M42, Orion Nebula

[frank777]

Upgrading from a mirrorless camera to a dedicated astrophotography camera, excellent mount and autoguiding has seen the expected increase in quality of my images. This is my first extended exposure using all of the above - taking 5 minute exposures instead of the previous 10-20 second exposures seems like a luxury.
Telescope: Celestron Nexstar 6
Main camera: ZWO ASI294pro (OSC)
Guide camera (through OAG): ZWOASI120mm
Mount: Sky Watcher EQ6-R Pro
Filter: Optolong L-eXtreme
50 x 300 sec subs, plus darks, biases and flats.



https://www.astrobin.com/full/xwh7m0/0/

[RyanJones]

Well done Frank.

Now you have all the gear it’s time to refine things. My first suggestion to you would be to back down your sub length significantly. At 1500mm focal length you are learning the hard way. That’s not to say it’s wrong by any stretch. There is clearly a lot of movement going on in your tracking shown by your star shapes and you should probably try to refine that before trying to push such a long focal length for such a long time. I would suggest trying to get round stars with 1min subs first. With that mount in calm conditions ( no wind or vibrations ) and with good balance, you should almost be able to get that unguided. Then work on your guiding from there. Get nice clean guiding graphs and then bump up the exposure time.

Another suggestion would be to get hold of a focal reducer. Maybe a 6.3 ? That will take your focal length down to a much more manageable 945mm. It will also reduce the required exposure time becoming f6.3 rather than f10. It will give you a wider field of view which will allow you to capture more of the brighter nebulae while you hone in your skills.

This hobby is so rewarding at each stage of your progress. Please don’t take my comments as criticism because they are entirely intended to be constructive. You’ve obviously taken a big step forward so I’m hoping I/we can help you to take the next one.

Cheers

Ryan

[frank777]

Thanks Ryan, I appreciate your comments. Actually I am using the 0.63 reducer but I know I'll eventually need to get another OTA of a shorter focal length to give me a wider FOV. I started with my 6 inch SCT a couple of years ago for visual observing only so I thought I'd just keep using it for AP while I'm learning the ropes. Nothing like jumping in at the deep end!

Frank

[Kuz]

Hi Frank, with the Zwo 294 camera it is better if you do not use bias frames. .as they are not required with this camera

[RyanJones]

I know the pain well. I started on a C5 on an Alt-Az fork mount. :rofl:

[Stephane]

Frank, beautiful image. It seems we have the same camera, filter, and mount! Just the OTA is different. Ironically, the OTA is one of the cheapest parts of the astrophotography setup. Can't wait to see your future images too. Well done.

Regards,
Stéphane

[frank777]

Yes, I found that out recently. I'm now taking dark flats which I believe are a better alternative - or I would be if the clouds above Sydney would go away :mad2:

[frank777]

Thanks Stéphane. I've been following your posts over the last few months and have learnt a lot from the responses - keep it up :)