Possible cost-cutting of CCDs for specific apps.

I would say that amateur astrophotography done largely for aesthetics and
not for research data. Again, there is no requirement for X arcsec
resolution when someone takes a prime focus photo of the Orion Nebula or
M-31, but there is a requirement for many pixels and large fields (i.e. high
definition). It is only your particular interests that dictate angular
resolution and small fields.

This is starting to sound like arguments for and against letterbox format on
a standard television.

Del Johnson



"Chris L Peterson" wrote in message
...

With astrophotography, the issue _is_ angular resolution. That is all that
matters. Once your imaging device, be it electronic or film, can fully
sample
the object at the limiting angular resolution, you have succeeded in
capturing
all the available information. Any arbitrary definition can be losslessly
achieved through post processing.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Tue, 10 Feb 2004 16:29:27 -0800, "Del Johnson" delastro@{right star in
Orion's belt}.sdsu.edu wrote:

I would say that amateur astrophotography done largely for aesthetics and
not for research data. Again, there is no requirement for X arcsec
resolution when someone takes a prime focus photo of the Orion Nebula or
M-31, but there is a requirement for many pixels and large fields (i.e. high
definition). It is only your particular interests that dictate angular
resolution and small fields.

Perhaps you missed the original post that started this thread. Richard was
specifically asking about using smaller arrays for small objects that don't
require a large field. Nobody is saying that high resolution images of large
fields don't require more pixels than high resolution images of small fields.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Tue, 10 Feb 2004 16:29:27 -0800, "Del Johnson" delastro@{right star in
Orion's belt}.sdsu.edu wrote:

I would say that amateur astrophotography done largely for aesthetics and
not for research data. Again, there is no requirement for X arcsec
resolution when someone takes a prime focus photo of the Orion Nebula or
M-31, but there is a requirement for many pixels and large fields (i.e. high
definition). It is only your particular interests that dictate angular
resolution and small fields.

Perhaps you missed the original post that started this thread. Richard was
specifically asking about using smaller arrays for small objects that don't
require a large field. Nobody is saying that high resolution images of large
fields don't require more pixels than high resolution images of small fields.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Tue, 10 Feb 2004 16:29:27 -0800, "Del Johnson" delastro@{right star in
Orion's belt}.sdsu.edu wrote:

BTW, regarding your email obfuscation. Would that be my right or Orion's right?
And perhaps if I were in the southern hemisphere, I would have a different
opinion on what the "right" side of Orion is g. Maybe you should go for the
western star in Orion's belt (assuming that's the one you are meaning).

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Tue, 10 Feb 2004 16:29:27 -0800, "Del Johnson" delastro@{right star in
Orion's belt}.sdsu.edu wrote:

BTW, regarding your email obfuscation. Would that be my right or Orion's right?
And perhaps if I were in the southern hemisphere, I would have a different
opinion on what the "right" side of Orion is g. Maybe you should go for the
western star in Orion's belt (assuming that's the one you are meaning).

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On 10 Feb 2004 22:52:19 GMT, (Jon Isaacs) wrote:

There are two sides to this...

Answer #1.

Not if you're using an 12 inch F10 scope....

I think Chris's point is that if one is imaging a specific object then the
resolution and pixel matching are important. If one is imaging the ring nebula
and that is all that is of interest, then 0.5 arc-seconds per pixel times 1.2
arcminutes equals 144 pixels and any more are just wasted....

Answer #2. If you are imaging large portions of the sky or an object and the
sky around it, then the ability to have a large number of pixels or many lines
of resolution is an advantage. Slapping a 28 mm photographic lens on an ST-237
will yield a field of view of something like 7.5 degrees x 9.5 degrees but each
pixel will have a value of almost an entire arcminute.

In this case the number of pixels is very important.

Personally I have both a film camera and a CCD camera. I am too lazy to use em
much, using a CCD is a gagetters delight and film cost money and the instant
gratification factor is not there.

Well put. I didn't think a sock puppet had the capacity to distill
and convey to others such advanced concepts.

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

On 10 Feb 2004 22:52:19 GMT, (Jon Isaacs) wrote:

There are two sides to this...

Answer #1.

Not if you're using an 12 inch F10 scope....

I think Chris's point is that if one is imaging a specific object then the
resolution and pixel matching are important. If one is imaging the ring nebula
and that is all that is of interest, then 0.5 arc-seconds per pixel times 1.2
arcminutes equals 144 pixels and any more are just wasted....

Answer #2. If you are imaging large portions of the sky or an object and the
sky around it, then the ability to have a large number of pixels or many lines
of resolution is an advantage. Slapping a 28 mm photographic lens on an ST-237
will yield a field of view of something like 7.5 degrees x 9.5 degrees but each
pixel will have a value of almost an entire arcminute.

In this case the number of pixels is very important.

Personally I have both a film camera and a CCD camera. I am too lazy to use em
much, using a CCD is a gagetters delight and film cost money and the instant
gratification factor is not there.

Well put. I didn't think a sock puppet had the capacity to distill
and convey to others such advanced concepts.

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

On 10 Feb 2004 22:52:19 GMT, (Jon Isaacs) wrote:

I forgot the grin...

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

On 10 Feb 2004 22:52:19 GMT, (Jon Isaacs) wrote:

I forgot the grin...

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

Wayne Hoffman wrote (of Jon Isaacs):
Well put. I didn't think a sock puppet had the capacity to distill
and convey to others such advanced concepts.

Well, reductio ad absurdum...

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt