly over-saturated as well. When buying toned coins online, you should always keep in mind that what you see may not be what you get.

Thoughts, questions? Any photo tips are also greatly appreciated.

 

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Great thread. Thanks.

 

First coin is not a peace dollar... might want to edit that This is a good example on how lighting can change the look of a coin. This is why sometimes a gold coin might look silver, and sometimes a silver coin has a gold look. It is all about lighting

 

Terrific read Volante.

 

Thanks guys!

Whoops! Nice catch. And yeah, it really is all about lighting. You can get decent photos with even a cellphone camera, as long as your lighting is on point.

 

For the record, 5500 color temp wouldn't be considered actual daylight... it's far too blue. I think daylight is closer to 3200.

On a separate point, you might want to diffuse the lighting for coins with a similar finish to the Franklin.

 

The charts I've seen all seem to have it like this, with daylight around the 5500-6500K range. The incandescents I was using had a label of 2800K. The CFLs I bought are actually marketed as a treatment for seasonal affective disorder because of their daylight color.

Diffused light is a good idea. I think I'll mess around with that and maybe try axial lighting as well, even though it's kind of a pain to set up.

 

5500K is generally considered daylight, although in reality "daylight" varies from 3000K at sunrise or sunset up to perhaps 10000K in heavy overcast. The once typical household 60W incandescent bulb, on the other hand, puts out light in the 2700-2800K range.

One concern with CFL bulbs is that the light output is often concentrated in a few frequencies, whereas sunlight or an incandescent bulb puts out light at all frequencies. You can see the difference in a spectral power distribution chart such as those shown by GE here. Using standard "supermarket" CFL's can result in a green cast, especially on red copper or gold.

It is possible to buy "high CRI" compact flourescents which minimize the "spiky" nature of the light output. They are sold for purposes of photography, aquarium lighting and plant growth among others. I use a brand called "Indoor Sunshine" which claims a CRI of 95 -- I've had no problems photographing gold with them.

Standard incandescent lights will also work perfectly well, so long as you use appropriate settings on your digital camera and your setup allows you to cope with the heat they generate. For those few of us still occasionally using film, it's a bit more of a challenge, but even then one can use color correction films as needed.

 

I always thought that was what filters are for... As for the daylight temp thing... I don't know. I've always felt that the 5500 CFLs are far too blue. This is evident when you stand near a doorway and look at the hue cast from the sun and the cast from the artificial light. I suppose that the color rendering index might be the issue, but I see this effect even with 5500/97 bulbs.

 

Very nice images for a point and shoot. One issue I have noticed with your new images is the loss of contrast/definition. Diffusing your lights with even a paper towel will help get that light spread out and improve the contrast a bit. Give it a try on that Thaler and let us see the difference. You should not need to do a composite either with the lights diffused. I would recommend having the lights up high and close to the camera, I am not sure what your working distance is though.

 

Outstanding work!

If your camera supports "custom white balance", you might be able to take a picture of a gray card and set your white point that way; it's more reliable than automatic adjustments. Shoot the gray card, use that as your reference, and then anything you shoot under the same lighting will be rendered correctly.

(I often see coins on eBay shot on a blue or red background. It usually throws the white balance off completely. I also see gold coins that have been auto-white-balanced to gray.)

@benveniste's comments about spectra are spot-on. I would expect some forms of toning to look noticeably different under CFL vs. halogen or standard incandescent lighting. (Or vs. sunlight, for that matter). I'm a big LED lighting enthusiast, but for the foreseeable future, LED light will always have a big blue spike and a broad spread from green through red, with a bit of a gap between them; I would expect blue-green toned areas to be muted as a result.

I've wanted for a long time to run some experiments like the ones you show here. Thanks for sharing your results!

 

Human eyes are very quick to adapt to different color temperatures. Not so digital sensors or film. As for filters, if I ever have to focus and compose through a combination of an 80A and 82C filter again it'll be too soon.

But to give you an idea, here's a shot I took a couple of weeks ago using my full spectrum CFL lights and Kodak 400VC daylight balanced film. I did no post-processing other than scanning, converting to a positive image and resizing. As you can see, while there's a minor green cast from the CFL's, the white balance is spot on.

 

I'm just glad it wasn't a thread about the Canadian Football League. Scared me there for a sec.

 

I've known for quite some time that multiple bulbs are the reason for some of the great photos we see out there. I thought the best solution might be to have one of those lamps with a circle fluorescent bulb, but no magnifying glass, just an opening for the lens of your camera. Haven't experimented yet, even though there is now a DSLR in the household arsenal. Anyone use such a contraption?

 

Ring lights are great for product shots and bugs but cause problems when imaging PL, Proof or coins in holders because of the reflection. You can not adjust the angle of the light to get the best compromise of contrast and color saturation with a ring light and adjusting for luster is not going to happen either. Yes I have tried multiple versions out and I currently use 3 100w equivalent LED lights with a small head on them attached to goose necks. Here is one of my images.

 

I'm not really focusing on proofs, so, it wouldn't really be a concern for the future.

I have played around with catching the reflection of a white sheet of paper in highly reflective coins or proofs. Just a point and shoot camera with macro. I've seen some wonderful results that way. Mine were amateurish, at best.

No paper reflection...



Paper reflection...



Paper reflection + Photoshop auto adjustment...

 

That is crazy, when you used photoshop the pope turned into an owl. lol just kidding. That is one way to do so but proper lighting will give you the best in hand look. Lighting is the hardest thing to get right imaging a coin. JMO

 

Thanks for the tip! Gave it another try with a paper towel and the results are great. I do have a huge portrait-size light diffuser but have always found it a bit too cumbersome to use on coins. I didn't realize that something as basic as a paper towel could make such a huge difference.

 

That image looks much better, contrast is much higher and the colors pop now. On the previous images you could not make out the SF and now you can. Just a little work on focus and making sure the camera is not tilted( right side is a little off) with just a little sharpness and they will be Darn Good.

 

What kind of camera are you using??? I have been using a Coolpix 310L and it is horrible with detail.