Testing an OAG on M51

[Anubis1311]

So it’s been a long while since I’ve been able to photograph anything. A combination of having a 9 month old baby with Cystic Fibrosis and good old English weather. But the past couple of clear nights gave me the chance to test out an OAG I picked up this time last year with the intention of shooting some galaxies on my C9.25.
I wasn’t expecting much as I’ve read that it’s hard to find a guide star with the sensor size on the asi120mm mini but I actually managed to find a star! To my complete surprise my old rusty C9.25 tracked perfectly. I must have the prism too close to my sensor as there’s some hinky shadows going on and I clearly have sensor tilt that needs resolving so I’ve had to crop in fairly close to remove the elongated stars. But all-in-all I’m pretty happy with my first effort. Once I’ve fixed the prism and tilt I’m excited about what I can shoot at this focal length

Equipment and Software:
=======================
Mount: EQ6 pro
Telescope: Celestron C9.25 w/0.63x focal reducer
Auto-Focuser: ZWO EAF
Imaging Camera: ASI183mm Pro
Guide Camera: ASI120mm Mini on Celestron OAG
Imaging Software: ASIair Pro
Image Processing Software: APP & PS

Exposure Details:
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Camera Temperature -10c
Gain: 111
L 30x 180
R 30x 60
G 30x 60
B 30x 60
Ha 15x 300

20 Flats per filter and 20 Darks per exposure time.

 

[JimFox]

This looks so awesome! It's nice when cropping can remove a few issues. I am glad you got a chance to try out that OAG, hopefully your busy schedule will give you a few more breaks.

You should go after that supernova in M101 with your setup.

 

[kiwiapple]

That's a great capture! I'm very sorry about your baby with CF--that disease is in my family too, and I lost a brother and cousin to it back in the 1970s. Hope your baby will be OK!

 

[Anubis1311]

That's a great capture! I'm very sorry about your baby with CF--that disease is in my family too, and I lost a brother and cousin to it back in the 1970s. Hope your baby will be OK!

Thank you. Sorry to hear you lost people close to you. Fortunately nowadays medicine has progressed so far that whereas people didn’t reach far into adulthood as you are all too painfully aware, now the life expectancy is well into 40s -50s. By the time he gets there it’s likely to be older than that. We have to work hard to keep him healthy with daily physio etc but wouldn’t change him for the world.

 

[Mike Lewis]

Wonderful result even with the issues you are dealing with on the tilt. I am guiding externally on my EdgeHD 925 so far but I believe I could do better if I jumped over to an OAG solution too. But with my ASI290MM guide camera I would also have a very small sensor to deal with. That, and the fact that my gear is located remotely have prevented me from getting on with that upgrade so far. Nice to know it is worth doing, based on your excellent result!

ML

 

[Anubis1311]

Wonderful result even with the issues you are dealing with on the tilt. I am guiding externally on my EdgeHD 925 so far but I believe I could do better if I jumped over to an OAG solution too. But with my ASI290MM guide camera I would also have a very small sensor to deal with. That, and the fact that my gear is located remotely have prevented me from getting on with that upgrade so far. Nice to know it is worth doing, based on your excellent result!

ML

Thank you. I think it is probably worth pursuing. I’m sorry I didn’t try it earlier as with a little time and effort I believe I could get some really decent images. I didn’t as a cursory Google of shooting galaxies with a C9.25 would have you believe it not worth the effort. Even if I cannot fix the tilt, there’s so few stars at this focal length that I could probably manually fix them.

 

[Dan Moorehead]

Fantastic