P r e t t y     P i c t u r e s     T o u r



Hello!

Hi, welcome to my tour of pretty astronomical pictures!
For nearly 20 years, I've been an early adopter and advocate for videoastronomy. First using old modified 1/4" CCD security cameras for Lunar/Solar/Planetary viewing, then progressing on to the StellaCam line of deep-sky cameras, doing video-observing.
As the StellaCam's advanced in their capability, going from being able to expose up to 2 seconds, then up to 8 seconds, then multi-minute exposures with a peliter cooler, my skills and telescope equipment also advanced, learning how to better polar align, balance my mount, and autoguide. I also began dabbling in taking dark frames and using imaging filters, and basic image processing.

But I never was very interested in moving up the ladder to become a full-blown astrophotographer, just too much post-processing on the computer for my taste. I enjoyed the near-realtime video observing experience and for years kept finding ways to continue expanding my observation projects using the monochrome 1/2" CCD StellaCam-3. But with the new astronomical CMOS 'video capable' cameras entering the mainstream, and the new "LiveStack" realtime ability of the SharpCap imaging program, I decided the time was right to begin phasing out my old analog camera.

      


Having already become familar with ZWO branded cameras from using my ASI120MC autoguider camera as a planetary camera, and reading the great reviews of their products, particularly their recent model - the "ASI294MC Pro", I took the plunge and bought one.
(you can thank me for the cloudy February weather,,, :) )

ZWO "ASI294MC Pro" color CMOS Peliter cooled astronomical camera
      
ZWO ASI294MC weblink:


Prior to ordering the new camera, I used my ASI120MC autoguider camera to self-train on using the latest version of the SharpCap imaging capture software program. I was already familar with the basic program features, having used it for the past year doing frame grabber video-capturing with my analog cameras. But the ASI cameras unlocks much more functionality, including the realtime stacking ability using short exposures. By activating the "LiveStack" feature, you can watch as the image begins to build in realtime from the stacked frames, and then you can adjust the Histogram and color levels on the fly. Once you are happy with what is being displayed on the screen, you simply pause the livestack, and save the image. (can also save the individual frame 'subs' if you want).
This is a game-changer! I can continue to enjoy the near-realtime experience of video-observing while acquiring 'astrophotography' quality images that reqire very little post-processing.

SharpCap: Using the "LiveStack" option Histogram function.



So below, you will find my 'Pretty Pictures' as I slowly begin to re-image the showcase objects that I've observed over the years. Other than resizing the saved image to fit on this webpage, (and perhaps a little brightness/contrast tweaking), I don't intend to do any other post-processing, so what you see is what I observed.


ZWO "ASI294MC Pro" image captures using SharpCap. (also occasional images using an ASI120MC & ASI290MC)

Emission & Reflection Nebula:

Dark Nebula:

Planetary Nebula & Supernova Remnants:

Open Star Clusters:

Globular Star Clusters:

Galaxies:

The Planets:

Recently, I added a ZWO filter drawer, (with additional filter holders), and a 2" ZWO IR/UV cut filter, along with a 2" Optolong L-Pro light-pollution filter to go with my Optolong 2" L-eNhance narrowband filter.
This now gives me a complete interchangeable 2" filter set that covers planetary, (IR/UV), starclusters & galaxies (L-Pro), and emission nebula (L-eNhance) imaging.
So I decided to test the filters. First I wanted to see how close the three filters were to being par-focal to each other.
My hope was that they would be close enough to not require re-focusing the telescope between swapping out filters. I used a Bahtinov focusing mask with the bright star Arcturus for the test.
Then I wanted to take a test exposure of a deep-sky object that would hit each filters strength. So I chose M20 'the Triffid Nebula as it's an object with a nice star field that in addition contains emission, reflection, and dark nebula. I kept the exposures short, 30 second subs for 15 minute total exposure. During the imaging, I kept nearly all the various camera settings the same for each filter, only making a few slight tweaks when using the L-eNhance filter to help bring out detail in M20, as the L-eNhance really needed a longer exposure. I've created a PDF of the test results. Here's a link to the doc: Filter Test PDF

Overall, I'm very happy with the test results. The IR filter gives an overall pleasant, natural looking image of M20, and should be excellent on the planets. The L-Pro light pollution filter also worked very well, and I think that if I had adjusted the the camera settings specifically for the filter, I would have produced an image close to that of the IR filter. I'm looking forward to seeing how the L-Pro will work on galaxies from my backyard. We already know that the L-eNhance works wonders on emission nebula from a light polluted or 'moon up in the sky' scenario. As with the L-Pro, I would have adjusted the camera settings to take better advantage of the L-eNhance capabilities, if it wasn't for wanting to keep the test conditions consistent, as close as possible.

I also occasionally utilize two additional ZWO cameras: a ASI120MC for planetary imaging at prime focus of a 8" & 14" SCT, and a ASI290MC attached to a Canon 25mm-100mm Zoom CCTV lens.
Here's a photo of the Canon lens and my 60mm Arcturus f4 240mm Refractor that normally functions as my guidescope, but is also used for wide-field imaging.

      


Hope you enjoyed the visit. Come again soon!
Larry McHenry,   Pittsburgh, PA. USA

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