[Brightcolours]

Thanks for all your opinions.

What I wrote wasn't an "opinion", it was an explanation.

[marco]

Lets describe contrast as a difference between pixel values (black white, red green, blue yellow) and dynamic range as the possible maximum and minimum color value at the same time. So it is described as difference too. But if people speak about contast they are describing mostly the local contrast. Local contrast could be described a very low frequency like sharpness is a high frequency. So global contrast is dynamic range local contrast is something different and depend of high dynamic range values and resolution so you can increase the contrast of clouds for example. But we are now really of topic.

[balacau]

I'd be interested to find out how a Sony e-mount 10-18mm F4 would compare against Sigma's 8-16mm F4.5-5.6?  Obviously the Sigma is far more expensive but it never fails to impress me even when used in harsh lighting conditions.  

[Brightcolours]

Lets describe contrast as a difference between pixel values (black white, red green, blue yellow) and dynamic range as the possible maximum and minimum color value at the same time. So it is described as difference too. But if people speak about contast they are describing mostly the local contrast. Local contrast could be described a very low frequency like sharpness is a high frequency. So global contrast is dynamic range local contrast is something different and depend of high dynamic range values and resolution so you can increase the contrast of clouds for example. But we are now really of topic.

High DR means that the white point and the black point lay as far from eachother as possible. With high contrast they lay very close to eachother. 

High DR = low contrast

Low DR = high contrast.

[marco]

Repeatation of arguments is sometime working sometimes not.

[Brightcolours]

Repeatation of arguments is sometime working sometimes not.

What you wrote still is not right, even after such a cheap stab.

[marco]

What you wrote still is not right, even after such a cheap stab.

 

How much do you have read about perception and computer graphics?

[mst]

Ah, I smell another round of BC wrestling. Ok guys, here are the rules:

 

1. No weapons

2. Be friends at the end of the discussion

 

Now, GO!

 

-- Markus

 

P.S.: Popcorn, anyone?

[Brightcolours]

How much do you have read about perception and computer graphics?

Asking such side tracking questions does not help you (and I have read more about those than you, is my guess. I have been developing software since the 1990's, including specialized presentation solutions back then). Just simple fact: high dynamic range puts two values relatively close together, high contrast puts those two values far apart. Computer graphics have nothing to do with that. 

 

I doubt you ever really looked at a high dynamic range image (no, I do not mean a low dynamic range image derived from a higher dynamic range via compression and tone mapping), but anyone who has ever used high a special high dynamic range B/W film formula and low dynamic range colour slide film knows that DR and contrast are opposites. 

 

High DR puts the black and white points far apart, what we in reality perceive as black and as white will look like a grey (almost mid tones) in high DR captures (talking about perceptions...). Not sure why you confuse contrast with high DR.

 

On the left a normal tonal curve (the way our eyes perceive the world) and 8EV or less dynamic range (which is normal). On the right a dynamic range extended to about 14 stops.

[ATTACHMENT NOT FOUND]

Notice how the "blacks" turned into greys, and the light parts turned into greys too. That is how a high dynamic range capture looks. Why is that? Because a high DR pushes the black- and white points apart (obviously, you are extending the dynamic range). Increasing contrast will pull them closer again.

The low DR image looks contrasty and punchy, the high DR image looks flat. Only by turning the high DR image into a low DR image one can make it contrasty and punchy again.

[marco]

Can we agree that language is context depend? That was my implicit main point.