It is sometimes unpleasant to discover a little annoying problem like a defective pixel on the sensor of a digital photo camera. It produces a small colored pixel (often black or white, sometimes of some other color). On a RAW file, it could be worse if it produces a colored streak.

It is most visible when shooting long exposures and the strategy used by most photo cameras is simply to shoot an additional black picture(without opening the shutter) just after the photo you wanted to find the hot pixels and remove/subtract them from the original photo. This is observable as a relatively long computation after a long exposure photo.

Sample kindly provided by Dan Thorberg.

It takes time in the field and it uses up the camera electrical energy. So, here is a small tool that allow to transfer this operation toward the studio PC: PixelFixer.

The list of photo cameras this tool is compatible with contains a lot of cameras from Nikon, Canon, Pentax and Leica. No Sony I know of (they are left with the in-camera option that works well too).

Téléchargement gratuit de PixelFixer.

During years we have been worried because people seemed only interested in getting more Mega-Pixels (MP) out of the new photo cameras (or camera feature sheets). It has been repeated often enough that this single quantity is not a good measure of camera performance. It was, when cameras had so few pixels (less than 3-5 MP) that picture quality was linked first to number of pixels, then to other parameters.

Since 2009, we can consider that the race for more pixels is over. All camera manufacturers decided more or less to go easy on resolution: Over 12-15 MP, you can easily print an A4 or Letter-size print in top quality. Most photographers will never need more. So, why go over 20 MP?

Most manufacturers followed the lead of Olympus and Nikon trying to enlarge the pixels in order to ensure they collect more light and this leads to a higher level of sensitivity as measured by the ISO standard. This is good, because this means that our pictures are going to be better and better, not only uselessly finer and finer. Moreover, maximum ISO sensitivity becomes a relatively good proxy for image quality.

However, there is a slippery slope here. It has already been observed in some Point-and-Shoot compact photo cameras: A manufacturer may be tempted to push a maximum ISO level to ridiculously stratospheric altitudes. It’s not only because you P&S camera can do ISO 1600, that its pictures are still usable (noise cancellation algorithms may be so energetic that most of the details are blurred in the process).

Usually, in the D-SLR market we do not see this happening too often, but there is a risk. With Canon and Nikon leading the race with (pro) cameras over ISO 100,000, we already see figures that are amazingly high and images that are already quite bad (for a pro).

Don’t get me wrong! I’m quite happy to see that technology will soon be allowing us to shoot pictures in darkness without using a flash. But those two very serious camera manufacturers have obviously been racing to reach an ISO landmark. Some others, maybe less able, will reach it not only with barely usable photos, but with really unacceptable pictures. Then, it would become a fruitless race again, with figures creeping into the fact sheets and a real-life comparison will be ever more critical.

For me, the Canon EOS 1D Mk IV and Nikon D3s are useful because they produce absolutely great photos at ISO 32,800, not just because they can collect a barely informational document at ISO 102,400. Let’s be attentive with the present products from Canon and Nikon and the future cameras from all the photo camera manufacturers.

We should still be photographers and not just number-seeking blind consumers. I hope we are.