Re: Canon's new astrophoto DSLR announced [ 4x5" FILM option? ]

On Sun, 05 Jun 2005 13:54:53 GMT, Chris L Peterson
<clp@xxxxxxxxxxxxxxxxxx> wrote:

>On Sun, 05 Jun 2005 12:44:07 +0100, Jim Attfield
><jamesatattfielddotcodotuk> wrote:
>
>>I can't follow your point about larger sensors making wide angle
>>easier.
>
>If you look at the pricing of lenses, they are lowest in the middle
>focal length ranges and rise (sometimes steeply) at the ends. So very
>short wide angle lenses and very long telephotos tend to be the most
>expensive. A small sensor essentially shifts your lens range upwards.
>This means you end up with more telephoto for your money, but less wide
>angle. I consider a "typical" useful wide angle lens to be around 28mm
>(if you get much shorter you start seeing fisheye effects). To get that
>same field of view with my 300D, however, requires using a 17mm lens. At
>that length, my lens options are much smaller, and generally a lot more
>expensive.

Sure, general point accepted, but while you use your 17-35mm F2.8L at
$1400 I can use my 11-22mm at $750 which at 6mm shorter and same
aperture at 11mm should, by your reasoning, be more expensive but it
is not :-)

>Sure, with lenses designed solely for a smaller sensor this doesn't need
>to be the case. But (except for the EF-S lens that came with the camera)
>I'm not comfortable committing to such lenses at this point. I already
>own a collection of standard Canon lenses, and I think it is far from
>certain that small sensors are going to be the standard for DSLRs. There
>are an awful lot of photographers, with an awful lot of (35mm format)
>lenses out there, and they don't want to replace their entire
>collections. It is far cheaper for them to spend a little more on a
>single camera body with a larger sensor. Any serious photographer knows
>that the camera body is the least expensive part of their setup in the
>long run.

Sure. Good glass is the real investment. It also represents the real
lock-in by the manufacturers - another reason why an open lens
standard (rather than closet reverse engineering) is not attractive to
the likes of Nikon and Canon et al. Oly glass can stand comparison
with anything in the world, how great to be able to use it on that
fabulous body from someone else at some point in the future without
worrying about compatibility issues.

>>I disagree. The 4/3 sensor format (for example) is confidently
>>expected to be good up to aroung the 12-16MP area. They used to make
>>similar comments about processors and memory chips, we all know what
>>happened there (and continues to happen).
>
>I didn't mean that there was a process limitation to increasing the
>pixel density. My point was that there is an optical limitation to doing
>so.

Not reached yet. Oly claim their lenses good to the 12-16MP area and
they know a thing or two about optics. We'll see!

>> Nobody _wants_ larger
>>sensors, the larger more expensive glass and the tank-like bodies
>>which accompany the 35mm format.
>
>I don't know. When I read the reviews, there seems to be a large
>contingent of photographer, especially pros, who like their cameras
>large and heavy for stability.

I dislike lightweight cameras for that reason but you don't need to be
large to be stable and if you have smaller lenses you don't need quite
so much weight to counterbalance them.

>> I see nothing wrong with wanting a
>>small, good hand-fit body with compact lenses which provide
>>double-digit megapixel performance with a good dynamic range and
>>acceptable high-ISO native noise performance.
>
>Nothing wrong with that at all. But the desire for that is up against
>the desire for a DSLR that is compatible with existing accessories. In
>the long run a format change is probably desirable, but I think the 35mm
>format is going to be around for quite a while yet.

I think it will too, but there comes a time when compatibility with
the older technology runs counter to improving new technology so at
some point it has to go the way of all things.

Jim

.

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