Chasing Orion Part 3

February 26, 2016

Flame Nebula and Horsehead Nebula

 Nikon D5300A, Skywatcher ED80  + Baader UHC-S filter 
+ 0.85x Focal Reducer/Corrector
Skywatcher EQ-3 Synscan, guided, ISO 400 5 mins  x 7

..and still chasing Orion. Last Friday night, February 26 was the warmest night ever! It was a warm +5C or so and hardly any wind. The skies were clear and I thought I would give a proper field test for my new D5300A, modified by LifePixel USA. So I brought down all the gear, and slewed the ED80 on Alnitak, the southernmost star on Orions Belt. Alnitak contains one of the most beautiful nebula's in the night sky, not to mention The Great Orion Nebula itself. Problem is I only have less than an hour of imaging time, before Orion is goes behind my neighbors rooftops. But it gave me an idea how the D5300A performed.

 Here is a comparison shot, although the sky conditions might not be exactly the same as there was a rising moon when i took the shot using the D610, but still one can see the big difference of using a modified camera. The horsehead is particularly difficult as it is quite dim. Though I would admit the the low noise capability of the D610 is superior to the cropped sensor D5300.

Response curve of the modified D5300. Red line indicates the stock filter, typical for most modern DSLRs. The H-alpha (teal color) is only at 20% or so. The new filter (blue) has the H-alpha sensitivity up to 98%.  (Graph is taken from another source)

 Monochrome version. I kinda liked this one. It gives me a sense of a vast lonely but beautiful space.

Chasing Orion Part 2

Chasing Orion Part 2

January 30, 2016

The Great Orion Nebula  (M42)  &  The Running Man Nebula

 Nikon D7000, Skywatcher ED80 ISO 400  + Baader UHC-S filter
Skywatcher EQ-3 Synscan, guided
3 mins x 25, 30 secs x 2

...and so the chase continues. We got a bit of a mild weather one weekend (at -6C) and  i finally decided to give it a try. It might be now or never. The night was not so cold but with the windchill it feels like -12C. Orion is not so "accessible" from my backyard. It doesn't rise high enough and by 10PM it is hidden behind my neighbors rooftops. I have small spot that I can position my scope in plain view of Polaris at at the same time be able to see Orion. So I carried all my gear down and set it up by the garage. Setup time, polar alignment and calibration ate up 30 minutes of my precious time and I only managed to acquire 1 hour and 40 minutes of data before my guiding program went "ding-ding-ding-ding!" I checked visually and there, my target  is already lost behind the rooftops. Well, I was happy with the results at the very least, but it could have been better.  I was able to image Orion from my backyard and from the looks of it, there might be no other place. 

Skywatcher ED80 with my homemade dew heaters.

Laptop running PHD guiding on my garage

Here is a comparison : straight  out of camera, after stacking 25 photos in DeepSkyStacker (including calibration files), and final adjustment in Photoshop

Not too bad considering my light polluted skies and my trusted old D7000. I have to limit my exposure time just enough to balance my signal with the light pollution. Too short and  I will not  have enough data to process, too long and well, it will overexpose.  Might be too hard to recover in post processing. I settled for 30 secs on the core, as it  can easily blow out,  and  3 minutes for the  rest of the nebula. It is interesting to note that the reflection nebula on the top of Orion ( Running Man Nebula) is almost absent on the RAW file and takes form only after stacking. But  I have this mistake that my stars are a bit out of focus.  I  can be forgiven, to think that it is not so easy to focus a telescope when it feels like -12C and your hands are frozen and stiff....