Jan van Dijk (janvdijk@bart.nl)
Wed, 16 Jun 1999 17:57:38 +0200
-----Oorspronkelijk bericht-----
Van: Jan van Dijk <janvdijk@bart.nl>
Aan: Ken Sinclair <photo1@telusplanet.net>
Datum: woensdag 16 juni 1999 17:49
Onderwerp: Re: DOF
>In the original question all three lenses were 55 degrees and with
different
>focal lenghts and filsize. The variables asked for were filmsize and circle
of
>confusion.
>So from this point of view (within the same negative size, e.g. 35 mm.and
>circle of confusion) you are right.
>But that makes my point still stand up. In the given examples the DOF is
>less with increased focal length/filsize and decreased circle of confusion.
>Simply look at the variables in the formulae, their values and definitions
>and forget about urban stories.
You forgot about more enlargment, with alters the predetermened values.
>
>
>Jan van Dijk.
>
>
>
>
>-----Oorspronkelijk bericht-----
>Van: Ken Sinclair <photo1@telusplanet.net>
>Aan: janvdijk@bart.nl <janvdijk@bart.nl>
>Datum: woensdag 16 juni 1999 16:53
>Onderwerp: DOF
>
>
>>Hi Jan,
>>
>>Without being "nit-picky", a wide angle lens will have a greater
"apparent"
>>at the same f-stop from an identical camera/lens position as a "normal"
>>lens.
>>Taking magnification of negative into consideration... DOF will actually
be
>>the same as long as the final image sizes show identical "image area".. ie
>>the 24mm lens image is enlarged to show the same "area" as the 58mm lens
at
>>the same f-stop.. and ignoring the resolution and graininess of the film.
>>
>>Ken
>>
>>[||/\/\/\/\/\/\|| Ken Sinclair RBP, FBPA
>>[|| ||-| Applied Photographic Services
>>[|| || | Lethbridge,
>>[|| || | Alberta, Canada,
>>[|| ||-| (403) 381-1654.
>>[||\/\/\/\/\/\/|| photo1@telusplanet.net
>>_0___________0______
>>|__________________ |
>> O
>>
>>
>
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