RTMC?

Haven't seen any reports about how it was this year? of did they all get
blown away by the winds?


--

The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
About my Car
http://www.bishopcarfund.netfirms.com/

Ah, I missed that. Don't webmeisters know us older guys and gals like larger
lettering?! ^_^

One thing I did think of though, and that I don't see, where it mentions if this
camera can autoguide. If not, then you'll need either a very expensive mount to
limit PEC, or get a separate autoguider to correct the tracking errors. Either
way, for good deep sky images, this is going to be a possible issue, especially
if you go deeper and deeper.

On the other hand, the camera's 5 frames per second mode might be useful for
planet and lunar imaging for use with stacking software to sharpen the images,
but the 23 frames limit means you'll have to press the shutter often to get the
couple of hundred images or so to successfully stack with good results.

I wish they'd post the individual pixel sizes. Given the CMOS size, the number
of pixels, and allowing for spacing between the pixels (pixel width 60% of
available space) I figure pixels of 4 um horizontal. Anyone got the specs on
this?

I still look at the specs for this camera, and see a camera that's designed for
dual roles, a general purpose camera and one that can be used for deep sky. But
this is a compromise, and I don't see this as really affecting the sales of
dedicated CCD cameras for Astronomy, which can autoguide, and have better
sensitivity and signal to noise ratios.

--- Dave

--
----------------------------------------------------------------------
Pinprick holes in a colorless sky
Let inspired figures of light pass by
The Mighty Light of ten thousand suns
Challenges infinity, and is soon gone




"Rob Johnson" wrote in message
...
[article below posted to the newsgroups listed in the header]

In article w_zne.12224$Vm4.7045@trnddc01,
"David Nakamoto" wrote:
I have to agree, based on the specs and comparing them to cooled cameras such
as the SBIG or Starlight Xpress line. The shutter speed is limited to 30 secs
max. Sure, stacking can extend the range, but the signal to noise ratio is not
going to be the same as for single exposure of the same sum duration. The use
of a CMOS chip is know to introduce noise that a CCD chip would not. Of
course, CMOS is getting better all the time, but it is an issue that needs to
be addressed through independent testing.

I did a search for the sequence "cool" and didn't get any matches, inferring
that this CMOS isn't cooled down.

Overall, I doubt that for the dedicated group of imagers who are seriously
into it that this camera is going to significantly affect their choices, but
it will appeal to those who are still "just getting started" and wish a
possible dual use camera. The market's such a niche one anyways that there's
not a whole lot of commercial traffic going on there compared to everyday DSLR
sales.

"Olga" wrote in message ...
Ridiculous -


RichA wrote:

http://www.dpreview.com/news/0506/05...20da.asp#press

Boy SBIG, that's gotta hurt!


The camera controlled shutter speed is limited to 30 secs, but using the
bulb setting, I have seen a simply marvelous 40 minute exposure of the
Horsehead using a Canon Digital Rebel in raw mode. I am trying to get a
copy and permission to post it.

Rob Johnson
take out the trash before replying

David Nakamoto wrote:
Ah, I missed that. Don't webmeisters know us older guys and gals like larger
lettering?! ^_^

One thing I did think of though, and that I don't see, where it mentions if this
camera can autoguide. If not, then you'll need either a very expensive mount to
limit PEC, or get a separate autoguider to correct the tracking errors. Either
way, for good deep sky images, this is going to be a possible issue, especially
if you go deeper and deeper.

On the other hand, the camera's 5 frames per second mode might be useful for
planet and lunar imaging for use with stacking software to sharpen the images,
but the 23 frames limit means you'll have to press the shutter often to get the
couple of hundred images or so to successfully stack with good results.

I wish they'd post the individual pixel sizes. Given the CMOS size, the number
of pixels, and allowing for spacing between the pixels (pixel width 60% of
available space) I figure pixels of 4 um horizontal. Anyone got the specs on
this?

I still look at the specs for this camera, and see a camera that's designed for
dual roles, a general purpose camera and one that can be used for deep sky. But
this is a compromise, and I don't see this as really affecting the sales of
dedicated CCD cameras for Astronomy, which can autoguide, and have better
sensitivity and signal to noise ratios.


Hi David:

You wouldn't be able to autoguide with it and image at the same time.
Autoguiders, in the form of the Meade DSI, the LPI, and modified
webcams are, however, cheap and plentiful.

OTOH, I rather doubt that the 5 frames per second frame rate would be
very effective for the planets. It's just hard to beat a webcam for
that, with its tiny pixels and .avi files.

Peace,
Rod Mollise
Author of _Choosing and Using a Schmidt Cassegrain Telescope_
Like SCTs and MCTs?
Check-out sct-user, the mailing list for CAT fanciers!
Goto http://members.aol.com/RMOLLISE/index.html

Which brings me to the question of how large each pixel is. Neither the Canon
site, nor any page listing the Creative Pro eX I use, tell you what the pixel
size really is. You can get some idea of the grid size from the size of the
imaging area and the number of pixels, but the actual pixel imaging area isn't
the simple division of these numbers because there has to be some silly-con
between the pixels to isolate the charge buckets and prevent charge spillover.

Anyone know of websites giving the actual pixel sizes?

Asking,
--- Dave

--
----------------------------------------------------------------------
Pinprick holes in a colorless sky
Let inspired figures of light pass by
The Mighty Light of ten thousand suns
Challenges infinity, and is soon gone




"RMOLLISE" wrote in message
ups.com...


David Nakamoto wrote:
Ah, I missed that. Don't webmeisters know us older guys and gals like larger
lettering?! ^_^

One thing I did think of though, and that I don't see, where it mentions if
this
camera can autoguide. If not, then you'll need either a very expensive mount
to
limit PEC, or get a separate autoguider to correct the tracking errors.
Either
way, for good deep sky images, this is going to be a possible issue,
especially
if you go deeper and deeper.

On the other hand, the camera's 5 frames per second mode might be useful for
planet and lunar imaging for use with stacking software to sharpen the
images,
but the 23 frames limit means you'll have to press the shutter often to get
the
couple of hundred images or so to successfully stack with good results.

I wish they'd post the individual pixel sizes. Given the CMOS size, the
number
of pixels, and allowing for spacing between the pixels (pixel width 60% of
available space) I figure pixels of 4 um horizontal. Anyone got the specs on
this?

I still look at the specs for this camera, and see a camera that's designed
for
dual roles, a general purpose camera and one that can be used for deep sky.
But
this is a compromise, and I don't see this as really affecting the sales of
dedicated CCD cameras for Astronomy, which can autoguide, and have better
sensitivity and signal to noise ratios.


Hi David:

You wouldn't be able to autoguide with it and image at the same time.
Autoguiders, in the form of the Meade DSI, the LPI, and modified
webcams are, however, cheap and plentiful.

OTOH, I rather doubt that the 5 frames per second frame rate would be
very effective for the planets. It's just hard to beat a webcam for
that, with its tiny pixels and .avi files.

Peace,
Rod Mollise
Author of _Choosing and Using a Schmidt Cassegrain Telescope_
Like SCTs and MCTs?
Check-out sct-user, the mailing list for CAT fanciers!
Goto http://members.aol.com/RMOLLISE/index.html

On Thu, 02 Jun 2005 18:55:02 GMT, "David Nakamoto"
wrote:

Which brings me to the question of how large each pixel is. Neither the Canon
site, nor any page listing the Creative Pro eX I use, tell you what the pixel
size really is. You can get some idea of the grid size from the size of the
imaging area and the number of pixels, but the actual pixel imaging area isn't
the simple division of these numbers because there has to be some silly-con
between the pixels to isolate the charge buckets and prevent charge spillover.

Anyone know of websites giving the actual pixel sizes?

AFAIK you can genuinely divide the sensor area by the pixel count to get
pixel size (I know it works with the 10D and 20D). These sensors use
lenses over each pixel to achieve very close to a 100% fill factor.

In general, however, there is little need to know pixel size. What is
important is the pitch, and that can be calculated for any sensor from
the pixel dimensions and chip size.

_________________________________________________

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

"David Nakamoto" wrote in message
news:B%Gne.124$mb2.110@trnddc07...
Ah, I missed that. Don't webmeisters know us older guys and gals like
larger lettering?! ^_^

One thing I did think of though, and that I don't see, where it mentions
if this camera can autoguide. If not, then you'll need either a very
expensive mount to limit PEC, or get a separate autoguider to correct
the tracking errors. Either way, for good deep sky images, this is
going to be a possible issue, especially if you go deeper and deeper.
It cannot autoguide. You need a seperate chip, or SLI type readout (and
this use is patented).
However the need for autoguiding is dependant on focal length. You can run
a DSLR, unguided on a reasonable mount, with say a 500mm focal length, and
good polar alignment, and take images for 20minutes+, with no problems.
Alternatively just guide with the scope you have it piggybacked on...

On the other hand, the camera's 5 frames per second mode might be useful
for planet and lunar imaging for use with stacking software to sharpen
the images, but the 23 frames limit means you'll have to press the
shutter often to get the couple of hundred images or so to successfully
stack with good results.

I wish they'd post the individual pixel sizes. Given the CMOS size, the
number of pixels, and allowing for spacing between the pixels (pixel
width 60% of available space) I figure pixels of 4 um horizontal.
Anyone got the specs on this?
Given it has microlenses, there is no effective 'gap' between the pixels.
The lenses serve to collect the light and feed it into the slightly
smaller real pixels below. This is the same system used on most current
colour cameras.

I still look at the specs for this camera, and see a camera that's
designed for dual roles, a general purpose camera and one that can be
used for deep sky. But this is a compromise, and I don't see this as
really affecting the sales of dedicated CCD cameras for Astronomy, which
can autoguide, and have better sensitivity and signal to noise ratios.
The key 'shortfalls' compared to existing colour astronomical cameras, are
the lack of cooling, and the reduced number of bits in the ADC.
It takes the existing Canon cameras, which are already great for some
types of astronomical imaging, and improves on the red response in
particular, which was normally rather limited by the inbuilt filters, but
it is only a small movement forward, not a 'great leap'.

Best Wishes

Strange goings on, under this message and attached to it are a bunch of
messages about a camera and stacking images. Strange.


"Starlord" wrote in message
...
Haven't seen any reports about how it was this year? of did they all get
blown away by the winds?


--

The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
About my Car
http://www.bishopcarfund.netfirms.com/

Strange goings on, under this message and attached to it are a bunch of
messages about a camera and stacking images. Strange.


"Starlord" wrote in message
...
Haven't seen any reports about how it was this year? of did they all get
blown away by the winds?


--

The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
About my Car
http://www.bishopcarfund.netfirms.com/

"Chris L Peterson" wrote in message
...

In general, however, there is little need to know pixel size. What is
important is the pitch, and that can be calculated for any sensor from
the pixel dimensions and chip size.

Where can I get more information on pixel size, array size, and the
significance of these compared to the focal length of the objective?

I'm not clear if-and-or-why a large sensor with small pixels is worse for
boosting image scale through long focal lengths, than a small sensor with
larger pixels.......

Seems to me that more smaller is always better.....

-Stephen

I attended RTMC on Sunday and it was a ghost town!! Meade, Celestron, and 90
percent of the vendors had packed up and left either Saturday evening or
Sunday morning. It is really too bad that everyone jams on Sunday morning. I
did attend a few good seminars that made the trip worthwhile. The weather
was perfect. I do not know about the seeing conditions as I did not stay
overnight.

-mij


"Starlord" wrote in message
...
Haven't seen any reports about how it was this year? of did they all get
blown away by the winds?


--

The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
About my Car
http://www.bishopcarfund.netfirms.com/