Christian Grüner wrote:
>
http://www.digitalmagasinet.dk/dof.asp <- har kigget lidt på denne, men
> den bruger jo "forkert" cropfaktor. Er der derfor nogle der kender
> formlen, så man evt kan lave sit eget beregningsscript?
Her er en tråd hvor det bliver diskuteret grundigt, med nogle gode
huskeregler:
http://www.fredmiranda.com/forum/topic2/106197
Et udpluk fra siden:
"To calculate DOF one needs to memorize only one number - 1m.
That is for the framing L/F=100 (2m for 20mm, 10m for 100mm, etc) and
fully open lens f/2.8 the DOF=1m (see the formula above and within 10%
agrees with DOF calculators). That's all you need to remember.
Then, say for f/5.6 the DOF will be twice as big - 2m. If the framing
changes, the DOF goes like (L/F)^2. The formula works well for L/F less
than 200." - gfiksel
Jeg tror i hvert fald at jeg vil prøve at huske 1m reglen fremover :)
/henrik