5d mark III - checking for dead/hot pixels in video?

[motifone]

Hi Everyone

Just picked up a new 5d Mark III and would like to test it quickly to make sure all is in order.  Specifically, I'd like to test for any dead pixels.  I know such things can be edited out of images in Photoshop, but I'm more concerned about dead pixels affected video footage as those aren't so easily removed. 

I'm a 5D classic user and new to video on the 5d. What would be a good quick test to check for such pixel problems -- shoot a short shot against a dark background? white background?  Then, check for white or colored pixels that remain fixed in the image?  Is there a particular resolution I should be shooting at to evaluate?

Should I see any in the still imagery, I'm aware of the manual sensor cleaning technique to attempt to clear those aup.

Appreciation in advance for taking the time to provide input.

[macrodust]

Why don't you test it the same way as for stills? Lens cap on and a long shutter time. If you have dead pixels, you'll see them and then they'll likely affect your video too. It's a bit tricky to find a guaranteed way of spotting them in a video clip.

[Chris Burch]

It's very easy to find hot pixels by shooting anything in total darkness.  You can add a second check by doing the same thing on a white surface -- I wouldn't blow out the image though.

For video, "hot pixels" are what you want to avoid because they show up rather distinctly on videos, especially in a dark environment.  The very first video I shot on my 5D3 showed a red hot pixel in the lower half of the screen, and I only had the camera for about a week at that point.  Fortunately, you can fix it rather easily...

1) Remove the lens and place the cap on the camera
2) In the menu functions find the Sensor Cleaning menu
3) Select "Clean Manually"
4) Let it sit for 30 seconds and then switch the camera off
5) When you power back on all pixels should be remapped

This apparently works on my of the newer Canon DSLRs, but I can definitely vouch for it successfully fixing a hot pixel on my 5D3.

[Rienzphotoz]

It's very easy to find hot pixels by shooting anything in total darkness.  You can add a second check by doing the same thing on a white surface -- I wouldn't blow out the image though.

For video, "hot pixels" are what you want to avoid because they show up rather distinctly on videos, especially in a dark environment.  The very first video I shot on my 5D3 showed a red hot pixel in the lower half of the screen, and I only had the camera for about a week at that point.  Fortunately, you can fix it rather easily...

1) Remove the lens and place the cap on the camera
2) In the menu functions find the Sensor Cleaning menu
3) Select "Clean Manually"
4) Let it sit for 30 seconds and then switch the camera off
5) When you power back on all pixels should be remapped

This apparently works on my of the newer Canon DSLRs, but I can definitely vouch for it successfully fixing a hot pixel on my 5D3.

Thanks for sharing ... I had a hot pixel in my 5D MK III and your above method, worked like a charm ... now no hot pixel ... me happy

[R1-7D]

Tonight playing with live-view mode I noticed some stuck red pixels. I followed the method as described above of removing the lens and putting the cap back on the camera, and then putting the camera in manual sensor cleaning mode for 30 seconds.

Nothing changed. I still have three stuck red pixels - one being right in the center.


What do people recommend? Sending it in to Canon under warranty? I have heard they just replace the sensor.

[Rienzphotoz]

Tonight playing with live-view mode I noticed some stuck red pixels. I followed the method as described above of removing the lens and putting the cap back on the camera, and then putting the camera in manual sensor cleaning mode for 30 seconds.

Nothing changed. I still have three stuck red pixels - one being right in the center.


What do people recommend? Sending it in to Canon under warranty? I have heard they just replace the sensor.

I had to do it twice before all the hot pixels disappeared ... maybe your camera requires a few tries.

[R1-7D]

I tried about 10 times last night. Nothing seemed to work.

Finally I gave up, removed Magic Lantern from the camera, and took the camera to the store I bought it at. They're sending it to Canon for me.

Tonight playing with live-view mode I noticed some stuck red pixels. I followed the method as described above of removing the lens and putting the cap back on the camera, and then putting the camera in manual sensor cleaning mode for 30 seconds.

Nothing changed. I still have three stuck red pixels - one being right in the center.


What do people recommend? Sending it in to Canon under warranty? I have heard they just replace the sensor.

I had to do it twice before all the hot pixels disappeared ... maybe your camera requires a few tries.

[Rienzphotoz]

I tried about 10 times last night. Nothing seemed to work.

Finally I gave up, removed Magic Lantern from the camera, and took the camera to the store I bought it at. They're sending it to Canon for me.

Too bad ... hope you get it back soon with the problem solved. Cheers