Interessante articolo dal sito di Tim Layton su come ricalcolare il tempo di esposizione per una stampa da effettuare nuvamente ma di dimensioni differenti.
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Variables you need to use:
(A) Original exposure time
(B) Original dimension (long edge)
(C) New dimension (long edge)
(D) New exposure time
New Exposure Time (D) = ((C/B) x (C/B)) x A
OR
New Exposure Time (D) = ((C / B)^2) X A (this version is faster because it uses square root)
Let’s say you made an 8x10 print at your exposure was 26 seconds
Now, you want to make the exact same print, but bigger, an 11x14 print.
New Exposure Time = ((14/10) x (14/10)) x 26
If we break the math down it looks like this:
((1.4) x (1.4) x 26
(1.96) x 26 = 50.96 or 51 seconds
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(A) Original exposure time
(B) Original dimension (long edge)
(C) New dimension (long edge)
(D) New exposure time
New Exposure Time (D) = ((C/B) x (C/B)) x A
OR
New Exposure Time (D) = ((C / B)^2) X A (this version is faster because it uses square root)
Let’s say you made an 8x10 print at your exposure was 26 seconds
Now, you want to make the exact same print, but bigger, an 11x14 print.
New Exposure Time = ((14/10) x (14/10)) x 26
If we break the math down it looks like this:
((1.4) x (1.4) x 26
(1.96) x 26 = 50.96 or 51 seconds
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Questo e' il link all'articolo completo