Re: Nikon D40 with 300mm lens AND teleconverter (Nikkor AF-S Teleconverter TC-20E II)

Wilba wrote:
David J Taylor wrote:
greg@xxxxxxxxxxx wrote:

I see there's more to focal length measurements than I realised!

Yes, a simple rule is that with cameras like the D40, multiply the
optical focal length (the one on the barrel, and the speicifcation)
by 1.5 to get the equivalent field of view, so the 18-55mm kit lens
has the same FoV as a 27 - 82mm lens on a film SLR, and the 70 - 300mm
lens has a 105
- 450mm FoV.

That's misleading. Let's stick with focal length, and not confuse
Greg with FoV.

Greg says he's new to photography, so 70-300 and 105-450 are equally
meaningless, so I don't see that you've done him any favours anyhow.
:-)

When dealing with DSLRs Greg will be buying lenses labelled, for example
70 - 300mm. As he is new to photography, he will, I hope, be reading some
books, many of which will still refer to film SLRs and the focal lengths.
I'm thinking of comments like "70-90mm makes a good portrait lens". With
the present generation of DSLRs having reduced size sensors, it is
important to distinguish between the two, and by far the best way is in
terms of FoV, as that determines what distance you will use, and hence the
perspective of the photograph.

It's better that these differences are appreciated sooner rather than
later, and expensive but inappropriate lenses have been bought.

David


.

Relevant Pages

  • 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: Sky Quality Meter
    ... I am using a 24 mm dia 18 mm fl lens that produces a 10 degree FOV ... The actually weighting with altitude would make the "effective altitude" closer to 60 degrees since the sensor response is lower at angles farther from the zenith. ...
    (sci.astro.amateur)
  • Re: night sky meter project needs SX programmer
    ... a smaller FOV would be nice and I do operate the meter at zenith or to the north a bit. ... I will dig up a lens and give it a go. ... sky brightness doubles between 60 degrees and ...
    (sci.astro.amateur)
  • 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, ... >length, max aperture, and usable area of focal plane. ... wide angle lenses than with telephotos, but I could imagine some long ...
    (rec.photo.digital.slr-systems)
  • Re: Nikon D40 with 300mm lens AND teleconverter (Nikkor AF-S Teleconverter TC-20E II)
    ... Yes, a simple rule is that with cameras like the D40, multiply the optical ... so the 18-55mm kit lens has the same FoV ... Greg says he's new to photography, so 70-300 and 105-450 are equally ... magnification, like what you see through 8 or 10x binocs. ...
    (rec.photo.digital.slr-systems)