Dead pixel on image sensor?

[chad_robinson]

I have three questions,

 

1,I own an eos 350d. Recently I have noticed a blue dot ( or pixel ) in the same

spot of my photos when I veiw them on my computer. If I shoot landscape or

portrait the blue dot is still there respectivley ( landscape top right corner,

portrait lower left corner ). The shots taken where night shots with long

exposures 2sec to over a minute and ranging between f4.5 and f22. I usually

shoot RAW format but it is also there in JPEG ( obviously ).

 

2, The image counter has jumped a few thousand counts from img200. to img4500+

and I'm very confused as to why this would happen.

 

3, I have somehow managed to get what looks like hair in the view finder and I

would like to know how to remove it.

 

I have spoken to the shop where I bought it from and they said to bring it in so

they can either send it for repair or just replace the body but I am very new to

this photography thing ( and bloody lovin' it ) and figure the only way to learn

is to ask. So please dont pound me with 150 years of knowledge to prove that you

like bashing us poor little newbies.

 

I'm very keen to learn as much as possible so I really do thank anyone who takes

the time to not only read this but posts an answer.

 

Cheers C.R.

[shambrick007]

#1 is normal for the conditions you've described - not a defect. You can clone it out in post processing.

[shambrick007]

Well, a defect yes, but extremely minor s far as the manufactures are concerned. Search on "hot pixel" or "stuck pixel". <p> No clue on #2. <p> Remove the lens, look at the focus screen, and try a blower brush for #3.

[bobatkins]

Depending on how it's set, the image counter can pick up on the number of the last frame shot on the memory card you put into it. If that card has a high number, shots on it will have a higher number. The camera may then remember that number.

 

To reset the counter, reformat your CF card (in fact reformat all your cards!) then shoot a picture, put the card in a card reader rename the folder with the number you want, and rename the image file to the number you want.

 

Using the camera's menu, change "File Numbering" to "Auto Reset." take a shot and then change "File Numbering" back to "Continuous."

 

Now put the card you changed the file name/number on into the camera and take a picture. Your numbering should now be what you want it to be.

[EricBoehm]

Number 1 - Hot pixels are relatively common, especially on long exposures. No sensor has 100% of all pixels operating perfectly. As the others have said, you can clone this out very easily in an image editor like PhotoShop.

 

Number 2 - best guess... Did you swap memory cards with another camera that may have had a higher count? Your camera will then write the next image file at that higher number + 1.

 

Number 3 - Rocket Blower by Giotto. This is a great hand squeezed blower that moves enough air to get rid of most debris. It's likely just a hair on the focusing screen.

[william_jennings]

1. Nobody says clean the sensor?

[bobatkins]

Why would they. From the description it's a hot/stuck pixel, not dust.

[jimstrutz]

1 & 2 were answered. As for #3, if you can't see it by looking at the viewscreen (just remove lens, and look at the screen) from the front of the camera, it's probably above the screen, between it and the penta-mirror assembly. You are probably better off just leaving it, but it is possible to remove the screen if you must.

 

Reach in with a pair of tweezers and grab the little tab on the front middle of the metal viewscreen bracket, push (bend) it back just a bit, and pull it down. The bracket will tilt forwards and the screen will fall out.

 

Don't touch the viewable part of the screen with your fingers or the tweezers; just the tabs along the edges. Use a soft brush to clean the screen and penta-mirror, and reassemble.

 

If this seems a bit much to do, and you just have to have that hair out of there, take it to a camera tech.

 

BTW, if you do mess up the screen, Canon will sell you a new one for $20-30. So this isn't really a high risk procedure.

[chad_robinson]

I just searched "hot pixel" and the images posted there showed the same "blue dots" that I'm getting, mind you I'm very happy that my problem doesnt seem half as bad as these examples, thank you Sheldon.

I will do the reformatting and such when I get home later, thank you Bob

and of course a blower will probably sort out the hair issue ( I'm a dick and shoulda thought of that myself ).

Once again this site and the people involved with it have helped me beyond words, so I'll stop saying thank you and put my new found knowledge into practice.

 

C.R.

[shambrick007]

"1. Nobody says clean the sensor?"<p>Well, I guess it *could* be a radioactive peice of dust....

[brucecyr]

The hot pixel responders are probably right -- afterall, its a blue pixel. But I suddenly got a reddish-pink pixel after a lens change, and a sensor cleaning cleared it up. In any case, you're going to have to learn how to clean the sensor sooner or later, so I say its worth a try even if it doesn't help the problem.

 

Bruce

[kelly_flanigan1]

pixels are very sensitive. These few lagards are not dead, just light challenged.

[steinardo_dawimsi]

Just how many hot pixels should be considered acceptable after a year? I did a test when the camere was new a year ago and counted 7 (after a 30s exposure). Now, repeating the test, I count 40-50...

[chad_robinson]

I found that using the in camera noise reduction feature ( for long exposure )has worked a treat. Maybe you can try that.

 

Cheers C.R.