[Paul Haese]

Thanks Ian, Lewis, Mark, Slawomir, Russell, H, Lee and Erik for the comments. Thanks for taking the time to contribute.

Originally Posted by gregbradley

Great detail and colour and you got some of that extra halo starting to show through. Very nice.

Aperture, F ratio and camera QE are a like a triangle for imaging speed. I have been impressed by how fast the Honders accumulates data with the Trius.

Of course every system has its advantages and disadvantages but there are quite a few scopes these days that have both aperture and fast F ratio. IDK,Harmer Wynne astrographs, Officina Stellare, OOUK, AP RHA are a few. Ceravolo F3.9 300mm was one of the first. I have often wondered do you get the same result of long focal length by using a small sensor on a fast scope. So far my experience is that it is similar but there is no substitute for aperture at the end of the day (or darks skies!). But fast wide aperture scopes like Mikes Astrograph or my Honders with a smaller chip with smaller pixels seems a little less sensitive to seeing than longer focal length with larger pixels. I am not 100% sure of that but so far it seems it is.

Greg.

Thanks Greg, I think that something like a 16" with a focal length of around 2400mm or slight longer would be the go. That would give an f ratio of 6. I don't think focal lengths under that are useful to me for what I would like to image. It's an interesting conundrum.

Originally Posted by SimmoW

Such a small target Paul, but so crisp! And yes, I spent a good few minutes galaxy hunting in your lovely image.

I too am realizing that aperture and F ratio are the key. I'm building a new scope, 250mm aperture f4 versus my tak's 130mm f3.3, should suck in a fair bit more light

Thanks Simon, this is why I have two rigs; one for long focal length work and one for the wide field stuff. There would be too much of a compromise otherwise.

Originally Posted by topheart

Good one Paul!

I agree - it is very illustrative to compare the different imaging setups and efficiency etc.

I also have been capturing this target over the last month and will probably have 40 to 60 or so hours of LRGB HaO3 data in total....I will get onto processing this data as a comparison - taken with the 4750mm focal length 20 inch with a PL16803.....
Cheers,
Tim

Thanks Tim, now that will prove rather interesting. I will look forward to that.

Originally Posted by Placidus

Bravo! Most minute detail in such a tiny target. I particularly like the super-fine almost overlapping shells in the main bright part of the nebula. One wonders if the true three-dimensional shape is a double cone seen axially.

The tiny galaxy and the bright orange star in the near field make for a photogenic background.

Thanks Mike and Trish, that is a distinct possibility about being a double cone seen axially. I had not considered that until now, but now that you mention it, that does make sense.

Originally Posted by alpal

Nice work Paul,
I don't know how you have patience or the time.

So - share with us all please -
what is your next telescope idea?
How about a 24" f3 Newt.?
That would pull in the faint ones & still have 1.8 meters of focal length
which would match the best seeing possible.

cheers
Allan

Thanks Allan. It won't be a Newtonian. It would not fit in my dome. So I am inclined to look at something like an f6 16" (with reducer if necessary). 2.4 metres is my aim for focal length.

Originally Posted by RickS

Nice work, Paul! It's a cool object and you've captured and processed it very well.

I first saw the Oiii halo faintly in an image by Martin Pugh. I have 75 hours on this object from last year that I should probably finish processing. Unfortunately, I wasn't able to get anywhere near the detail in the Oiii halo that Don Goldman had in his inverted image (and no other image that I've seen has come close either.) I think that with his aperture and image scale he's able to take read noise limited subs in a manageable time which is something that those of us with 12" scopes can only dream about in narrowband. Still, it's fun to try

Cheers,
Rick.

Thanks Rick, agreed, Don's superior aperture has it over the rest of us. Still I like to try. There is always a limit to what can be achieved but like you say it is fun to try.