Can you see the dark-gray circle here? Do you see nothing but a black square? If you can't see the circle at all, then you need to calibrate your monitor.

Any monitor can be a bit off in calibration, but the Windows operating system is particularly prone to displaying images darker than they should appear. Most people don't calibrate their monitors; many don't even know how to go about it.

The result is that many people viewing photos on flickr are not seeing images as they should appear, and are losing subtle detail in dark images. (Sometimes these people will even complain that a photo is "too dark"!)

Another problem resulting from poor calibration is that photographers/artists sometimes post an image which they think looks fine, but which has been Photoshopped in ways which are really obvious to people who have properly calibrated monitors. This happens surprisingly often. If the photographer can't see the details in the dark areas of their own photos, the result can be embarrassing as other people can and will see those flaws.

So I'm posting this image as a helpful tool for anybody who wonders if they're missing something. If you don't see the circle, then there are details in other photos on flickr that you are missing -- which means, yes, you are missing something. Calibrating your monitor will fix that.

Adjust your monitor until the background of the square still is absolutely black, but so you can just barely see the dark-gray circle.

Senior Airman Brian Bianco, 379th Expeditionary Maintenance Squadron precision measurement equipment laboratory journeyman, calibrates a multi-gas detector, which monitors oxygen and gas levels inside aircraft fuel tanks, at a deployed location in Southwest Asia, Nov. 24, 2009. The 379 EMXS PMEL, the only PMEL shop in the Air Forces Central Command area of responsibility, supports more than 15,000 different types of equipment such as spectrum analyzers, torque wrenches and pressure gauges by thoroughly fine-tuning them to meet its four criteria of accuracy, reliability, traceability and safety. Airman Bianco is deployed from McGuire Air Force Base, N.J. in support of operations Iraqi Freedom and Enduring Freedom. (U.S. Air Force Photo/Tech. Sgt. Jason W. Edwards)