P3D Re: Grain of Truth

[Brian Reynolds <reynolds@xxxxxxxxx>]

Michael K wrote:
> 
> > I haven't seen any digital camera in a 35mm format that comes close to
> > film.
> 
> What does "digital camera in a 35mm format" mean?  I ponder this and
> don't quite understand what it means (let alone having seen one
> myself).
> 
> As opposed to digital camera in APS format?
> 

Basically I meant cameras of roughtly the same physical size.  Almost
everyone else's less than $1000 cameras could be considered (on the
basis of camera size) to be equivalent to 35mm cameras.  The Kodak DCS
cameras are actually based on 35mm SLR bodies (Nikon and Canon).  Some
of the smaller digital cameras are more on the size of 35mm point &
shoots.

This is in contrast to the digital cameras based on medium format or
large format cameras.

> P.S. - What would it take for a digital camera to match an old 110-film
>        format camera (bought for $5 at Kmart) that was loaded with
>        ASA-1000 *film*?  Perhaps if we start low and break barriers
>        one by one....
> 

I think (but I'm not sure) that 110 film is about the same size (10x10
mm) as many of the CCDs in inexpensive digital cameras.  Kodak claims
that the scanning for a Photo CD is at about the limits of film
resolution.  The Photo CD 16Base is approximately 2200dpi and the
64Base (Pro Photo CD) is approximately 4400dpi (both based on 35mm
film examples on the Kocak web page).  In order for a digital camera
to be better than 110 film it would have to have more than 1700x1700
pixels (on a 10x10mm CCD chip) to equal a Pro Photo CD of the same
image taken with 110 film.  Of course you can't get a Pro Photo CD
made from 110 film.

I don't think there was ever a 1000ASA film available for 110 cameras,
and it wouldn't be a good comparison since digital cameras are more
like 100ASA than 1000ASA.  CCDs are not high speed.  They have
exposure advantages over film (especially in astronomical
applications) because their responce to light is linear over their
operating range.  Film is very non-linear.  The available digital
cameras do not take advantage of the linear feature of CCDs because
they are not cooled.  The only cooled CCD camears I'm aware of are for
the professional and amateur astronomy markets.  These cameras are
very specialized and not meant for taking snapshoots.

> P.P.S. - The Kodak 120 and 210 sell new for about $600-700 now (see in
>          local Camera World of Oregon newspaper ad).  How would those
>          compare image quality wise with that 110 camera above?  I'd
>          expect those be be under $500 around Christmas time.
> 

It's been a long time since I've seen or used a 110 camera.  Most of
them were probably junk.  Certainly all the ones I owned.  My
god-father had the Pentax 110 SLR system, and I think Minolta made a
similar camera.  The junk cameras may have been worse than the current
digital cameras, but they cost far less.  The Pentax (and other high
end) 110 cameras are likely to be better than the current digital
cameras, and are more or less at the same price point.

Digital cameras are a neat idea, but they are not currently cost
effective, and their image quality still has a long way to go.  For
example, for a couple of hundred dollars you can buy a 4x5 pinhole
camera, 4x5 film holder, and an Artec Scanrom 4e scanner (a 400dpi
film and print scanner available for $100 mailorder) and get images of
2000x1600 pixels.  If you build the camera it'll cost less, and if you
spend another hundred dollars or so you can get a press camera with
lens (although an optimized pinhole used with large format film can
produce images indistinguishable from a lens image).  You can't get
anything near that resolution in a digital camera for the same price.

-- 
Brian Reynolds                  | "Humans explore the Universe with five
reynolds@xxxxxxxxx              |   senses and call the adventure science."
http://www.panix.com/~reynolds/ | - Edwin P. Hubble


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