EAA Mono Adventures...

[Xio1996]

Hi Everybody,

After days of waiting, I managed to have a first session with my new mono camera, a ZWO ASI 533MM. For the last 4 years I have been using my trusty one-shot-colour camera, an Altair Astro 294C, but I wanted to try a monochrome sensor.

When I swapped my eyepieces for a camera, I wanted to see colour, more detail and fainter objects. In the last 4 years of EAA I have seen more than in the last 4 decades of visual astronomy! My goal with a mono sensor was to “see” faster. I lose the colour but gain speed of capture or even more detail and fainter objects than my OSC camera.

The telescope is a CPC-800 on an Alt-Az mount, imaging software is Sharp Cap (latest 4.1). In SharpCap ‘Hot and Cold Pixel Removal’ was used (the 533 sensor is so clean compared to the 294!) and ‘Low Frequency Wave’
background extraction acted as a flat. However, there is a large dust mote bottom right that really requires a flat or cleaning (maybe next time). All the images are cropped and scaled in GIMP.

In no particular order, here are some of my observations from the first night.

NGC 206 - 09 January 2024 20:38:38 (UTC) - Subs: 75, Sub Exp: 8.0 sec, Total Exp: 600.0 sec, Gain 300, Brightness 10, Alt: 56.3°, Az: 271.4°, Airmass: 1.2
The bright cluster of stars is set against the dust clouds of its host galaxy (M31). The speed the image built up was incredible.

In December I observed M74, so I thought a cheeky non-scientific comparison between the colour and mono images would be good. The mono image was impressive from the first frame. A real joy to use for EAA, with the spiral structure building very quickly, to reveal the intricate makeup of the galaxy. Plus! No colour balancing!

The mono image (533mm) is 09 January 2024 18:44:26 (UTC) - Subs: 90, Sub Exp: 4.0 sec, Total Exp: 360.0 sec, Gain 300, Brightness 10, Alt: 54.9°, Az: 187.4°, Airmass: 1.2, App Mag: 10.1.
The colour image (294C) is 09 December 2023 20:24:23 (UTC) - Subs: 90, Sub Exp: 4.0 sec, Total Exp: 360.0 sec, Gain 1000, Black Level 100, Alt: 55.0°, Az: 178.2°, Airmass: 1.2, App Mag: 10.1.

When I started EAA all those years ago my first target was the Orion Nebula (awesome colour), but my second target was the famous Horsehead Nebula (Barnard 33). The mono camera did not disappoint, with the increased contrast and detail making up for the loss of colour. I spent far too long being mesmerised by this nebula complex.

09 January 2024 22:13:28 (UTC) - Subs: 132, Sub Exp: 8.0 sec, Total Exp: 1056.0 sec, Gain 300, Brightness 10, Alt: 36.7°, Az: 174.5°, Airmass: 1.7

NGC 7635, The Bubble Nebula in Cassiopeia was my next target. Again, the mono imager revealed the structure of this object very quickly.

09 January 2024 20:18:25 (UTC) - Subs: 90, Sub Exp: 8.0 sec, Total Exp: 720.0 sec, Gain 300, Brightness 10, Alt: 55.3°, Az: 311.7°, Airmass: 1.2, App Mag: 7.2

I thought I would try my hand at binning (2x2) on IC342. Wow! Swapping the resolution for increased SNR (I watched a video ) was amazing. Even faster image build-up. This is the only image I edited in GIMP, a bit of a stretch and a little more bilateral noise removal. All the other images are as they came off the camera.

10 January 2024 02:40:03 (UTC) – Bin 2x2, Subs: 60, Sub Exp: 15.0 sec, Total Exp: 900.0 sec, Gain 300, Brightness 5, Alt: 45.6°, Az: 327.8°, Airmass: 1.4, App Mag: 9.4

In summary, wow! That was like purchasing a bigger telescope. The speed the image built-up compared to the colour 294 imager was incredible. No messing about with colour balance, just simple stretching of the image. Also, due to the size of the 533MM and the side entry USB cable I didn’t need to use a star-diagonal to get the 105mm of back spacing. A simple straight-through configuration that my CPC-800’s stubby little fork-arms can swing up to the Zenith.

The uncooled 533 sensor was also amazing. Really clean, no need to use darks, no banding. It maintained a temperature within 4 degrees Celsius of ambient. Last night the ambient temperature was around 0 C.

The mono EAA adventure begins…

Have fun.

Pete

[Bigzmey]

Beautiful captures Pete!

[pakarinen]

It might be a hangover from my student days when we used Kodak astro emulsions on glass plates, but I really like mono shots.

[Xio1996]

It might be a hangover from my student days when we used Kodak astro emulsions on glass plates, but I really like mono shots.

Unfortunately, I'm old enough to remember when all astro images were monochrome in astronomy books. The 533mm gives amazing monochrome images in realtime but then again the 294c OSC gives amazing colour images. I Iove both. Maybe I need a filter wheel :-) or the next generation colour camera.

Have fun.

[Xio1996]

I was really inspired by ( @Ken_nneth ) Kenneth's SeeStar composite of NGC 2244 and realised that on my first night out (Tuesday 9th Jan) with the 533mm (CPC-800 @ F6.3) I observed in the same area and had two overlapping images.

I don't normally process my images, beyond what SharpCap does in real-time, but the mosaic Kenneth created looked amazing. I don't have PixInsight but I do have an old copy of Microsoft's Image Composite Editor (very old, experimental app for stitching images). I cropped the two images in Microsoft Photo viewer and let I.C.E. do its stitching (it was all automatic!). Then in Windows Photo viewer I adjusted shadows, highlights etc before finally applying a bilateral noise filter and resizing the image in GIMP.

The source images information is given below. They are different as I was experimenting with different settings and used the Brain Histogram function in SharpCap for NGC2238 to automatically set the camera properties. The I.C.E. application really did a great job of blending the images together.

NGC 2244 (left image) - 10 January 2024 00:08:55 (UTC) - Subs: 75, Sub Exp: 8.0 sec, Total Exp: 600.0 sec, Gain 300, Brightness 5, Alt: 43.1°, Az: 196.4°, Airmass: 1.5, App Mag: 5.2
NGC 2238 -(right image) - 10 January 2024 00:31:14 (UTC) - Subs: 50, Sub Exp: 15.0 sec, Total Exp: 750.0 sec, Gain 179, Brightness 5, Alt: 41.9°, Az: 204.0°, Airmass: 1.5

Thank you once again Kenneth for your image and the inspiration.

Have fun.

Pete

[Ken_nneth]

Nice job, now we wait for the mosaic function from ZWO.
Clear Skies
Kenneth