D*ist hot pixels?

I'm having problems with my D*ist. I get + shaped coloured pixels on some images. They don't appear on a 'dead pixel' test (with lens cap on) but they appear in the same place on every shot that shows them - night shots in particular.

Are they down to sensor pixel problems, dust on the sensor, or???

http://67.15.48.20/~bearuk/spots.jpg
http://67.15.48.20/~bearuk/spots1.jpg

If they don't show up on a correctly-run hot pixel test, but they do show up consistently on images, then they sound more like debris on the sensor, although I don't understand your description: "+ shaped". Sensor dust usually shows up as light grey smudges.

The easiest cure for sensor dust is to blow clean air at it. You can buy cans of air, but make sure they don't contain any gunge in them.

George

I included a couple of pictures to show what I meant George. Basically there's a bright centre pixel surrounded by less bright pixels to the north south east and west, hence the + shape. There's a small cluster of one red, one green and two blue, and others scattered around the images.

As they don't show up on a dead pixel test, I could only guess that their appearance is light related. Some shots show these + spots loud and clear while others have no sign of them.

Yes, these look like hot pixels.
A number of things contribute to them: a warm camera, hot-spots on the CCD, ISO setting, exposure time.

The usually occur at exactly the same pixel locations, and for me, usually at ISO1600 and definitely ISO3200. I think I have two or three that regular show their face. If you have a huge number and the camera is in warranty it might be worth trying to get a replacement (but check the replacement one first!).

There's not a great deal you can do with a JPG image, except use Photoshop's healing brush (or Elements 3). With a RAW file packages like Capture One LE does a great job of eliminating them.

Also, make sure you have noise reduction enabled on the custom menu. If this still fails, the best way is known as dark frame subtraction. You take your real shot, then immediately afterwards put the lens cap on and take exactly the same exposure. Then, in Photoshop you subtract the lens-cap-on image from the real image - gets rid of the common elements between the two.

Hope that sheds some light (excuse the pun!)
Matt