>> What is the conspiracy against f23?
>>
>>
>> Even here, even when it is so flagrantly discriminated against ... it
>> is as if it is ignored.
>
>Right you are - I missed it. A full stop, too.
>It does need a different explanation from the rest.
>I can only observe that (some?) other camera brands seem to
>agree with Canon on that point, at least my Ricoh GR1s does.,
Yes, I think it's quite off-topic :-)
>and I seem to recall I've seen f/22 in other brands as well.
>I suspect that's a historical mistake that's become so
>entrenched in photographers' collective memory that
>changing it now would be dangerous...
Each time you close two stops the f/ number doubles.
f/11 is, in fact, 2^(7/2) = f/11.31 that rounds to f/11
f/22 is, in fact, 2^(9/2) = f/22.63 that rounds to f/23
But 23 is not the double of 11, so I suspect that 22 is used in order to
obtain the series: f/1.4, f/2.8, f/5.6, f/11, f/22 (odd) and f/2, f/4, f/8,
f/16 (even)
As can be seen you always double the f/ number for a two stop closing.
OTOH, f/45 is the correct value but it's not the double of f/22. But I
suspect that f/45 is not an usual f/number.
>Tapani Tarvainen
Best regards
Vicente
*
****
*******
***********************************************************
* For list instructions, including unsubscribe, see:
* http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************
