Difference between lenses (Nikon)

Well, the G version (the cheap one) has a plastic mount. That scares me.

 

Yeah, but the reason I wanted f4.5+ is so that it would be lighter.
If I'm hiking or travelling, I don't really want to haul around a
kilogram(s) monster.

Too bad; some of Canon's IS offerings aren't too expensive, at least
not all in the $1000+ range of f2.8 zooms.

 

Does it not meter at all or is simply 'off'? There must be some kind of
reading coming through & it seems you could adjust the +/- to suit.

 

Without the CPU, I believe the camera can't tell what the aperture is so it
can not meter at all.

 

Correct. Some other cameras, such as the N90s film camera, have
a second moving tab to tell the camera what the current aperture setting
is (correction to this below), and those will work in aperture-preferred
mode, although not in shutter-preferred mode.

O.K. While I knew that was a proper description of the way such
lenses would be used on the N90s, It did not seem to make any sense,
without the camera knowing what the maximum aperture of the lens was.

So -- I just dug out the N90s and several lenses, and discovered
that what the ring and tab *actually* tell the camera is how many stops
below the maximum aperture the lens is currently set to. So -- it can
correct the measured light at full aperture to what will actually get
through at the moment of exposure.

And this is why the D70 will *not* work in any auto mode with
these older lenses (at least until someone transplants a CPU into the
lens). While it has a sensor to tell when the lens is set to the
minimum aperture (so the range of apertures is available through
controlling the motion of the stop-down lever inside the lens mount
ring), it has no way of knowing what the maximum aperture of the lens
is, or how many stops below that may be currently selected.

I hope that this helps,
DoN.

 

So the camera doesn't know what aperture is being used but even in
manual mode, the meter picks up a signal & tries to tell you +/-. It
seems you could set aperture on the camera dial to match the lens & even
run in aperture priority mode but I don't know. The point is there is a
light meter in there no matter what reading what hits the sensor just
like the green dot for focus apparently works with non-af lenses.

 

Is Pacific Rim Camera out of the conversion kit for your lens? They bought
out
the remaining Nikon conversion kits and it is much nicer than having a notch
ground
into your lens.

 

[ ... ]

[ ... ]

I don't know. I had not heard of them until this moment. Do
you have contact information for them?

Never mind -- a quick web search found them, and I do find it
quite interesting what is there. What I find for the lens in question
is:


======================================================================
70514 NIKON LENS AI CONVERSION KIT NO.76, FOR 80-200/4.5 NIKKOR WITH
SERIAL NUMBERS BETWEEN 101911-210000, NEW OLD STOCK REPAIR PART $25.00
======================================================================

Which based on the wording, and also on the photos on some other
nearby ones, is purely the replacement aperture ring to provide the tabs
to communicate with the N90s and similar. My lens (in the 168xxx serial
number range) already has *that* conversion.

What I was talking about was the installation of a CPU to tell
the D70 what the maximum aperture is, so it can do its metering magic.
The "AI conversion" would also be necessary if I did not have that.

However, I can see that I should check through for certain other
lenses which I may wish to so modify.

Nope -- my favorite lens is not among those listed, so I guess
that it is time to do some precision machining -- to convert that for
use on the N90s, if not the D70. At least, I now know what to do,
thanks to this discussion prompting me to study just how the mechanical
coupling mechanism works, and I have the machine tools needed to do that
job.

Now, if I only had the means to add a CPU to the 80-200mm zoom,
I would be really happy.

Thanks,
DoN.

 

Sorry, my mistake...I thought you were looking at the AI conversion (didn't
know anyone
hadn't done that) and not chipping the lens. If you do have the lens
chipped, please report
back on your experience...I was considering having it done to a fisheye
(8mm) but have been
leery after seeing one posting on the newsgroups that reportedly had a bad
experience.

George

 

The fellow who does the chipping has removed the 80-200mm from
the list of ones which he will work on. Presumably he found that was
more difficult than he had otherwise expected.

He *has* done my 180mm f2.8, and I am quite pleased with the
results. (Other than the fact that it lies to the camera, claiming that
it is a 300mm instead of a 180mm, bu that doesn't hurt anything, as I
don't *have* a 300mm to confuse it with. (And it actually has coverage
close to a 300mm on a full-frame 35mm camera.

And I have a 20mm which I plan to send to him for chipping --
some of these days. (He also does not chip the 16mm fisheye, which is
my only other with the AI ring other than the 28-105mm which is my
everyday lens.)

I am considering setting up the necessary fixturing to modify the
aperture ring on an older 50mm f1.4. That one is not covered by the NOS
spares which I just looked at, so if it is to be converted to AI, I will
have to do it myself from scratch. (I at least have the skills and
the machine tools to do this at need.)

Then comes the question of whether that one can be chipped.

Enjoy,
DoN.