30 second Lagoon Nebula

[laser_jock99]

Single 30 second shot of the M8 Lagoon Nebula. Not something I'd recomened of course (noisy as anything) but interesting to see how much data you get with a fast scope in a short time on a bright target!

imaged with 8" F2.9 GSO Newtonian scope, Canon 40D (full spectrum mod) single 30 second sub @  ISO1000, from dark sky site in Mid Wales.

(click for full size image)

[Guest]

Very nice !!

[wimvb]

Very nice indeed.

I hope you had enough clear sky for more than just that one shot colour. ?

[tooth_dr]

Jeepers that some amount of detail for 30s

[Dinglem]

Very nice, with such a fast Newtonian how difficult is it to collimate?

[laser_jock99]

58 minutes ago, wimvb said:

Very nice indeed.

I hope you had enough clear sky for more than just that one shot colour. ?

The 30 seconds was my 'framing' shot- working on the main imaging run right now.

 

EDIT- For refence each 180s unprocessed subframe looks like ths

[gorann]

Yes, impressive. I just wonder why just one shot and what you did during the rest of the night, or did the clouds move in?

EDIT: Aha - you answered my question at the moment I posted my comment!

[laser_jock99]

4 minutes ago, Dinglem said:

Very nice, with such a fast Newtonian how difficult is it to collimate?

Once the collimation is 'close' not difficult at all- maybe 1 minute or so tweaking before each imaging run.

The main requirement is a quality collimating laser tool (eg Howie Glatter etc) - this makes the job easier and quicker.

Also the F4 GSO Newtonian scopes as shipped will need some modifications to make them more stable for shooting at fast focal ratios (replace mirror collimation springs etc.)

For these reasons fast Newts are not recommened for beginners.

[wornish]

The unprocessed sub frame looks amazing. Cant wait to see the "final" image.

[laser_jock99]

49 minutes ago, wornish said:

The unprocessed sub frame looks amazing. Cant wait to see the "final" image.

Your wish is granted! Stack of ten 180 second subs.

[vlaiv]

There seems to be a lot of star distortion in these fast images you are doing at F/2.9 (sorry to be such a pixel peeper). Do you know the cause?

[laser_jock99]

6 hours ago, vlaiv said:

Do you know the cause?

Yes- laziness! I should re-focus between imaging runs. There is always the possibility that focus will shift or the main mirror will tilt after slewing from one target to another. In theory a re-colimation and focus check should happen. In reallity , at the end of a session, this might not happen!

Hence metal tube Newts are bit too twitchy for easy use.....

Also bear in mind I have posted the full APS-C frame. The corrected area of the coma corrector reducer I used does not cover the full frame.

[Ola Skarpen]

the stars look like eggs, could there be bad guiding?
It also appears in 30 sec exp

[vlaiv]

48 minutes ago, laser_jock99 said:

Yes- laziness! I should re-focus between imaging runs. There is always the possibility that focus will shift or the main mirror will tilt after slewing from one target to another. In theory a re-colimation and focus check should happen. In reallity , at the end of a session, this might not happen!

Hence metal tube Newts are bit too twitchy for easy use.....

Also bear in mind I have posted the full APS-C frame. The corrected area of the coma corrector reducer I used does not cover the full frame.

I wondered about that ASA reducer / coma corrector and it did look like a good match to IMX183 type of sensor with its 1" format, both for imaging and for EAA, but I've also seen that at that speed everything gets blown out of proportion - people have issues with collimation, tilt, you name it ...