06-12-2013 10:22 AM
Many astrophotography forums are on the web and Canon is the most popular brand DSLR for that use, I may get some argument on that but it is. Cloudy Nights is a very good general Astronomy site with separate forums on astrophotography. I think it would be a good place to start. Many amateur astrophotographers use a program called Backyard EOS ( this is a commercial program about $30. and has a 30 day free trial) to capture both Deep space and planetary objects. Backyard EOS is only for use with Canon DSLRs and they have an active Yahoo group for support. I use the program and have no other connection with the company. I'm assuming that you might be new to the hobby , so if you want advise on specifics I maybe able to help sort out some basics for you such as what type of telescope to use and what you might need for a mount. You might just want to take wide images of the night sky I've seen many wonderful examples of this style of astrophotography. There are many programs needed for DSLR photography and many of the best are free developed by astrophotographers for atstrophotographers all are discussed in great detail on Cloudy Nights. I have a few astro images on my photo album here. If you give me some idea of what type of AP you are interested in I may be able to help you.
06-17-2013 03:41 PM
Thanks for the thorough response and the useful info. Being a newby at DSLR AP, this will be extremely helpful. Sorry I was late in the response. I was participating in this year's Grand Canyon Star Party for the past 4 days and otherwise engaged. Talk about "Dark Skies", I think the NPS - Grand Canyon, has a corner on the market. Thanks again. I'll be in touch.
06-17-2013 09:01 PM
One forum I'd recommend with lots of enthusiasts (including Canon owners) is at astronomy.com. Also, for a free program that is an indespensible tool with astrophotography I can't recommend enough The Photographer's Ephemeris. Do a Google search and visit their web site, download the free software for your Windows machine or Mac, and be stunned and happy.
06-27-2013 10:43 AM
Grey gave you some great advice on forums and Backyard EOS is _very_ popular (only runs on Windows). I primarily use a Mac and have just started using a program called Nebulosity ... not exactly the same as Backyard EOS but it has many similarities. AP work is divided into your skill for "image capture" and then skills for "image processing". The guys who post amazing AP photos are good at both. I'm still working on "image capture".
I use a 60Da for astrophotography -- that's the only body Canon makes specific for AP. They made a 20Da years ago. Many people will use any Rebel body for astrophotography and these can either be unmodified or modified (warning: modification voids warranty -- not for the timid -- don't do this if you can't afford to break your camera and be ok with that.)
90% of all "normal" matter in the universe are hydrogen atoms. That means there are many nebula emitting light dominantly following the Ballmer series for Hydrogen emission lines. The strongest of these is the hydrogen alpha line at about 656nm (which shows up as a rich blood red color.) The visible spectrum for humans is roughly 400nm (violet) up to 700nm (red). Above 700nm is the near infrared. So the Ha line at 656 is solidly inside the visible spectrum. The "problem" with digital cameras is that they all need to filter out both UV and IR light because the sensor would be sensitive to those. Each unique wavelength focuses at a slightly different distance -- when you start allowing UV and IR light to pass, you start getting "fringing" around things that should otherwise be sharp. By blocking those wavelengths you get a sharper image.
But traditional cameras start blocking IR beginning at around 600nm ... WELL inside the visible spectrum. It cuts reds quite a bit (much more than most people would guess.)
The 60Da has a much better IR filter (it still has a filter) which doesn't block much of anything until it gets safely past the Ha line. This allows the camera to collect about 3x more Ha than an unmodified DSLR -- which makes for better light collection and shorter exposures. Shorter exposures means less noise and less time for something to go wrong with tracking.
The exposure times in AP will be long enough that you will want Canon's AC power adapter (a good AP session will kill a fully charged battery before you're done.) The 60Da includes the adapter. It also includes an adapter cable that allows you to use the Canon TC-80N3 intervalometer with the 60Da (the connection is different.) It does not include a TC-80N3... but if you use a computer and a program like Backyard EOS then you wouldn't need a TC-80N3... you'd just need an extra long USB cable and the computer will control everything.
You can modify a camera body either by removing the factory filter and installing a better filter -or- you can just remove the filter and replace it with a clear "filter" (which isn't really filtering anything but serves to protect the sensor and also the low-pass filter on the camera is part of the piezoelectric dust-cleaning system so the replacement is also a dust protector.) If you have no filter at all then you must use external filters (which most astrophotographers are happy to do.)
The Gary Honis website discusses modification of various Rebel bodies and how to do it (warning: this WILL void your warranty... this will likley become obvious as you start reading and looking at photos of how this is done, but I thought it bears repeating.) Google for "Gary Honis" to find his site.
06-27-2013 06:45 PM
Thanks a bunch Tim. All of what you say is great info. I'm on the brink of deciding whether I should move ahead with a CCD Camera Apogee or something similar but very partial to DSLR because I tried CCD (inexpensive stuff) and not really happy.I sat throught a presentation in last year's SCAE (OPT) expo last year when Canon presented the 60da. I was impressed. A buddy of mine has one and is totally sold on it. I saw a bunch of his AP stuff and it looks outstanding. So I'm leaning in that direction. In terms of modifying my T2i, I would rather bite the bullet and buy a 60da. Thanks again for your input. Gets me closer to my decision. I will also Google Gary Honis and get on his site.
06-30-2013 03:53 PM
I've compared the results between both as well as the requirement to learn a new way of AP. It keeps me leaning in the 60Da direction. I wish I had the money to buy one today. Although the piggy bank is not fat enough yet, I might just have to break into it sooner than later.
06-30-2013 09:38 PM
I've been eyeing an SBIG monochrome CCD with filter wheel. The CCD cameras are basically unfiltered so you use a filter wheel to control what gets through. They're also cooled cameras to keep the temperature down (which results in much lower noise).
As I don't have a permanent observatory, it's a bit tough to justify the expense of a CCD imaging system that would basically run $10k -- vs. a modified DSLR that runs just shy of $1500 -- especially considering I don't live in or even near a decent dark sky location.