[Leica] Leica M digital back

[Grégoire Vandenschrick <vandenschrick@geog.ucl.ac.be>]

Hi everybody,

This is only a dream:

I was thinking about that, but lack some reflexions and details, so I post
this dream and if someone has any idea, it's welcome.

Ok, so, I was dreaming of a full scale digital back for leica M. The CCD
would be kept in place in an interchangeable back, very similar to the
current back. Maybe there would be enough surface to have a little TFT on
its back to choose functiuns, look the picture to control (not to compose,
the cloth shutter would work as usual). Electronic could be put in place of
the film can, and in an attached piece, the same size of a Leicavit,
containing also batteries and maybe flashcard (here, I don't know if there
is a flash memory card tiny enough to go anywhere in a leicavit volume, and
as I dream it, I don't want to have the digital back protruding too much,
so, no flash card insert slot on the digital back itself). Contact between
the CCD back and the bottom part is something easy, as there is an
overlapping zone at the bottom of the back (same contacts as the one you can
find between an SLR body and its back (R8 for example). One could also have
an intelligent use of the rewind knob/lever, as a turning pad, like the 2
selectors on an F5 for example (under the index and thumb), to rock between
options of the digital part. The digital back should also have a sensor
placed near the first film advance cylinder, in order to be informed to
prepare itself to take another picture.

I know full frame (24x36) are sensible to the incident angle of the light,
but couldn't this be corrected by the means of a special
micro-fresnel/catadioptric device placed just before de CCD, protecting it
also.

All this seems to be possible, but I don't know how a picture is actually
taken from the CCD. I think the "take the picture NOW" instruction is given
to the CCD when the shooter is pushing the trigger. In this case, the
trigger is not actuating any electronics, aside the light cell, and I don't
see how this triggering info could be given to the digital back. So I was
thinking, and this is where I was wondering: Is a CCD able to detect by
itself when to take the picture, assuming all the time it receives no light
(the shutter of the M being closed), and suddenly, the shutter opens, and
the CCD gives the picture (the record of all the light received). Is such a
behaviour electronically possible? So: to have a CCD in a waiting proccess,
and having the digital picture recorded when the light falls on the CCD.

In fact, I'm quite ennoyed because I don't know how exactly a digital camera
is taking a picture, is there a mechanical shutter, how is the ISO factor
managed, how is the shutter speed done and so on. So, If someone has info
about that, I would like to have more info to conceptualize more this.

This design have a lot of advantages despite a first quite cumbersome
aspect:

- -you have a Leica M? Fine, you have the choice of film or digital media,
having the huge advantage of using your M lenses for both

- -the device is in three parts:
    1-the interchangeable back, with sensors for the "advance of the film"
info if required by the electronic (maybe two versions, one cheaper without
TFT screen, another with)
    2-the false film can, connected by contacts to the base third part, and
to the rewind knob of the camera as a rocking mollet, and maybe to the
digital back, but I should have a look if this is technically possible, but
maybe these contacts could be relayed trough the bottom part to the digital
back
    3-the leicavit size bottom part, with batteries, flash memory, and or
flash memory card slot, usb or firewire port, stuff like that. This part
will attach to the M body the same way as the current bottom
plate/motor/leicavit, and will have contacts for the false film can part,
and for digital back part.
the enormous advantage is the modularity, you can have the digital back
separately, when a CCD upgrade is available, you can have the false film can
part separately, for software upgrade, you can have separate bottom part for
other batteries / memory capacity. In case of one part failure, the
diagnostic and SAV (in french Service après vente) is easier.

- -you can continue to take picture the same way, exactly the same way, the
camera has the same dimension, practicaly the same size, and the same
weight, you only have to play with the rewind knob and maybe some knobs on
the back and bottom parts.

Maybe the first versions would require to take picture in Bulb mode (let's
say for one second opening), and the speed fixed electronically, a sort of
aperture priority for every M body, nice, no?

So, the only part I can't think of it is: Is it possible to have a CCD
triggered itself by the light it recieves quickely enough to have the
quickest speed (1/1000s) fixing an even exposed picture? Like a bias, no
light, waiting/ light for less than 1/1000s, recording according to the ISO
setting accumulating all the light entering or fixing the speed according to
light intensity like a TTL flash cell.

This is my dream, nothing else, why O why haven't I made a Master in
electronic ingeneering in place of my PHD thesis in climatology?

Best

Gregoire Vandenschrick


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