Super-Zoom P&S Camera Beats DSLR (again) - Film at 11

On Wed, 03 Dec 2008 06:18:01 -0600, warren mikkels
wrote:

On Wed, 03 Dec 2008 07:06:13 -0500, Stephen Bishop wrote:

On Tue, 02 Dec 2008 11:18:25 -0600, Kenny Andersen
wrote:

On Tue, 02 Dec 2008 05:28:50 -0500, Stephen Bishop wrote:

On Mon, 01 Dec 2008 15:09:09 -0600, AlexDules
wrote:

mercy snipping


I don't see the relevance if anything it seems to be supporting my position.


Then you are again a total moron.

A point source is imaged by an airy-disk. A point-source of light is just a
convenient way to see just one single airy-disk. A single airy-disk from a point
source of light, whether it is from a star or from the sun reflecting off of a
chrome ball-bearing from the other side of a football field, is just a
convenient way of analyzing the true resolving power of optics, to determine how
close those optics are to being diffraction limited and to assist with alignment
of those image forming surfaces. Each bit of light coming off of every point on
the surface of an illuminated subject is its own "point source." Any image
formed by optics from the surface brightness of any object is comprised of a
nearly infinite number of overlapping airy-disks coming from a nearly infinite
points on the subject's surface. The size of those airy-disks is what determines
your true resolution. The size of those airy-disks is dependent on the physical
diameter of the aperture (as you have now finally learned, perhaps). Just the
f-ratio alone is meaningless when trying to determine airy-disk size unless also
accompanied by either focal-length or aperture measure. Cambridgeincolor's
website was written by a complete and total moron who doesn't even comprehend
basic optics and light. They should rename their domain to Cambridgeinthedark.
They are fools pretending to be professionals. Anyone dealing with them
professionally should have their head examined.

Go back to kindergarten where you belong. You're clearly never going to ever
comprehend any of this. You're wasting the valuable time of people, of which you
don't deserve even one more second.


More evidence of being educated beyond one's intelligence.

Of course, when you are a legend in your own mind and the rest of the
world is stupid, anything you say sounds good. To yourself, that is.

Let's see the proof that you actually know what you are talking about.
A professional portfolio would be a good place to start. Or perhaps
you can at least tell us where you received your advanced degree in
physics or optical design?

OBTW, responding to this with your "Dear Resident-Troll" list of
debunked points only shows that you aren't capable of original
thought.

Pictures, please. Where have you actually put this theory into
practice? Dazzle us with your brilliance.

If you are reluctant to do so because your photography skills aren't
that good, there are many people here who would be more than happy to
offer you suggestions as to how to improve.





Dear Resident-Troll,

Many (new & improved) points outlined below completely disprove your usual
resident-troll bull****. You can either read it and educate yourself, or don't
read it and continue to prove to everyone that you are nothing but a
virtual-photographer newsgroup-troll and a fool.


1. P&S cameras can have



... I thought so.



Dear Resident-Troll,

Many (new & improved) points outlined below



Right, you still don't have an original thought. Maybe you'll
understand someday that photography doesn't really have much to do
with the camera you use.

Let's see some of your camera work. I'm sure it is brilliant.

On Wed, 03 Dec 2008 18:06:55 -0500, Stephen Bishop wrote:


Uh huh.... let's see the proof of your expertise.



Does anyone else see a similarity of this moron's ignorance and a 3-year old
tugging at its parent's clothing, relentlessly asking "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?", "Why?",
"Why?",...........................

Until the parent finally has had enough and just shoves the child off a cliff,
or fills the tub too full and holds its head under to make it shut up.

It can't figure out anything on its own so it has to find every way it can to
manipulate someone into educating it on its 3-year old level.

Anyone care to adopt this thing and help it out? Its obviously suffering in
ignorance. It's been shown that its ignorance is no longer the bliss it once
thought bliss was and it can't deal with that realization.

On Wed, 03 Dec 2008 17:14:13 GMT, "Andrew Koenig" wrote:

"Davis-J" wrote in message
.. .

When diffraction limited optics are matched to the proper photosite sizes
there
is no loss of resolution due to diffraction.

However, even in a perfect world this can only happen at a single aperture,
because the "proper photosite size" for a diffraction-limited lens changes
with the aperture.


I thought at least you could comprehend the physics of light, optics, and the
principles of airy-disks. But this comment of yours shows that you too don't
have a clue.

Note to self: Give-up trying to educate these morons, they just can't grasp what
is really going on in their cameras.

On Wed, 03 Dec 2008 10:21:57 -0800, Paul Furman wrote:

wrote:
Andrew Koenig wrote:
wrote

Correction: A lens that has diffraction-limited glass will always
out-resolve a
smaller sensor's photosites, but it does it best at widest apertures with
less
spreading of the edges of the light.
Correction: A lens that has diffraction-limited glass will NOT always
out-resolve a smaller sensor's photosites. If you stop the lens down past
the critical aperture, (approximately 1.8 times the pixel pitch in microns),
the Airy disk from a point will cover more than one photosite.

You don't know much about the properties of an airy-disk. Just because the
airy-disk extends beyond a set unit of measure, you have to remember that the
vast majority of luminance is still constrained within the central peak (in
diffraction-limited optics). The airy-disk is a sharp-peaked bell-curve. So if
an airy-disk extends 1.8 times the photosite-pitch, it could mean that 75% of
the airy-disk's light is still within that central photosite. This is why larger
diameter optics can resolve a smaller airy-disk. More of the
information/luminosity (in diffraction limited optics) is constrained to a
smaller central peak.

Unfortunately, no dSLR optics are diffraction-limited quality so they can't take
advantage of their larger diameters to accomplish this. The resulting images
formed by 2-6+ pixel details from any dSLR glass is enough proof alone that none
of them are diffraction-limited quality. If they were truly diffraction limited
then they could form even sharper images on a P&S sized sensor at all apertures.
That's never going to happen, they can't even resolve individual pixels on their
own larger sensors with larger photosites, and most certainly not at all
apertures. Stray from where the lens performs best at 2+ pixel resolution and it
quickly degrades either side of that f/stop = crap optics.

When diffraction limited optics are matched to the proper photosite sizes there
is no loss of resolution due to diffraction. There will be an overall loss of
contrast between pixel-sized details, but each pixel still contains valid
information with which a scene may be faithfully reconstructed. Contrast between
adjoining pixel-sized details can be recreated in editing if so needed. Any
simple Fourier-transform is capable of that.

You use Fourier-transform for pictorial photography? Sounds like an
astro thing for squeezing data from faint observations. You can't be
serious?


Film at 11: Paul Furman reveals its ignorance and stupidity yet again. It's
trying for a world-record in displays of ignorance.


Putting that airy-disk diffraction
back where it belongs into its originating photosite. Aren't you aware that this
is how they "repaired" all images from the Hubble Telescope until they could get
corrective optics installed? Same difference. But unless you can get each
individual photosite to record valid information, no matter how low-contrast
from one to the next, then not even a Fourier-transform can help you get it back
into individual pixels again. E.g. the dSLR's 2-6+ pixel resolution from bad
glass means it can't faithfully reconstruct valid data any smaller than that
original 2-6+ pixel light-spread. You can't reconstruct data that wasn't
originally recorded/defined by the smallest available unit of measure.

On Wed, 03 Dec 2008 10:22:03 -0800, Paul Furman wrote:

Paul Furman wrote:
_________ wrote:

A lens that has diffraction-limited glass will always out-resolve a
smaller sensor's photosites,

No it won't. As soon as you stop down, diffraction strikes. There is
only one spot that's optimal, remember?


but it does it best at widest apertures

The 2 stops from f/4 to f/8 are easily equivalent after you increase ISO
a bit to match exposure on the DSLR with matching DOF. Diffraction kicks
in at the same time with equal field of view & pixel count. The
difference is the DSLR can also turn the ISO way up and open the
aperture further to explore more opportunities. It can make good photos
under all sorts of conditions. Even the airy disc is potentially sharper
with that big absolute aperture if you can afford that glass g. There
is plenty of data showing lenses that perform well at apertures larger
than f/8.


Go find some clues to cram into that small empty space you have for a mind. You
can't compare the properties of non-diffraction-limited glass to
diffraction-limited glass. You know when you have created diffraction-limited
optics by the very presence of an airy-disk with its diffraction-rings.
Non-diffraction-limited glass (ALL dSLR glass for example) can't create an
airy-disk. Shorter focal-lengths create smaller airy-disks when using
diffraction limited glass. Ergo, you are comparing apples to oranges and don't
have one ****ing clue as to what you are talking about.

It would probably take someone over three years of giving you lessons before
you could even begin to comprehend anything that you are talking about.




with less spreading of the edges of the light.
The diffraction pattern does not contain the full percentage of
information, just a smaller percentage of it.
This only appears as a softening of details, not true loss of details
on a photosite to photosite basis.


OK so in P&S cameras, with less 'spreading out', that means a smaller
aperture and smaller sensor there is less information gathered, but
that's still enough information, so don't worry, it can be usable under
good conditions. Have I interpreted that correctly? I thought you were
saying there was some advantage before, oh well.

"This only appears as a softening of details, not true loss of details"

Right? So there is a little bit left. Even after being stuck at noisy
low ISO with slow shutter speeds and tiny apertures gathering a faint
bit of light on a 20x zoom compromised on the ends. It does still make a
decent photo considering all that, if conditions are right. I think you
make a good point. Cell phones are getting better & better too, handy stuff.

On Wed, 03 Dec 2008 18:47:08 GMT, "Andrew Koenig" wrote:

"Paul Furman" wrote in message
...

I am saying that if you give me a camera, I can tell you how far you can
stop the lens down ON THAT CAMERA before the performance degrades ON THAT
CAMERA due to diffraction.

So where is this data coming from:
http://www.dpreview.com/lensreviews/..._n15/page5.asp
That shows sharpness exceeding the sensor's "nyquist fqcy" at f/2.5 in the
center, and all the lenses tested do it below f/8.

I don't know where the data are coming from, but they do corroborate what
I've been saying.

Visit the page you cite and move the "aperture" slider at the bottom of the
graph. You will see that when you move that slider to f/11, the MTF-50 line
is just about equal to the Nyquist frequency. If you move the slider to
F/16, the MTF-50 line declines to a point below the Nyquist frequency. This
phenomenon is the image degradation due to diffraction that I've been
talking about.

You can't obtain diffraction-limited effects in non-diffraction limited optics.
What you are seeing is the poor performance of glass that is poorly figured and
only works "okay" at one aperture.

Do you even have a clue as to how diffraction rings form and what it takes to
reach diffraction-limits? Of course not. And your treatise of ignorance show it,
loud and clear.

Tattoo this on your forehead: BLURRING OF IMAGE DETAILS FROM NON-DIFFRACTION
LIMITED GLASS IS NOT THE SAME AS LOSS OF DETAIL-CONTRAST FROM
DIFFRACTION-LIMITED GLASS.


Now...if you move the slider f/8, you will see that the line is higher than
the Nyquist frequency. That means that the sensor is what is limiting the
image resolution at that aperture. It even says so in the green writing
under the graph:

Whenever the measured numbers exceed this value [the Nyquist frequency],
this simply indicates that the lens out-resolves the sensor at that
point...

I am not making, and have never made, any claims about how a lens will
perform at apertures wider than what I've been calling the critical
aperture. All I'm saying is that if you stop a lens down beyonds the
critical aperture that corresponds to your sensor's pixel pitch, the
sensor's resolution will exceed what the lens is capable of providing.

As far as I can tell, the graph you've cited is consistent with this claim.

And I have no idea how they can tell that the lens is out-resolving the
sensor -- though in principle one could infer that from contrast
measurements at lower resolutions.

________ wrote:

Shorter focal-lengths create smaller airy-disks when using
diffraction limited glass.

Yes, smaller cameras create smaller airy discs *and* dimmer fainter airy
discs, and they have to cram them onto smaller, less sensitive sensors
with more noise using 20x super-zoom lenses stretched to their limit. I
do think you are beginning to understand this.

AndyTalberts wrote:

You can't obtain diffraction-limited effects in non-diffraction limited optics.

You are talking gibberish. Of course you can see diffraction in any lens
that can be stopped down. What the hell are you talking about???

On Wed, 03 Dec 2008 19:03:57 -0800, Paul Furman wrote:

________ wrote:

Shorter focal-lengths create smaller airy-disks when using
diffraction limited glass.

Yes, smaller cameras create smaller airy discs *and* dimmer fainter airy
discs, and they have to cram them onto smaller, less sensitive sensors
with more noise using 20x super-zoom lenses stretched to their limit. I
do think you are beginning to understand this.

The light is spread over a larger area on a larger sensor to try to illuminate
larger photosites, there is no net gain to luminosity level at identical
f/ratios between lenses on their correspondingly matched sensors.

I do know (which is quite different than just thinking or believing something)
that you're still just as ****ingly ignorant as you've always been and continue
to prove to be with every sentence that you attempt to post.

_________ wrote:
Paul Furman wrote:
________ wrote:

Shorter focal-lengths create smaller airy-disks when using
diffraction limited glass.
Yes, smaller cameras create smaller airy discs *and* dimmer fainter airy
discs, and they have to cram them onto smaller, less sensitive sensors
with more noise using 20x super-zoom lenses stretched to their limit. I
do think you are beginning to understand this.

The light

More light, due to larger lenses...

is spread over a larger area on a larger sensor to try to illuminate
larger photosites, there is no net gain to luminosity level at identical
f/ratios between lenses on their correspondingly matched sensors.

Right, it's a wash at the same aperture and ISO on that basis. You are
getting it...


Except that the DSLR is gathering more light so it has less noise even
at base ISO, and works in lower light when you need to crank up the ISO.