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Old 25-07-2021, 10:50 PM
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DavidLJ (David)
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Join Date: Jun 2011
Location: Sydney
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Some years ago I tried my hand at traditional astrophotography using a cooled mono CCD camera, a range of filters and an autoguided 8 inch Newtonian. Typically it would take from 1 to 3 hours to image the brighter DSOs and from 4 to 6 hours for the fainter ones. And then, of course, there was the time taken to calibrate the individual subs, combine the separate colours and apply a range of post-processing procedures The end results were quite credible and personally very satisfying although they were never going to set the AP world on fire.

And then I discovered “video astronomy” (or EAA or EAV or whatever other acronym is now in vogue) which largely did away with most of the time and effort. And it was fun! Initially the results were pretty humdrum but over time the cameras and software got ever more sophisticated and the results started to close in on those of the earlier cooled CCD camera. Nowadays when using the same (but now unguided) 8 inch Newtonian and a cooled colour CMOS camera I invariably use SharpCap's livestacking feature to get fairly decent on-screen views of even quite faint DSOs and then go on to post process the saved results. In many cases the end result is almost as good as the earlier CCD camera work. But whereas with that earlier work it took some hours to produce a final image I can now produce its close equivalent in a matter of minutes. Let me be the first to admit that from a purist AP point of view the resulting images probably have many flaws but they are more than good enough to share with family and friends.

SharpCap offers many features and it is worthwhile taking the time to get really comfortable with using them. This includes, but is not limited to, determining which binning level is best suited to your camera and target; learning how to combine exposure and gain settings to best advantage; building a library of darks and flats that can be called on for most circumstances; and optimising the use of the livestack's histogram and other features. But thereafter using SharpCap is a breeze.

Some examples should suffice to illustrate where I have got to. None is of a particularly bright DSO. All use the camera's 2 x 2 binning mode which produces an image of 2,072 x 1,410 pixels resolution. All have been severely reduced here to conform to the 200 Kb limit for each file.

In the first case two images of the Gabriela Mistral Nebula and surrounds are attached. The first image is a screenshot of the displayed on-screen view. It is a livestack of 4 x 30 second exposures at 500 gain with the camera. The second is the saved livestack image after applying some mild post processing with a very old version of Photoshop.

The second case shows a further two equivalent images of the interesting region that is a camera frame or two away from the Lagoon Nebula. In this case the livestack was 15 x 60 seconds exposures at 400 gain.

The third case shows two final images, the Cat's Paw nebula ( 13 x 60 seconds exposures at 400 Gain) and the War and Peace (or Lobster) Nebula (7 X 120 seconds exposures at 300 gain).
Attached Thumbnails
Click for full-size image (Capture Gabriela Mistral small.jpg)
197.9 KB12 views
Click for full-size image (Gabriela Mistral small.jpg)
191.0 KB15 views
Click for full-size image (Capture IC 4685 small.jpg)
191.4 KB13 views
Click for full-size image (IC 4685 small.jpg)
195.9 KB15 views
Click for full-size image (Cats Paw small.jpg)
196.0 KB15 views
Click for full-size image (Lobster small.jpg)
195.2 KB13 views

Last edited by DavidLJ; 25-07-2021 at 11:27 PM.
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Old 26-07-2021, 08:03 AM
garymck (Gary)
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Join Date: Aug 2005
Location: Geelong
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Have a look at this excellent Sharpcap tutorial. It transformed my EAA results.



Last edited by garymck; 26-07-2021 at 08:22 AM.
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