From: John Sheehy on
rfischer(a)sonic.net (Ray Fischer) wrote in news:48824a67$0$17197
$742ec2ed(a)news.sonic.net:

> John Sheehy <JPS(a)no.komm> wrote:
>>I am showing the visual, and I hope that it also shows that standard
>>methods of quantitative noise measurements are faulty.
>
> It shows that your measurements are faulty and deceptive.

Really? Maybe the just require some reading comprehension and a little
basic knowledge of the subject material, otherwise people who think they
understand more than they do might think that I am trying to say that the
FZ50 gives higher image quality than the 400D. Is that what you think my
demo is demoing? If that is the case, then you are a functional
illiterate.

>>You can clearly see that at 100% pixel view for both cameras, that the
>>FZ50 has more pixel noise. It always has less visible noise, however,
>>when both crops are scaled to the same size.

> But why would anyone ever want to do that?

To see what the different pixel densities would do with the same area
responsibility. Pity you can't understand such simple things.



--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS(a)no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
From: John Sheehy on
Bob Newman <bob.csx133(a)gmail.com> wrote in
news:dee26fb0-6700-4f10-99a2-1e4eee494cb9(a)b1g2000hsg.googlegroups.com:

>> But then there is no current evidence that there is a dependence of
>> read noise with pixel size; see Figure 3
>> at:http://www.clarkvision.com/imagedetail/digital.sensor.performance.s
>> um...
> Yes, but as I pointed out above, there's no evidence the other way,
> either.

There is a loose correlation between read noise relative to maximum signal
at base ISO and pixel size. The worst DSLRs are worse than average P&S
cameras, but the best DSLRs have about 1 stop less than the best P&S
cameras, and we don't know how much of that has to do with the amount of
money spent on the electronics, as big pixel cameras tend to be more
expensive cameras, with a more critical consumer base. If more money was
spent on reading out small pixels, they could conceivably have their read
noises decreased over what the $150 to $500 camera budgets for compacts
allow.

--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS(a)no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
From: John Sheehy on
"Roger N. Clark (change username to rnclark)" <username(a)qwest.net> wrote in
news:488234A2.9070803(a)qwest.net:

> Gee David, That's what I've been saying. There is an optimum.
> The above was to illustrate the effects of DR and pixel size and
> John's math errors regarding his DR claims.

What DR claims? The demo that started this thread was a comparison of
absolute SNR. I said that DR was another test but that I expect it to be a
little better, but not as much better as the absolute SNR.

--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS(a)no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
From: Ray Fischer on
John Sheehy <JPS(a)no.komm> wrote:
>rfischer(a)sonic.net (Ray Fischer) wrote in news:48824a67$0$17197

>>>You can clearly see that at 100% pixel view for both cameras, that the
>>>FZ50 has more pixel noise. It always has less visible noise, however,
>>>when both crops are scaled to the same size.
>
>> But why would anyone ever want to do that?
>
>To see what the different pixel densities would do with the same area
>responsibility.

Who cares? People don't care about "pixel densities". People care
abut noise per pixel, not noise per sensor area.

--
Ray Fischer
rfischer(a)sonic.net

From: acl on
On Jul 17, 1:02 am, ASAAR <cau...(a)22.com> wrote:
> On Wed, 16 Jul 2008 21:54:02 +0900, David J. Littleboy wrote:
> >> Uh, OK. So why not compare cameras with the same size sensors but
> >> different numbers of pixels?
>
> > That would make it too easy. Which would you rather have: a D70 or a D300?
>
> That's also too easy since a G9 and 5D were mentioned. Switch a
> '0' and you can have the D30 while I'll take the D700 that's left.

I haven't posted here for ages, and also won't in the future, but
ended up reading this thread nevertheless (a good reminder of why I
decided not to bother!).

However, I can't resist reminding *someone* of the WORLD-FAMOUS
INSANELY SMALL PIXELS of the D2X, hence also of the D300?

Carry on :)