First light for my celestron 11" RASA

[h0ughy]

an unguided and unprocessed shot of eta carinia NGC3372 of 1 second, 5 seconds 10 seconds 15 sec 20 sec 25 sec, 30sec, 40sec, 60 sec and 90sec at iso 400 with the canon 450d.and the celestron RASA 11
OMG this is so awesome and i am finding focus is critical i havent taken darks, flats or bias's yet

[h0ughy]

the rest

[leon]

Wow, now that is some great shooting, I can see you
are going to have some fun with your new toy, well done indeed.

Leon

[h0ughy]

forgot to say no light pollution filter used and the light pollution was bad

[RickS]

f/2.2 is too fast for the light pollution :)

[h0ughy]

Absolutely agree but how much fun at a dark sky sites

[RickS]

Hmmm. That didn't come out how I meant it. I was light-heartedly suggesting it was so fast that the light pollution doesn't matter. Which is true to a degree... a fast scope gives you an advantage because you need more signal to minimise the effects of light pollution.

[h0ughy]

well it's been a while since I have done any deep sky stuff and this should give me some practice. Need to relearn PI. Also need to learn how to do flats with it, and suggestions

[RickS]

I'm sure that your PI chops will return quickly :thumbsup: Will be interesting to see if flats are tricky. At least you won't have to worry about dust too much - it will be well out of focus.

[LewisM]

Is there any way to mitigate diffraction spikes with these? We need a BlueTooth CCD Cam so you don't need cables and such :)

Nice preliminary results! Impressive.

[glend]

Very promising first light images! The right camera will make a big difference. No disrespect to the venerable 450D ( and i still have my cooled version), something like an ASI1600MC-C would really take advantage of that scope. Fitting within the central obstruction it will maximise light grab, increase contrast, and with its ultra low noise you can take very short subs to escape sky glow saturation. It would excel at fast narrowband, if you go for a cooled mono camera (like the ASI1600MM-C), but a filter drawer system (try Teleskop-Services) would be needed to avoid a filter wheel blocking signal. Add a set of high speed narrowband filters and you have it all. An exciting project for sure.

[Atmos]

You’ve got to wrap the cables in a circular way so that the diameter of the circle is about a third of the aperture.

[bojan]

Very nice...

I had a look at pricing for RASA/Fastar/Hyperstar... prohibitive.
On the other hand, Freestar alternative, being much cheeper, is not a real alternative.

Does someone know about anything it the middle of those two?

[RB]

@ h0ughy - more clouds huh?
Oh wait, it's Eta. :lol:
Beautiful mate, congrats on first light.
Gee, that didn't take you long to take out of the box and start imaging.
You're exactly like me {/not}.

:rofl:

[JA]

That signal is great and it'll only get better with a filter.

Best
JA

[h0ughy]

I wait with baited breath for the unboxing of the doorstop :rofl:

[h0ughy]

Thanks for that information. So how do you do flats :question:

[h0ughy]

You might be onto something there Glen. May look into that option. BTW I undeleted your post. It was constructive :thumbsup:

[Nikolas]

With a giant mallet?
(No idea sorry)

[JA]

You could do it in the classical way or more easily with either one of these.....
1. Use Adobe Camera Raw or
2. on some Nikon cameras there is a vignette control. Perhaps also on Canon.


Here is the function in Adobe Camera Raw (start at 44 seconds in for an intro and then skip to 12:40 ish for Processing in Adobe, GRRRRrrrr software wont go there automatically despite instruction to do so..... Oh well maybe watch the lot it's entertaining and interesting)

https://youtu.be/PZoCJBLAYEs?t=44s

Best
JA

[Octane]

High resolution Moonage incoming?

Congratulations; what a great piece of gear.

H

[glend]

It looks like there is a filter drawer solution for the RASA:

https://stargazerslounge.com/topic/254198-filter-slide-for-celestron-rasa/

[LewisM]

Or he could use a really good sensitive OSC CCD like the SX M25C or M26C...

[h0ughy]

Could try that with the gstar ex3

[RB]

You know you have an open invitation.

:P

[glend]

With respect, the read noise for those two cameras are very high compared to modern CMOS cameras, meaning he would be forced into longer subs. In his light polluted environment, many short subs from an ultra low read noise camera is going to beat sky glow to a large extent.
And at that RASA focal length, 620mm, smaller pixels have a lot to offer in terms of resolution,imho.

[RickS]

With a fast scope and heavy light pollution sky limited subs will be short on a CCD camera too and there will be negligible difference in the outcome.

Smaller pixels may be more suitable depending on the resolution/FOV trade off that David is looking for, but they will also collect signal more slowly.

[h0ughy]

Just ordered a asi zwo 071mc pro

[RB]

Of course you did....
I wouldn't expect anything less from you....

:lol: :drink:

[RickS]

Is that all? :lol:

[h0ughy]

Yep ;)

[h0ughy]

Sorry Photoshop is not my best instrument of photon mangling but here is a scrappy 2h11m ISO 400 unguided conglomerate image

Will redo in pixinsight later

[LewisM]

Lovely Mr. Hough! That's one hell of a Photon Pacman!

May I humbly recommend BackgroudNeutraliser in PI...

[RickS]

Looks just like a bought one :thumbsup:

[h0ughy]

I am hoping that the 71 will allow better star colours and depth than the old 2008 Canon 450d.

And must relearn bad habits of PI;)

[h0ughy]

well the other part of the puzzle arrived today - the specialised light pollution filter for the RASA

[ChrisV]

Wow, how long are your subs going to be, like 10 sec ?
With my ASI071 I'm totally swamping read noise with 60-90 sec subs at F5.9 - buts that's in outer Sydney suburbs.

[h0ughy]

Will have to see, may not be longer than 60s

[glend]

Good to see Celestron offering this filter. One of the big issues with ultra fast scopes like the RASA and HyperStar conversions, is the problems that emerge using standard filters, particularly narrowband ones and LPs, as the fast ratio light angles can be somewhat blocked by standard filters and can slew spectrum ranges outside the norms. :thumbsup:

[h0ughy]

Pixinsight version
http://www.iceinspace.com.au/forum/attachment_browse.php?a=226785

[strongmanmike]

Well, everything is looking pretty cool so far Dave :thumbsup:

Mike

[h0ughy]

So what do i get an asi071 or an asi094?i could mosaic the 71, probably be doing that anyway with the 94?

[multiweb]

Didn't realise they needed a dedicated LP filter for that scope. Any reason?

[h0ughy]

Well if you look at the scopes design You See using a filter drawer is problematic. In my environment at home it will be a must. Will install it after spsp. BTW I am considering a a zwo asi094mc Pro :D

[multiweb]

I meant the LP filter packaging mentions RASA. I thought any LP filter would do. If the filter drawer is small enough it would fit in the shadow of the secondary. I have one but still to try with the hyperstar. The central obstruction looks a bit bigger than the RASA though. :question:

[h0ughy]

Apparently not

[h0ughy]

Might have vignetting issues with the 94, but the real estate is inviting