Quote:
Originally Posted by UdubBadger
oh nice, how much?
wait... they make a 100-400 F4 IS? or did you mean the 70-200?
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Oops. I meant the 100-400mm f/4.5-5.6L IS.
Quote:
Originally Posted by UdubBadger
Now that I think about it, if I do a 70-200 2.8 on my 40D (1.6x crop ratio) thats a 280mm equivalent still shooting @f/2.8. Then if I do a 1.4xTC I only lose 1 stop but my range goes up to 448mm and ends up being faster and longer than the f/2.8 losing 2 stops with the 2xTC @400mm.
Does that math make sense or am I not multiplying correctly?
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The latter.
The 70-200 f/2.8 on my 40D gives you 200*1.6 = 320mm equivalent at f/2.8.
If you do the 1.4x TC, then on your 40D, you'll have 320*1.4 = 448mm equivalent at f/4.
If you use the 2x TC on your 5DM2 with that lens, you'll get 400mm at f/5.6.
Is that what you are trying to compare?
