hot/dead pixels

i think i have some hot or dead pixels, whatever you want to call them in my night shots ive been taking. is that the camera or the lens? any way to get rid of them or do i have a somewhat busted camera?? i just got it! its a nikon d80.

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Originally Posted by slayer7124

i think i have some hot or dead pixels, whatever you want to call them in my night shots ive been taking. is that the camera or the lens? any way to get rid of them or do i have a somewhat busted camera?? i just got it! its a nikon d80.

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Lenses do not have pixels. You might have a bad pixel on the sensor or it might just be dust. Post an example.

http://i15.photobucket.com/albums/a3...DSC_0435-1.jpg

they are located in those white circles. save the pic and make it bigger. they are very noticeable on my computer screen when i preview them in adobe photoshop album starter or when i make them my background. in one session theres 1 spot thats in almost every shot and the night before theres some that are in the same spot in a few shots. i've read up on hot pixels and how your exposure time and iso settings can affect them. i did not know that.

p.s. leaving for vacation today for a week. sorry if i dont respond!

Quote:

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Originally Posted by slayer7124

they are located in those white circles. save the pic and make it bigger. they are very noticeable on my computer screen when i preview them in adobe photoshop album starter or when i make them my background. in one session theres 1 spot thats in almost every shot and the night before theres some that are in the same spot in a few shots. i've read up on hot pixels and how your exposure time and iso settings can affect them. i did not know that.

p.s. leaving for vacation today for a week. sorry if i dont respond!

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This is never the lens.

Do you have the long exposure NR turned on? The hot pixels should show up in the same positions on all photos as they a cells on the sensor which may have a flaw . If they do not, your memory card my have stuck bits.

Quote:

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Originally Posted by slayer7124

they are located in those white circles. save the pic and make it bigger. they are very noticeable on my computer screen when i preview them in adobe photoshop album starter or when i make them my background. in one session theres 1 spot thats in almost every shot and the night before theres some that are in the same spot in a few shots. i've read up on hot pixels and how your exposure time and iso settings can affect them. i did not know that.

p.s. leaving for vacation today for a week. sorry if i dont respond!

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When you resize the hot pixels will go away (depending on the resize function they are basically averaged away) , you need to crop the image.

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Originally Posted by freygr

When you resize the hot pixels will go away (depending on the resize function they are basically averaged away) , you need to crop the image.

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Yes - I don't see any hot pixels in the shot above, even downloaded and blown up to 400% because of this. I've had hot pixels show up usually as green. It's a bright neon green dot (one pixel of course) and usually bleeds into the surrounding pixels to the left, right, up and down so a total of four that have a greenish tint around it. I'll try to look for an example. I only have it happen with long exposures - occasionally with my DSLR but almost always with my Coolpix 5000 at over 1/4 sec.

Post a 100% crop in an area that has the problem and we can tell you for sure what it is. There may be an easier way to do this, but I would open the image in Photoshop and enlarge it to 100% using the Navigator tool. Then use the Crop tool (make sure to clear the settings for size, resolution, etc) and make a selection roughly the size of the image posted above. This will give you a small part of the image but will be at a size that will show the problem. If anyone has a better way of doing a 100% crop I'd like to hear it!

I had a bad pixel show up jus recently. It seems to be in all of my pics, not just long exposures. I dont like it but I'll live with it for now.
The first example is what it looks like when enlarged to 40x60. This is what the print would show. the second example is original size viewed at 1600%.
To take the math out of it and show what I see on screen I use the print screen function
on the keyboard. Of course I've cropped it, but thats all. The image stays the same size.
Mark.

Send the camera in to Nikon service. They will map out the hot pixels for you under warranty.

hey guys, im back! heres a zoom/crop of the pixel that pops up in almost every night shot.

http://i15.photobucket.com/albums/a398/xhbcx/pixel2.jpg

Do you have the long exposure NR turned on in the memu?

NR (noise reduction) doesn't solve the hot pixel problem with my Coolpix 5000, but newer cameras might be better at this. And if I left NR off, the problem may be worse than it is. Curious...

no i didnt. i should probably try some test shots with it on. i also have some pictures of a sunset and i see a dead pixel in that too, and that wasn't a long exposure

If its appearing in normal shots just send the silly thing in, Nikon will map them out in no time.

Whenever you do a long exposure, turn on the NR feature though. Otherwise no matter what camera you'll have some serious quality issues.

its mostly appearing in night shots, and some day ones. if i send it in it will be covered under the 1 year warranty that came with it right? and what exactly does mapping out the pixels do? would that fix the problem?

A large percentage of image sensors actually have one or more hot or dead pixels. Normally, prior to shipment from the factory these are mapped out, so the camera does not use them and uses other methods to compensate for the missing pixel. Since the pixels on the array are covered by the bayer color filter array (R-G-B-G pattern) and then interpolated to have an RGB value for each pixel, it's far less of a problem than it might seem.

Yes, it would be covered under warranty. Since you're east of the mississippi, you should send your camera to:

Nikon Inc. Photo and Digital Service
Nikon Factory Service
1300 Walt Whitman Road
Melville, NY 11747.

Be sure to include the information described here.

I suggest you pack it in the original box (do not bother with the additional accessories or manuals though), include your warranty card (keep a copy though), a copy of your original receipt, and a paper with:
your name
your address
your telephone #
your e-mail address
Camera serial no.
Camera purchase date
Camera purchase location

Description of your problem and request of what you would like done.

Include at least two copies of this paper. I usually put 3+ just to be safe- one with the body proper, one additional copy in the camera box, and one more either in the outer box or a packing list pouch.

When it arrives (please use a quality courier with tracking like UPS/FedEx with insurance) you can call Nikon the next day and get your service order number by camera serial number and your last name. With this you can track the status of the repair online. Otherwise you will have to wait for the letter to come snail-mail with your service order number. On 3 of my 5 run-ins with Nikon service, the letter has arrived *after* the camera was back in my hands.

thank you soo much. i probably wont get around to do it until 2 weeks from now. im going on vacation in a week and id like to have my camera with me for that. do they usually fix these dead/hot pixels when its sent out? thank you again!!

yea, i tried taking some night shots with the NR option on and with the high iso option on too, still got that pixel in the same spot. so i'll ship it out when im back from vacation in 2 weeks.