Confused from Slough

OK so I've got the web cam; I've got various adapters; I've got a
scope, a barlow and a selection of eyepieces and as mentioned earlier
I've got a laptop on the way - though I might have to resort to moving
the PC downstairs and thoughts of SWMBO's face nah forget that idea
;-)
What now? software (s/w) - Toucam comes with its own software, I've
downloaded Registax and I've got the address of K3CCD
I'm aware of (though haven't delved too deep as yet) the QCUIAG site.
[See also below my sig]
And I also have a string of questions:
Firstly about the s/w -
As I understand things at the moment -
The Toucam s/w drives the camera and can capture still frames and AVIs
Registax is used to take said frames and/AVIs and stack and process
them.
K3CCD seems to do a combination of both - have I missed something or
is there only actually a need for K3CCD or does this do some things
better and some worse?

Next there is a lot of talk about modifying the cameras for long
exposure. I understand that a longer exposure allows more light to
collect on the CCD but how does a 30 second single exposure differ
from a stacked 30 second AVI? At the end of the day the CCD has
received 30 seconds of light but the single exposure is more
susceptible to tracking errors (e.g. the light could fall on 2xthe
pixels in the CCD if the tracking is off, whereas with AVI the entire
image will move over so "just" [1] needs aligning.
[1] I put this in inverts, as I do not know how difficult aligning an
image is. You see I'm new to all this, no seriously, I'm surprised
you had not guessed :-)

Finally (this time) - I'll take Andrea Tasselli as an example (more
excellent work btw, I'm always pleased to see what others are doing).
A lot of the more recent pictures have been taken with an 8" F6 scope
and a 5x powermate - what sort of magnification are these pictures?
Better still how is this worked out? E.g. If I have a 7.5mm EP and
2xBarlow visually I see 200x (750mm/7.5mmX2) if I put the web cam in
place what magnification would I be looking at?

Sorry to be a PITA but with all these images kicking about lately and
Pete's advice about Perseu what more is a man supposed to do? g
Thanks in advance
--
Simon
51:31N 0:38W
http://www.cookie-pool.co.uk/Pool1.htm
http://www.maidenhead.astronomical.s...care4free.net/
http://www.popastro.com/home.htm
Further info as mentioned in the post:
Registax - http://aberrator.astronomy.net/registax/index.html
K3CCD - http://www.pk3.host.sk/Astro/index.htm
QCUIAG - http://www.qcuiag.co.uk/

lid (ChrisH) wrote in message . ..
On 10 Sep 2003 04:18:02 -0700, (SimonP) wrote:

.....

Another tough one. Forget 'magnification', think about it as 'Image
Scale' - the number of pixels in your image per arc-second of sky
(actually it's usually the number of arc-seconds per pixel as there is
little point in imaging at a resolution beyond the resolving power of
your telescope - or finer than the local 'seeing' permits for that
matter). Now you can bring into the equation the focal length of the
telescope, and the size of pixels on your CCD chip (about 6.4 microns
on the ToUcam I think). snipped for brevity

The Toucam Pro sensor has 5.6x5.6 micron pixels.

Andrea T.

My Astronomy Pages at:
http://www.geocities.com/andreatax/index.htm

"andrea tasselli" wrote in message
om...

In reality, as posted by Chris (Heap) what counts is the pixel scale,
i.e. the number of arcseconds covered by a pixel. In my case this
value is 0.17/0.18 arcseconds per pixel. The powermate 5x does not
yield 5x for the toucam sensor is further away from the nominal design
point (which is inside the barrel) so for all accounts it behaves as a
6.7x barlow (if I did the math correctly).

Ah yes, I forgot the x5 powermate (unlike the others) is still affected by
the separation. I wish I could afford any of them ;-)
So your set up works out at f40 - neatly at the top end of what I suggested.
As I am usually working with a focal reducer, trying to squeeze DSO onto the
chip I am more used to thinking about FOV - no worry about that with the
planets!

BTW put us out of our misery and tell us if you have entered the Sky at
Night competition so the rest of us need not bother ;-)

Clear Skies
Robin

On Wed, 10 Sep 2003 19:05:27 +0100, lid
(ChrisH) wrote:

Anything that compresses that much is going to be 'lossy'. Personally
I keep the original AVIs (each 20sec is about 300frames and 130Mb) by
burning them onto DVD disks. At about 60p for 4.7Gb of storage it's
pretty cheap and you never know when someone might come out with a
really good algorithm for selecting the best frames (even Registax
isn't too hot on that score). So it's worth keeping the raw data - but
not as compressed video.

I suspect that the natural capture mode of digital cameras (MOV or
AVI) will be lossy compressed. A simple calculation for my captures
gives a file size of 113Mb raw for 320x240 frames (43s @ 12fps). It's
a pity that a format cannot be introduced which will compress each
frame without loss (most of our frames are black!).

Who's going to be the first kind soul to write such an astronomical
utility?
--
Pete
Homepage at http://www.pbl33.co.uk
CCD/digicam astronomy

On Wed, 10 Sep 2003 21:59:11 +0100, Pete Lawrence
wrote:

I suspect that the natural capture mode of digital cameras (MOV or
AVI) will be lossy compressed. A simple calculation for my captures
gives a file size of 113Mb raw for 320x240 frames (43s @ 12fps). It's
a pity that a format cannot be introduced which will compress each
frame without loss (most of our frames are black!).

Who's going to be the first kind soul to write such an astronomical
utility?

Which of course is what zipping the AVI is doing, more or less,
anyway.
--
Pete
Homepage at http://www.pbl33.co.uk
CCD/digicam astronomy

"Robin Leadbeater" wrote in message
...
Hi Michael,

In the ToUCam recording program, tell it to produce uncompressed AVI
without
sound. Preferably 320x240 (pixels binned 2x2) rather than 640x480; it's
smoother and the files are much easier for Registax to deal with.

Don't you throw away alot of detail if you bin planet images? All the best
results I have seen on Mars are using 640x480 and limiting frame speed to
5fps to minimise compression problems

That's what I *thought*... I think this evening I'll try recording with
K3CCD (which I found clumsy to use) rather than with the ToUCam recorder
(which is clumsy in another way), and see what I get.

Great Astrophotography book BTW, my copy is well thumbed :-)

Glad to be of service!

"andrea tasselli" wrote in message
om...
Pete Lawrence wrote in message
. ..
On Wed, 10 Sep 2003 10:14:53 -0400, "Michael A. Covington"
wrote:

"Pete Lawrence" wrote in message
.. .

Actually, I cannot Registax my Toucam output at the moment.

In the ToUCam recording program, tell it to produce uncompressed AVI
without
sound. Preferably 320x240 (pixels binned 2x2) rather than 640x480;
it's
smoother and the files are much easier for Registax to deal with.

No way. Registering at 640x480 is as smooth and easy as it is at
320x240. It's going to be slower though.

Hmmm. I have had Registax actually choke on my files... maybe I need to make
them smaller.

Capture with no recompression (it does compress a bit but not by much)
and use 352x288 format. If your program is like mine you'll get a
window of that size with the planet captured at full resolution. This
will allow for faster recording, less frame loss, less compression and
much smaller files.

Will try that. Thanks!

Thanks to several who gave useful advice. I've just confirmed (indoors,
using the ToUCam's lens) that the 352x288-pixel mode gives you an area in
the center of the field, at full resolution. Thus it's the best of both
worlds -- nice fine detail but the files aren't too big. Now to Mars...

--
Clear skies,

Michael Covington -- www.covingtoninnovations.com
Author, Astrophotography for the Amateur
and (new) How to Use a Computerized Telescope

(SimonP) wrote in message . com...
OK so I've got the web cam; I've got various adapters; I've got a
snip
And I also have a string of questions:
snip

Pete, Robin, Chris, Michael, Andrea and anyone else that responds
after this...
Many thanks for your replies, that has given me some food for thought.
I do intend to dig deeper for more info, I just know what a good
resource UKSA is. g
Creeping over - at some point I might write up this thread, plus other
stuff I find out, my experiences, etc. Obviously, I'll give credit
where it's due and hope you don't mind me quoting your responses.
Cheers
--
Simon
51:31N 0:38W
http://www.cookie-pool.co.uk/Pool1.htm
http://www.maidenhead.astronomical.s...care4free.net/
http://www.popastro.com/home.htm

"Robin Leadbeater" wrote in message ...
.....

BTW put us out of our misery and tell us if you have entered the Sky at
Night competition so the rest of us need not bother ;-)

Well, I might not be the best after all and you all might be so who knows...

Anyway I'm entering the fry...

Andrea T.

My Astronomy Pages at:
http://www.geocities.com/andreatax/index.htm