Ngc5128 - Easy HDR applied

[Bolts_Tweed]

This is just a quickie to see how Ken Crawfords MLDB ans selective smooting techniques work on 5128.

L(60), R (30) G (30) B (30)

AP130EDT, ST8300, Astrodon E series LRGB

I know the core is bright but I pushed it a bit to get the outer dust lane detail. Might try masking it into a less exposed core if I get sky again tonight.

Mark Bolton

[renormalised]

Core is a bit overcooked, but that's no worry...can be fixed:)

However, it certainly brings out the details in the dust lane:)

[gregbradley]

Yeah its overcooked but you got some nice detail there. Its easy to overcook, I have done it many times!

Again, a surprising amount of detail for 130mm of aperture.

Now you know why AP scopes are so highly sought after. I was going to
sell my AP140 to fund a larger scope but decided against it. They are too
hard to replace.

Greg.

[Bolts_Tweed]

Thx guys

Yeah I found it necessary to push it for the outer detail. Looks like its going to be fine tonite so I can cover the blown out core.

Ive been toying with the idea of going RC as well but this AP is like driving a ferrari compared to what i'm used to so i tink i'll stick with it for a while.

Mark

[gregbradley]

If you do go larger aperture I would suggest corrected Dall Kirkhams or corrected Cassegrains. I guess they are all quite similar now as even an RCOS needs a flattener ideally with the larger chips these days. So its 2 mirrors of whatever shape and a corrector/flattener that seems to be the u-beaut formula.

Planewave CDK is best bang for your buck or perhaps Orion Optics UK optimised Dall Kirkham although he is not meeting delivery times currently and there are very few examples out there with proof of performance although I believe their instruments will prove to be awesome.

There is a new RC maker from Germany selling on Astromart (Anacortes). Alluna. Their spot sizes are amazingly low. I see they also have a built in corrector/flattener which is as I say all the rage now.

The "advantage" of CDK is the primary mirror is easy to make so its easy for them to get it very accurate like a Newtonian. RC mirrors are not easy to make hence the high cost for these high end scopes.

Your 130 would also make an awesome widefield scope with a large chip and an RC would make a great instrument for galaxies, planetary neb etc.

At the end of the day unless your long focal length image is really super well done you will produce more pleasing images with your AP130
more often.

Greg.

[Bolts_Tweed]

Yeah I agree re the scopes greg. I had a 10inch ACF - doesnt compare - but I just could not use it - my limitations not the scopes. Peter Ward also just made the comment re quality of seeing etc required by larger scopes.

I was just at Optcorp's store in California and they had a huge CDK on a Paramount for sale just as you walk in the door. My wife grabbed me by the arm and dragged me to the counter to get me away from it.

Little did she know I spent a bundle on a IFW from Optec and some astrodon filters.

I think I am just a refractor kind of guy and happy that way.

Mark

[strongmanmike]

Great for resolution for sure but a small aperture is a killer for collecting photons :( of course it helps having almost the best APO available too :D

Your Cen A image is not far from this really...of course the AAT shot is tiny but as presented...I recon your shot creams it :thumbsup:

http://www.mpe.mpg.de/~hcs/Cen-A/Pictures/cen-a-aat7-new.jpg

Mike

[DavidTrap]

Ok,

I've decided to start asking you guys questions to try to understand a bit more of what you are saying - I really need to improve my knowledge of processing images.

I can see what you mean by blowing out the core. Is this a problem of lowering the white point too far when processing, or is it an exposure problem from the wells being overfilled?

Ta

DT

[Bolts_Tweed]

Thx guys

Yeah mike - small aperture + faint detail = HDR I agree but hopefully I can reduce it a bit. Imagine a few years ago comparing an AAT image to a 2.5 hour amateur image. Digital imaging has come a long way. I us David Malins 'Colours of the Universe' as a colour guide (admittedly not very well some times :lol:) but I easily remember thinking the images in that were mind blowing. I would be dissapointed if I got someof them now. Although not fair to compare - I'd love to see what David could come with digitally with all that gear.

DAvid - Yeah mate - full buckets - I pushed the exposure for longer subs to try and get detail in the fainter outlying dust lane with a resulting histogram that looks like a ski jump.Tongiht hopefully I can cover the dynamic range of the galaxy (as much as the 5 inch will allow) and mask that longer dust lanethrough ontot it.

Ask away my firend - Im not an expert but what little I do know came from asking hte right questions to people like Mike and others on this forum as well as others I know. Questions are how you learn

Mark

[Bolts_Tweed]

I reduced the core with Easy HDR (Wireless Internet is wonderful in the bush).

It has reduced it a fair amount but needs more I think. Almost looks 'ringed'. Maybe more intermediate subs - never used this before - will experiment.

Mark