Is there a method/purpose to the specific labeling of focal lenths on zoom lenses.
For instance: on my efs 15-85mm the lengths are markedon the lens as 15, 24, 35, 50, 70, 85.
Why aren't lenses marked with even zoom intervals?
thanks!
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Is there a method/purpose to the specific labeling of focal lenths on zoom lenses.
For instance: on my efs 15-85mm the lengths are markedon the lens as 15, 24, 35, 50, 70, 85.
Why aren't lenses marked with even zoom intervals?
thanks!
Good question, I'm curious as well. Since I'm young I didn't live in the film-days (at least not photographing) and perhaps these focal lengths were the standard lens-lengths and you had less zoomlenses?? I don't know. I do know that the focal lengths you mention are all lengths of prime lenses, so there must be a specific reason. Good question [:D]
Quote:
Originally Posted by nimblybimbly85
I guess that one is not to hard. The difference in composure between (in your lens) 15-18mm and 82-85 is really big. The 3mm difference at the wide end is totally more noticeable than the 3mm at the long end. Even zoom intervals would make it less easy to compose good and would make the zooming very long I guess.
Jan
For 'alignment' to other common lenses, I would think. 15 and 85mm are obvious, as those are the ends of the range. 35mm and 50mm are 'classic' prime lens focal length, and Canon makes a very popular 24-70mm zoom lens.
But, I wonder who looks? Personally, I'm looking through the viewfinder, and I zoom until I get the composition and perspective I want, without regard to the focal length. I can check that later in the EXIF data (and that is useful, if only to inform what lens(es) I should be looking at next - for example, I find that I'm shooting with my 17-55mm mostly in the middle, so I'm considering the 35mm f/1.4L).
The one time when I think the focal length markings on the lens barrel would be useful is along the lines of an 'assignment' - it's often stated that a prime lens spurs creativity by forcing you to use one focal length and 'sneaker zoom', so you could set your 15-85 to 35mm to approximate the 'classic' 50mm prime lens (on a film/FF body), then shoot all day at that setting.
that makes a lot of sense that the markings correspond to prime lenses. i never look or set a specific focal length either, i was just curious if there is a specific reason for the incremental markings.
THANKS!
ok, I have one for you....on my 100-400's window there are some red markings and some numbers (100-200).anyone knows what is that about?
thank you
Quote:
Originally Posted by neuroanatomist
This is what I always guessed- plus you want a geometric rather than arithmetic progression. (The sequence marked is fairly close to geometric, up to the last one.)
The 'window' is the distance scale; the white line indicates the approximate distance to the in-focus subject. I believe the lines marked by the red numbers are the distance scale for infrared photography.
thank you neuroanatomist, does it have lasers or anything else I should know? just kidding