«

Actually, noise (in the form of hot pixels) is a problem at longer exposure
settings. There are several programs in the public domain which can be used
to extract the hot pixels (by taking a second "black" frame immediately
after while the same hot pixels are still glowing). One such program is
called (funnily enough) Blackframe. You can get it from www.mediachance.com.
The 10D is probably better as it uses a "cooler" CMOS sensor rather than a
10D.
In any case, Mars, as the brightest star in the evening sky will not take
anything like 15 seconds to capture, even at high magnification through a
telescope.

Lionel <> wrote in message news:bgsjsb$qem$...
> On Wed, 6 Aug 2003 00:08:49 +0000 (UTC), in
> <bgpguh$2jo$>, "Luke" <>
> said:
>
> >From what I understand as far as the average consumer goes you will be
able
> >to do much better with film than with any normal digital camera.
> >
> >To get a good exposure you need very slow shutter speeds and you will
> >generally end up with too much noise in a digital camera.
>
> This is incorrect. You're confusing long exposures with high ISO
> settings. I've done many long (15 seconds & up) exposures on my 10D &
> S30 at ISO 100 with no more noise than I'd see with a 'normal' shutter
> speed.
>
> --
> W
> . | ,. w , "Some people are alive only because
> \|/ \|/ it is illegal to kill them." Perna condita delenda est
> ---^----^---------------------------------------------------------------

>
> This is incorrect. You're confusing long exposures with high ISO
> settings. I've done many long (15 seconds & up) exposures on my 10D &
> S30 at ISO 100 with no more noise than I'd see with a 'normal' shutter
> speed.
>

Lionel you're getting the wrong end of the stick, I'm talking exposures of
several minutes and longer. This kind of work is totaly alien to the would
of comsumer photography. That kind of exposure is only possible with a ccd
if it is cryogenically cooled but it is possible with normal film if you
have the right sort of camera.

As DL pointed out earlier the only way you can compete using a digital
camera is to take lots of individual exposures and average the results.
However this doesn't help you if the signal level is so low to start with
that it is down in the amplifier noise.

Luke

Luke wrote:

> >
> > This is incorrect. You're confusing long exposures with high ISO
> > settings. I've done many long (15 seconds & up) exposures on my 10D &
> > S30 at ISO 100 with no more noise than I'd see with a 'normal' shutter
> > speed.
> >
>
> Lionel you're getting the wrong end of the stick, I'm talking exposures of
> several minutes and longer. This kind of work is totaly alien to the would
> of comsumer photography. That kind of exposure is only possible with a ccd
> if it is cryogenically cooled but it is possible with normal film if you
> have the right sort of camera.
>
> As DL pointed out earlier the only way you can compete using a digital
> camera is to take lots of individual exposures and average the results.
> However this doesn't help you if the signal level is so low to start with
> that it is down in the amplifier noise.
>

Here are some examples of what the 10D can do in astrophotography.
It is revolutionary:

http://www.hostultra.com/~ghonis/050503D10.html

For 1Ds, D60, check these astrophotos out:

http://www.pbase.com/jayseejay/messier

http://panther-observatory.com/deepsky.htm

http://panther-observatory.com (go to gallery then 2003)

Roger

Lionel wrote:

> On Wed, 06 Aug 2003 18:15:31 +0100, in
> <. uk>, Kulvinder Singh
> Matharu <real-address-in-> said:
>
>>Took a hand-held photo of the Moon using my 28-135mm IS zoom lens a
>>couple of months go...
>>
>>http://www.metalvortex.com/photo_art/moon/index.htm
>>
>>I rather like to think that it came out OK!
>
> Nice!
> I'm very impressed. I'll have to try it myself with my 100-300mm 'L'
> lens.
>

Here's a shot taken last night with the 10D and the 100-400 f/4.5-5.6L IS (at
400mm)

http://members.shaw.ca/jamestownsend/moon400.jpg

Having said the below, I tried photographing Mars last night
with a telephoto lens and tripod to see just what might
be done. So here is Mars with a Canon 10D, 500mm and 1.4x
teleconverter:

http://www.clarkvision.com/astro/mars2003.html

Here is a moon, jupiter and saturn example I did with a D60:
http://clarkvision.com/astro/moon_saturn_jupiter.d60.v1

Note the Mars image has been enlarged 3x compared to the
moon, jupiter and saturn image.

Roger Clark

"Roger N. Clark" wrote:

> To photograph distance planets you need a long
> focal length. Mars will be only about 25 arc-seconds
> in apparent size, so you need a large aperture telescope
> so that it has a small diffraction spot size, and
> a long focal length to spread the detail across
> your pixels.
>
> The 10D has about 7-micron pixel spacing, so at
> 700 mm focal length you would get:
> arctan(0.007/700) = 0.00057 deg = 2.1 arc-seconds per
> pixel. So on the 10D that gives about 12 pixels.
> You really need at least 4 pixels per diffraction
> spot size (because of the RGBG pixels).
> On a 10-inch telescope the diffraction spot size is
> about 0.5 arc-second, so 0.1 arc-second per pixel
> is needed. This is 21 times longer focal length
> than 700mm = 14700 mm. On a 10-inch telescope
> that is f/58! Next: you need a really stable
> atmosphere or turbulence will wipe you out.
> Also a very stable mount that tracks compensating
> for the Earth's rotation. The Earth rotates at a
> rate of 15 arc-seconds/time-second on the celestial
> equator. Focus will be
> critical too. Thus, it is very difficult.
> Anything above f/20 or so should be pretty good
> (5000 mm focal length).
>
> That said, the 10D is superb. If you can pull it
> together, take lots images trying for the most
> stable air (which may last only a fraction of a second
> every minute or so).
>
> Good luck.
>
> Roger Clark
> Photography, digital info, astrophotos:
> http://www.clarkvision.com

Roger, those photos are simply amazing ! Thanks for sharing.
james

"Roger N. Clark" <> wrote in message
news:...
> Having said the below, I tried photographing Mars last night
> with a telephoto lens and tripod to see just what might
> be done. So here is Mars with a Canon 10D, 500mm and 1.4x
> teleconverter:
>
> http://www.clarkvision.com/astro/mars2003.html
>
> Here is a moon, jupiter and saturn example I did with a D60:
> http://clarkvision.com/astro/moon_saturn_jupiter.d60.v1
>
> Note the Mars image has been enlarged 3x compared to the
> moon, jupiter and saturn image.
>
> Roger Clark
>
> "Roger N. Clark" wrote:
>
> > To photograph distance planets you need a long
> > focal length. Mars will be only about 25 arc-seconds
> > in apparent size, so you need a large aperture telescope
> > so that it has a small diffraction spot size, and
> > a long focal length to spread the detail across
> > your pixels.
> >
> > The 10D has about 7-micron pixel spacing, so at
> > 700 mm focal length you would get:
> > arctan(0.007/700) = 0.00057 deg = 2.1 arc-seconds per
> > pixel. So on the 10D that gives about 12 pixels.
> > You really need at least 4 pixels per diffraction
> > spot size (because of the RGBG pixels).
> > On a 10-inch telescope the diffraction spot size is
> > about 0.5 arc-second, so 0.1 arc-second per pixel
> > is needed. This is 21 times longer focal length
> > than 700mm = 14700 mm. On a 10-inch telescope
> > that is f/58! Next: you need a really stable
> > atmosphere or turbulence will wipe you out.
> > Also a very stable mount that tracks compensating
> > for the Earth's rotation. The Earth rotates at a
> > rate of 15 arc-seconds/time-second on the celestial
> > equator. Focus will be
> > critical too. Thus, it is very difficult.
> > Anything above f/20 or so should be pretty good
> > (5000 mm focal length).
> >
> > That said, the 10D is superb. If you can pull it
> > together, take lots images trying for the most
> > stable air (which may last only a fraction of a second
> > every minute or so).
> >
> > Good luck.
> >
> > Roger Clark
> > Photography, digital info, astrophotos:
> > http://www.clarkvision.com
>
>

On Thu, 07 Aug 2003 07:50:01 -0600, "Roger N. Clark"
<> wrote:

[snip]
>http://www.hostultra.com/~ghonis/050503D10.html
>
>For 1Ds, D60, check these astrophotos out:

Wow, those are pretty good!

--
Kulvinder Singh Matharu
Contact details : http://www.metalvortex.com/form/index.htm
Website : http://www.metalvortex.com/

"It ain't Coca Cola, it's rice" - The Clash

>
> Here are some examples of what the 10D can do in astrophotography.
> It is revolutionary:
>
> http://www.hostultra.com/~ghonis/050503D10.html
>
>

Like I said, using multiple stacked exposures.

Luke

On Thu, 07 Aug 2003 08:18:43 -0600, "Roger N. Clark"
<> wrote:

>Having said the below, I tried photographing Mars last night
>with a telephoto lens and tripod to see just what might
>be done. So here is Mars with a Canon 10D, 500mm and 1.4x
>teleconverter:
>
>http://www.clarkvision.com/astro/mars2003.html

Interesting...1/45 sec exposure. How many stops do you lose with the
teleconverter?

--
Kulvinder Singh Matharu
Contact details : http://www.metalvortex.com/form/index.htm
Website : http://www.metalvortex.com/

"It ain't Coca Cola, it's rice" - The Clash

On Wed, 06 Aug 2003 13:18:51 -0400, Charlie D
<> wrote:

[snip]
>I think so too. I like the clouds. We usually see "just the moon" shots.

I thought that I'd post both types!

Thanks for the comments. Mostly luck to get the clouds like that.

--
Kulvinder Singh Matharu
Contact details : http://www.metalvortex.com/form/index.htm
Website : http://www.metalvortex.com/

"It ain't Coca Cola, it's rice" - The Clash