Andromeda Galaxy (Skyguider Pro, 200mm, Bortle 4)

[soundwave]

Hello all,

Me and my brother drove out to a Bortle 4 site in the desert Thursday night for an all-nighter. There was a fair amount of wind and dust, but we tried to position the car in a way to will block some out.

The big surprise of the night was a not-so-small blur we saw in the sky with our eyes. At first we thought it was a small faint cloud with a few stars poking through it at times, but it moved with the stars.
Then we lunched Stellarium on my phone, pointed it at the blur and discovered we're looking at the Pleiades! It was really awesome! 🤩 

The scary surprise of the night was this pretty big, white spider that decided to rest near the Dec release knobs on the mount just as I reached to rotate the camera, but we managed to flick it off with a roll of tissue paper after we freaked out for a bit 😱

Equipment:

• Skyguider Pro + cheap tripod
• Canon T2i / 70-200mm (f4) lens
• 5V USB Dew heater for camera lenses.

Photo Details:

• About 42 minutes of final integration (70% of 25 x 150sec @ iso 3200)
• Unfortunately only 2 dark frames were taken that night before the batteries ran out (we got greedy tried to photograph other targets as well, thinking we'll have time for darks).
• 10 flats / flat darks (taken when we arrived home, after being careful not to disturb the focuser).
• Stacked in DeepSkyStacker
• Processed and cropped in Pixinsight (free trial, but it looks like I'll be buying it when it ends soon)
• Color noise removal in Photoshop
• While my polar alignment was fairly good, there is a bit of drift in a certain direction if I look at the first/last image, which resulted in some 'walking noise' and had to be aggressively removed. 
  Yesterday, I experimented with Sharpcap Pro's polar alignment from my backyard just before clouds rolled in (using the DSLR itself, not a guide-camera). I managed to get 'excellent' alignment and did a 5min exposure on Polaris at 200mm, and the stars looked very round. I'll try it again today and check for drift over time.

Good day and clear nights!

Edit: I think I may have flipped the image in an unnatural way - sorry for any disorientation it might cause hehe 

Edited August 16, 2020 by soundwave

[TerryMcK]

Looking good. The stars seem to be pinsharp and round

[soundwave]

3 minutes ago, TerryMcK said:

Looking good. The stars seem to be pinsharp and round

Thanks! I used a 3d-printed bahtinov mask on the lens-hood to focus. It's not an easy task with a lens focuser, but after some (and some more) fiddling, the center spike was pretty bang in the center.

[tomato]

Great M31, beautifully framed. It can be quite a challenge imaging from a remote site, but you have achieved a fine result for your efforts.

[MarkAR]

Lovely image.

[Victor Boesen]

Great image with no evident star trailing from what I can see;)

With regards to your 5 minute exposure of Polaris, keep in mind that this (together with the south celestial pole) is the area of the sky where the stars move the least (relative to Earth that is). You'd notice the mount would have trouble tracking something placed at the equatorial plane (Dec = 0deg). Enough boring numbers though, what matters is that you're able to shoot 150sec exposures at 200mm without noticable star trailing, which is very impressive!!!

Victor

[soundwave]

13 hours ago, Victor Boesen said:

With regards to your 5 minute exposure of Polaris, keep in mind that this (together with the south celestial pole) is the area of the sky where the stars move the least (relative to Earth that is).

That makes sense Thanks for the kind words!

[feverdreamer1]

Wow, I've got a 550D too and this is just mind blowing. I've got the exact same setup as you (except lens heater) and I've also tried to image M31 but at ISO 1600 I had terrible noise. How did you manage to get rid of so much noise?

Also, if you dont mind, could you post a single raw sub? If you dont want to its understandable

Amazing image man, congrats.

Clear skies!

Edited August 18, 2020 by feverdreamer1

[soundwave]

On 18/08/2020 at 15:59, feverdreamer1 said:

Wow, I've got a 550D too and this is just mind blowing. I've got the exact same setup as you (except lens heater) and I've also tried to image M31 but at ISO 1600 I had terrible noise. How did you manage to get rid of so much noise?

Also, if you dont mind, could you post a single raw sub? If you dont want to its understandable

Amazing image man, congrats.

Clear skies!

Check your photos' temperature using Dark Master. I've had some raw files that looked extra noisy and I noticed that my camera's chip temperature was over 40c. When it's around 35c, I can get a workable image.

I've attached 2 raw images taken that same night: the first one is at 35c, and the second one is over 40c (same settings otherwise). I'm not sure what caused the temperature spike, but you can see the difference it makes.

Also, in hindsight, I would have lowered the ISO a bit for that image.

_MG_8674.CR2 2020-08-14_01-43-46___150.00s_1.cr2

[feverdreamer1]

15 hours ago, soundwave said:

Check your photos' temperature using Dark Master. I've had some raw files that looked extra noisy and I noticed that my camera's chip temperature was over 40c. When it's around 35c, I can get a workable image.

I've attached 2 raw images taken that same night: the first one is at 35c, and the second one is over 40c (same settings otherwise). I'm not sure what caused the temperature spike, but you can see the difference it makes.

Also, in hindsight, I would have lowered the ISO a bit for that image.

_MG_8674.CR2 30.45 MB · 1 download 2020-08-14_01-43-46___150.00s_1.cr2 44.66 MB · 0 downloads

Yeah, temperature was running quite hot, about 41 degrees, checked with magic lantern.

Thank you very much for the subs, they're really helpful.

Clear skies and keep up the great work!