Tokina AT-X 840 AF D 80-400mm f/4.5-5.6 or Tamron SP AF200-500mm F/5-6.3 Di LD (IF)??

Which lense should I buy?
According to the specifications the (new) tokina lense has a 1:5.4
magnificationratio and the tamron a magnifictionratio 1:5.0. However
the tamron has a (max) 500mm against a 400 mm for the tokina so I
would expect a larger magnification for the tamron. Are the
specifications not correct or has tokina indeed build a lens that
brings in more light and more magnification.

Of course quality is important as well. Can anybody tell me something
usefull about this aspect?

I have written the old tokina performed pretty well, but I have not
found any reviews/test of the new tokina lense yet. However the tamron
is praised as well.
(considering the prices of course!)

Can anybody help me out.

On Fri, 22 Dec 2006 02:46:42 -0800, yuri wrote:

Which lense should I buy?
According to the specifications the (new) tokina lense has a 1:5.4
magnificationratio and the tamron a magnifictionratio 1:5.0. However
the tamron has a (max) 500mm against a 400 mm for the tokina so I
would expect a larger magnification for the tamron. Are the
specifications not correct or has tokina indeed build a lens that
brings in more light and more magnification.

Of course quality is important as well. Can anybody tell me something
usefull about this aspect?

I have written the old tokina performed pretty well, but I have not
found any reviews/test of the new tokina lense yet. However the tamron
is praised as well.
(considering the prices of course!)

Can anybody help me out.

Magnification has nothing much to do with focal length, the
magnification reported in the lens specifications is a reflection on the
closest distance at which the lens can focus--at that closest distance the
tokina will fill the frame with an object 5.4 times the size of the film
or sensor frame while the tamron will fill it with one 5 times the size of
the frame.

Perhaps if you said what you were trying to do someone could advise you.

Oh, and there is only one "e" in "lens".

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

Thanks for you reaction (and sorry for my poor english),

I already learned a lot the last few hours. I know now that the
magnification ratio does not comply with how much you can zoom in on an
object. (I have to start somewhere on learning these things).

Perhaps I can simplify my questions. If I want to make a picture of a
bird about 50 metres away (using a tripod which i learned is necessary
for these lenses). Using which lens will result the best picture. (For
example saying that you use both lenses at 400mm).

On Fri, 22 Dec 2006 04:47:17 -0800, yuri wrote:

Thanks for you reaction (and sorry for my poor english),

I already learned a lot the last few hours. I know now that the
magnification ratio does not comply with how much you can zoom in on an
object. (I have to start somewhere on learning these things).

Perhaps I can simplify my questions. If I want to make a picture of a
bird about 50 metres away (using a tripod which i learned is necessary
for these lenses). Using which lens will result the best picture. (For
example saying that you use both lenses at 400mm).

Haven't used either, but unless the 400 is vastly better than the 500 in
sharpness, which is unlikely, you'll get a better result with the 500 at
500 than with the 400 at 400. At that distance you're not going to fill
the frame with the bird in either case unless it's a _huge_ bird--the
field of view is about 2.7 meters diagonally across, 2.2 meters wide, and
1-1/2 meters high. For the 400 the field of view is about 25 percent
larger.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)