Thread: Proposal for Photographing Hones

I posted this in Sham's coticule thread, but I had more to add and didn't want to hijack that thread any further than I already had... The stuff in quotes is basically the same as it is posted in that thread. I am adding some new information at the end...

This is a long post, so I'm going to put the most important point first... I propose that if we want a system for standardized colors, that anyone photographing stones use a set of white, gray, and black cards for adjusting color balance. You can order cards from the links below, WilsonArt has free ones (shipping included) that are pretty close to commercial ones. The set on Amazon will be *very slightly* more accurate, but I don't think it will be that big of a difference for our purposes.

Now to the longwinded stuff:
The problem with getting accurate colors lies in the temperature, tint, and saturation of the photos... Most cameras will automatically adjust these things, but they are not 100% accurate. In fact, many cameras automatically increase color saturation because most photos will look better with a little more dramatic saturation and contrast. When marketing to consumers, most are looking for the camera that produces the best pictures, not necessarily the one that renders color most accurately.
All of these things can be adjusted later, if you can adjust to a known. When I've taken photos of stones in the past, if I wanted to represent them 100% accurate, I've actually held the stone up to my monitor and made adjustments to get it just right.

Now, even if I get a perfect representation of color on my monitor, it doesn't mean that you're seeing the same thing on your monitor... I am guessing that less than 0.5% of SRP users are viewing color calibrated monitors, which means that how colors render on my calibrated monitor probably don't look the same as they do on your monitor. The amount of sunlight, vs tungsten light, vs flourescent lighting in the room that you are viewing your monitor, and even the colors of the walls and carpeting will all have an impact on color rendition.

Sooo.... Now that I've written a dissertation on why we will never get 100% accurate colors of stones over the internet, here's my recommendation as to how to get them as close as possible:

1. We need to have standard (correct) white balance in the photographs. The standard white paper is on the right track... It would be best to photograph the stones with a standard white, a neutral gray, and a standard black card.
You can order a set on Amazon for $18.99: Amazon.com: Digital Grey Kard Premium White Balance Card / Gray Card for Digital Photography: Camera & Photo
OR... if you want free ones that will get you really really close, order the free sample chips from WilsonArt (get the matte ones)
https://samples.wilsonartcontract.co...e-d354-60.aspx
https://samples.wilsonartcontract.co...ea-d90-60.aspx
https://samples.wilsonartcontract.co...k-1595-60.aspx

2. If your camera can lock white balance from your white or gray card, do that. (consult your manual for instructions)
If the camera doesn't do custom white balance, then take a photo of the stone with your color cards in the photo. With a photo editing program that is capable of adjusting white balance (Photoshop if you have it) or the Gimp, which is free: http://www.gimp.org/ adjust the white balance (set the white point, gray point, and black point with the cards).

3. Adjust the saturation of the image manually to get the final bit of accuracy.

(Again, this won't get the photos to 100% on everyone's monitor, but it will get them as close as we possibly can)

Finally... If that is too confusing for anyone: If you get a set of cards, and need help adjusting the white balance I'm more than happy to help out. Just send me a PM with the photo. It's a quick and easy adjustment to make if you take a picture of the stone and all three cards together. I won't be able to adjust the saturation without actually seeing the stone, but we can at least get pictures that are closer.

I still recommend ordering color cards, but if anyone is in a real hurry to take some pictures before the cards ship, I've attached an image that you can print that will get you pretty close... Note that different printer inks will look a little bit different, and printer softwares will sometimes make adjustments, assuming that you are too stupid to get the colors correct on your own. Also, different papers will absorb ink differently, and have different brightnesses which will also affect colors. For all of those reasons, the colors won't print exactly as they are supposed to. So... again, I still recommend the cards. In the meantime, if you do print this out, try to uncheck anything in the printer settings that automatically adjusts color or brightness and contrast. Also, if you have the option, print this sheet as CMYK.
Then order some cards.

the links are truncated, and the image is not showing up yet

edit: oh there it is

edit2: I wonder if monitor color-calibration would be a helpful topic for the more refined viewers out there

Originally Posted by hoglahoo

the links are truncated, and the image is not showing up yet

edit: oh there it is

edit2: monitor calibration...

The BB software automatically resizes an image at the pixel dimensions I had, even though the file size was 10kb... I had to resave it as a PDF to get it to the pixel dimensions I wanted.

As to calibration, I just had to do some searching for free stuff that works well enough to get people close, isn't too confusing but contains enough elements of calibration to make a difference...
This site: http://www.lagom.nl/lcd-test/ was about the best I found... It does require making manual adjustments, and there isn't a real way to test how accurate it is. If you're looking around for other ways to calibrate your monitor, AVOID ANYTHING THAT REQUIRES YOU TO PRINT SOMETHING TO ADJUST YOUR MONITOR TO. Remember, your printer is probably not calibrated either. Out of the box, printers are notoriously worse than monitors for getting colors right.

edit: Here's a free program that will help you get your brightness and contrast settings right, and then let you adjust your gamma and save it as an ICC profile. http://www.calibrize.com/
It does basically the same thing as Adobe Gamma, and you don't need Adobe software.

None of that will be as good as a professional calibration of course, but it will get us all in the same ballpark without having to spend $100's or even $1000's.

I always use a grey cards to get the color balance correct using Photoshop but it is going to be difficult to get everyone to use one. The concept of color balance is difficult to grasp for some not into photography. For instance, the only card that gives true color balance correction is the Grey card. I may be wrong but the Black and White don't offer anything but clipping points and if a photo is properly taken then the clipping points are not necessary when determining the curve.

One thing that might help is to include a grey card at the very bottom corner of the photograph so that all those that wish to correct it can do so at their leisure. One only needs about a 50 pixels to be able to pick up the grey.

Take Care,
Richard

Good points Richard. The big thing is to get people to use the cards.
I find that with some jpegs, it is useful to be able to set a black and a white point. It hadn't occurred to me that those are just clipping points...