Digital back for F3?

In article coh.net,
Philip Homburg wrote:
In article ,
DoN. Nichols wrote:
5) Thus -- for a full frame sensor, you would need to machine away
part of the film support -- which is also support for the focal
plane shutter. At this point, you have an F3 (or whatever other
camera) which is no longer capable of using film.

Mounted slides are not full-frame either. Losing a millimeter or so should
be no problem.

It may well be significantly more than that.

You first need the border of wire bonding pads around the active
area of the sensor -- probably with an inner border of amplifiers for
each line.

Then, you need the surrounding row of wire bonding pads on the
substrate to which the sensor is mounted.

And the wire bonds need to be made between those (with 0.001"
diameter (0.0254mm) wire -- usually gold.)

And then, there needs to be the seal where the glass cover with
the anti-aliasing filter included. That seal alone will probably be on
the order of 2mm thick -- or 4mm added to the border of the sensor.

I could probably open up the back of my NC2000e/c and determine
how much border there is on that one -- but since it dates back to
around 1995 or so, there have probably been improvements in the
technology.

I'm certainly not going to disassemble my D70 to see how much
border there is on its sensor. Someone else want to volunteer one?

Enjoy,
DoN.

--
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In article ,
DoN. Nichols wrote:
In article coh.net,
Philip Homburg wrote:
Mounted slides are not full-frame either. Losing a millimeter or so should
be no problem.

It may well be significantly more than that.

You first need the border of wire bonding pads around the active
area of the sensor -- probably with an inner border of amplifiers for
each line.

I opened up a Pentium 133 processor. Those wires are really on the edge of the
chip. With CMOS, you can probably do buffer amplifiers on the sensor itself
(and small enough that you can'tsee them with a naked eye).

And then, there needs to be the seal where the glass cover with
the anti-aliasing filter included. That seal alone will probably be on
the order of 2mm thick -- or 4mm added to the border of the sensor.

I don't think that you can put 2 mm glass in front of the focus plane without
hitting the shutter.


--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it had been hard done
by. It was allowed to keep its horse, since horses were so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency

In article coh.net,
Philip Homburg wrote:
In article ,
DoN. Nichols wrote:

[ ... ]

And then, there needs to be the seal where the glass cover with
the anti-aliasing filter included. That seal alone will probably be on
the order of 2mm thick -- or 4mm added to the border of the sensor.

I don't think that you can put 2 mm glass in front of the focus plane without
hitting the shutter.

I was not suggesting that the thickness of the glass was 2mm,
but the seal would cover a 2mm border around the sensor and pads on the
substrate. A narrower seal would be more likely to open up under
thermal stresses (as the camera heats up and cools to match the
environment), letting air and other contaminants into the focal plane
sensor itself.

O.K. I've just opened the NC2000e/c (built on a Kodak N90s, as
I have mentioned before), and measured both the step from the
surrounding reference plane (aluminum) to the top of the sensor cover
(1.6mm), and the distance from the camera body's film plane to the
shutter (barely touching at 2.5mm), so a 2mm thick cover plate (plus a
little spacing to clear the sensor surface would fit without problems.

While I was at it, I took some quick and dirty photos of the
sensor and its surrounds. You can see them, with some comments at the
following URL:

http://www2.d-and-d.com/misc/SENSOR/index.html

I retain my conviction that a reversible conversion of a film
camera to a full 24x36 digital frame size is possible.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

(Philip Homburg) wrote:

In article ,
DoN. Nichols wrote:
5) Thus -- for a full frame sensor, you would need to machine away
part of the film support -- which is also support for the focal
plane shutter. At this point, you have an F3 (or whatever other
camera) which is no longer capable of using film.

Mounted slides are not full-frame either. Losing a millimeter or so should
be no problem.


Leica and Imacon have faced precisely this problem in the design of
the Digital Module-R for Leica 35mm SLRs (R8 and R9 to be precise).

The best focal length multiplier that could be achieved was 1.3X.

There is no reason to believe that any company could achieve a lower
multiplier in a back for the Nikon F3, or any other 35mm SLR.

"Aaron Blacksmith" writes:

Is there any powerful digital back for F3?

Well, the original Kodak DCS (no number) used an F3 body. But you
don't want it; it had a separate case with the disk drive and
electronics, and offered only 1.3MP. See
http://www.mir.com.my/rb/photography/companies/Kodak/
or
http://www.epi-centre.com/reports/9306cs.html.

It would be a splendid thing for all F3-owners. Besides, the F3 is a
far better camera than the toys that are sold today.

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.