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

David J Taylor wrote:
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, ...

Yes. He needs to understand that, but I predict that he won't from what you
say.

... and by far the best way is in terms of FoV, ...

OK, but then you say things like, "105 - 450mm FoV", which is nonsense,
since FoV is an angle, not a range of focal lengths.

... as that determines what distance you will use, ...

"Distance"? WTF are you on about now? :-)

... and hence the perspective of the photograph.

You sound very confused by these terms.

I believe that magnification is a much easier way to think your way through
these things, as explained in my previous message.

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

Correct. He won't be able to do that for himself using your gibberish
explanations.


.

Relevant Pages

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