first light CDK17 and reducer giving F4.51

[gregbradley]

This is really a test image to see how the reducer on the CDK17 works.

The guiding was done with a Vixen 95VMC and an SBIG ST402ME.
This worked really well and no sign of flexure with 15 minute subs.

The reducer gives F4.51. Collimation is a touch out still so further tweaking is still to be done on a clear night.

I am happy with such a deep image with only 2:45 hours with a 5nm Ha filter.

http://www.pbase.com/gregbradley/image/136352364/large

Here is an inverted image showing the large extent of the nebula not often seen:

http://upload.pbase.com/image/136352411


Greg.

[Ross G]

Hi Greg,

Amazing quality for a test image.

Wow..17" at F4.5.....a hypertuned hyperstar!

This will let you image some very dark parts of the sky.

I am looking forward to seeing some unique photos.


Thanks.

Ross.

[Tandum]

WOW Greg, thats a lot of signal. I've got hours of Ha @ F8 on helix but it's nothing like this. What is the imaging camera?

[alan meehan]

Greg aweinspiring the outer nebula is just amazing what a perfect set up well done
AL

[multiweb]

Wow! Light bucket! :lol: Splendid shot. Deep as. :thumbsup: The field looks very good too.

[Paul Haese]

I really like the third outer ring visible in the top of the image. Nice scale too.

[strongmanmike]

He he he, we got ourselves Schmidt cameras huh? :thumbsup:...David who..?? :question:

Mike

[netwolf]

Greg,
Wow so much signal and great details on the rings. I cant wait to see the Color version of this. You could do your own sky survey with that thing.

[Saturn%5]

Great Shot:thumbsup:

[gregbradley]

I think this setup will now allow doing some dust shots and some narrowband during the moon weeks much better with the reducer. Also the image scale on some of the more common objects is probably better for framing and composition.



It is a very faint nebula. I took several hours of it a few times and both were very poor. So the reducer and binning helped a lot.
Camera is a FLI Proline 16803 with about 62% QE at -35C and an Astrodon 5nm Ha 50mm square filter.



Thanks Alan. It takes a while to setup these things up so you are happy with them.



Thanks Marc. I did M8 too!



The extent of the nebula is surprising. Its a massive improvement over some Ha I took of it about 6 months ago which was really disappointing.



Hehe. We've both got our fast light buckets now.



Thanks Fahim. I plan on doing a narrowband on this to start. I'll add some RGB once the moon goes.



Yes I was pleased it caught so much.

[sjastro]

Great image Greg.

Regards

Steven

[Stevec35]

That's very impressive Greg. I bet you are going to have loads of fun with this latest toy.

Cheers

Steve

[bartman]

Wow Greg !
Great shot and so sharp ( in my eyes!).
Love how you can see that center star so clearly.
Cheers
Bartman

[Bassnut]

Most impressive Greg, the extention is amazing. 20min Ha subs on a 10"at f8 and hiQE and I cant get remotely close. A real eye openner.

[strongmanmike]

It is visible in the normally processed version but I also did a pushed negative version like Gregs and yep, 2hrs with 5min subs and the 12" at F3.8 nails it all too, WFW does rule in some cases :thumbsup: he he

Mike

[strongmanmike]

Mines a bucket.. your's is closer to a wheely bin :thumbsup:

[Tom Davis]

Right on!! Now that is a scope combo! Shoot 'em up Greg! Who needs a Honders!!!!

Tom

[marc4darkskies]

Whoa! Can't argue with that Greg!! Nice! I'd consider imaging at that FL more often than not. It's probably a better image scale for these parts anyway (?)

Cheers, Marcus

[gregbradley]

Thanks Steven. I think the reducer brings the system into being a better match for my camera and location where the seeing is OK sometimes and poor other times. At my dark site the seeing is good most often and average only sometimes.



Yes I am happy. You'd be amazed at how poor several hours of Ha was I took about 6 months ago though. So the reducer works a treat. Mind you gradients will still be a challenge with a bright moon.




The centre stars are really tight and out to the edge they aren't as tight but still quite good. There is a touch of coma and distortion due to my focuser no longer being 100% square. I also tweaked collimation last night and could also see my primary to secondary spacing needs adjusting. When does it stop eh?




Cheers Fred. It looks like all roads lead to large aperture and fast focal ratio. This will really be a strong setup for narrowband now and I can finally recommend it for that whereas I could not before.



Funny how we've ended up at a similar spot Mike. There must be some basic principle at work here that we are following.



:lol:



Now Tom you have to do penance for saying the Honders name in vain.
I would like a Honders! But then... no, Honders doesn't need collimation, it portable? and its light? and very compact plus its an AP so everything will be super perfect.



I agree Marcus. I think it is taming the beast to the local conditions and matching the camera to the focal length better. So that is 1953mm at F4.51 with 9 micron pixels. I figured 12-13 micron pixels would be a better match for the scope and now with the reducer the 16803 has the equivalent of 14micron pixels compared to native focal length.

I plan on doing more Ha exposure and a narrowband image of this. Perhaps a 20 hour plus epic as I have always thought the Helix is one of the absolute best targets.

Greg.

[Lester]

WOW, now that is really catching the dark stuff in a hurry. Outstanding views of the Helix, Greg. I will look on with interest at what you get next. All the best.

[DavidU]

That's impressive !

[CoolhandJo]

A whole new league! Excellent detail.

[John Hothersall]

I love this kind of deep reach imaging and your Helix is an eyeopener for sure with all that extra material.

John.

[gregbradley]

Thanks Lester. I intend to take some more exposure time to take it a bit deeper - maybe 6 hours or more total and then the other narrowbands.



Cheers David. It certainly went deeper than I expected.



Thanks for that. I was happy that it is performing the way I'd hoped it would.



Thanks John. I was hoping the large aperture would some horsepower in this direction.