Ngc 55

marc4darkskies (Marcus) · #1 12-10-2008, 05:41 PM

NGC 55 is a challenging target (for me anyway) - especially when the seeing never seems to get better than 2-3 arcsecs!

In spite of being binned 2x2, the chrominance had low S/N, so noise was pretty hard to control while still being able to deliver reasonably rich colour. I guess it's the kind of target that lends itself to megadata so I may add some more chrominance and Ha (to accentuate the HII regions) later. The overall result isn't tooooo bad though.

Small: http://www.pbase.com/gailmarc/image/104403073/large
Large: http://www.pbase.com/gailmarc/image/104403073/original

Hope you like it!

Cheers, Marcus

spearo (Frank) · #2 12-10-2008, 06:12 PM

Very nice
wish i had an SBIG...
frank

strongmanmike (Michael) · #3 12-10-2008, 06:19 PM

Well Marcus ju Karkus that's pretty dam nice mate!

Good to see you leaving some colour noise in the image too

..mind you, some of that other "noise" looks to be actual stellar resolution, cool!
NGC 55 is a very interesting galaxy when imaged well, like you have here.

Your image does look slightly clipped though..? I am sure there is more outside the galaxy to see, any chance you could try bringing some of that up? (no ya don't have to add a slight blue cast...if you don't want to

)

How are you extending the FL of your Tak? I've always wanted to do that with my AP but never got around to it. I think the NJP, in good conditions, would have good enough tracking without the need for the AOL..? That AOL looks to be working well though, how would you rate it as a device in general..?

Nice job and an enjoyable view

Mike

Peter Ward · #4 12-10-2008, 07:32 PM

Marcus,

Really great stuff!

I have nothing meaningful to add, other than keep doing what you're doing.

Again...well done!

AlexN · #5 12-10-2008, 08:43 PM

Very nice and detailed mate.
Well done.

gregbradley · #6 12-10-2008, 08:51 PM

Wow Marcus, that is a sensational image.

Rob Gendler just scored APOD with an image not too dissimilar to that.

How do you do your polar alignment? - it seems spot on. I am wanting to improve mine.

Astrodon filters?

Greg.

marc4darkskies (Marcus) · #7 12-10-2008, 09:37 PM

Quote:

Originally Posted by strongmanmike

Well Marcus ju Karkus that's pretty dam nice mate!

Good to see you leaving some colour noise in the image too

..mind you, some of that other "noise" looks to be actual stellar resolution, cool!
NGC 55 is a very interesting galaxy when imaged well, like you have here.

Your image does look slightly clipped though..? I am sure there is more outside the galaxy to see, any chance you could try bringing some of that up? (no ya don't have to add a slight blue cast...if you don't want to

)

How are you extending the FL of your Tak? I've always wanted to do that with my AP but never got around to it. I think the NJP, in good conditions, would have good enough tracking without the need for the AOL..? That AOL looks to be working well though, how would you rate it as a device in general..?

Nice job and an enjoyable view

Mike

Hey Mike - thanks mate! Yep, there was no escaping SOME colour noise here

. Oh well, I'm in excellent company!

I was careful not to clip but the histogram is pretty steep at the dark end ... I like my sky dark

. I tried getting some more of the halo, but it looked too forced & noisy ... and I'd hate to be critisized for over processing!

I use the TOA extender 1.6. It yields a vignetted field so you've got to have some flats on hand. It's a reasonably flat field too - but not perfect. I like my setup - being able to go from F5.5 to 7.3 and 11.7 give me lots of choices when framing a target. Although, I'm sure some would argue (rightly?) that imaging at 1.03 arcsec / pixel with 2-3 arsec seeing is a bit of a waste of time ... but it makes me feel good

Besides, you never know when the seeing is going to crisp up!

I always use the AOL at F11.7 now. To be honest, I can't say for sure whether it's better that native mount guiding - I haven't tested it - but it looks like it's better. The difference is likely to be small given the EM-400 tracks so well. The corrections performed are of course very fast - and that's got to be good. The guide rate on a guide star of mag 8 - 8.5 is 2-3hz or so for Lum (when the seeing is good). It'll do 5hz for brighter stars. The fastest it can correct is around 8hz I think.

Quote:

Originally Posted by AlexN

Very nice and detailed mate.
Well done.

Thanks Alex

Quote:

Originally Posted by Peter Ward

Marcus,

Really great stuff!

I have nothing meaningful to add, other than keep doing what you're doing.

Again...well done!

Thanks a lot Peter - much appreciated!

marc4darkskies (Marcus) · #8 12-10-2008, 09:53 PM

Quote:

Originally Posted by gregbradley

Wow Marcus, that is a sensational image.

Rob Gendler just scored APOD with an image not too dissimilar to that.

How do you do your polar alignment? - it seems spot on. I am wanting to improve mine.

Astrodon filters?

Greg.

Thanks Greg! Yes, Rob Gendlers image is gorgeous - I used it as colour reference to get my balance right. I think with better seeing I could get even closer to Robs image though - resolution wise

.

A rough Tpoint analysis hints at a polar alignment accuracy around 30 arcsec (achieved via the polar scope). I need to do a better model to be sure though and to be able to refine it - I do see some dec drift when I look at the guide logs.

No, SBIG standard filters (Custom Scientific??)

Cheers, Marcus

Peter Ward · #9 12-10-2008, 10:44 PM

Quote:

Originally Posted by marc4darkskies

No, SBIG standard filters (Custom Scientific??)

Cheers, Marcus

Indeed CS filters have very little crosstalk and deliver better saturation than more fashionable filters.....

winensky · #10 13-10-2008, 12:51 AM

Lovely. I hope to tackle this one with Ha this week and then get some LRGB when the moon goes away.

Garyh · #11 13-10-2008, 11:58 AM

Excellent result Marcus! thoroughly enjoyed viewing this galaxy!

marc4darkskies (Marcus) · #12 13-10-2008, 11:29 PM

Quote:

Originally Posted by spearo

Very nice
wish i had an SBIG...
frank

Thanks Frank.

Quote:

Originally Posted by winensky

Lovely. I hope to tackle this one with Ha this week and then get some LRGB when the moon goes away.

Thanks Matt - and good luck - look forward to seeing your rendition.

Quote:

Originally Posted by Garyh

Excellent result Marcus! thoroughly enjoyed viewing this galaxy!

Glad you liked it Gary although I'm still not entirely happy with it. If I can muster the perserverence, I'd like to double the amount of colour data and grab some Ha. Then again - there are too many other targets that need to be imaged!

Cheers, Marcus

Jen · #13 13-10-2008, 11:35 PM

Beautiful pic thanks for sharing

RB (Andrew) · #14 15-10-2008, 10:47 AM

Marcus that looks fantastic, I love the colours and detail.
Well done.

The 150 is sure popping out some top images and as you say, the versatility of going from f5.5, f7.3 and up to f11.7 gives you a nice choice on a lot of targets.
Gotta love the EM400's performance too, it really is a work of art ah?

Well done mate.

janoskiss (Steve H) · #15 15-10-2008, 11:38 AM

That's amazing, Marcus. Just brilliant!

Craig_L · #16 15-10-2008, 06:20 PM

Lovely shot Marcus. Love all those other fuzzies too.

I wonder whether the TOA extender 1.6 will work with a Sky 90 Tak? I have a Q extender 1.6 but it seems far from flat with lots of vignetting and some chromatic aberration.

I'd love to be able to get in closer to some of these targets.

Craig

marc4darkskies (Marcus) · #17 15-10-2008, 09:49 PM

Quote:

Originally Posted by Jen

Beautiful pic thanks for sharing

Thanks Jen! Glad you liked it!

Quote:

Originally Posted by RB

Marcus that looks fantastic, I love the colours and detail.
Well done.

The 150 is sure popping out some top images and as you say, the versatility of going from f5.5, f7.3 and up to f11.7 gives you a nice choice on a lot of targets.
Gotta love the EM400's performance too, it really is a work of art ah?

Well done mate.

Thanks Andrew. Yeah, the 150/EM400 is a nice combo for sure.

Watch out though when I get a few nights worth of 1 arcsec seeing!

Quote:

Originally Posted by janoskiss

That's amazing, Marcus. Just brilliant!

Cheers Steve.

Quote:

Originally Posted by Craig_L

Lovely shot Marcus. Love all those other fuzzies too.

I wonder whether the TOA extender 1.6 will work with a Sky 90 Tak? I have a Q extender 1.6 but it seems far from flat with lots of vignetting and some chromatic aberration.

I'd love to be able to get in closer to some of these targets.

Craig

Thanks Craig. Not too sure about the "TOA" extender and the Sky 90 - a question for the Yahoo Tak forum. The TOA extender yields vignetting too but is easily removed using flats. Field flatness is also an issue but I usually crop out the effect. I've experimented with the Filter->Distort->Lens Correction option in PS too - I think it would be effective if used gently. Thankfully, I have no chromatic aberration.

Thanks all for your kind remarks!

Cheers, Marcus

multiweb (Marc) · #18 16-10-2008, 07:42 AM

Wow!

Very nice Marcus. I saw your rho ophucius on the ASNSW front page too. Very impressive. Personaly I think that's the best I've seen.

Lester · #19 16-10-2008, 08:21 AM

That is a stand-out image Marcus. The brilliance of the detail is very eye catching. I like it a lot.

marc4darkskies (Marcus) · #20 16-10-2008, 10:35 PM

Quote:

Originally Posted by multiweb

Wow!

Very nice Marcus. I saw your rho ophucius on the ASNSW front page too. Very impressive. Personaly I think that's the best I've seen.

Thanks Marc! Appreciate that. Very nice to see my Rho image making the ASNSW site too.

Quote:

Originally Posted by Lester

That is a stand-out image Marcus. The brilliance of the detail is very eye catching. I like it a lot.

Thanks Lester.