Sony A100 to A700

Fred McKenzie wrote:

> In article <6a9v4rF36336nU1.DeleteThis@mid.individual.net>,
> Chris Malcolm <cam.DeleteThis@holyrood.ed.ac.uk> wrote:
>
>> I think this approaching point where the full-frame sensors have
>> medium format film resolution is one of the critical elements in a
>> number of impending developments which will make a radical change in
>> digital camera design possible. The first important change, as you
>> mention, is that in order to take full advantage of the resolution a
>> completely new range of higher precision lenses will be required.
>
> Chris-
>
> There are existing lens designs for film cameras in formats ranging from
> 110 film to 8" X 10" sheet film. There is likely to already be lens
> designs for any sensor format you can propose.
>
> At present, my 10 megapixel APS sensor's images are approaching the
> resolution of lenses designed for 35mm cameras, but they aren't there
> yet. Looking at actual images, I estimate the break-even point to be at
> least 24 megapixels, where the image becomes lens-resolution-limited
> instead of pixel-limited.

I saw a passing reference, the other day, to something like "our 30MP
eyes". Is that an accepted ballpark estimate of our (ideal) visual
acuity, or more of a metaphor for "more than digital offers at this
point"?


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Fred McKenzie <fmmck.DeleteThis@aol.com> wrote:
> In article <6a9v4rF36336nU1.DeleteThis@mid.individual.net>,
> Chris Malcolm <cam.DeleteThis@holyrood.ed.ac.uk> wrote:

>> I think this approaching point where the full-frame sensors have
>> medium format film resolution is one of the critical elements in a
>> number of impending developments which will make a radical change in
>> digital camera design possible. The first important change, as you
>> mention, is that in order to take full advantage of the resolution a
>> completely new range of higher precision lenses will be required.

> Chris-

> There are existing lens designs for film cameras in formats ranging from
> 110 film to 8" X 10" sheet film. There is likely to already be lens
> designs for any sensor format you can propose.

The important point you're missing is that there are currently no
lenses available for full frame 35mm size sensors which can support
the resolution of medium format. The reason there aren't any such
lenses is that there are no cameras which would require such
sensors. However, if announcements by some of the big camera makers
are to be believed, there soon will be. The lenses will naturally
follow because we now know how to develop and make such lenses with
mass production methods.

> At present, my 10 megapixel APS sensor's images are approaching the
> resolution of lenses designed for 35mm cameras, but they aren't there
> yet. Looking at actual images, I estimate the break-even point to be at
> least 24 megapixels, where the image becomes lens-resolution-limited
> instead of pixel-limited.

> Once you reach either limit with any given format, the only way to
> increase image resolution is to increase the format size, so less
> magnification is required for a given print size.

> Don't kid yourself. If you say full frame sensors are approaching the
> resolution of medium format film, you are really saying that you are
> satisfied with 35mm images.

No I'm not. Modern technology is in the process of erasing the
significance of that old 35mm/medium format boundary.

The existing distinction between the image detail which can be
captured by 35mm film cameras and medium format cameras was settled a
long time ago by what were then the limits of film technology and
handling and mass lens manufacturing methods. Those in turn were
constrained by the laws of physics (and physical chemistry) which
apply to those methods.

> You can't change the laws of physics.

No change is required. Digital sensors have already exceeded the
resolution of the best films, and there is still enough development
life left in current technologies to push the boundaries up to at
least the point I'm proposing. That's not just my personal
opinion. Some of today's sensor manufacturer's have quite explicitly
stated that's where their current development programmes are aimed
at. We won't know until independent people assess the resulting
cameras whether that point will be reached with 24MP or 40MP in a 35mm
full frame size of sensor, but there seems general agreement that it's
somewhere in that region, and that in a year or few cameras with such
sensors will appear.

> What we are seeing now, is that most people are satisfied with what they
> are getting with the common sensors, whether they be APS or the 4/3
> system. Most people don't blow up images to poster size prints, or crop
> poster images to 4" X 6" prints. In other words, current digital
> cameras are "good enough". And they have been since the one megapixel
> sensor was developed!

There are enough photographers around who are still using medium
format cameras such as Hasselblad, both film and digital, to finance
the development of that small and very expensive sector of the
market. A DSLR sized camera which can do everything a current DSLR can
do, plus deliver images of Hasselblad medium format quality at much
less than current Hasselblad prices looks very likely to attract a lot
more photographers than are currently paying the much higher prices
(and carrying the much bigger heavier cameras) necessary to get images
of that resolution.

There's no doubt that as far as sensors and lenses are concerned that
the sensor sizes and lens qualities I'm talking about are going to be
produced by at least some of the top players in the DSLR
market. They've said so and they're already well engaged in the
development programme. Within the next few years the first attempts to
reach that goal will appear on the market. The sensors will arrive
first and the lenses will follow.

What I'm pointing out is that at around the same times as that new
range of DSLRs appears there will be a technology convergence
permitting the development of a new kind of camera design which by
omitting the reflex mirror will allow better image quality at lower
prices in exchangeable lens cameras of DSLR size. Such technological
discontinuities are a golden windows of opportunity for a well funded
innovative camera maker to move into that new market ahead of the big
established players who have the largest investment in the current
marketplace.

I suspect that at least Sony has its sights set firmly on that goal.

--
Chris Malcolm cam.DeleteThis@infirmatics.ed.ac.uk DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]