From: Talker on 30 Jul 2007 20:42
On Mon, 30 Jul 2007 23:04:13 +0100, John <batm(a)bile.com> wrote:
>> Yes, they are expensive. I bought my Starlight Express several
>>years ago, and I got it on sale for $1,800.(then you need a telescope
>>to mount it on). Keep in mind that they are black and white cameras,
>>since you can't take accurate color pictures through our atmosphere.
>>My camera is only a 1 megapixel model. The 6 mexgapixal cameras are
>>around $6,000....a little out of my budget.<g>
>> Oh, if you're wondering how they take color pictures with a black
>>and white camera, they use a color wheel to generate color. The only
>>true color pictures of outer space come from the Hubble telescope, or
>>any camera that was outside of our atmosphere when it took the
>For most amateur astronomers then I think 35mm or preferably medium
>format film is still going to be your best bet because you will be
>able to pick them up cheap, they won't drain batteries as you will be
>able to get a full manual control camera. $1800 is an awful lot to
>spend on a camera you would have to be into it in a big way.
>For people that can afford this type of digital camera with cooling
>then go for it, I would.
>But if it is a straight decision bang for buck wise between regular
>digital camera and film cameras, for the amateur astronomer you would
>still pick film every time. Less hassle and less expense, and less
>faffing around stacking your 1 minute exposures on top of each other
>in software. Incidentally, would you not be able to get a much better
>picture using medium format and scanning it with a film scanner than
>with 1mp digital?
>What telescope have you got mate? I've not got one yet but am hoping
>to get into this in the near future. Perhaps when some of my shares go
>up in price I will sell half of them, and get a decent telescope.
Hey John! Well, to be honest, a digital camera is still the way
to go, but you don't need to spend a lot of money. You can pickup one
of those webcam cameras for around $50-100, and mount that on the
telescope and get a decent picture.( I wish I had thought of that
before spending $1800<g>).
The reason I think digital is the way to go is because of what
you mention, stacking. There is decent software out there, some of it
free (registax comes to mind) that will automatically stack the pics
you want to stack, and remove those you don't want. You couldn't do
this with film cameras.
You probably already know this, but when you take long exposures,
say 20 minutes or more, you will invariably get heat inversions. When
heat rises from the surface of the planet at night, it looks like
those heat waves you see coming off of the surface of a road that look
wavey and distort the view behind it. When you have your shutter open
for a long time, these waves will distort the image in the picture.
By taking many short exposures....say 30 seconds each, then
stacking the best 200 exposures, you will eliminate any pictures that
had the distortion in them, and that results in a much sharper
picture. Of course, using a digital SLR means having to release the
shutter many times, whereas a dedicated astronomy camera has no
shutter. You take pictures by remotely turning the sensor on and off,
so you can control it with a computer.(same with a webcam).
My telescope is a 12 inch Meade LX200. It's the older, classic
18 volt version that doesn't have the builtin GPS. They came out with
the new version one month after I bought this one. I have it on
wheelie bars so that I can roll it out of my garage onto my driveway.
I also have it on a custom, black anodized Milburn Wedge. I have
Meade's electric focuser as well as a JMI electronic focuser which
adjusts in .001 inch increments, with digital readout.
I have a Meade dew shield, a set of Plossell lenses which was a
special offer that they included with the telescope, a mirror flop
eliminator kit, Starry Night software, various alignment tools,
including a 12 mm lighted reticular lens, and a laptop computer to run
everything, including the telescope's built-in computer.
It's a monster of a scope, and even though my garage door is 7
feet high, I have to lower the telescope to a perfectly level postion
to get it through the door.<g>
Sad to say I don't use it much since my workplace transferred me
from second shift (2pm-10:30pm) to 1st shift (6am-2:30pm). Second
shift was ideal to do some night viewing, since I was home by 11:30pm
and I could stay up all night. Now I have to be in bed by 8:30pm so
that I can get up at 3:30am.....not good for stargazing.