Need advice-possible damage... :(

Phatman113

So, i took some low light photos last weekend and while I was going over the .CR2 files I noticed some reocurring, off-color pixels. Blues, greens, and a couple of reds, all in the middle of what shoud have been a very black background. Some preliminary looking shows that they're all in the same location. Is this a problem with my camera that I should get fixed? I can't see them on regular, well lit pictures, but I'm not happy that they're in my black space... I took some pics with the lens cap on and they're in those pics also.

Anyone have an idea of what I should do?

Thanks!

ziggy53

Phatman113 wrote:

So, i took some low light photos last weekend and while I was going over the .CR2 files I noticed some reocurring, off-color pixels. Blues, greens, and a couple of reds, all in the middle of what shoud have been a very black background. Some preliminary looking shows that they're all in the same location. Is this a problem with my camera that I should get fixed? I can't see them on regular, well lit pictures, but I'm not happy that they're in my black space... I took some pics with the lens cap on and they're in those pics also.

Anyone have an idea of what I should do?

Thanks!

Were these fairly long time exposures by any chance?

Which camera?

What were the ambient temperature conditions?

Had the camera been in the sun?

Phatman113

Yeah, they were pretty long, I was using a tripod and playing with dark photos, they were between 5 and 30 second exposures.

The camera was(still is I hope... ) a Canon Digital Rebel XTi

The outdoor temp was fairly cool, I'd say around 60 or so and it had been in the sun, but these shots were taken around 9pm or so, so the camera wasn't still warm at all...

It was also somewhat misty, if that may have attributed to anything...

Nikolai

Hot pixels. It happens. Digital plague, so to speak, with the exception it's not contageous.. :-)
Don't worry too much, unless there are a lot of them and you camera is still under warranty.

Phatman113

I was just hoping they weren't a harbinger of camera death... It's probably not under warranty anymore, but I do have an insurance policy with the written statement "if it can happen to the camera, it's covered"

Not sure if it's worth dealing with right now, or if I should just hold out until it's unbearable...

Tee Why

If there are only a few pixels and unless you are doing a lot of long exposure photography, I'd probably just let it be and clone them out when you see them occasionally.

Phatman113

There's probably 10-12 of them, but they really only seem to show up on really dark backgrounds, seems like it shouldn't be too tough to touch up those spots when the show themselves...

Thanks for the input everybody! at least I know it won't explode in my hands now...

ziggy53

I suggest turning on the "Long Exposure Noise Reduction". That should automate the removal of those noisy pixels.

Richard

ziggy53 wrote:

I suggest turning on the "Long Exposure Noise Reduction". That should automate the removal of those noisy pixels.

Yes, that should work. Just be aware that the processing time in the camera for noise elimination is equal to the exposure time, so you will have to wait longer between shots.

Phatman113

ziggy53 wrote:

I suggest turning on the "Long Exposure Noise Reduction". That should automate the removal of those noisy pixels.

Well that's a handy custom function... I haven't played with the custom functions much, so I didn't even know that was in there.

Thanks for the suggestions everybody, I'll look at my options for dealing with this issue...

Rhuarc

Seymore wrote:

Another suggestion... Setup a script in your PP SW and clone each pixel with the one literally right beside the hot pix. Right, left, top or bottom doesn't matter. Then when you see the problem again, you can clone them out right away. This will also tell you, weeks or months down the road, if the problem is getting worse. You'll have new hot pix that are not cloned out after you run the script.

This would be a handy script to have! Anyone ever created something like this already?

Nikolai

Seymore wrote:

I had a D100 with 1/2 a dozen hot pix and used this before. Please note that one script doesn't fit all.

It would, provided it operates with a camera-specific "mask". It's a two step operation:
1) take a dark frame shot and create a hot pixel mask based on it
2) use the script to apply this mask to the images

Gotchas:
1) I use the term "mask" loosely
2) it would only work on uncropped images

Essentially, I don't think it's a good ROI - you'd spend gobs of extra time and in most cases you wouldn't even need it.

Alternative solutions:

A) for Canon 40D-like camera you can create a "dust mask" that would be applied automatically. Instead, you can create "hot pixel" mask.
GOtcha: IIRC you need to use Canon s/w to apply it.

With ACR 4.x+ you can apply a bunch of tiny "healing brush" touches and save this preset. Then you can simply apply it to any new crop from the same camera.
Pros: relatively fast and operates on RAW files at the very early stages of your RAWFlow:-)
Cons: you need to remember to do it. However if you have a certain default RAW preset you always do, this should not be a problem.

Rhuarc

Nikolai wrote:

It would, provided it operates with a camera-specific "mask". It's a two step operation:
1) take a dark frame shot and create a hot pixel mask based on it
2) use the script to apply this mask to the images

Gotchas:
1) I use the term "mask" loosely
2) it would only work on uncropped images

Essentially, I don't think it's a good ROI - you'd spend gobs of extra time and in most cases you wouldn't even need it.

Alternative solutions:

A) for Canon 40D-like camera you can create a "dust mask" that would be applied automatically. Instead, you can create "hot pixel" mask.
GOtcha: IIRC you need to use Canon s/w to apply it.

With ACR 4.x+ you can apply a bunch of tiny "healing brush" touches and save this preset. Then you can simply apply it to any new crop from the same camera.
Pros: relatively fast and operates on RAW files at the very early stages of your RAWFlow:-)
Cons: you need to remember to do it. However if you have a certain default RAW preset you always do, this should not be a problem.

I like that last option. I could do this in Lightroom.

Nikolai

Rhuarc wrote:

I like that last option. I could do this in Lightroom.

We aim to please:-)