From: Scott W on
On Jul 15, 8:45 am, Paul Furman <pa...@-edgehill.net> wrote:
> John P Sheehy wrote:
> > I've made a direct comparison of RAW data per unit of area in the deep
> > shadows of ISO 100 between the FZ50 (1.97 micron) and the 400D (5.7
> > micron).  Exposure is the same, same Av (f/4.5), same Tv (1/100), same real
> > focal length (22mm), both shot at "ISO 100" pushed to ISO 13,500.  Large
> > crop is 100% for FZ50 (0.4MP), and small crop is 100% for 400D (0.05MP),
> > and the other two are the other camera scaled to the 100% crop of each.  As
> > I already knew, the bigger pixels of the DSLR are inferior compared to the
> > higher pixel density of the small sensor camera:
>
> >http://www.pbase.com/jps_photo/image/100092629
>
> Of course, the DSLR image is enlarged more than 3x!
>
> 7.18 x 5.32 mm
> 24  x  18 mm

The test is interesting but some thought is needed to interpret what
it means. If you had a really good lens on the DSLR and had 1.97
micron pixels across the same size sensor area then you might get
improved results over the larger pixels. This would require a pretty
good lens however, past what most lenses 35mm lenses will produce.

Given the limits of the current lenses we start to get to diminishing
returns for more pixels on the same size sensor. It seems that going
much below 4-5 microns for the current 35mm lenses does not make a lot
of sense.

Of course there is nothing to stop someone for designing a large
sensor with 2 micron pixels and designing a new set of lenses to go
with it, but the cost of a lens starts to go up fast as it is required
to resolve smaller pixels. IN the case of the FZ50, its lens covers
a much smaller image circle then the 400D, so you could not simple use
this lens on a larger sensor camera.

If we are just looking at whether small pixels or large pixels are
better, given a fixed number of them, then the test photos should
really cover the same field of view rather then having the same FL.

My conclusion is that there is a potential for improved images with
more pixels, but to realize this potential we need better lenses.

Scott


The test is interesting but some thought is needed to interpert what
it means.

From: John Sheehy on
"Roy G" <roy.gibson1(a)virgin.net> wrote in
news:kd4fk.631$Ro1.115(a)newsfe17.ams2:

> I am glad you are happy with the results of your testing.

> Please continue to enjoy the results from your FZ50.

> I hope you don't mind if I still prefer the quality I get from my
> Nikon D300.

Thank you for making sure you fully understood what was going on before
commenting! You can go back to sleep now!


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John P Sheehy <JPS(a)no.komm>
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From: John Sheehy on
Paul Furman <paul-@-edgehill.net> wrote in
news:Ze6fk.14817$mh5.10460(a)nlpi067.nbdc.sbc.com:

> Of course, the DSLR image is enlarged more than 3x!
>
> 7.18 x 5.32 mm
> 24 x 18 mm

Of course, but 2.89x, not 3x+. That's the point, or at least part of it.

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John P Sheehy <JPS(a)no.komm>
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From: John Sheehy on
Juf� <b0wser(a)h0me.c0m> wrote in news:UL6fk.316$6O4.307(a)trnddc06:

> I suggest you call the NY Times or Scientific American since your
> expirement completely contradicts what every tester has shown to date.

What were they testing, *exactly*? Did they have access to the RAW data,
or just JPEGs and conversions?

> Do you think there might be a problem with your methodology?

Not at all; this is as close to "all other things being equal" as we can
expect to get, for comparing the IQ effects of pixel density in light-
starved situations. In all probability, the lens on the 400D has nowhere
near the MTF of the lens in the FZ50, but even a B&W checkerboard pattern
with 1-pixel tiles would be relatively soft blown up 289%.

> How about
> just shooting the same scene, same angle of view, and enlarging each
> image to 100%? Too complicated?

No; too *irrelevant* to the issue of PIXEL DENSITY.

> Sorry, but larger pixels always win the day.

Sorry, but that's wrong. With a few exceptional situations (specifically
read noise, but not shot noise, at ISOs 1600 and above, in a very small
number of DSLRs), smaller pixels filling the same sensor area give better
imaging. Larger pixels are only universally better when they are doing
the same job; IOW, when they have the same imaging responsibility.

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John P Sheehy <JPS(a)no.komm>
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From: Roy G on

"John Sheehy" <JPS(a)no.komm> wrote in message
news:Xns9ADCB77972C69jpsnokomm(a)199.45.49.11...
> "Roy G" <roy.gibson1(a)virgin.net> wrote in
> news:kd4fk.631$Ro1.115(a)newsfe17.ams2:
>
>> I am glad you are happy with the results of your testing.
>
>> Please continue to enjoy the results from your FZ50.
>
>> I hope you don't mind if I still prefer the quality I get from my
>> Nikon D300.
>
> Thank you for making sure you fully understood what was going on before
> commenting! You can go back to sleep now!
>
>

YAWN !!!!