Re: Full-frame or 1.5 DSLR?

In article <bjm7f1lrdktjntr09r7uvab0mn2j7teitu@xxxxxxx>, <JPS@xxxxxxx> wrote:
>In message <3lgh4vF12hnn8U2@xxxxxxxxxxxxxx>,
>Stacey <fotocord@xxxxxxxxx> wrote:
>
>>So a 300mm lens on a 1Ds works just like it does on a 20D? And I guess a
>>28mm lens provides the same usefulness on the 1Ds as it does on the 20D as
>>well.. Glad you don't think FOV is important, seems most people do.
>
>You are a simpleton. He didn't say "FOV isn't important".
>
>FOV is not *RELEVANT* to the issue of lens size, for a given focal
>length, max aperture, and usable area of focal plane.

Hmm ... what is the difference between FOV and your last
parameter "usable area of focal plane"?

Granted, a lens can have a larger "usable area" than a given
camera actually takes advantage of -- as for example a lens designed for
a full-frame 35mm mounted on a DSLR body with a 1.5 or 1.6 crop factor.

But -- there are also lenses made explicitly for the crop factor
of a DSLR which will not adequately cover a full frame 35mm. They will
have the same focal length range, and same maximum aperture, but they
will be noticeably lighter. (This is more often a consideration with
wide angle lenses than with telephotos, but I could imagine some long
lenses made somewhat lighter by restricting the coverage to a DSLR crop
factor.

>You have the same logical prowess and the same sense of responsibility
>in paraphrasing others that George Preddy has.

And it would seem that you are not properly considering what
your own words say.

Enjoy,
DoN.

--
Email: <dnichols@xxxxxxxxxxx> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
.

Relevant Pages

  • Re: Full-frame or 1.5 DSLR?
    ... >28mm lens provides the same usefulness on the 1Ds as it does on the 20D as ... Glad you don't think FOV is important, ... FOV is not *RELEVANT* to the issue of lens size, ... length, max aperture, and usable area of focal plane. ...
    (rec.photo.digital.slr-systems)
  • Re: Nikon D40 with 300mm lens AND teleconverter (Nikkor AF-S Teleconverter TC-20E II)
    ... by 1.5 to get the equivalent field of view, so the 18-55mm kit lens ... Greg with FoV. ... many of which will still refer to film SLRs and the focal lengths. ...
    (rec.photo.digital.slr-systems)
  • Re: Rambling load all right
    ... a telecentric lens maps objects of the same ... If you draw out a simple lens then all of the principle rays to every point between the object and its image on the focal plane passes through the centre of the lens. ... However, since telecentricity means that the principle ray to every point in the image is perpendicular to the focal plane, there is an argument that it is ideal in digital sensors to ensure that the amount of leakage from one filter to adjacent ...
    (rec.photo.digital)
  • Re: Rambling load all right
    ... If a lens is fully telecentric, wouldn't that mean that a one foot ... > principle ray is the central ray in the bundle) to every point between ... > the object and its image on the focal plane passes through the centre of ... However, since telecentricity means ...
    (rec.photo.digital)
  • Re: Rambling load all right
    ... >>that was let's say 2 feet from the lens and a one foot ruler that was ... > group at the back which bends all of the ray bundles back towards the ... > ray bundles still all come to a focus at the focal plane, ... the edge of the frame will ...
    (rec.photo.digital)