# Why 'more or less stopped using ISO'?

Started Feb 19, 2014 | Questions thread
Shop cameras & lenses ▾
Re: Maybe this will help.

jackdan wrote:

bobn2 wrote:

jackdan wrote:

bobn2 wrote:

crames wrote:

bobn2 wrote:

How does brightness figure into this? That is, CIE brightness, or are you using another definition?

I don't see how the connection between luminance and brightness would cause there to be "no such thing as ISO."

You can calculate a brightness for an sRGB value of 118, since the viewing conditions are defined and you have enough info to plug into a CIECAM02 calculator.

What would be the brightness for an sRGB value of 118, in candela per square metre?

-- hide signature --

Bob

CIECAM02 brightness correlate Q of the 8 bit sRGB value (118,118,118), Q=102.28.

Candelas per square meter are the units for luminance, not the unit-less brightness, so your question doesn't make sense.

You're obviously fishing around for something, without explaining how brightness, that is CIE brightness as discussed in this sub-thread, has anything to do with the existence or non-existence of "ISO."

Apparently "'brightness' is dependent on 'absolute luminance of the stimulus' ".

While you mull things over,

Sorry, you have the mulling the wrong way round. It's you that needs to be mulling. Apparently 'brightness' is dependent on 'absolute luminance of the stimulus' and yet we find that 'brightness' has nothing to do with luminance, so mull that one over.

I found the post where your "Apparently 'brightness' is dependent on 'absolute luminance of the stimulus' " originated, but have not found the origin of "'brightness' has nothing to do with luminance,". Can you point me to that post please?

It came from you, 'candelas per square meter are the units for luminance, not the unit-less brightness'.

-- hide signature --

Bob

I am guessing you thought I was someone else. What I said was, "So although there are no units for brightness there are units for the measurment of the perceived brightness to the human eye." Those units, of course, being for luminance".

I probably have got confused between you and crames. So, the units for measurement of the perceived brightness to the human eye are candela per square metre? Really?

-- hide signature --

Bob

Complain
Post ()
Keyboard shortcuts: