Has my camera's CCD thrown a pixel?

[andygates]

I've just noticed a single white pixel appearing in all my pics.  Here's an example - it's high left, just above the treeline, and could be mistaken for a star except that it also appears in hedges and on buses.

Aww, I have my own star, how cute!

I've not noticed it before but I only just switched up to highest-quality mode.  I think it gets compressed away on lower-quality modes (and to be fair, once the photos enter the real world, it gets compressed away too). 

Is my CCD throwing a benny?  Can it be fixed?  Or is this the first of many and signifies the start of the slow death of my camera?

[Adam]

I was more intrigued by the red glowing upright things.........

The pixel error could always have been there.  IIRC, on new LCD screens, they can get away with a certain number of dead pixels before you can classify the screen as not fit for purpose.

Anyway, it could be worse - rather than a star, you could have a UFO.

[andygates]

They're inflatable boys buoys, for swimming around.  But it's not the LCD that's misbehaving, it's the pictures the camera takes - so I'm assuming it's the CCD, the sensor chip. 

[Adam]

Sorry - I should have said that I assumed the same rules apply to CCD's as LCD's. So I don't think it means you'll have to ditch it.

[Biggsy]

It's a very common problem.  Most digital cameras will eventually develop a few stuck pixels on the CCD, if they don't already have any.  Google "stuck pixels" and "hot pixels".  They can be red, green or blue (sub-pixel), as well as white (whole pixel).

Some cameras can be remapped, which disguises the problem - but it wouldn't be a cheap job.

You've got a second small white pixel - between the two buoys.

For your best pics, it'll be worth cloning out the dodgy pixels with an editing program, or you could try an automatic hot pixel remover.  I haven't found one that works very well, though, except for Silkypix with RAW images.

[Biggsy]

Pixia is a free program with a neat cloning function.

- - -
I don't agree with Wikipedia's definitions of hot and stuck pixels.

My understanding is that hot pixels are temporary and stuck pixels are permanent, both on rather than off, any colour, but "hot pixels" is often used casually to mean temporary as well as permanently stuck pixels.

[Jaded]

Some cameras have an automatic remapping.

It may have been there all the time? Anyway - probably only you will notice it (and all of us too, now you've told us  ) and a bit of cloning will sort it on the most critical photos.

[Pete]

This is a common occurrence in astrophotography, mainly because astronomers take very long exposures and these 'hot pixels' always show up on long exposures at high ISO numbers.

The standard astro solution is to take a 'dark frame'.  Once you have finished your series of night-time shots (and this problem is mostly going to occur then), put the lens cap on and take another image, with exactly the same ISO and exposure time as the pictures you've taken (if you've varied your exposure times, take a separate 'dark' for each time you've used).  You will need to be in manual exposure mode of course.  Do these 'darks' during the same session as when you do your photography - i.e. don't wait until next day to do them.  Ideally the camera should be at the same temperature throughout.

Then it's a simple matter to subtract the 'dark' of the same length from the data image using any image processing software (like PhotoShop or PaintShopPro) which contains an 'arithmetic' tool.

HTH.

[andygates]

Good, as long as it's not a Sign of Doom then I'll just tweak any shots where it's noticeable.  Ta.

[David Martin]

I've just noticed a single white pixel appearing in all my pics.  Here's an example - it's high left, just above the treeline, and could be mistaken for a star except that it also appears in hedges and on buses.

Get the exposure right and it will be less obvious..

Yes it is a hot pixel. just ignore and clone out as required.

..d

[tonycollinet]

You've also shot in the dark. Probably a long exposure or high iso. Hot pixels tend to show up much more with long exposures/high iso.

[andygates]

Indeed I have, for it was at 05:30, and I was deliberately trying to capture that darkling-blue, black silhouettes and those luminous orange buoys.  It's exactly the photo I was after for the day's narrative and that triathlete's feeling of early-morning cold-water dread.