Question about lighting dynamic range


#1

Hi folks,

Who hasn’t experienced the trouble of having too much lighting contrast in a picture (sunlight/shadow)?

Under this situation I end up either:

-Overexpose or underexpose part of the image;

-Taking two shots with different exposure settings and then mix them in GIMP.

My questions:

Is there any camera that has got as much dynamic range as the human eye, i.e. can contain accurate information of both shadow and sunlight regions in a single shot?

Does the lighting dynamic range have to do with bit depth of the image?

Do cameras that support raw format have an advantage over say “.jpeg only” cameras?

Thanks


#2

Loads of cameras these days have extreme amounts of dynamic range.

Even if some of the scene is dark, you can lift the shadows using tonemapping or luminance masking and they won’t be objectionably noisy.

This is not something you can do with JPEGs, only raws. However, some cameras will do this for you in the JPEG.


#3

The advantage (and disadvantage) of digital cameras is that they see things differently than the human eye; i.e., the camera doesn’t capture what you see. From that point of view, they don’t have the dynamic range that is close to the eye, though the tech is always getting better.

Having more bit depth is good because you have more shades of grey per colour channel, meaning that you have more possible variants of colour. Editing in high bit-depth is especially important in post-processing. That is why we would like to use raw files.


(Mica) #4

Pentax and Nikon both have HDR modes, and Pentax for sure can produce a raw file from this mode.


(Ingo Weyrich) #5

Pentax produces a container with 3 raw frames from this mode. It’s a single file (PEF or DNG), but contains 3 raw frames.


(Morgan Hardwood) #6

The eye (and brain) do not work the same as a camera. The eye’s retina consists of mostly rod cells which are highly sensitive to luminance, and three types of cone cells which are sensitive to various wavelengths thanks to which we distinguish color. The most common type of camera sensor consists of identical photosites and a color filter array over them. The human eye needs time to adapt to different light situations, while the digital sensor is probably more affected by temperature. The camera has an analog-to-digital converter between the sensor and the brain; the eye uses chemical reactions to send a signal to the brain. It doesn’t seem like a 1:1 dynamic range comparison to me.

This website shows that the best digital cameras can capture up to 12 stops of dynamic range in their raw files (the human eye has around 20 stops, says the internet):
http://photonstophotos.net/Charts/PDR.htm

This website lists which cameras those are:
https://www.camerastuffreview.com/en/camera-guide/review-dynamic-range-of-60-camera-s

And this guy sheds some light on the subject:
https://www.reddit.com/r/photography/comments/5s4gxw/will_future_dslrs_ever_reach_16_stops_of_dynamic/ddchp31/

I’m into panography, which almost always includes dealing with very high dynamic ranges. While photographers would normally bracket using a typical camera, people working in (rich departments) forensics etc. would use something like this:
http://hts-3d.com/camera-systems/

Question unclear. A high dynamic range scene could be stored in an 8-bit JPEG, but it would be posterized due to the low bit depth.

Vastly. The raw data is close to what the sensor saw, like a raw ball of dough, while the JPEG is like a baked breadroll. You could turn the ball of dough into a breadroll, but you could also turn it into a pizza, while once you have a breadroll, there’s no going back. It’s hamburger time.


(Mica) #7

Indeed, this is what I meant (with your recent post in mind!). Sorry for not being clearer.


(Simon) #8

Whilst it’s true that cameras are increasing in DR, there’s been little change in display DR for still images.

Prints are limited by the contrast ratio that you can achieve with inks - if your black ink reflects 0.5% of the incident light and your glossy paper 90%, then you’re stuck with a contrast ratio of 180:1

Screens are currently mainly SDR, and the file formats in use have low DR transfer functions. Even high brightness screens are only stretching the luminance and bodging the gamma to match. The movie and broadcast industries are moving to HDR displays - hopefully the stills industry will follow (HLG HDR is easy to implement).