Taking night sky pictures with a common digital compact camera.

[TSPenguin]

I have acces to a Canon PowerShot A720 IS. A simple compact camera, yet a very good one.
I live in the center of a heavily light polluted city, you can easily spot from LEO in daytime and much much easier at night.
I don't have a telescope or a tripod.

Yet I am determined to make some nice sky shots.

Here are the most important camera datas:

• 
  1/2.5 " Type CCD
  8.0 million effective pixels
  5.8-34.8mm (35-210mm equiv)
  F2.8-4.8
  6x optical zoom
  15-1/2000 sec

I'll post an unedited picture taken under worst possible conditions soon.
In the meantime I am looking for some friendly community know how.
What programs can you recommend for noise reduction, combining different shots, letting a software identify the stars and possibly calculate date and location?

 

[Tex]

Unfortionately astrophotography is one of the hardest things to do when it comes to objects to photograph. The problem rises that the objects you are shooting are so faint and in a light polluted sky this only makes the problem worse. I'm not sure how much your knowledge is with photography, but taking really good shots of the night sky requires long exposure times (leaving the shutter open), often several nights consisting of several hours of exposure each night just to photograph one object, especially in deep space. A motorized tripod with a decent telescope on an equatorial mount is a must have for this. The site I linked below is by a guy out in New Mexico who takes some incredable shots. Check out the intro movie, it's very inspiring. But to get shots like that with the kind of equipment he is using can get very costly, easily over $10,000 just in equipment. Don't get me wrong, you can still try, but you may find that the results are rather disapointing without the right equipment.

http://www.darkatmospheres.com/slideshow/

 

[TSPenguin]

Thanks for the information and the link.
Actualy I am kinda sophisticated when it comes to making pictures. So I know all about chip noise, exposure time, focal length and such. 15 seconds is a joke, but it is enough for this chip to get stars magnitudes higher than visible with the naked eye.

I made a first attempt last night and from what I can see on the screen of the camera there seems to be much potential in simply documenting the sky. Catching nebulas and other faint objects will of course not work... well... maybe it might, just a little. Taking dozens of 15s exposures. combining them afterwards and calculate the rotation and noise out might give a faint blob for some nebula...

I actualy was thinking of combining my 4x scope, with a magnifying glass and stripping the IR filter of my webcam. Getting an unlimited exposure device. There are even some guides out there on how to build such a system including the cooling of the chip via peltier elelemt. Unfortunately the filter is not a foil in my model so that project died...

All I need to do is get the cam to darker place. I might yield results close to this APOD.

 

[agentgonzo]

With Canon cameras (including yours) that have DiGiC 1 or 2, you can download and run the Canon Hackers Development Kit (CHDK - http://chdk.wikia.com/). This allows you to override settings on the camera, like shutter speed. With my S3 IS, I can get up to 60s exposures which is a LOT better for astrophotography. You can also run custom scripts, so you can set it up to take an exposure every minute indefinitely (until the memory card runs out of space). It's a most excellent enhancement and doesn't void your warranty or re-flash the camera or anything dangerous. You choose to run it every time you turn the camera on, so there's no worries about it messing anything up. You turn the camera off, and it's gone.

 

[TSPenguin]

I already have CHDK on the cam for a long time.
Unfortunately it is a DIGIC III model and the property cases are a little different. There is a completely functional version that runs the cam very well.
After getting to know the language with modifiying and making HDR scripts and therelike, I tried to adjust the exposure time via hard setting the appropiate property case. Didn't work

 

[Woo482]

good luck with taking some pic's

 

[jholley309]

TSP, I'd love to see some of the pics as soon as you get some processed. What software are you using for registration and stacking? I've had pretty good luck with Registax in the past (plus it's free), but since I got a "real" CCD camera for the 'scope I've been using MaximDL Essentials a lot more. It's a scaled-down version of the full MaximDL (what a monster!) with drivers specific to the Orion Starshoot camera.

Cheers!

Jim

 

[TSPenguin]

Good news for me! Bad news for the impatient.

I now can squeeze 64 seconds of exposure time out of the baby. Maybe with a different CHDK build even more.
Also I can now extend the ISO span from 40 to 2500.
My approach was too complicated, it did work from within the CHDK menu all along.
Of course there will be a lot of testing needed.

Bad news: The weather has been (and will be) a little too ****ty for taking some pics. And due to an accident my previous pictures I meant to post here got deleted. (accident, as in "you wanted to keep the black pictures?!?")

As for software, I will try a lot. Main reason I opened this thread was actualy to get advise on which ones to use. Thanks jholley309, I'll take a look at it.

If I get around to it, I'll do some testings with ultra low exposure and flash times. If I am lucky, I could get to estimated 1/60.000s. In any case it will make for some nice pictures of drops or lighting lighters.

Happy CHDKing

 

[tblaxland]

I found this tutorial on Registax that shows what it is capable of:
http://www.russsscope.net/staxtutorial.htm

 

[TSPenguin]

A very good tutorial, I like it a lot.
Great find tblaxland *secret handshake*

 

[SiberianTiger]

An astro observation advice, please?

People,

I've got two things: a Kodak Z730 camera and A 110 mm Newtonian Reflector on an equatorial mount. One thing doesn't fit the other. And I am going to be at the August 1st full solar eclipse site. What good observations and pictures I can make with these?

 

[agentgonzo]

If it's a small compact camera, you can just hold the camera up to the eyepiece of the telescope and take a photo. There have been some good pics done that way. You can also Heath-Robinson up an adapter out of cardboard, elastic bands and the like to hold it next to the eyepiece so it's easier to use.

 

[SiberianTiger]

If it's a small compact camera, you can just hold the camera up to the eyepiece of the telescope and take a photo. There have been some good pics done that way. You can also Heath-Robinson up an adapter out of cardboard, elastic bands and the like to hold it next to the eyepiece so it's easier to use.

The latter sounds fine, but this is a camera that hasn't got a controlled focal distance. However, it can be set to take pics at infinity. Does that help? I assume from your words that such an adapter can be made out of materials found at home. Can I see a drawing of such a thing?

Also, the object to observe is the solar eclipse. A difficult thing to catch - and I certainly don't want to burn the camera up. Any ideas on how to get a shot of an eclipse?

 

[agentgonzo]

I found something about it ages ago, but can't remember where it was. Basically you want something similar to this:
http://www.telescopesales.co.uk/digiscoping.htm
Google for homebrew digiscope adapter. You'll get a load of sites (mainly about bird watching).

You're right, you don't want to burn out your camera (or retina). OBSERVING THE SUN THROUGH A TELESCOPE CAN BLIND YOU INSTANTLY! Be very careful. You'll want some solar filters for your telescope. I've never done it, so don't feel qualified to offer advice for solar observing. There are plenty on this board who are though. I'll hand you over to them.

Edit. Sorry, I just realised that I was posting to the orbiter forum, rather than the astronomy group. Go over here http://www.popastro.com/phpBB2/viewforum.php?f=1. There's loads of friendly people who will be more than happy to help you out.

 

[TSPenguin]

Nice Hijack
But it fits enough to be in here.

Assuming you get a serious filter designed for solar eclipse observations, you will be able to make some very nice pictures. If you don't get that filter, you WILL destroy your camera. Under no circumstances use any homebrewn solutions!(!!!)

As agentgonzo said, check the sites of those bird photographers. They lifted fitting common cameras to telescopes to a true art form!

Happy McGyvering

 

[SiberianTiger]

Assuming you get a serious filter designed for solar eclipse observations, you will be able to make some very nice pictures. If you don't get that filter, you WILL destroy your camera. Under no circumstances use any homebrewn solutions!(!!!)

Hmm, what kind of filter that might be?

 

[Quick_Nick]

Hmm, what kind of filter that might be?

Solar Filter
Just search for that and you'll surely find the telescope filters that you're looking for.

 

[TSPenguin]

Does anyone know of a hosting service that will take these large files?
They can be as large as 4 MB and 3264x2448. I only encountered services that either resize them or refuses them because of filesize...

 

[tl8]

mediafire.com will host any file for download.

 

[TSPenguin]

mediafire.com will host any file for download.

AFAIK, mediafire, rapidshare, zshare, badongo etc. etc. don't allow for direct file linking. I would prefer to do that, that is why I asked for a image hoster.