Some Astro stuff

Started 1 month ago | Photos thread
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Messier Object Forum Pro • Posts: 10,729
Some Astro stuff

I've been waiting for clear weather and moonless sky to do some astro shooting.

Here in Sydney we're in lockdown with steadily growing COVID-19 so traveling to a dark sky site isn't an option at the moment and  I had to make do with the home sky from our backyard.

We live on the southern edge of the city and the sky to the south up to about 60° elevation is pretty dark. But this time I wanted to image the region around Antares in Scorpius which was right overhead

I knew that the light pollution would limit how deep I could go so I didn't spend too much time getting precise polar alignment and decided on 8 sec exposures with the ZD150mm at f/2

As mentioned in another thread I used Olympus Capture to tether the E-M1 III to my old laptop and using Live Boost 1 and MF was able to get reasonably sharp focus.

the setting were:

Camera: E-M1III USB tethered using Olympus Capture
Lens: Olympus Zuiko Digital 150mm F2
Mount: German EQ with polar clock-drive, unguided
Focus: Manual Focus 'by wire' using the Olympus Capture fine controls
Exposure: 20 frames, 8sec f/2
ISO: 1600
Shutter mode: ♥[ ] 2sec delay
Noise Reduction: In-Camera auto dark frame subtraction
Interval shooting: via Olympus Capture

orf -> dng -> Lightoom 6.14 for culling and pre-processing -> tif
Stark Labs Nebulosity: tif Alignment and stacking -> .fit file -> tif -> Lightroom
Lightoom: Brightness, Contrast, Tone curve, WB, NR etc -> jpg

here's what a single frame looks like . . .

here's the final result with a stack of 20 frames . . .
The Rho Orphiuchi cloud complex - field of view is around 5 degrees

Plenty of noise in there and some star drift due to alignment error.  Nowhere near as good as the deep stacks we see from folks using auto-guided systems and hundreds of frames stacked totaling hours of exposure under truly dark sky.

If I get another break in the weather I'll try this with a wider lens and with the 5DIV
but for this amateur enthusiast it was an enjoyable and satisfying project.


Comment & critique:
Please provide me constructive critique and criticism.
Olympus E-M1
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