Coin Shutterbugs - What lighting do you use for your "copy stand" lights? Also Macro Lens question.

Connecticoin

Based on forum discussions here about 12 or so years ago, I have always used the "GE Reveal" or "Sylvannia Daylight" incandescent bulbs, which remarkably, have not burned out yet.

Given the advances in bulb technology since then, what is recommended for today? LED Bulbs? What kind? I still find it challenging to get the white balance right (I do custom on white sheet of paper with my Canon EOS Rebel T2i SLR Camera), so any bulb which is conducive to better white balance results would be great. I think I get close with true WB my current setup, but I sense the Reveal bulbs still result in some residual distortion.

Also, what would you recommend for a Macro Lens? I currently use a 100mm, which seems to work well for larger coins (nickel size and up), but not as well as for smaller coins (especially half dimes and gold dollars). I am thinking of getting a 150mm but am wondering if the camera will need to be 4 feet away for silver dollars! I could switch out lenses based on coin size if I need to I guess.

Thanks in advance for your input!

rmpsrpms

I've used a T2i for many years, and can say that its white balance is a bit off. Many Canon cameras have this problem for some reason. The result is a bit of a greenish hue. Luckily it's easy to fix the problem though, using the WB Shift function. The process is:

• Perform Manual White balance using a trusted reference such as a Kodak Gray Card. Make sure your focus is a little off either high or low to eliminate any surface effects

• Shoot the reference card and open the file for viewing

• Check the RGB values at various places on the image. The goal is for R, G, and B to be equal values

• If there is a significant difference between RGB values, more than say 2%, adjust the WB Shift to compensate, re-shoot the reference, and re-check RGB. Repeat until R, G, and B are as close as possible

The process above will give you accurate white balance, but that does not guarantee the color will "look right" on your monitor. You need to be careful to separate these effects, since your monitor may not be accurate, and neither will 99% of the folks viewing your image online. If you adjust the color so that it looks right on your monitor, it may mess up the color for a lot of other folks. Better to be accurate so that, on average, the color will look right for most folks.

Regarding the lens, most macro lenses shorten their focal length considerably when focusing at closer distances. For instance, your 100mm shortens its focal length to around 60mm at closest focus (1:1 magnification). causing you to get a lot closer to small coins than you would expect given how far you are from larger coins. This is the main reason I went away from macro lenses many years ago in favor of fixed focal length lenses. For example, a 75mm or 85mm duplication lens will have both more working distance for smaller coins, and less working distance for larger coins, versus a 100mm macro lens.

Lighting type is much less important for digital cameras than it was for film, given the ability to accurately white balance the camera for most any situation. Only thing you need to be careful of is to use just one type of light, including making sure room lights are not shining on the coin, as this makes proper white balancing impossible. I personally prefer LED lights to incandescent or fluorescent since their small size and cooler operation allows me to get them into positions not possible with the other types. They do need diffusion but that's fairly easy to implement, and can be customized and optimized for best light distribution, avoiding glare on slabs, improving color presentation on raw coins, etc.

Ray

yosclimber

I use a Canon T2i with 100mm macro lens also, and I use it almost exclusively on half dimes.
It's not hard to fill the vertical frame with a half dime, so that's about 3100 vertical pixels as I recall.
I normally prefer to shoot the entire coin; I can crop it to smaller areas later as needed.
Occasionally I want to get even closer on the date area, and I will add an extension tube for that.

My favorite light bulb is the Phillips PAR30L .
I have it located at about 10:30 relative to the coin, pointed down at about 45 degrees.
This minimizes reflections off the surface of a slab or holder into the lens.
I use the Custom White Balance on a piece of white paper. Sometimes I get a little red fringe.

Unfortunately Home Depot stopped selling the Phillips and is selling a LED version of the PAR30 which is bad,
as there is too much separation between the LEDs.

I think with a point source light bulb (vs. parallel), you will likely get an unwanted reflection off of some part of the convex coin.

For awhile I tried using the very bright and hot tungsten lamps that Kaiser makes (RL30?).
But I found their internal fan creates too much vibration if I attach them to the base of the copy stand.

BryceM

I use halogens, which get hot. You have to be careful not to melt the plastic gasket in the slabs - did that once. They also tend to over-emphasize reds, which can be mitigated by proper white balancing. They throw off a ton of light though and allow for very quick shutter speeds. The physical size of the bulb acts as a sort of automatic diffusion since it's not acting as a point source. Sometimes this is a huge advantage - on occasion, not.

neildrobertson

@BryceM said:
I use halogens, which get hot. You have to be careful not to melt the plastic gasket in the slabs - did that once. They also tend to over-emphasize reds, which can be mitigated by proper white balancing. They throw off a ton of light though and allow for very quick shutter speeds. The physical size of the bulb acts as a sort of automatic diffusion since it's not acting as a point source. Sometimes this is a huge advantage - on occasion, not.

I find that the size and shape of the light is just as important as the color.

Connecticoin

@yosclimber said:
I use a Canon T2i with 100mm macro lens also, and I use it almost exclusively on half dimes.
It's not hard to fill the vertical frame with a half dime, so that's about 3100 vertical pixels as I recall.
I normally prefer to shoot the entire coin; I can crop it to smaller areas later as needed.
Occasionally I want to get even closer on the date area, and I will add an extension tube for that.

My favorite light bulb is the Phillips PAR30L .
I have it located at about 10:30 relative to the coin, pointed down at about 45 degrees.
This minimizes reflections off the surface of a slab or holder into the lens.
I use the Custom White Balance on a piece of white paper. Sometimes I get a little red fringe.

Unfortunately Home Depot stopped selling the Phillips and is selling a LED version of the PAR30 which is bad,
as there is too much separation between the LEDs.

I think with a point source light bulb (vs. parallel), you will likely get an unwanted reflection off of some part of the convex coin.

For awhile I tried using the very bright and hot tungsten lamps that Kaiser makes (RL30?).
But I found their internal fan creates too much vibration if I attach them to the base of the copy stand.

Thanks for the info. There are PAR 30L “Eco Vantage” 53w (75w equivalent) on Amazon, not LED. Are these comparable to yours? Also, how far away is your camera from a half dime? Do you position the lights at the same level as the bottom of the lens? Thanks again.

yosclimber

Yes, the one I use is the Phillips PAR 30L "Eco Vantage" 53w 920 lumens. Should be $11.28 on amazon.

The bad one that I tried is the "EcoSmart" (LED) at WalMart.

When shooting a half dime, the tripod mount on my camera body is about 35 cm above the surface of my copy stand.
Of this 35 cm, the camera body and extended macro lens take about 23 cm.
So the end of the lens is about 12 cm above the half dime.

The light is slightly above the bottom of the lens if trying to point it straight down.
But often I have it closer to the coin.
Normally I only use one light, because I am trying to light one side of a raised die crack.
If I was shooting high grade coins and trying to show the luster, then yeah, a second light would be good.
And the higher the light, the more vertical the angle, and less shadow from an old NGC style slab.

This light gets somewhat hot, so I get concerned sometimes as I feel the lens getting hot as well.
So I turn it off and take a break.

jtlee321

I've been using the Ikea Jansjo gooseneck LED lights for years. Unfortunately, they have been discontinued. They are small and easy to get in real tight. I use a frosted square tube for half dollars as a diffuser. They slip over the head of the LED nice and tightly. I use an X-Rite Colorchecker Passport for setting a custom white balance and creating a color profile for the camera, lens and lights. I of course also profile my monitor which has a 100% sRGB gamut coverage and 99% of the Adobe RGB gamut. If one thing in your entire process is off, your end results won't be accurate.

messydesk

Two gooseneck desk lamps with daylight balanced LED bulbs. I shoot a white balance card (by WhiBal), so it really doesn't matter a lot whether they're daylight or not, as long as they're the same, but I like how they look while I'm working. I can calibrate the white balance through the software I use for tethering my camera (ControlMyNikon) or later in Adobe Camera Raw. Lens is usually a 200mm Micro-Nikkor on a Nikon D610, 105mm Micro-Nikkor for slabs and really big stuff. If you are using a crop-sensor (not full-frame 35 mm size), then 200 mm is too long for many larger coins and slabs.

Connecticoin

@jtlee321 said:
I've been using the Ikea Jansjo gooseneck LED lights for years. Unfortunately, they have been discontinued. They are small and easy to get in real tight. I use a frosted square tube for half dollars as a diffuser. They slip over the head of the LED nice and tightly. I use an X-Rite Colorchecker Passport for setting a custom white balance and creating a color profile for the camera, lens and lights. I of course also profile my monitor which has a 100% sRGB gamut coverage and 99% of the Adobe RGB gamut. If one thing in your entire process is off, your end results won't be accurate.

Yeah, I think I may need to do more with my monitor, including upgrading the one on the computer I have my camera tethered to. Will any newer HD monitor with an HDMI port accommodate monitor profiling? Also I am not really familiar with monitor profiling, but I will look it up.

Thanks all for the responses to date!

jtlee321

@Connecticoin said:

@jtlee321 said:
I've been using the Ikea Jansjo gooseneck LED lights for years. Unfortunately, they have been discontinued. They are small and easy to get in real tight. I use a frosted square tube for half dollars as a diffuser. They slip over the head of the LED nice and tightly. I use an X-Rite Colorchecker Passport for setting a custom white balance and creating a color profile for the camera, lens and lights. I of course also profile my monitor which has a 100% sRGB gamut coverage and 99% of the Adobe RGB gamut. If one thing in your entire process is off, your end results won't be accurate.

Yeah, I think I may need to do more with my monitor, including upgrading the one on the computer I have my camera tethered to. Will any newer HD monitor with an HDMI port accommodate monitor profiling? Also I am not really familiar with monitor profiling, but I will look it up.

Thanks all for the responses to date!

You will want to shop around a bit. You don't need to put a lot of money into a monitor, but you don't want the cheapest one you can find. Look for one that will display 99 -100% of the sRGB color gamut. The internet is all in the sRGB color space and most JPEG files are saved in the sRGB color space. So if you can cover that, you should be good. Also, you'll need to invest in the hardware to profile the monitor. Something like what is linked below is what you will need to calibrate.

https://amazon.com/Calibrite-CCDIS-ColorChecker-Display/dp/B0973LPR9T/ref=sr_1_4?crid=23SLBLPVC7Z6U&keywords=color+calibration&qid=1661886229&sprefix=color+calib%2Caps%2C133&sr=8-4