«

The UN disease is seen where people use overly diplomatic language
which is designed to water-down problems to describe clearly serious
situations. The situation being that the new $2600 Nikon 70-200mm
lens when set at 200mm and used on short distance shots is actually
something like a 115mm in-terms of its true magnification.
Here is how Dpreview words it:

"Naturally, though, all is not perfect, and there are a couple of
catches. The most obvious is the marked increase in angle of view on
focusing closer (otherwise known as focus breathing), which means that
despite the closer minimum focus of the new lens, its maximum
magnification is rather lower. This has implications for users who
frequently find themselves shooting at 200mm and relatively close
distances, who may need to consider carefully whether this behavior
might be a deal-breaker (you won't be able to replicate the tight
close-ups possible with the older lens). However we can't help but
feel that for most shooters it simply won't be a problem; indeed in
many cases it will be more than offset by the dramatically improved
close-range image quality."

This is typical because although they acknowledge the problem, they
word it softly and immediately try to deflect the seriousness of it
with a benefit that has nothing to do with the problem. To really
relate it though, what good is a superbly sharp 115mm lens if your
goal is a close-up where your options of getting closer are limited?

On Thu, 25 Feb 2010 14:30:23 -0800, RichA wrote:

> The UN disease is seen where people use overly diplomatic language which
> is designed to water-down problems to describe clearly serious
> situations. The situation being that the new $2600 Nikon 70-200mm lens
> when set at 200mm and used on short distance shots is actually something
> like a 115mm in-terms of its true magnification.

'True magnification' is not measured in focal length. Nikon's 60mm, 105mm
and 200mm Micro lenses all offer 1:1 magnification.

And where did you get the 115mm-figure?

"By our reckoning, at closest focus the image field is about 1.2x larger
in each direction, making the effective focal length roughly 160mm at
1.4m."
http://www.dpreview.com/lensreviews/..._n15/page5.asp

--
Regards, Robert http://www.arumes.com

On Thu, 25 Feb 2010 20:02:43 -0600, Rich wrote:

>> And where did you get the 115mm-figure?
>>
>> "By our reckoning, at closest focus the image field is about 1.2x
>> larger in each direction, making the effective focal length roughly
>> 160mm at 1.4m."
>> http://www.dpreview.com/lensreviews/..._n15/page5.asp
>>
>>
> I read the 115mm on another test site, but I don't understand Dpreview's
> "roughly" 160mm at 1.4m. Is it that hard to measure?

Is it important enough to measure?



--
Regards, Robert http://www.arumes.com

On Feb 26, 11:28*am, Robert Spanjaard <spamt...@arumes.com> wrote:
> On Thu, 25 Feb 2010 20:02:43 -0600, Rich wrote:
> >> And where did you get the 115mm-figure?
>
> >> "By our reckoning, at closest focus the image field is about 1.2x
> >> larger in each direction, making the effective focal length roughly
> >> 160mm at 1.4m."
> >>http://www.dpreview.com/lensreviews/..._n15/page5.asp
>
> > I read the 115mm on another test site, but I don't understand Dpreview's
> > "roughly" 160mm at 1.4m. *Is it that hard to measure?
>
> Is it important enough to measure?
>
> --
> Regards, Robert * * * * * * * * * * * * * * * * * * *http://www.arumes.com

Obviously, yes.

Anon wrote:
> All long lens have a shorter focal length at their nearest
> distance. The 70~200 is only 200mm at infinity.

Not all but it's a common approach for complex modern retrofocus
designs. The result of moving elements & groups rather than the whole
assembly so there is less weight on the AF mechanism.