Red Grain in the Under Exposed portions of the Image. Canon 70D

[MatthewB]

With the majorit of the images I take, any section of the image that is slightly underexposed turns to the red grain as you can see on the bottom of the balconies in the image above. Is there a setting I can change or is it just what the Canon 70D does?

[Stephen]

Hi, MatthewB!

Thanks for your post!

So the community can help you better, it might be helpful to have all of the EXIF information with your photo (the shooting details). Has your photo been altered in any way? If so, how? Which software (if any) do you use to post-process your images? Do you have the original file that you can share with the community? If your original file is too large to upload directly to the Forum, consider using OneDrive, DropBox, Google Drive, etc, but please ensure to allow public viewing only. 

If you find that you'd like one-on-one help with your photos, don't hesitate to reach out to our friendly, US-based support team! They're available weekdays from 9am to 9pm (ET) and Saturdays from 9am to 7pm (ET). Support at Canon USA is free and is never outsourced. 

[MatthewB]

https://drive.google.com/file/d/1x7gk4oLlLkn5K2Ul5T6-vD_SJrv9HyEV/view?usp=sharing

Does that allow you to see the full image with the photo data?

[kvbarkley]

Do you have the underexposure warning turned on?

[MatthewB]

Possibly. Where in the settings could that be turned off?

[ebiggs1]

Whenever you get unknown results and you don't know why, reset your camera.  Menus under tools.  You have set something and don't know what. Then you probably need to read your manual.

[kvbarkley]

Sorry, you only have a highlight alert not an underexposure one.

[Waddizzle]

---

@MatthewB wrote:

https://drive.google.com/file/d/1x7gk4oLlLkn5K2Ul5T6-vD_SJrv9HyEV/view?usp=sharing

Does that allow you to see the full image with the photo data?

---

1/80, f/7.1, ISO 100 : EOS 70D, EF-S 18-55mm f/3.5-5.6 IS II

The histogram is saturated in both highlights and shadows, especially the shadows.

The only time I have seen this type of noise has been in very underexposed astrophotography photos.  Image data gets drowned out in sensor noise.  I needed a longer shutter to capture more light.  It is odd to see it like this, though, and so strong.  I usually have to crank exposure up to like +5 Ev to see this type of noise.

Judging from the histogram, I suspect that this image has more dynamic range than the camera can handle.  I would be curious to see the results of bracketing this shot as an HDR capture.

[MatthewB]

This seems to only happen when I'm shooting during the day with bright sulight and then the dark portions of the image become covered in the red grain. Does this make sense?

[Waddizzle]

---

@MatthewB wrote:

This seems to only happen when I'm shooting during the day with bright sulight and then the dark portions of the image become covered in the red grain. Does this make sense?

---

Yes, it does make sense.  Was this shot in sunlight?  It seems overcast.