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F-stop and linear tonemapping
Posted: Mon Aug 10, 2009 11:02 pm
by Jambert
I've made lot of test and I don't understand why but F-stop and linear tonemapping give change tonemapping!? Is it right?
Re: F-stop and linear tonemapping
Posted: Mon Aug 10, 2009 11:56 pm
by fused
its correct. the lower the fstop the more light will reach the film

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 12:22 am
by Jambert
fused wrote:its correct. the lower the fstop the more light will reach the film

Thanks

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 1:26 am
by PureSpider
But it hasn't been like that in older releases of indigo. What about not changing random stuff without letting the user know, Ono?

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 1:38 am
by pixie
PureSpider wrote:But it hasn't been like that in older releases of indigo. What about not changing random stuff without letting the user know, Ono?

If it wasn't as such before, it was wrong, therefore changing to right can only be the right thing to do

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 1:45 am
by fused
of course it was like that before. it has always been like that

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 1:59 am
by PureSpider
Sooooo... Cindigo compensates the changed F-Stop? o.O
My pics never changed their brightness when I changed the F-Stop!

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 2:04 am
by Josh
Tonemapping (other than linear) masks the change of illumination, I suppose.
Edit: Camera tonemapping without auto exposure (and no manual exposure adjustment) should not compensate.
Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 2:05 am
by fused
probably because you used reinhard

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 2:12 am
by PureSpider
Just checked - and yes, I do use Reinhard in that scene I was talking about

Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 5:38 am
by CTZn
Hey Jambert, I think the topic deserves a complement of information, but I am no expert in the field, hopefully my says will be also completed or corrected if necessary.
F-stop is an inverse value (1/n) wich refers to the width of the aperture for the shutter. Obviously, the bigger the divider n, the smaller the aperture.
F-stop = divider of aperture = divider of luminosity
Q: Is it correct to say that an F-stop of 32 means that the shutter aperture is 1/32th of its widest possible aperture?
Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 6:05 am
by dougal2
CTZn wrote:Q: Is it correct to say that an F-stop of 32 means that the shutter aperture is 1/32th of its widest possible aperture?
Not quite, it means that the aperture is 1/32 of the focal length.... which is why low f-number telephoto lenses (large focal length) are expensive and massive - because the glass needs to be bigger.
Re: F-stop and linear tonemapping
Posted: Tue Aug 11, 2009 6:19 am
by CTZn
Ah, thank you Doug ! I got it all wrong
