Total Beginner in need of HELP !
Posted 01 January 2013 - 07:49 PM
I have some questions and need some advice on a project I offered to help my daughter with. For her 7th grade science fair project she decided on light pollution as her subject. Our idea is to take one of our telescopes to multiple areas with skies that have different light pollution. On nights with no moon interference, we plan to center telescope on Polaris and take a picture using identical camera settings, and eye piece at each location.
By doing so we hope to capture a view of how many stars are visible in the same field of view, with light pollution being the only variable.
Now, I need to connect my Canon G10 camera to the focuser of one of our scopes. I have nothing at all in this area.. no equipment, no experience. Hoping to do this the easiest, most economical way possible. I have seen some adapters at a CNC website, as well as on eBay. I thought coming here I could get some great advice before I spend any money.. (trying something new for 2013)
Thank you in advance for any advice, thoughts, links....
Happy New Year !
Posted 01 January 2013 - 08:09 PM
Posted 01 January 2013 - 09:11 PM
When reducing data, however, make sure to remember sky transparency and seeing are also going to be significant factors in how many stars are recorded. Poor transparency can be mistaken for light pollution and poor seeing can blur images of faint stars over a sufficient number of pixels so as to make the stars invisible to the sensor. Ideally, you'd want to estimate both these factors when taking each exposure and somehow factor them in when reducing the data.
Posted 01 January 2013 - 10:56 PM
Posted 01 January 2013 - 11:57 PM
Set you camera on a tripod pointed at Polaris with the camera settings the same every night use either a cable release, remote release or the camera timer to trip the shutter. Put the camera on manual with roughly a 30 second exposure and ISO 1600.
An even better way would be to get a Sky Quality Meter and take readings at each site.
Posted 05 January 2013 - 04:54 PM
Any other hints or tips? Seems grainy or something ? Thanks for the help so far and any other recommendations you could offer up.
Posted 05 January 2013 - 06:09 PM
Posted 06 January 2013 - 12:50 AM
The compression required to post images here makes it difficult to provide a good assessment. Create an account at astrobin and post full size images.
You camera has multiple ways to save the image to the memory card. Use the "RAW" mode. RAW is an uncompressed image and has a lot more detail than you can see visually. When you save your images in one of the default modes they are saved in JPEG. In the JPEG format the camera compresses the image and a lot of the detail is lost.
Posted 08 January 2013 - 02:54 PM
I've seen this effect when imaging from home, a club observatory, and a truly dark site. For all but the dark site, maximum imaging time is limited by sky brightness, which shows up as the average pixel value in an image.
Posted 08 January 2013 - 08:26 PM
It's gonna be grainy/noisy, that's just the way it is, point n shoot cameras have a lot of digital noise, but, like I said, take 40 of them, put them in Deep Sky Stacker, then use software like Photoshop, Gimp, Fitswork, etc to process the picture and you will reduce the noise exponetially.
But there is a steep learning curve to all that, don't know if you want to spend that much energy on this project. You COULD just use a noise filter on your single exposures to make it a "little" better and go with that. Lower ISO will have less noise but show less stars n stuff.
Careful, your kid's project may lead you to the "dark side" of astro imaging.