old school exposure

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old school exposure

Postby abstrax » Sat Dec 13, 2014 11:41 am

abstrax Sat Dec 13, 2014 11:41 am
Hi all,

Since some people miss the old school exposure settings for reasons that are totally beyond me, I have whipped up a little Lua node graph that emulates the old exposure settings:
old_school_exposure.orbx
(3.37 KiB) Downloaded 449 times


Just download the file and import it into your project (via RMB click in the node graph editor -> Import...) and connect it with the exposure pin of the camera imager node like:
old_school_exposure.png


Cheers,
Marcus
In theory there is no difference between theory and practice. In practice there is. - Yogi Berra
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Re: old school exposure

Postby p3taoctane » Sat Dec 13, 2014 4:32 pm

p3taoctane Sat Dec 13, 2014 4:32 pm
Thanks
THough it may seem like you are creating a bit of code that is old school ... being older than school myself... I love it

Thanks

Peter
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Re: old school exposure

Postby bepeg4d » Sun Dec 14, 2014 4:07 pm

bepeg4d Sun Dec 14, 2014 4:07 pm
Hi Marcus,
first of all, the lua node is fantastic, thanks for sharing this example ;)
here is my simple version but i don't think is correct in terms of calculation:
EV_exposure.orbx
(2.73 KiB) Downloaded 194 times

could you have a look at it?
ciao beppe
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Re: old school exposure

Postby roeland » Mon Dec 15, 2014 9:02 pm

roeland Mon Dec 15, 2014 9:02 pm
The exposure on a camera is a logarithmic scale, +1 EV means double the exposure. The formula is exposure * 2 ^ EV.

Check the times you typically find on a shutter speed dial:
  • 1/1000
  • 1/500
  • 1/250
  • 1/125
  • 1/60
  • 1/30
  • 1/15
  • 1/8
  • 1/4
  • 1/2
  • 1
Every stop doubles the exposure.

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Re: old school exposure

Postby bepeg4d » Tue Dec 16, 2014 10:19 am

bepeg4d Tue Dec 16, 2014 10:19 am
thanks roeland for the info ;)
fortunately for my old brain, Marcus has create a brilliant solution that solves my needs :)
ciao beppe
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Re: old school exposure

Postby Phil_RA » Wed Jan 21, 2015 3:16 am

Phil_RA Wed Jan 21, 2015 3:16 am
The reason it was useful to have the three settings is to match a photo's EXIF data. I'm trying to make sure the scene I'm working on is physically correct, so using the exif data and putting in the same values allows me to make sure that mights are of the correct intensity.
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