Red spot on images

[Bob Jenner]

I use a canon 40D with a standard lens and a sigma 500mm stabilising lens.
On every image I get a small red spot irrespective of which lens I am using.
Can anyone help as to what is causing this please?

 

[purpleclouds]

It sounds like hot pixels on your sensor...they are common at high ISO settings...although more in the appearance of 'noise' than a single large spot! If you post an example we can diagnose it better

 

[pxl8]

Could be a hot pixel, could be something on the sensor. Posting an example shot would help narrow the cause down

 

[InaGlo]

I had this recently when shooting in a dark club at high iso, odd thing was, it didnt always appear in the same place in the frame!

 

[KayJay]

Hot pixels tend to appear also in long exposures. Can you post some example images?

 

[Lomond Lad]

You've not got your auto focus point enabled have you? Is it a red square or a dot?

 

[mastertrinity]

after hearing on other forums with the same problem, it sounds like a hot pixel as said above.

 

[KayJay]

Need images.