Telephoto Reach and Digital Cameras - lens comparison

A comparison of fixed focal length lenses & consumer zooms on DSLRs when
photographing distant objects:

http://www.clarkvision.com/articles/telephoto_reach/

including a comparison with a super-zoom P&S.

http://www.clarkvision.com/articles/...are.moon.a.jpg

A longer zoom may not be better than a shorter fixed focal length lens.

On Mon, 6 Dec 2010 16:20:48 -0000, "David J Taylor"
wrote:

A comparison of fixed focal length lenses & consumer zooms on DSLRs when
photographing distant objects:

http://www.clarkvision.com/articles/telephoto_reach/

including a comparison with a super-zoom P&S.

http://www.clarkvision.com/articles/...are.moon.a.jpg

A longer zoom may not be better than a shorter fixed focal length lens.

Yes, anyone intent on taking amateur photographs of the moon from
their backyard should pay heed to this study. All six of them.
--
Tony Cooper - Orlando, Florida

On Mon, 6 Dec 2010 16:20:48 -0000, "David J Taylor"
wrote:

A comparison of fixed focal length lenses & consumer zooms on DSLRs when
photographing distant objects:

http://www.clarkvision.com/articles/telephoto_reach/

including a comparison with a super-zoom P&S.

http://www.clarkvision.com/articles/...are.moon.a.jpg

A longer zoom may not be better than a shorter fixed focal length lens.

Just more of Clark's garbage in, garbage out results. No wonder he was
fired from so many jobs. His glaringly biased attempts to try to justify
why he has spent all that money, like every other test he's ever done.

You'll note that he should have used ISO100 and larger apertures on the
superzoom, where the images would then have been nearly identical, because
the superzoom lens improves on resolution at larger apertures, unlike on
DSLR glass where the figure isn't good enough to hold to
diffraction-limited resolutions at larger apertures. Instead he made sure
to use the superzoom on settings where noise and diffraction limitations
start to set in just to try to make his expensive gear look better to him.

If you look at both images at pixel level you'll note too that he took a
higher-resolution image from the DSLR then applied much higher JPG
compression to the superzoom image.

He just loves fudging his own tests to get the results he wants, always
leaving out these important bits of details in his biased explanations. And
all you fools fall for it, every time, guaranteed.

I was alerted to this thread by another.

Superzooms Still Win wrote:
On Mon, 6 Dec 2010 16:20:48 -0000, "David J Taylor"
wrote:

A comparison of fixed focal length lenses& consumer zooms on DSLRs when
photographing distant objects:

http://www.clarkvision.com/articles/telephoto_reach/

including a comparison with a super-zoom P&S.

http://www.clarkvision.com/articles/...are.moon.a.jpg

A longer zoom may not be better than a shorter fixed focal length lens.

Just more of Clark's garbage in, garbage out results. No wonder he was
fired from so many jobs. His glaringly biased attempts to try to justify
why he has spent all that money, like every other test he's ever done.

The above statement is outright libel! I have never been fired from
any job in my life. This is absolutely outrageous, and a complete
lie. I have been with my present employer for 27 years and I
was promoted this year.


You'll note that he should have used ISO100 and larger apertures on the
superzoom, where the images would then have been nearly identical, because
the superzoom lens improves on resolution at larger apertures, unlike on
DSLR glass where the figure isn't good enough to hold to
diffraction-limited resolutions at larger apertures. Instead he made sure
to use the superzoom on settings where noise and diffraction limitations
start to set in just to try to make his expensive gear look better to him.

Any astronomer knows that resolution is limited by aperture.
It is a simple computation. The lens apertures found in
superzoom cameras are quite small. Changing ISO does not
change resolution, except in changing post image acquisition
in camera noise reduction. The high zoom ratio of super zoom cameras
are impressive in that they deliver OK image quality over a large
range, but are soft compared to fixed focal length lenses.
Stopping down a stop or so improves image quality on every zoom
lens I have tested. So opening up the super zoom lens would
have reduced diffraction up to 40%, but other aberrations would
have reduced the image quality more. Figure 1 on the web page illustrates
that effect using another zoom lens.

If you look at both images at pixel level you'll note too that he took a
higher-resolution image from the DSLR then applied much higher JPG
compression to the superzoom image.

They were the highest resolution jpeg each camera produces.
And since the web image is one image with both the DSLR and P&S
image embedded in it, the jpeg compression of the web image
is identical.

Of course the DSLR raw data could be used to produce and even
better image.

He just loves fudging his own tests to get the results he wants, always
leaving out these important bits of details in his biased explanations. And
all you fools fall for it, every time, guaranteed.

BS. If you can match or better the DSLR+300mm+1.4xTC moon image
shown with a P&S super zoom camera, the show us. You can't because
simple physics proves you can't. The Dawes limit, is
4.56/D where D is the clear aperture diameter in inches:

Thus:
300 mm f/2.8 lens, Dawes limit = 4.56/4.22 = 1.08 arc seconds.
300 mm f/4 lens, Dawes limit - 4.56/2.95 = 1.54 arc-seconds.

FZ35 super zoom at max focal length of 86.4 mm
fastest f/ratio, f/4.4, aperture =19.6 mm: Dawes limit =
4.56/0.77= 5.9 arc-seconds (and it only achieves that if other
aberrations are smaller, and they are not at f/4.4).

All superzoom P&S cameras have small clear apertures which
limits resolution on a subject, regardless of focal length.
It is simple physics, no bias.

You have stated on rec.photo.digital that superzoom cameras are diffraction
limited. Fine, but the diffraction is so large from the small
aperture that it limits detail on a subject. DSLRs using telephoto
lenses with larger clear apertures do not need to be diffraction
limited to better the resolution on a subject over a P&S camera.
Simple physics.


Regarding Rich's comment:
Anyone trying to take good moon shots by using a telephoto lens
instead of a telescope is making a mistake.

The point was not to compete with telescopes, but to show the relative
performance of each camera and lens. The Moon is a natural
target that anyone anywhere in the world can image, so they can
test their own lenses and techniques and compare to others.
At short focal lengths like 300 mm, atmospheric distortions
are minimal. The Moon has effectively infinite detail and is
not a bar chart, so more natural in terms of complexity of
imaging in the real world. These results extend to wildlife,
sports, people and other photography.

Good telephoto lenses can take great images of the Moon.
For example, check this out (be sure to click on the link
to the full resolution image):

http://www.clarkvision.com/galleries...0mm_e-900.html

Let's see a P&S superzoom camera with its "super" telephoto lens beat that,
or for that matter, even come close. It can't due to the simple physics
of diffraction. No bias, just simple physics.

Roger

On Mon, 13 Dec 2010 23:20:21 -0700, "Roger N. Clark (change username to
rnclark)" wrote:


Any astronomer knows that resolution is limited by aperture.
It is a simple computation. The lens apertures found in
superzoom cameras are quite small. Changing ISO does not
change resolution

Of course not, you ****ing moron, it changes the amount of sensor noise.
The VERY thing that you are complaining about that's robbing the images of
detail. You might want to learn how to use a camera properly to get proper
exposures too, that too was used in your "tests" to bias your crap results
to what you wanted them to be.

lens I have tested. So opening up the super zoom lens would
have reduced diffraction up to 40%, but other aberrations would
have reduced the image quality more.

Wrong, you ****ing MORON. Because the smaller glass for superzoom cameras
allows the makers the ability to figure them to diffraction limited quality
at an affordable price, whereby opening up the aperture DOES increase
resolution. Unlike your piece of **** DSLR glass that ALWAYS degrades the
images at larger apertures, because *NO* DSLR glass can ever be figured to
diffraction-limited quality without putting their cost outside the reach of
everyone.


They were the highest resolution jpeg each camera produces.
And since the web image is one image with both the DSLR and P&S
image embedded in it, the jpeg compression of the web image
is identical.

So because they were the highest resolution available from each camera,
you thought nobody would notice that if you didn't crop 1:1, pixel for
pixel, representations from each camera, that NOBODY would see you trying
to bias your test results with this blatantly obvious and simple TROLL'S
BULL**** of yours again. As for JPG compression, I'm talking about SOURCE
images you ****ing MORON.

Care to trip over your side-stepping bull**** some more? So far your dance
in your field of bull**** isn't going very well, is it.

The rest of your BULL**** is just more of the same BULL****. No sense even
replying to more than this. A waste of everyone's time.

BTW: Someone already proved that they can get images of the moon with more
detail and clarity using a handheld superzoom camera compared to $5000
worth of your DSLR crap gear. Even when your waste of money is mounted on
sturdy tripods with mirror lock-up engaged too. Don't you remember that
test? About 2 years ago. The last time you were laughed out of these
newsgroups. Of course you do. That's why you've now spent two years of your
useless life in fudging tests of images of the moon while trying to climb
out of that pit you dug for yourself, and still you fail. Have some more
omelet on your face.

You're nothing but a ****ing joke.

Superzooms Still Win wrote:
On Mon, 13 Dec 2010 23:20:21 -0700, "Roger N. Clark (change username to
wrote:


Any astronomer knows that resolution is limited by aperture.
It is a simple computation. The lens apertures found in
superzoom cameras are quite small. Changing ISO does not
change resolution

Of course not, you ****ing moron, it changes the amount of sensor noise.
The VERY thing that you are complaining about that's robbing the images of
detail. You might want to learn how to use a camera properly to get proper
exposures too, that too was used in your "tests" to bias your crap results
to what you wanted them to be.

Wow what a foul mouth you have. That does not help your case.
Both cameras were operated at the same ISO, thus no bias.

lens I have tested. So opening up the super zoom lens would
have reduced diffraction up to 40%, but other aberrations would
have reduced the image quality more.

Wrong, you ****ing MORON. Because the smaller glass for superzoom cameras
allows the makers the ability to figure them to diffraction limited quality
at an affordable price, whereby opening up the aperture DOES increase
resolution. Unlike your piece of **** DSLR glass that ALWAYS degrades the
images at larger apertures, because *NO* DSLR glass can ever be figured to
diffraction-limited quality without putting their cost outside the reach of
everyone.

Again, your foul language does not help your case.
The fact is that the FZ35/FZ38 (same camera different label depending on
where sold) as well as every other lens test of a superzoom cameras
I have seen, none are diffraction limited wide open at full zoom.
Here is an example:
http://www.imaging-resource.com/PRODS/FZ35/FZ35A4.HTM
The center shows a quite soft image, definitely not diffraction
limited and as you move off center, the lens is really bad.

They were the highest resolution jpeg each camera produces.
And since the web image is one image with both the DSLR and P&S
image embedded in it, the jpeg compression of the web image
is identical.

So because they were the highest resolution available from each camera,
you thought nobody would notice that if you didn't crop 1:1, pixel for
pixel, representations from each camera, that NOBODY would see you trying
to bias your test results with this blatantly obvious and simple TROLL'S
BULL**** of yours again. As for JPG compression, I'm talking about SOURCE
images you ****ing MORON.

Again your foul mouth does not help your case. I was talking about
source images.

Care to trip over your side-stepping bull**** some more? So far your dance
in your field of bull**** isn't going very well, is it.

The rest of your BULL**** is just more of the same BULL****. No sense even
replying to more than this. A waste of everyone's time.

BTW: Someone already proved that they can get images of the moon with more
detail and clarity using a handheld superzoom camera compared to $5000
worth of your DSLR crap gear. Even when your waste of money is mounted on
sturdy tripods with mirror lock-up engaged too. Don't you remember that
test? About 2 years ago. The last time you were laughed out of these
newsgroups. Of course you do. That's why you've now spent two years of your
useless life in fudging tests of images of the moon while trying to climb
out of that pit you dug for yourself, and still you fail. Have some more
omelet on your face.

You're nothing but a ****ing joke.

Again wrong on all counts. I was not laughed out of this newsgroup.
I chose to leave, like many of the other excellent photographers,
because of the degradation of any discussion, like you are dragging
this one into the mud with your foul language and lies.

It has not ever been shown that an image from a superzoom camera with its
lens at full zoom could match a DSLR and fixed focal length telephoto.
Not even close.

If you can't actually prove a point with facts, foul language and
name calling does not help your case.

Roger

On 12/14/10 PDT 8:37 AM, Roger N. Clark (change username to rnclark)
wrote:

Again wrong on all counts. I was not laughed out of this newsgroup.
I chose to leave, like many of the other excellent photographers,
because of the degradation of any discussion, like you are dragging
this one into the mud with your foul language and lies.

It has not ever been shown that an image from a superzoom camera with its
lens at full zoom could match a DSLR and fixed focal length telephoto.
Not even close.

If you can't actually prove a point with facts, foul language and
name calling does not help your case.

Hi, Roger, nice to see you back. We don't allow mission posters, haters
or those spewing 6th grade obscenities to deter us.

Many have found that simply ignoring this pest is the best we can do.
I've even prayed for his tormented soul—didn't work!

You don't need to defend anything, and thanks for your contributions
over the years.

--
John McWilliams

Oh, he'll be sure to "refute" any and everything, but see if you can let
it slide, please...

Hi, Roger, nice to see you back. We don't allow mission posters, haters
or those spewing 6th grade obscenities to deter us.

Many have found that simply ignoring this pest is the best we can do.
I've even prayed for his tormented soul—didn't work!

You don't need to defend anything, and thanks for your contributions
over the years.

--
John McWilliams

Yes, welcome back. Most of us have simply kill-filed the pest, and I hope
it's obvious to any newcomers that something which needs to resort to such
foul language in that manner has little of value to contribute.

What is perhaps confusing is the effect of diffraction in object space and
sensor space. As I understand it, in object space - what the camera
sees - the effect of diffraction can best be visualised in angular terms,
so that a larger diameter lens has a smaller diffraction "cone" (if you
like), and hence can resolve more detail on a given surface. In sensor
space - where the image is produced - the effect of diffraction can be
visualised making each image spot a finite diameter for a particular
f/number. When the pixel size is larger than the diffraction spot, the
pixel size tends to be the limiting factor in resolution, and this can
happen in large-pixel DSLRs with the best lenses. Where the pixel size is
smaller than the diffraction spot, the effect of diffraction would be the
dominant factor in determining resolution.

So while the small-sensor camera /may/ be closer to diffraction-limited,
given good enough optics (which is questionable at the price), that
diffraction limit is a much lower resolution in object space, due to the
smaller actual diameter of the optics. The ratio of the sensor sizes
might be 30/6.5 (for an APS-C camera to a "1/2.7-inch" sensor camera) - so
about 4.5 times, and hence the scale of the optics, and that ratio might
set the upper limit for the resolution ratio if both cameras had
diffraction-limited systems working at the same f/number.

Your comparison shows the benefit of the larger diameter optics....

http://www.clarkvision.com/articles/...are.moon.a.jpg

Thanks,
David

On 2010-12-14 12:57:22 -0800, "David J Taylor"
said:

Hi, Roger, nice to see you back. We don't allow mission posters, haters
or those spewing 6th grade obscenities to deter us.

Many have found that simply ignoring this pest is the best we can do.
I've even prayed for his tormented soul—didn't work!

You don't need to defend anything, and thanks for your contributions
over the years.

--
John McWilliams

Yes, welcome back. Most of us have simply kill-filed the pest, and I
hope it's obvious to any newcomers that something which needs to resort
to such foul language in that manner has little of value to contribute.

Agreed. Welcome back.
I had not seen much evidence of "He who remains unnamed" for some time
until this exchange. All I can recommend is to filter/kill-file, or
just ignore.


--
Regards,

Savageduck

On Tue, 14 Dec 2010 09:37:58 -0700, "Roger N. Clark (change username to
rnclark)" wrote:


It has not ever been shown that an image from a superzoom camera with its
lens at full zoom could match a DSLR and fixed focal length telephoto.
Not even close.

The test two years ago, pitted against your OWN photos, shows that the
superzoom not only matched your PIECE OF **** DSLR gear, but it BEAT IT.

THAT'S WHY YOU'VE NOW SPENT 2 YEARS OF YOUR USELESS LIFE TAKING IMAGES OF
THE MOON TO TRY TO PROVE THAT IT COULDN'T BE TRUE.

What a ****ing MORON!

LOL!!!!!!!!