2 Corona Australis's

[gregbradley]

I managed to image Corona Australis but again hampered by weather.

I also found I had imaged the same thing under the same conditions
using my AstroPhysics 140 scope and same camera about 2 months ago.

So the 2 images are much the same exposure (the AP had more usable luminance) so it provides an interesting comparison between an AP140 and a TEC180 fluorite.

The images look much the same except for image scale and of course the larger aperture gets a bit more detail.

TEC 180FL LRGB 20 10 10 10

http://www.pbase.com/gregbradley/image/115775756

AP 140 LRGB 40 10 20 10

http://www.pbase.com/gregbradley/image/115775760

same camera (Apogee U16M) same mount and location, smilar weather conditions, the TEC shot the object was higher in the sky but it was also under a 2/3rds moon whereas the AP140 was during no moon.

Both are super scopes.

Of course both of these shots are really really short total exposure time.

Greg.

[multiweb]

Two very nice pictures. When you say LRGB 40/20 10 10 10 I assume we're talking 10min? Does this mean you did only 10min on each color and 20 on the luminance to get that result? Just confused.

[gregbradley]

Almost Marc.LRGB 40 10 20 10 means 40 mins luminance, 10 minutes red, 20 minutes green and 10 minutes blue. Its not that I wanted 20 minutes
of green it was that there were 2 usable green subs but only 1 out of red and blue despite several taken of each which were ruined by cloud.

Very short total exposure time and I would not normally
publish an image that short but they were reasonably bright anyway and with the weather I have had, I have little choice.

I imaged this with an FSQ106N and an STL11000XCM for 5 hours once.
But it isn't really a dim object.

Greg.

[multiweb]

Ok, that's what I thought first but then I didn't undertand how many subs you got. How long were your subs then? 5min? I mean you still need a couple to stack and do some basic data rejection no? I'm just amazed that there is no noise in the pics for such short total exposure time. Even under dark skies. :eyepop:

[gregbradley]

10 minute subs, so a lot of it is a single exposure. Basically I took more but they were too badly flawed with cloud.

The Apogee U16M has 60% QE which is no slouch and I guess both refractors are quite large aperture with practically no light loss.

I agree I did not expect it to be worthwhile but it turned out better than I expected with so little exposure time.

Both scopes have a large corrected image circle. Not sure what the TEC's is but the AP's is something like 100mm which is outrageous.

Greg.

[multiweb]

Well, just wow then! :eyepop: The quality of the scope and camera just put everything into perspective. No way I could get 10min of data that good with no noise :thumbsup:

[DavidU]

Quality +
Quality gear
Very very nice !

[renormalised]

Very nice shots there, Greg. The TEC's is somewhat sharper and has more detail. Colours seem a bit more intense too. An extra 40mm does work wonders. I'd be happy with either:D

[bluescope]

Nice ... I think the Tec image has a slight edge over the AP but it might just have been conditions etc ... oh and ofcourse 40mm extra aperture

:whistle:

[strongmanmike]

Nup hardly any difference from where I sit..? :shrug:

So, no point in you having two scopes that deliver just about the same thing is there :screwy: ...so give the 180 to me please :D

:whistle:

Mike

[marki]

Both images are great, be happy with half that, speaking of which Mike is just being greedy, I'll have the AP :D.

Mark

[AlexN]

Mark and Mike have got me laughing.. :) hahaha

In any case, given the short overall exposure times, they are both fantastic images... I'd be stoked to have something even remotely similar...

Let me just get this straight... The AP140 has a 100mm image circle? Are - You - Serious!?

Guess what is at the top of my list of "things I want" right about now? That and a camera housing a KAF-39000 or KAF-50100 sensor.... Granted the KAF-50100 only has a QE of 0.25%, I'd deal with taking 40min exposures if I was getting a 50 megapixel image, with a 61mm diagonal sensor size... The KAF-39000 might be better, same physical size, 39mp and 30% QE... all this being said the KAF-16803 is perhaps the most likely.. and with the same 60% QE as your U16M, should produce similar results..

Oh wow.. that was quite off topic :D haha... my bad.. got caught up in dream land for a moment there...

Awesome images, Awesome scopes, Awesome processing...

Awesome!

[gregbradley]

Yes they are absolutely beautiful scopes and the Apogee U16M is a very nice camera too alhtough if I were buying again today I'd get the FLI Proline 16803 instead as it has better cooling. But I can upgrade the cooling on the U16M to match only it takes a bit longer to cool down. They have different cooling philosophies.



Thansk David. The gear makes it easy to be honest.



The AP is more a wider field type scope but as Mike has shown with his 152 you can wrench a lot of detail out of that perfect lens.






The AP is one mean purpose built no nonsense 30 years of know-how built into a scope. You'd be hard pressed to find anything wrong with it.



You got me excited about it now! There have been some images with the KAF39000 done by Richard Crisp. It comes only as a one shot colour and has super large files. The 16803 is the practical chip still.

[AlexN]

I was just reading the Kodak site and thought there was mention of the KAF-39000 mono sensor, I may have been mistaken as I've been reading lots of information about many different imaging sensors over the past few months... I agree the 16803 looks to be the best option out there at the moment... nearly double the QE of the KAI-11002M, bigger physical sensor, pixels are still small enough to give a good stellar resolution... Seems to be a real winner..

To follow on from Mike and Marks comments before, If you send me the AP140, I'll sell everything I own, including my soul, to get a FLI PL16803 and we'll both get to see how it goes! :) hahahaha!

Aahh.. The simple joy that is dreaming.. :)

[Alchemy]

clean for single exposure on each channel, however lacking in color as a result and looks largely monochrome,.... just have to get back out and add to it. admittedly hard if its cloudy:P

not a lot of difference between the two scopes, if this was a long exposure i would expect much much more detail on both.

hope im not coming across as harsh, but i know you could do much better with more exposure and the comments are with that in mind.

[bluescope]

Get in line Big Boy ... I've told Greg before that I will happily take good care of the TEC 180 should he need somewhere to store it for a while ;)

:thumbsup:

[Tom Davis]

Two great scopes, two great images!

Tom

[Craig_L]

Great processing Greg - lots of detail and little noise for so little exposure.

[telecasterguru]

I think both images are fabulous. Clear as a bell across the interstellar highway.

Frank

[gregbradley]

Its good to have dreams.



Yes I agree the colour is lacking and I would not normally publish such a short exposure (I like to do at least 6 hours on an object) but as you can tell a bit desparate at the moment from a string of poor weather which won't last for too long as in Feb I got 10 clear nights in row.



Hehe, it is a very nice scope. I am about to try some planetary imaging with it thanks to Fahim lending me a camera.



Thanks Tom.



I remember having to take 5 hours with an FSQ and one shot colour STL11 and struggled big time with noise in the dust bands. Mono is the way to go for that sort of thing. Plus the 16803 chip at -25C is very very clean.



Thanks Frank. My dark site has virtually no light pollution and usually extremely transparent skies. The seeing is usually pretty good (I think).

[spearo]

Lovely shot Greg
brilliant
well done
frank

[gregbradley]

Thanks Frank.

Greg.