Strange dots!

[Im Bald Ok]

Firstly hello everyone, first post

I keep seeing these strange single dots on some of my pictures taken with the kit lens that came with my 450d. They show up quite strongly on night shots because of the colours in them. If you click on the full size image, you can see in the center of the picture at the bottom there's a small white dot as an example and another towards the right of the centre dot. Ironically, the other 2 that always show up in the same place have been lost while uploading to imageshack.

They are always in the same place, sometimes white, sometimes red. Anyone know what they are, or how to get rid of them?

 

[On the Huh]

They are termed dead/hot pixels IIRC, you normally get a few on long exposures

 

[Im Bald Ok]

Yes, looking at other pictures taken they only appear on longer exposures, Thanks.
Is it a problem with the lens or the camera? I could use an excuse to upgrade

 

[On the Huh]

This is fron the sensor. Not sure if an upgrade will solve the problem, just the nature of sensors with a long exposure.

You'll have to clone them out.

 

[MartynK]

As above. The hot pixels are on the sensor. Changing/upgrading the camera may or may not help, but I wouldn't bother unless you have other reasons for wanting to do so. Many cameras display hot pixels following long exposures and, to the best of my knowledge, manufacturers don't regard this as a warranty issue unless they exceed quality control tolerances. Just clone them out.

 

[Alastair]

If you check the manual I'm sure you can remap the sensor to deal with these (usually involves being in a specific mode and taking an exposure with the lenscap on). Once you've done that software such as Lightroom will pick-up this data and automatically apply it to raw images (the camera will apply it automatically to jpgs).

 

[Musicman]

If you check the manual I'm sure you can remap the sensor to deal with these (usually involves being in a specific mode and taking an exposure with the lenscap on). Once you've done that software such as Lightroom will pick-up this data and automatically apply it to raw images (the camera will apply it automatically to jpgs).

Lightroom maps out hot pixels from RAW files automatically without any user intervention.

I believe the recent versions of Canon DPP do too.

 

[Alastair]

Lightroom maps out hot pixels from RAW files automatically without any user intervention.

I believe the recent versions of Canon DPP do too.

Ahh.. I thought it was pulling the data from the camera for that. When I first started using Lightroom (v.2) I remember having to clone out hot pixels manually. But once I'd done an incamera map this task disapeared from my workflow as LR was dealing with them automatically.

 

[Nod]

Yes, looking at other pictures taken they only appear on longer exposures, Thanks.
Is it a problem with the lens or the camera? I could use an excuse to upgrade

To be honest, neither - they are pretty much a fact of life and unavoidable. They are simply errant photons which have been amplified by the long exposure or tiny manufacturing faults on the sensor - and a pixel failure rate of one in umpteen million ain't bad!. Easily disposed of in seconds in PP (clone 'em out) and often barely noticeable even uneditted once printed to a reasonable size (6x9).
Why does anyone need an excuse to upgrade - if youwant to and can afford to, don't dither, do it!

BTW, welcome to the forum and with regard to your user name, so am I - with the current added attraction of a still crusty surgical wound over the top from ear to ear!