# find shutter open and close

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anyone know a simple equation to find the time that the shutter is opened and closed given shutter offset, shutter time, and the current frame?

Thanks!

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to me it looks like:

shutteropenF = currentF - 0.5*shutter*(1-shutteroffset);
shuttercloseF =  currentF + 0.5*shutter*(1+shutteroffset);

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Thanks for the quick reply Tomas!

If I try that with

currentF = 5

shutter = 0

shutteroffset = -1

Then I get

shutteropenF = 5

shuttercloseF = 5

It seems like the scaling of shutter is kind of reversed, where lowering it shouldn't change shutteropenF and should bring shuttercloseF closer to 4 (keeping the other variables unchanged)

Does that make sense?

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not sure what you expect

if shutter is 0 then it opens and closes in the same time, and since 5 is your current frame 5, will be your shutteropenF and shuttercloseF, regardless of the shutteroffset, so to me it seems correct

EDIT: oh, maybe you expect shutteroffset -1 to always start at previous frame and shutteroffset 1 to always end at next frame

well, that's not the case since:

shutteroffset -1 always ends at currentF and goes from currentF - shutter

shutteroffset 0 goes from currentF-0.5*shutter to currentF+0.5*shutter

shutteroffset 1 always starts and currentF and goes to currentF + shutter

in other words the same way as the equations  posted previously

Edited by anim
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Thank you Tomas, that was my mistake

I did some testing and it matches mantra

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