topic Re: 5D MKIV RED DOTS ON IMAGES in EOS DSLR & Mirrorless Cameras

5D MKIV RED DOTS ON IMAGES

PEPNYC — Thu, 02 Jul 2020 22:04:46 GMT

Have a high mileage 5D MKIV and just noticed patches of red dots when I zoom in on raw photos in Photo Pro software. Just checked the previous shoots and those are fine, so it's definitely a new issue.

I've tried cleaning the sensor manually without success. Any ideas? or is this a trip to Canon service?

Best,

Phil

Re: 5D MKIV RED DOTS ON IMAGES

wq9nsc — Fri, 03 Jul 2020 10:49:21 GMT

What is your exposure information for the shots showing red dots, ISO in particular? These red pixels from "hot" pixels are likely at high ISO and/or long exposure settings. Maybe a camera setting was accidentally changed causing it to use a higher ISO creating more color noise.

Rodger

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Fri, 03 Jul 2020 10:59:25 GMT

Thanks Rodger,

Nothing unusual...ISO was 400-800. Shutter speeds around 500-1000.

Re: 5D MKIV RED DOTS ON IMAGES

wq9nsc — Fri, 03 Jul 2020 13:59:04 GMT

You are welcome Phil and with a sudden and large increase in hot pixels it sounds like it is time for Canon service. If the camera was stored/used in very hot conditions that will also cause an increase in sensor noise but it would have to be unusually hot to cause a sensor to suddenly start showing more noise.

Google hot and stuck pixels to see more about this issue.

Rodger

Re: 5D MKIV RED DOTS ON IMAGES

Peter — Fri, 03 Jul 2020 14:36:13 GMT

Doesn't your raw converter have a hot/dead pixel remover?

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Fri, 03 Jul 2020 17:00:42 GMT

Thanks Peter...
Will explore as a remedy

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Fri, 03 Jul 2020 23:50:40 GMT

Wondering what the cost of the repair would be? Is this a sensor replacement?

Re: 5D MKIV RED DOTS ON IMAGES

Peter — Sat, 04 Jul 2020 05:14:26 GMT

Normally just a pixel mapping in the software if it just are hot pixels. Do you have a sample file (raw) you could upload?

Re: 5D MKIV RED DOTS ON IMAGES

Ray-uk — Sat, 04 Jul 2020 11:08:48 GMT

Chasing hot/dead/stuck pixels can sometimes be a pointless excercise because they can show up in different positions with each shot.

My old 50D suffered with quite a few and I tried the supposed "manual remapping procedure" which worked for me at the time (but it may have been a coincidence). Here's how it's done:

Make sure you have a fully charged battery.

Remove lens & fit body cap.

Activate "manual sensor clean" in the camera menu.

Leave for 30secs to 1 minute.

Turn off camera at main switch.

That's it, dodgy pixels should now be gone.

Some people say that this works, others say it's a myth but it seemed to work for me some time ago and you have nothing to lose. Apparently it only works for still photography and does nothing for pixel problems with video.

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Sat, 04 Jul 2020 12:22:56 GMT

Will try to upload a photo next week...thanks Peter.

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Sat, 04 Jul 2020 12:24:10 GMT

Thanks Ray....
Will give that method a try.

Re: 5D MKIV RED DOTS ON IMAGES

wq9nsc — Sat, 04 Jul 2020 13:15:33 GMT

The manual sensor clean will map the hot pixels but I would be concerned if suddenly a lot of new hot pixels appeared which was what I got from the first post.

If a large number suddenly appeared then something is going on in the sensor/LNA/A to D converter area and it could continue to get worse. If you are relying upon this camera for paid shoots I would get it to Canon for a checkup to see if anything unusual is going on, otherwise use the manual cleaning/remap and keep a close eye on it for a few weeks to see if new hot pixels keep appearing.

I did the clean/remap with my original 1DX last Fall after a single hot pixel appeared at moderate ISO and that resolved the issue but if a large group suddenly appeared I would be concerned.

Rodger

Re: 5D MKIV RED DOTS ON IMAGES

Peter — Sat, 04 Jul 2020 13:43:59 GMT

Is it worse than what this animated GIF file shows? 6 seconds and ISO 200.

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Mon, 06 Jul 2020 14:58:44 GMT

Thank you...
I tried the manual clean/power off technique but it didn’t seem to have any effect. I did notice that I usually use the Canon DPP 4 software to view my photos which yields the best look at the raw files. Yes, when I opened the files via Adobe Camera Raw the stick/hot pixels went away completely. Interesting to note that when using the Canon DPP software and transferred the image to Photoshop the hot/stuck pixels were still there.

Re: 5D MKIV RED DOTS ON IMAGES

Peter — Mon, 06 Jul 2020 17:27:27 GMT

Adobe removes hot pixels automatically from raw files. DPP4 doesn't. When you transfer a file from DPP4 to Photoshop you have already demosaiced the picture. Hot pixels are removed before demosaicing. As you saw in the GIF animation at page 1 it is easy to understand why it is important to remove hot pixels before the file is demosaiced.

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Mon, 06 Jul 2020 22:15:59 GMT

Thanks Peter,

Using Adobe Raw is definitely a servicaeable workaround. Shame that DPP doesn't remove hot pixels but perhaps they can add to future version. Appreciate all of the support of the Canon Community. I've attached a photo illustrating my hot pixel situation.

Phil

Re: 5D MKIV RED DOTS ON IMAGES

Peter — Tue, 07 Jul 2020 01:41:17 GMT

That is much worse than I expected and perhaps something else than hot pixels. All red and with the same intense even in full daylight. No red dot in dark area or bright area. Do you have a raw sample? Easier to check the pixels before . Two raw files taken in daylight and another one with lens cap on with the same shutter speed. Use a filehost like Google Drive or Dropbox.

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Tue, 07 Jul 2020 03:55:44 GMT

https://drive.google.com/drive/folders/1keP05tAwhzuPBpLiIU2aQnoTJzz1DmCw?usp=sharing

Re: 5D MKIV RED DOTS ON IMAGES

Peter — Tue, 07 Jul 2020 07:06:02 GMT

The red pixels move around. Some of the red pixels have a green hot pixel beside them but the red is alwas the strongest. You have no red pixels in your last frame, the black one. I would say that they are not the classic hot pixels but the way to remove them in post works. Both darktable and RawTherapee are able to remove them and so does Adobe Camera Raw as you wrote.

Call Canon for a repair because this is not normal for any camera model from Canon.

Re: 5D MKIV RED DOTS ON IMAGES

PEPNYC — Tue, 07 Jul 2020 15:21:20 GMT

Thanks Peter...The black frame was actually shot after I performed manual cleaning process so I'm not sure if that's contaminated our analysis. That said, I recently replaced the shutter on this body and concerned this sensor issue may be an expensive fix. May not be worth sinking more money into it but perhaps someone in the community can speak to potential cost to repair/replace sensor?

Best,

Phil