topic Re: Weird Pixels in EOS DSLR & Mirrorless Cameras

Weird Pixels EOS R6

pillarpaul — Fri, 06 Oct 2023 19:07:05 GMT

I shoot with an R6 and lately have been getting a very large # of seemingly hot pixels (red, blue and white streaked ones) in dark areas of short exposure, good light images .Ran the covered lens cap test that showed no hot pixels. A sample photo attached. Image has been denoised in LR (Enhanced). Similar results when run through Topaz DN. Look at the dark feathers on the back of the Night Heron as well as the rocks to see the worst. Any thoughts? Gotten worse lately so perhaps a sensor issue although note it's all over the image.

Re: Weird Pixels

Anonymous — Fri, 06 Oct 2023 16:51:34 GMT

Viewing your sample photo, I couldn't tell what you are referring to. The spots just look like sunlit highlights/reflections to me. Can you provide a less busy photo showing the problem?

Re: Weird Pixels

Peter — Fri, 06 Oct 2023 17:37:40 GMT

Share raw samples.

If you want to take a look at hot pixels, make sure you do it before demosaicing is done.

dcraw, LibRaw, darktable, RawTherapee, AnotherRawTherapee, RawDigger all have that feature.

Re: Weird Pixels

pillarpaul — Fri, 06 Oct 2023 18:08:36 GMT

My bad - it is hard to tell from the samples so here is a screenshot of a portion of a SOOC raw image that has no sun on it to appear to be a sunspot. Pixels obviously marked with arrows.

Thank you for your help.

Paul

Re: Weird Pixels

Anonymous — Fri, 06 Oct 2023 18:14:45 GMT

I don't think that they are stuck pixels. If you have taken a photo with the lens cap on, and saw no stuck pixels, I think your camera is fine. Can you take a photo of a simple background without editing and upload for us to evaluate?

Re: Weird Pixels

pillarpaul — Fri, 06 Oct 2023 18:31:12 GMT

Here is a screenshot of a SOOC Raw image from just now. No stuck pixels but it's an overcast day so not the high contrast of the past week. Thank you, Bob.

Re: Weird Pixels

Anonymous — Fri, 06 Oct 2023 18:33:51 GMT

Since this photo shows no stuck pixels, your camera is fine. The heron photo, in my opinion, is showing specular highlights from sunlight reflections.

Re: Weird Pixels

pillarpaul — Fri, 06 Oct 2023 18:38:58 GMT

Thank you for checking, Bob. I had originally thought that but the large number of those stuck pixels in shaded, dark areas that would get no sunlight reflections (I have many other images with them that have no sunlight) makes me still wonder about it.

Paul

Re: Weird Pixels

Waddizzle — Fri, 06 Oct 2023 18:43:34 GMT

Your arrows seem to be pointing at drops of water. Your camera seems fine, to me.

Also, you are looking at images that have gone through a “de-noise” algorithm. Were those “spots” present in the image before you processed it? That’s the first question that you need to clear up.

Re: Weird Pixels

Anonymous — Fri, 06 Oct 2023 18:47:48 GMT

Stuck pixels wouldn't be elongated and blurry like that. They would be small, round and fairly sharp. A lot of dust on the sensor might look similar to what you are referring to. Take a look at your sensor to see if it is dirty.

Re: Weird Pixels

pillarpaul — Fri, 06 Oct 2023 18:49:43 GMT

Actually, the two images with arrows are unprocessed SOOC RAW images simply screenshot. It may not show well but the pixels I question are either red or blue (not the white reflections) and are identical to what I get in my Milky Way shots in terms of hot pixels, which are usually caused by high ISO, of course, whereas these were shot at about 800 ISO.

Paul

Re: Weird Pixels

Anonymous — Fri, 06 Oct 2023 18:52:03 GMT

Taking a photo with the lens cap on will reveal the stuck pixels, if any. You have already done this test, so I believe you are in the clear, so to speak.

Re: Weird Pixels

pillarpaul — Fri, 06 Oct 2023 18:55:50 GMT

Had the sensors professionally cleaned about a month ago and some other shots have this while others don't so not universal since the cleaning.

Re: Weird Pixels

Waddizzle — Fri, 06 Oct 2023 18:56:59 GMT

@pillarpaul wrote:
Actually, the two images with arrows are unprocessed SOOC RAW images simply screenshot. It may not show well but the pixels I question are either red or blue (not the white reflections) and are identical to what I get in my Milky Way shots in terms of hot pixels, which are usually caused by high ISO, of course, whereas these were shot at about 800 ISO.
Paul

No one noticed any noticeable issues in the original image.

This is why “pixel peeping” is bad for your brain. It can and will make your head spin as chase problems down rabbit holes. I still say it looks like drops of water. Water can reflect light.

The original image is a very nice shot.

Re: Weird Pixels

BurnUnit — Fri, 06 Oct 2023 18:59:16 GMT

Do you see similar results if you do your RAW processing in DPP4?

Re: Weird Pixels

pillarpaul — Fri, 06 Oct 2023 19:04:14 GMT

LOL. I know - I need to reduce my pixel-peeping habit!

Thanks for the compliment on the original image.

Paul

Re: Weird Pixels

pillarpaul — Fri, 06 Oct 2023 19:26:28 GMT

I do have it but have never used. I will try to see if I can import some images. I guess that could tell me if the problem is in LR rather than the camera if I don't have the same issue in DPP4. Thank you!

Paul

Re: Weird Pixels

BurnUnit — Sat, 07 Oct 2023 19:57:12 GMT

And it's not even to say that LR itself is causing the issue you're seeing. It may be something in your workflow in LR that is neither right or wrong in itself. But working in DPP4 or DxO OpticsPro or some other RAW editing software may force you to unconsciously change your workflow and provide equal or better results.

Re: Weird Pixels

pillarpaul — Sat, 07 Oct 2023 21:59:21 GMT

Thanks, BU. Interesting observation. I downloaded DPP4 yesterday and I tried to use but I will need to watch the video tutorial first. I do have a rather complex workflow currently so you may be on to something. Hopefully I can test it out this week.

Paul