I’m well aware I’ve said several times that I wasn’t at a point where I needed to modify my camera, and that I needed it for dual use, and I liked the “true color”, and, and, and… Well I’m allowed to change my mind! And I have. And I did it. Myself.
Over the course of this past Winter, I knew in the back of my head that there had to be something more to the images I was making, and something I was missing. Imaging from my polluted skies and obtaining four or five hours of data on an object resulted images still lacking any punch. I kept pointing to things like the moon, or borderline guiding accuracy, or weird seeing. Sure, those all played a factor. But the truth in imaging from my location is that I only have a few hours on a target at best before it ducks into the branches of one of the 70-year-old oaks and silver maple my backyard, or any of the other backyards in my neighborhood. Ducking in under the trees, objects quickly dip too low in the sky to try to fight the pollution. In short, I need to acquire data quickly, and I had lost the patience do it with an unmodified camera.
I would have loved to just throw out some money for an ASI071MC-Pro. It’s essentially a full spectrum TEC cooled crop-sensor DSLR with a 50k -e well depth. And the images it produces are amazing. But I don’t have $1300 laying around. So I searched around for the best DLSR modification option to shoot during the day and under the stars. For me, that was the BCF-1 filter replacement from Baader. For now, I’ve left the low pass filter in to retain auto-focus more easily. There are other ways fix the focus issue, but I’ll probably mess with that later. The anti-alias/moire filter included in the low pass actually reduce resolution, so it should be worth the fidgeting.
I’m impatient, so I removed the anti-alias/moire filter. Check out I Modified My Camera: Part Two for non-astro results. Hint: Autofocus works without any further modification.
Full Well Depth is the measure of how much light a pixel can accept before it maxes out. My Canon t1I is a tiny 4612 -e @ ISO800. What this means is that an Astronomy camera like the ASI071, or even better, a true CCD imager with a higher full well capacity can pull out a lot more faint data before blowing out the stars or slamming the histogram up against the right edge. (I reference ZWO a lot, but I’m not paid by or tied to ZWO in any way. I just like their offerings, innovation and price-point).
I do not recommend modifying your camera yourself unless you are very comfortable disassembling and reassembling electronics. I have no issue in taking apart the camera, as I’ve been in IT for 20-something years and have hardware repair certifications for companies that don’t even exist anymore. If you’re not 100% sure about it going in, but you still want to do it yourself, be sure you know exactly what type of mod you want and have everything ready. There are a lot of screws, so being organized helps too. The whole process took me about an hour, which included heating up dinner for the kids. Should you do it yourself, find an instruction set online, follow it EXACTLY and take your time. Gary Honis’ instructions are the best I’ve seen (link below).
dslrmodifications.com Select your camera from the Modification DIY menu at the top. He is lo longer performing the modification service directly, but his instructions are great. There are also a few YouTube videos for some camera models.
Now, for the proof. I wanted to get through the mod quickly so I could test with the similarly terrible sky conditions I had the night before while testing out some mount adjustments. The moon was between 80% and 90%, and although the Soul Nebula was away from the moon, I was still fighting with challenging conditions as the jet stream was hanging out overhead for a couple days making for poor seeing. I wanted to use this object because it is dim and typically requires a lot of integration time. The images below are of horrible quality and were for testing purposes only. Both consist of a series of two-minute exposures at ISO 1600. The unmodified camera image was 48 minutes of integration (24 exposures), and the modified image was also 48 minutes of integration (24 exposures).
Unmodified – 48 minutes
48 Minutes – Modified (UV/IR Cut maintained)
So it’s quite a big difference, and I’m glad I did it. If you’re handy, and your camera will be used exclusively for astrophotography, you can just take all the glass out of the camera and get a clip-in IR cut filter to complete the filtering and keep dust off your sensor.
There is also an added bonus to Camera modification that I plan on taking advantage of this weekend. That big bright moon will be lighting up the sky all night long this weekend. I’ll be giving it the finger with an H-alpha filter that arrives before then. Although it’s sagging a little low in the sky this time of year, I will be trying to grab enough data on the Wizard nebula before it goes away for the Summer.
Clear Skies – KA