Finished taking pictures of my coins...I think.

[MikeInFL]

I should have mentioned in my previous post a shortcut you can take with some digital cameras that allows you to do color correction automatically in-camera, as opposed to in photo editing software.

 

The feature is called "white balance." On some cameras the adjustment is manual, and on others it's automatic. The automatic flavor makes life sweet.

 

The "white balance" feature allows you to tell the camera what it should consider to be neutral color (i.e. gray, or equal parts red, green, and blue). In the manual version, you add or subtract red, green, or blue independently until the image looks right. But that's a bit tricky because you're relying on a teensy little screen and eyeballing the result.

 

The automatic version is cool. You point the camera at an 18% Gray card and take a picture of it while the "white balance" feature is engaged. This tells the camera that the 18% Gray card is what the camera should interpret as neutral color. Internally, the camera compares the color values from the image it took to see if they're equal. If not, it applies appropriate corrections and remembers them. Thereafter, it applies the same exact correction to every photo you take until you set a new "white balance" correction or disengage the feature.

 

In other words, with the camera's automatic "white balance," you make the correction once in the camera, and the camera applies it to each photo in turn. Consequently, no color correction in the computer should be necessary.

 

The above is how I set my white balance, and it works very well....for those of you who are having trouble getting the colors right, you should investigate if your camera supports this "custom white balance" feature. If it does, the above method is the way to go -- no question. If it does not, simply take a picture of the 18% grey card, then take pictures of your coins, then in post processing use the shot of the 18% grey card to calculate the RGB curves to correct the color cast from your lighting. Either way, the purchase of an 18% grey card will pay large dividends and will produce far more accurate color than you would ever be able to do manually.

 

If you don't have a grey card, they can be purchased at just about any photography store, or online here.

 

Understand, however, that lights can and do change their color. This can be due to the light warming up and/or getting old, so it makes sense to calibrate your white balance from time to time rather than simply doing a "set and forget"....Mike

 

p.s. great photos and website!

[stevepalm-migration]

Your photos are wonderfull.

After reading "Using 18% Gray For Color Balance"

I can ask the right questions and get a camera suitable.

They make many Coolpix models.

I will go to a camera shop and see what I can find out.

Maybe one of the dealers on ebay can help.

Your photos are great I hope to come close.

[MikeInFL]

I'm going to visit your web site right very soon but I wanted to let you know something before I forgot. If you are taking photos against a white background then you will fool the camera into thinking the image is brighter than it is, therefore, you may be able to get better images if you place black velvet over the slab with a cutout area around the coin. This will darken the field considerably and allow the camera to think the image is darker. It works well.

 

Tom,

 

I would caution you from using this technique unless absolutely necessary.... Let me explain...

 

The feature of the camera you are referring to is known as "metering". It is how the camera calcluates what exposure (i.e. Aperature/Shutter) is necessary for a correctly exposed photo.

 

There are several types of metering available on cameras. As you might guess, the more expensive cameras have better and more ways of metering, and some low end cameras have no options -- it is "auto" or nothing). Some common types of metering include:

 

Matrix (or Auto on some low-end cameras)

Center Weighted

Spot

 

The effect you are referring to (a white background "fooling" the camera into thinking the coin is brighter than it is and leading to underexposure) is what happens when you use Matrix metering. In this type of metering, the camera looks at the entire photograph in determining what exposure to use. Since the "white" area of the slab or background is included in this calculation, the camera is "fooled" into underexposing the shot. Similarly, a black background will fool the camera into thinking the exposure needs to be increased. Neither are optimal...

 

Rather than play games with the background and with matrix metering, using either of the other two metering modes will give better and more consistent metering when taking photographs of coins. Center Weighted metering uses the center portion of the photo to calculate exposure -- in coin photography, this is exactly what you want, as the coin is what you are interested in exposing correctly and not the slab. Spot metering works in the case the coin is a very small area of the photo, but can lead to problems where there is a bright or dark area in the "spot". If given the choice, use Center Weighted metering for the most accurate and repeatable exposure.

 

Please understand that some cameras don't support Center Weighted (or Spot) metering, but if they do, using Center Weighted metering will almost always produce more consistent and accurate exposure than "fooling" the camera whlie using Matrix/Auto metering.

 

All that being said, I use manual exposure and the histogram to get the correct exposure, and ingore what the camera says. Once you understand how to get the correct exposure the meter is just a suggestion anyway...

 

Hope this helps...Mike

 

p.s. here are a few links for additional reading, if you are interested:

 

Understanding the Histogram

 

Understanding Exposure

 

The entire Understanding Series at Luminous Landscape

[TomB]

Hey Mike, thanks for taking the time to write all that out, but my post regarding this is over three years old (this is an old thread) and at the time I was using a Canon AE1 from 1979, which is a bit different than the Nikon D70 I use today. I was also taking shots using diopters and was not that close to the coins, so they took up very little of the field of view and this allowed the background to have a greater weight.

[MikeInFL]

Wow, I was wondering how I missed the post the first time. Hopefully somebody else will find use in the info -- I see the "fool the camera with a different background" all the time.

 

So now that you use a D70, do you agree? What type of metering and white balance do you use?

[Hoot]

Wow, I was wondering how I missed the post the first time.

 

Don't be concerned, Mike, as it was one of Tom's grandkids that invented the SLR. Tom would have posted to questions about coin photography as posed by Mehl and the like, if there had been an internet.

 

Hoot

[Wihlborg]

Hoot,

 

You're so bad....

 

John

[Hoot]

Hoot,

 

You're so bad....

 

John

 

 

Tom would agree (if his memory would allow), although not for the same reasons.

 

Hoot

[TomB]

What's going on here? Eh? Is anyone there?

[Hoot]

What's going on here? Eh? Is anyone there?

 

Speak up sonny or I'll whap ya with my cane.

[MikeKing]

talk about revival...

 

 

whatever happened to evillageprowler? I haven't seen him around.

[TomB]

Cane!?!?!? Why, we didn't even have trees back in my day! Get over here and I'll whack you with a meteorite!

[Wihlborg]

That’s a good question Mike. We’ve seemed to have lost a number of veteran posters, including Jom, the originator of this thread.

 

John

[Wihlborg]

Hey Tom, did you happen to have saved any of those meteorites?

 

They are avidly collected and bring big money. Did you know that Dave Bowers collects them?

 

John

[Hoot]

Cane!?!?!? Why, we didn't even have trees back in my day! Get over here and I'll whack you with a meteorite!