Here is a one exposure image taken in the middle of a Bortle Red Zone with 2 light pollution filters in place to help with all the LP. I managed to get quite a bit of nebulosity with 5 minute sub-images at F/2.8 and ISO 200 on my older, modified Canon XS camera.
What helped was the sky conditions, which were very transparent and clear. I am glad I did not waste one of the few great nights of the year.
The above image is just a tease, btw. I have a number of these subs just waiting to get calibrated, stacked and processed. I will probably just tack the finished product onto this thread when I am done.
Here’s one I haven’t shot in a while. I was using it as a test to see how bad the LP would be. Not long after this was taken, Comet Lovejoy was in the same general area LP-wise, so I had a pretty good idea how much comet I might get.
On the night following the encounter between M108, Comet 41P and the Owl Nebula, the comet was still in the field of view of my setup, so I went back for seconds. I just couldn’t pass up the opportunity to shoot a comet conjunction again!
I went with 3 minutes sub-images at ISO 200, since the 1 minute ISO 800 subs were too cooked by the LP for my taste. Unfortunately, the sky was not as transparent as the previous night and that half-stop of underexposure was needed to get around that. The trade-off was I didn’t get as much of the comet’s coma. Oh, well.
Also, at that exposure length, the comet’s pseudo-nucleus trailed a bit, since it is moving with respect to the Earth and stars and slowly picking up speed as time goes on, to boot. It was not enough to notice if I carefully over-exposed it a bit in processing to make it fatter, luckily. Check the star streaks version, which I did not overexpose, and you can see how far the comet moved in 3 minutes:
A Televue TV-85 w/0.8x focal reducer/field flattener, a Canon T3, my laptop running EQMOD, driving my Atlas EQ-G mount and PHD2 Guiding with an Orion StarShoot guider/Orion Ultra-Mini guidescope was some of the equipment used.
It is not uncommon for comets to pass near famous Messier objects or NGC catalog objects and put on a good show. This comet encounter is special in that there are two famous objects that the comet is having a conjunction with. One is a relatively bright galaxy called M108. The other is the Owl Nebula, one of the better planetary nebulae in the skies.
I shot this with the Canon T3 and Televue TV-85 combo. I used one minute sub-images at ISO 800 and that was about max for the skies I was under. I’m sure people with darker skies got better results. However, I think being able to pull anything out of the skies at this location is great. LP was bad and I had terrible gradients to deal with in post-processing, but I managed. 🙂
I also did a quick star-streaks version that seems to show a longer tail. Not sure, since there were some dust doughnuts left over from an apparently bad batch of flats I used and I had to clone them out. These aberrations were in the tail area, so it could be some remnant of that.
The target of choice, if it is available, is always M42 when you have some new astrophotography gear to try. I went after it as my first object of the night for this session. I missed it the previous night which was first light for the new RisingTech Sony IMX224 camera because my mount was being a pain when trying to get it aligned and pointing accurately.
This was captured in the RisingTech (RT) version of ToupSky, the software that comes with all ToupTek cameras. RT has it re-branded and calls it RisingSky. lol. I installed it, even though I already had ToupSky installed.
One thing it has that the regular download of ToupSky doesn’t have is Live Stack. It is similar to what SharpCap does and the main reason why I was using that program instead of ToupSky when I imaged with the ToupTek Aptina AR0130 camera.
It does a decent job of stacking when the stars are bright, not so decent when they are dim. About the same as SharpCap. That’s why others are using AstroToaster to live stack, since it uses DeepSkyStacker as its backend, which is more powerful than the ToupTek offering and has better calibration support.
My only gripe about RisingSky is the TIFF save and export supports only 8-bit, and I used that instead of FITS when I saved. My bad for not checking first. The post processing would have went better if I had 16-bit to start with. Live and learn, as they say.
The next night after the above image was taken, I tested the camera shooting with a 0.8X focal reducer for F/5.6. It definitely made a difference in the speed and I got more nebula with less exposure time. Plus, the field of view was wider:
The F/5.6 setup is also better since the camera is screwed onto the focal reducer with a T to C adapter. At F/7, I had to use an 2 inch extension with a regular eyepiece holder and leave it and the camera hanging out of the focuser a ways to even reach focus. So, there is less chance of misalignment or something slipping out of place with the reducer and T to C adapter.
In addition to M42, I also got some time on M41, which is an open cluster in the constellation Canis Major, next door to Orion. Open clusters are too easy with this setup. I can’t wait to try it on some globular clusters!
Images of Comets, Nebulae, Galaxies and Star Clusters