From: Tim Conway on

"Savageduck" <savageduck1@{REMOVESPAM}me.com> wrote in message
news:2010042807500250878-savageduck1(a)REMOVESPAMmecom...
> On 2010-04-28 06:26:48 -0700, "Peter" <peternew(a)nospamoptonline.net> said:
>
>> "Tim Conway" <tconway_113(a)comcast.net> wrote in message
>> news:hr95fu$d94$1(a)news.eternal-september.org...
>>> I want one of these. Hey, it's only $7,000. dream on. :-)
>>>
>>> http://www.imaging-resource.com/NEWS/1272386298.html
>>>
>>
>>
>> Try the new 2.8 70-200 with the new aspherical 2x extender. Yes I know
>> it's f5.6 and not f4, but the price and weight difference may be worth
>> it.
>>
>> But, yup! I like that lens.
>
> Rita_B/Larry_Thong will probably have sample shots of the South end of her
> North bound dog up here by the end of May. ;-)
>
yeah, always entertaining LOL

From: Russ D on
On Wed, 28 Apr 2010 17:26:52 +0200, Robert Spanjaard <spamtrap(a)arumes.com>
wrote:

>On Wed, 28 Apr 2010 10:00:46 -0500, the more highly educated
>and vastly more experienced photographer wrote:
>
>>
>> Or get any of the superzoom P&S cameras and you'll increase the
>> focal-length reach and enlarge the aperture by 3-fold
>...
>> Any difference in ISO performance is made up
>> in 3 times more aperture
>
>Name _one_ superzoom with an aperture of 150mm (f/4 at 200mm x3) diameter.

Your thinking is twisted--from trying to justify your poor choices in life
and from relentlessly parroting the same nonsense that all the DSLR-Trolls
do, just like the rest of you archaic DSLR-Dolts. Since the sensor is
smaller the light is spread over a smaller area for the same amount of
aperture. The exposures will be identical, f/stop for f/stop. A smaller
entrance pupil is required for smaller sensors. Since larger f/stops are
available on superzoom lens designs than DSLR lens designs, they then get
the full benefit of those larger apertures, overriding any need for the
higher ISOs as are required by DSLRs in order to obtain the exact same
exposures in the same light levels. With the added benefit of getting a
working DOF within which your full subject can be in focus, instead of only
a miniscule part of it. Luckily too, that smaller sensor cameras are often
combined with contrast-focusing methods, instead of phase-detection
methods. This ensures that all your images are in perfect focus, instead of
using the faster but hit and miss methods employed on DSLRs. I'd rather
walk away with 100 perfectly focused images for 100 shots, rather than 10
out of 1000. Often interrupted with having to change lenses too. All those
missed images, from back/front focusing problems, changing lenses, too
shallow DOF, etc. In real-life performance the smaller sensor with a single
lens is far faster, more accurate, and more efficient.

But you go ahead, keep imagining what is not, in your little role-playing
pretend-photographer's world.



From: Robert Spanjaard on
On Wed, 28 Apr 2010 11:08:13 -0500, the P&S troll wrote:

> On Wed, 28 Apr 2010 17:26:52 +0200, Robert Spanjaard
> <spamtrap(a)arumes.com> wrote:
>
>>On Wed, 28 Apr 2010 10:00:46 -0500, the P&S troll wrote:
>>
>>
>>> Or get any of the superzoom P&S cameras and you'll increase the
>>> focal-length reach and enlarge the aperture by 3-fold
>>...
>>> Any difference in ISO performance is made up in 3 times more aperture
>>
>>Name _one_ superzoom with an aperture of 150mm (f/4 at 200mm x3)
>>diameter.
>
> Your thinking is twisted--from trying to justify your poor choices in
> life and from relentlessly parroting the same nonsense that all the
> DSLR-Trolls do, just like the rest of you archaic DSLR-Dolts. Since the
> sensor is smaller the light is spread over a smaller area for the same
> amount of aperture. The exposures will be identical, f/stop for f/stop.
> A smaller entrance pupil is required for smaller sensors. Since larger
> f/stops are available on superzoom lens designs than DSLR lens designs,
> they then get the full benefit of those larger apertures, overriding any
> need for the higher ISOs as are required by DSLRs in order to obtain the
> exact same exposures in the same light levels.

So now, superzooms don't have a large aperture. Instead you now claim that
they don't need it because of their small sensors.

--
Regards, Robert http://www.arumes.com
From: Doug McDonald on
On 4/28/2010 10:00 AM, Russ D wrote:

>
> Or get any of the superzoom P&S cameras and you'll increase the
> focal-length reach and enlarge the aperture by 3-fold,


REALLY? the square root of three is 1.73.

A 400mm f/4 lens like the Nikon has a 100mm diameter entrance pupil.

sqrt(3) * 100 = 173mm.

To get three times the aperture you'd need a lens 173mm in diameter!

OH! The P&S troll means f/number, not aperture.

But that, as is he, is wrong. What matters is not f/number .... it
is the actual entrance pupil diameter. That's what determines number of photons,
and hence signal to noise ratio.

Doug McDonald
From: Doug McDonald on
On 4/28/2010 11:08 AM, Russ D wrote:

> Your thinking is twisted--from trying to justify your poor choices in life
> and from relentlessly parroting the same nonsense that all the DSLR-Trolls
> do, just like the rest of you archaic DSLR-Dolts. Since the sensor is
> smaller the light is spread over a smaller area for the same amount of
> aperture. The exposures will be identical, f/stop for f/stop. A smaller
> entrance pupil is required for smaller sensors.


UH, **NO**

The number of photons ... which determines the S/N ratio ... depends
on the actual aperture SIZE, not f/number.

Doug McDonald