How lighting affects coin pictures online.... Which most accurately portrays the actual grade.

I'll let the discussion roll on from here. But one expert reveals the true story of lighting and how it can be both deceptive and revealing in grading coins from pictures posted online. I'll reveal the book and the author's findings tonight after what I hope to be some accurate predictions or the sharing of knowledge of other writings on the subject.

I'll check as usual between clients, if there are any questions?

 

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With the examples you've shown, this is simply a case of not correctly setting white balance. It applies to any photo, online or not.

 

Yes, and not only photos; grading coins by TPG's are done with one of these types of lights.

The photos are just my quick attempt to set up this post before work.

 

You aren't showing the difference between three different types of light. You're showing three pictures that have different light sources. None are lit evenly. One has bad white balance. Two have both overexposed and underexposed parts.

Yes, lighting can be used strategically when photographing coins, or anything else, for that matter. This is not much of a revelation. Differences in light sources are well-documented, and different people have different preferences for what they use. I've used them all, and currently use daylight-balanced LED bulbs.

 

TPGs use lights that are close to being a point source, typically small halogen lights, but the point source is more important than the construction of the bulb. This helps to see problems. Even more important is that the lighting is consistent. There are some people who will take their own lights with them to a coin show and inspect coins under their more controlled lighting before making a purchase decision.

 

Cool about your light source.... Is it full spectrum daylight that you are using and do you use a lamp, flashlight, or multi axial setup?

Yes many different opinions . and Yes there have been well documented writings on this subject. But for those that do not know, let's help them out.


Cool about your light source.... Is it full spectrum daylight that you are using and do you use a lamp, flashlight, or multi axial set up?

As for my photos this morning, as I was getting ready for work I thought of this idea, had some Morgans on hand, put a bears jersey down flat on my bed and quickly set this post up.

I currently use a multi axial coin light set up with three different light sources for my better photos. I made it about three years ago, but i may change it later on after what I learned last night.

 

Two gooseneck lamps that I can move freely. The bulbs are not high CRI bulbs, but fairly decent daylight bulbs. For most coins, lack of a fully balanced color spectrum isn't a big issue.

 

The positioning of the lights is for me the hardest part for coin photography, because it makes such a dramatic change. Changes not only of where and how much reflection and highlights are shown, but most devious is the rainbow coloring that can be obtained from a coin that in hand looks like a pretty ordinary toned silver coin.

 

If you can see something on the coin in-hand, you can set up your lights to see the same thing in a photo. And vice-versa...if something shows up in a photo, then you can light it so you can see it in-hand. There are no mysteries here, just the hard work to get the lighting to match the type of look you want to show in the photo. I always tell people that if you want to match the in-hand look, figure out how the light is hitting the coin when you view it in-hand, and make it hit the coin in the same way for the photo. "It's that simple".

 

Dear OP,

This area of inquiry is no small issue to numismatics. The "standard" light by which to grade is rapidly becoming impossible to purchase - the good old incandescent bulb. You are dealing with two issues at once and risking conflating them. Every light source has its own characteristic color, and any digital camera needs to be calibrated to it. People call this "white balance" It is not wise to just snap coin pictures casually. Doing it right takes preparation and care. Now, EVEN AFTER you get the white balance right, light source SIZE matters. Too small is not good, and too large is also not good. LED bulbs that look like incandescent bulbs might be about optimal. Then there is exposure. Auto exposure is to be avoided. Manual exposure is king.

Good luck.

 

The more important point - the greater goal - here is not so much figuring out what the "best light" is for shooting coins, but learning what the differences in lighting do to the appearance of a coin. You can look at other people's images do until you're blue in the face, but until you compare the pics with the coin you're holding in-hand there will always be a mystery hidden to you. Any of the lighting discussed here can result in essentially the same image, or radically different images, depending on the photographer's choice of lighting placement and imaging parameters.

And until you start looking in-hand at the coin under the same light with which you photograph it, you'll never know what it's "supposed" to look like. One of the biggest improvements in my photographic learning process happened when I started inspecting my coins under the same light with which I lit them under the camera.

 

Now do it with one eye closed and you'll understand lighting and what the camera will capture even better, unless you're using one of these:

 

Ooooh. I bet that improves depth of field, doesn't it?

 

The ONLY incandescent bulbs that might be hard to find are the standard E26 base bulbs over 60 watts. They're still available in 50 watt and less sizes. Except that non-standard bulb shapes are still available with that base, like spotlights, floodlights, oversize bulb, tubular shaped, etc. Also, heavy duty bulbs of 100 watts are still available. Incandescent bulbs in any other base sizes (candelabra, miniture, etc.) are still widely available. If you really want an E26 bulb, go here https://www.1000bulbs.com/category/standard-shape-light-bulbs/

 

ok finally am back... here's what I had been applying in my grading of coins ... but exciting things are coming out of our NIST labs.

Excerpts from the writings of Scott A. Travers, Author of "The Coin Collector's Survival Manual"


I've also been taught that to grade proofs you should use a Halogen Bulb.

Heres what Travers said about that...
"(5) Examine every coin under a halogen lamp or a high-
intensity pinpoint light source.
When looking beneath the toning of a coin or otherwise
searching for imperfections, it’s essential that you use the
right kind of lighting. I first pointed this out in an award-
winning article published in COINage in 1979. I later
elaborated on this in my best-selling book The Coin
Collector’s Survival ManualTM.
A halogen lamp is especially beneficial when looking at
proof coins. It will help you spot hairline scratches, which
can detract considerably from a proof coin’s overall grade. A
tensor light is adequate for mint-state business-strike
coins.
Ordinary light sources such as floodlamps or bare
filament lights–the kind commonly used in chandeliers–make
coins appear more attractive than they actually are. For that
reason, if you’re looking at coins at an auction-lot viewing
session, you should always make sure there’s a halogen lamp
or a tensor light source nearby"


But how many of you have heard of the new visual spectral science standard called QCS, overtaking the older consumer preference based CRI standard. The National Institute of Standards and Technology is developing this system using metrics that take into consideration reflectivity and definition over what people just like in their homes.

Heres an article on the new standards.

https://www.nist.gov/news-events/news/2017/03/standard-lighting-color-preference

And I am excited about new Neodymium Glass Lamps and RGB lamps that are scoring high on the QCS scale which goes from 0 to 100.

Read about that here.

https://www.nist.gov/publications/development-color-quality-scale-0

For now Im sticking to my multiaxial halogen and incandescent mix.

 

Most popular stereoscopic 35mm camera made. Stereoscopic photography was popular in the 1950s, and the Stereo Realist was made from 1947-71.

 

This is a really confusing chart from the award-winning article and best-selling book. A bare filament bulb and a halogen bulb are both rather intense point-source lights, yet they have opposite effects on perception of grade in the article. Likewise if you compare fluorescent bulbs (of the time) to a diffused floodlight, both of which are quite soft. The use of a single light source that is small and bright (but not too bright, like the sun) is going to get you the best results if you are consistent in using it.

 

A single, un-diffused Jansjo LED lamp is excellent for grading. Its color temp is fairly close to a standard incandescent, and the CRI is fairly good as well.

 

Yeah especially considering how the TPGs use incandescents. Maybe they switch to halogens when grading proofs.