Lens Question

On Wed, 13 Sep 2006 16:12:00 +1200, frederick <lost.DeleteThis@sea.com> wrote:


>>
>It remains f2.8.
>The image you get is a 23.5 x 15.7 mm crop from the center of a 36 x
>24mm 35mm frame. Effectively your 80-200 becomes a 120-300. But you
>get slightly deeper FOV at 200m f2.8 than you would with 300mm at f2.8
>on 35mm, assuming same final print size.

Thank you for the information. Now all I have to do is choose which
particular body to get, and look around for a decent wide angle.
Thanks again.
 >> Stay informed about: Lens Question 

Slim wrote:
> Hi,
>
> I have an 80-200 f2.8 Nikon Zoom left over from a late and totally
> unlamented F-100 that I used to own. It was the most unreliable and
> fragile 35mm that I've ever had!
> Anyway- it seems that when you use 35mm lenses on digital cameras
> there are 'correction factors' needed in order to ascertain the
> equivalent parameters... jeez.. I can't believe I wrote that....
>

Nice lens. I can't believe you wrote that, either.

> If I use my 80-200 f2. on a digital camera, what happens to the
> f-stop?? I know the focal length changes, but what about the f-stop??
>

No effect. Also, the focal length does not change. 80mm is 80mm. 200mm
is 200mm. What changes is the angle of view, since the sensor sees only
the center of the image circle. It is as if you took a 35mm picture
with the lens and then cropped an APS-C frame out of the center of it.
Nothing else changes.

Of course, this has distinct advantages in some respects, not least of
which is that vignetting is gone. Another is that since you are using
only the center part of the image, you are using the best part of the
image produced by your lens -- sharper, brighter, better color than the
edges. All lenses lose quality toward the edges; now you just cropped
off that part. It has some disadvantages, too, not least of which is
that if you really wanted the whole picture you can't have it.

So, for practical purposes, multiply your focal length by 1.5 to get
the focal length of a lens required to produce the same image on 35mm
film. Your 80mm lens will produce the same image as a 120mm lens would
on 35mm; the 200mm end will produce the same image as a 300mm lens on
35mm. But always remember that it is not really a 120-300mm zoom; you
are just doing the same thing as if you were using the 80-200mm lens on
35mm and taking an APS sized frame out of the center.
 >> Stay informed about: Lens Question 

Roy G wrote:

> If you do decide to get the D80 or the D200, get the 18 -70 DX "Kit" lens,
> if you can, it is very good indeed.
>
> It will fit in neatly with your existing 80 -200, and bring your range (35mm
> equivalent) with 2 lenses from 27mm to 300mm.
>

Right. And if he wanted to go wider, he could get the 12-24mm DX lens
and have very little overlap through the whole system. The 18-70mm lens
is one of the best mid-range zooms made by anybody anywhere.

> Nikon now seem to be pushing the new 18 -135 DX as the "Kit", which will
> overlap quite a bit with your 80 -200.
>

Yes, and this lens has not received as favorable reviews as the 18-70mm
lens. The very existence of this lens seems kind of pointless to me.
 >> Stay informed about: Lens Question 

"Slim" <spickens.DeleteThis@diablo.hr> wrote in message
news:jireg2dkldd1mb45q6ocghpbij3q285l8e@4ax.com...
> On Wed, 13 Sep 2006 16:12:00 +1200, frederick <lost.DeleteThis@sea.com> wrote:
>
>
>>>
>>It remains f2.8.
>>The image you get is a 23.5 x 15.7 mm crop from the center of a 36 x
>>24mm 35mm frame. Effectively your 80-200 becomes a 120-300. But you
>>get slightly deeper FOV at 200m f2.8 than you would with 300mm at f2.8
>>on 35mm, assuming same final print size.
>
> Thank you for the information. Now all I have to do is choose which
> particular body to get, and look around for a decent wide angle.
> Thanks again.
>
>
Hi.

If you do decide to get the D80 or the D200, get the 18 -70 DX "Kit" lens,
if you can, it is very good indeed.

It will fit in neatly with your existing 80 -200, and bring your range (35mm
equivalent) with 2 lenses from 27mm to 300mm.

Nikon now seem to be pushing the new 18 -135 DX as the "Kit", which will
overlap quite a bit with your 80 -200.

DX indicates that the lens is designed for the smaller sensor, so it will be
smaller and lighter than a similar 35mm lens.

Roy G
 >> Stay informed about: Lens Question