Author Topic: NGC 7000 - Canon EOS R first light  (Read 70 times)

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MarkS

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NGC 7000 - Canon EOS R first light
« on: Sep 08, 2021, 14:15:57 »
This is first light with my unmodified Canon EOS R full-frame mirrorless camera:



Full size version is here: http://www.markshelley.co.uk/Astronomy/2021/ngc7000_20210902_srgb.jpg

Please excuse the fact that it is out of focus.  My only excuse is that I was concentrating on the camera itself, getting the right settings, very much at the expense of trivial operations like focusing!

Buying a Canon EOS R full frame mirrorless camera is one last throw of the dice after using both a Sony A7S and a Nikon Z6 with all their inherent problems.

Acquisition details are the following:
 * Unmodified Canon EOS R on Takahashi Epsilon 180ED
 * 60 x 2min dithered exposures at ISO 1600
 * Sky quality reading averaged 20.85 but transparency was variable

Processing was done in PixInsight with a view to preserving natural colour.  To that end I applied the relevant EOS R colour correction matrix (published on the DXO website) after white balancing and I applied the relevant gamma curve for the colour space.  Here are the main steps:
 * Calibration with darks, flats, bias
 * CFA drizzle stacking with a scale of 2
 * Noise reduction followed by 2x2 binning back to original size
 * White balance, AdobeRGB colour correction matrix, BackgroundNeutralisation, ArcsinhStretch
 * Apply gamma of 2.2 for AdobeRGB colour space then convert image to sRGB

If you think the finished result looks rather pink (rather than red), it's because that's how Hydrogen emissivity appears to the human eye!

I'm doing a serious amount of testing on this camera before I decide whether to modify it or sell it.  Unlike with the A7S and Z6 I want to find potential gremlins before modification. My first impression is that the data are so much easier to process than the Sony A7S data or Nikon Z6 data.

Thermal noise and camera self-heating are both impressively low, definitely outperforming the noisier Nikon Z6 and very close to the (so far) unmatched Sony A7S.

After an imaging hiatus over the last 12 months I now intend to be back in the game!  I'll begin by re-learning how to focus  :)

Mark
« Last Edit: Sep 08, 2021, 15:43:22 by MarkS »

Mac

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Re: NGC 7000 - Canon EOS R first light
« Reply #1 on: Sep 08, 2021, 16:37:47 »
That is impressive for an unmodded camera and only 120s exposures.

Good idea to find the gremlins first,
So looking at the specs, compared to dedicated CCD's nowdays,

Might not be worth going down the CCD Route anymore when you look at comparing the costs.

24-30MP & 4K video,
Now i'd love to see a 4k stacked video of the moon or planets.

Mac.
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If you argue with an idiot, there are two idiots.

Roberto

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Re: NGC 7000 - Canon EOS R first light
« Reply #2 on: Sep 08, 2021, 18:09:43 »
Beautiful colours Mark  8)  I love the contrast of the starry fields, the emission Ha and the dust clouds all mixed in one.  That Tak 180ED is a superb scope.  When are they making a bigger one?!

I am working on this exact same area as a 2x2 mosaic combining OSC data, Ha and OIII.

Roberto

MarkS

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Re: NGC 7000 - Canon EOS R first light
« Reply #3 on: Sep 08, 2021, 23:14:50 »
So looking at the specs, compared to dedicated CCD's nowdays,

Might not be worth going down the CCD Route anymore when you look at comparing the costs.

For RGB imaging that's certainly the way I see it.  But for narrowband imaging, nothing beats a mono camera.

Amateur astro-imaging has changed quite a lot in the last few years with the effective demise of CCD.  Everything is now CMOS and the new generation of one-shot-colour CMOS dedicated astro-cameras use the same sensors as you find in consumer Sony, Nikon, Pentax, Panasonic and Fuji cameras.  As long as thermal noise is not a limiting factor then there is no need for sensor cooling and so a modified consumer camera should in theory give identical results to the cooled astro-camera.  However, the big difference (as I've found to my cost) is the amount of hardcoded raw data processing performed by consumer cameras.  This causes issues such as star-eater, PDAF stripes, concentric colour banding and failures of dark calibration - especially when a consumer camera is pushed to its limits with stacked long-exposure imaging.   

I will give my verdict on the Canon EOS R in due course, once I've completed my testing.

Quote from: Roberto
I am working on this exact same area as a 2x2 mosaic combining OSC data, Ha and OIII.

I'm looking forward to your result.

Mark
« Last Edit: Sep 09, 2021, 08:28:35 by MarkS »

Mac

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Re: NGC 7000 - Canon EOS R first light
« Reply #4 on: Sep 09, 2021, 11:15:02 »
Quote
I will give my verdict on the Canon EOS R in due course, once I've completed my testing.

As always,

one thing i did like about the canon cameras was the ability to add non permanent hacked firmware to allow better functions to be added / remove restrictions to the camera.
Is there anything on the CHDK or magic lantern for your camera yet?

Might be worth a look, especially if they add a true raw (pre processing), which i think they did do for a few cameras.
I've always wanted a function for changing the exposure length, so after Bulb you would have custom where it would just allow you to set a time limit up to 999 seconds, that would be so much easier for the astronomers.

Mac.
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If you argue with an idiot, there are two idiots.

RobertM

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Re: NGC 7000 - Canon EOS R first light
« Reply #5 on: Sep 20, 2021, 20:09:37 »
Sooo much dust ! That's looking like a great replacement for the Sony  ?