Taking night sky pictures with a common digital compact camera.

[TSPenguin]

First Moon Result

The light pollution is kinda pissing me off, so I went on to work with Luna.

This is my very first try with Registax and I am impressed! I had made 115 free hand shots of the moon within a minute.
The final stack for processing was 25 images.

Make sure to view the pictures at fullscreen to be able to make out the subtle difference.
Notice the halo around the moon? That are the processed JPEG artifacts

moonres.png is the result
moonbase.jpg is the base image used for aligning and quality decision.

 

[spcefrk]

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.

I've been happy with Flickr. It allows people to download full size pictures (which became a must when DBF students came knocking at my facebook page for pictures of their planes)

 

[TSPenguin]

I've been happy with Flickr. It allows people to download full size pictures (which became a must when DBF students came knocking at my facebook page for pictures of their planes)

Last time I checked Flickr had an absolutely laughable upload limit per month.
I might be confusing it but it didn't it also have a maximum filesize?

 

[Phrozin]

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?

well, many things come to mind here. First off, are you going to be imaging with a laptop (I use my Canon 350D moddified with a laptop), or will you be doing your imaging the old fashioned way of shot and pray?

Second, what kind of mount are you going to use? I assume you are wanting to do widefield because of no scope, so I would suggest a barndoor (unless you have a motorised tripod around).

Third, is the camera digital zoom, or mechanical zoom?

as for software, I would suggest you give Deepsky Stacker a try. It doesn't do any capturing (at least the last version I used didn't), but it's sweet and easy to use, and it does a jam up job of stacking. Here is an image I used DS on to stack. If I remember correctly it was 150 15 second images. Click on image for broadband full size. (Edit* went back and looked at one of the orginial RAW files. it was about 150 45seconds images)



personally, I think if you want to get into this, then you should run down to a local camera shop buy a used Canon A-1 (or Olympus OM-1 with correct lenses), some FD telephoto lenses, and some Fuji 400F Provia film. I was just down at the camera store today (getting film before the hurricane. Yay me!) and saw an A-1 for 30$. so should cost alot less then a new digital setup. Don't forget to get a hartmann mask to help you focus if your lens is big enough to use one. Hartmann mask generator.

If you use Photoshop, then there are some great plug-ins out there for astronomy. Here's one.

If your camera supports it, make sure to use a remote trigger. Some remote triggers have timers, and these are the best in my opinion. Some homemade versions can even hold the shutter open longer then normal, but I believe this requires seriously moddifing you camera. Don't let that scare you though. I was scared about removing the IR filter from my 350D, but i decided to try to the day I bought it and it took all of 30 minutes, and worked like a charm.

If you are near street lights, you can purchase filters to block the wavelengths from them, or buy a laser pointer (I use green) and aim it at the light sensor on top of the light to shut it off. (that's what I do when I don't want to mess with a filter wheel).

If you need more let me know.

PS. how much space are you looking to get for photo hosting?

Later,
Joe

 

[TSPenguin]

Thank you for your interest.
This is actualy about making due with what I have access to. If it was my camera, or even one dedicated to astrophotography, the IR filter would be long gone.
So this is more of a guerilla astrophotography attempt

Unfortunately, there is currently no way to image directly to a computer. I can use one as remote trigger though (or built one myself). But I usaly don't do that. I use the internal camera delay which I can freely choose. So it really is find a stable spot, put camera there and then shoot and pray.
Also I don't have a mount and won't purchase one, I might build an equatorial mount one day.

Also note that this is not an SLR camera but a compact camera. With CHDK (firmware expansion) I can expose up to 64 seconds (which doesn't do me any good without a mount). This camera has 6x physical zoom (see original description). Although if fully zoomed the focal length ranges from F4.8 to F8. I can override some of that but I have not yet measured the effect, I am guessing it won't have any, as this seems to be a physical limitation of the lens stack.

Unfortunately there is a limited range of filters I could put in there. Any more would be home made (which does not need to be a bad thing). But this would go against the mantra of not buying things
I am interested in the laser solution, I've seen this method before and am wondering how well it would work against a general city glow. I am not shooting near lights, I rather have to fight the reflected and refracted light by particles, aerosols etc.
Would this method still do any good?

I'll take a look at your recommended software. I've been using registax for a series of moon shots before.

JPEGs comming out of the camera at the lowest compression are up to 5.something megabyte. So having a free hosting service that supports such filesizes would be great.

Last but not least,
to the forum!

 

[Ghostrider]

Try Photobucket.

 

[TSPenguin]

The free Photobucket offers only 1GB space and a maximum of 1024x768 resolution and 1 megabyte file size.
Even if you pay for a pro account you only have 5MB filesize and 2240x1680 resolution limits.
The camera produces JPEGs with 3264x2448 resolution, even a little more if I do raw pictures.