will Nikon release professional "digial" lenses ?

Regarding that Nikon say they will not offer 35mm sensor cameras and
many Nikon pros now drop the film stuff in favor of D2x (plus D200), it
would make sense to offer the professional line of lenses in "digital"
versions, being able to do them lighter and less expensive in the same
quality.

Any rumors if/when (e.g.) a digital "AF-S VR 300mm/2.8G IF ED"
(performing equivalent to a 450mm on 35mm, of course) is planned ?

-Michael

 

I would have thought that a 300mm f2.8 would generally be tripod mounted so
there would not be much demand for a lighter DX version.

 

I don't know about the VR part, but for regular 300/2.8 lenses,
designing for DX doesn't make things any easier. A straightforward 300/2.8
will cover 35mm, you have to do anything special for that. So, designing
for DX doesn't give you anything.

But to make things worse, a DX design can be expected to have a much higher
MTF at high frequencies (D2X sensor elements are very small). So if anything,
the lens will have to be better than the 35mm version, which comes at a cost.

 

If it was tripod mounted in a studio it would be one thing. But when you
have to haul camera, lens, and tripod up the mountain on your back along
with food, water, and shelter you soon learn that every gram matters.

 

Because the optics are smaller and the lens is lighter this usually amounts to
a reduced cost as well. I think that is one reason right there.

 

The optics can't be much smaller. A 300mm f2.8 still requires a front
element
(300/2.8) at least 108mm wide or 4 inches.

 

There is no real benefit in making a 300mm lens in a "DX" version.

 

Do you have a slave who carries your equipment around ?

-Michael

 

Are you sure the necessary front diameter is independent of the picture
area size ? Are "full format" 300/2.8 lenses not _much_ bigger than 35mm
ones ?

The size of front element of course is responsible for the amount of
light captured. But with a 35 mm capable optic half of the light (in the
sharp area) falls beside the small sensor. So I suppose you need to
capture less light and thus a smaller front element should suffice (but
I'm not an expert in optics).

-Michael

 

I don't know about the VR part, but for regular 300/2.8 lenses,

Why do they build "DX" lenses for e.g. 80-200 (or similar) ?

What do you mean by "straightforward" I suppose there are "full format"
lenses as well as "straightforward" 35 mm don't cover that picture are.
I _suppose_ a 300/2.8 for full format is a lot bigger (and of course
performs equivalent to something like 100 mm on 35mm).

Of course the mount diameter _could_ be smaller for a pure DX design,
but Nikon decided to keep the mount with their small sensor digital
cameras, so it will stay and add a little bit of unnecessary metal to
the lenses.

That holds when using a 35mm-designed lens on a small sensor camera as well.

-Michael

 

There is no real benefit in making a 300mm lens in a "DX" version.
Why ?

-Michael

 

"300/2.8" isn't just a designation, it's math. 300 divided by 2.8 is
107.14 (rounded). That's how big the front element has to be.

The *rear* element can be smaller for a smaller image circle. Big whoop.

 

Because you can't make a 300mm lens much smaller. The size benefit is
with wide angle lenses. The gain from doing a "DX" 300mm would be
minimal, not even worth the design and manufacturing effort.

 

They don't, at f/2.8. They have the 55-200, but that's f/5.6, and
designed to save every possible penny at the expense of, you know,
picture quality and whatnot.

 

Should have "DX" in that string of letters somewhere; that's the
designation for the Nikon lenses that don't cover the full 35mm
frame.

 

Actually, I think all elements except the front element can be smaller and the
closer to the sensor they get, the smaller they can be. So, there are saving
to be had. Perhaps a more conical looking lens. Perhaps less compromise in
construction to meet the design requirements of the lens .... perhaps.

 

I understand.

OTOH, if you use a smaller target, can a 300/2.8 lens designed for that
purpose perhaps concentrate more light in there, and thus the camera
could use a shorter time or a lower ISO setting for the shot, or, vice
versa, could you use a smaller (e.g. 300/4.2) "DX" lens to get the same
effect (ISO, time) as with a 300/2.8 non-DX lens ?

Perhaps the DX lenses called 200/2.8 in fact are 200/4.2. (Or are they
even called 300/2.8 ?)

-Michael

 

Maybe the f/5.6 DX in fact directs the same amount of light to the
sensor as a 35mm f/3.7 would do ?!?!?

-Michael

 

For these kinds of comparisons, it is best to look at lens designs relative
to the image diagonal. Telephoto lenses usually have an image circle
much larger than the image diagonal.

As you move down from longer focal lengths closer to normal and then beyond
normal to wide angle, to have to work harder to get a design that covers
the entire image format.

So, where you can get 35mm coverage more or less for free in a 300/2.8
design, that doesn't have to be true for the 80mm end of a zoom lens.

On 8x10" large format, 300mm is a normal lens. So it is quite likely that
a telephoto design for 35mm does not cover the entire frame.

On the other hand, one of Nikon's engineers claims that Nikon's first
300/2.8 does cover medium format.

I don't know how often you used a 300/2.8, but I sort of doubt that a
smaller, DX only, lens mount would have a big impact on the size of the lens.

Yes. But suggestion is usually that DX designs will be smaller and cheaper.
The way forward for a 300/2.8 is to make it even more expensive to
deliver the higher resolution demanded by the D2X.

 

I see.

What we (my wife) in fact would like to have is a lens that has the same
effect as a 450/2.8 on a 35mm camera. Now it looks like this would be a
"DX" type 300/4.2 lens.

_This_ could be designed quite small and would not cost a fortune, even
with the best Nikon glass available (which is of course the minimum
necessary, due to the very high resolution required by the sensor).

So the question should be rephrased to be about the availability of a DX
300/4.2 or similar lens.

-Michael