Unmodded DSLR Test – California Nebula
The following photo of the California Nebula was captured using my DSLR camera before it was modified for astrophotography. NGC 1499 in Perseus is perhaps the best example of the difference removing the stock IR cut filter from your DSLR camera can make.
For an emission nebula like this, an image with a stock camera vs. modified is night and day. Some emission nebula are well suited for a stock camera, such as the Lagoon Nebula in Sagittarius. As you’ll be able to tell from the photo below, the California Nebula is not one of them.
NGC 1499 – The California Nebula.
Canon Xsi unmodded
54 x 3 Min Frames @ iso 1600
Stacked with Dark Frames in DeepSkyStacker, Processed in PS CS5
Compare this to a more recent version of the California Nebula captured using a modified (Full-Spectrum) DSLR.
When I shot the North American Nebula, my Astro-buddies said things like “Wow your unmodded Xsi picks up a lot of red” and I thought, hey, maybe I can hold off on an expensive and intrusive mod to my precious Canon. All of those thoughts disappeared as I began to process my photo of NGC 1499 yesterday.
This nebula doesn’t even EXIST with an unmodded DSLR! I suppose the photo above shows a pleasant mix of colored stars and faint pink nebulosity, but if you’ve ever seen a REAL photo of the California Nebula, you will understand my predicament.
My Canon EOS Rebel XSi DSLR camera.
If you’re not familiar with the concept of modifying a DSLR camera for astrophotography, it involves removing the stock IR cut filter that sits over the camera sensor. Once removed, the camera is able to record more details in the h-alpha portion of the visible spectrum.
The h-alpha wavelength is very important to amateur astrophotographers, as many deep-sky objects such as the Eagle Nebula emit a strong signal in this bandpass.
Related Post: Narrowband Imaging for Beginners
Here’s the plan: Since I do not want to rip apart my 450D just yet, as I use it A LOT for daytime photography, I will wait until boxing day, at which point I will buy a new DSLR, then either mod the 450D myself, or fork out the cash to do it right at KW Telescope.
UPDATE: Dec. 14, 2012
California Nebula with Unmodified DLSR
I decided I would give this object a fair kick in the can. I added about 2 hours of data under dark skies at the CCCA. It was a nightmare to process, however. Because I stretched it to its limits, I revealed light pollution, amp glow, gradients… you name it! I don’t usually like to stretch images this far. Needless to say, I won’t be imaging the California Nebula again until I modify my 450D.
If you are not familiar with this nebula, it is located near the bright star, Menkib, in Perseus. The constellation Taurus and the beautiful Pleiades star cluster is not far away.
The location of the California Nebula in Perseus.
Before you go down the modded route, try a 7 or 8 minute exposure at the observatory.
For sure I will. I want to push my exposures to the limit.. but it would have to be under dark skies at the CCCA!
Any other good emission nebulae for unmodded? Im just not in the position to modify my camera yet, but ive tried targets like California nebula and heart and soul, and have ended the night with basically nothing.