Helix

[Tandum]

Here's the Helix Nebula from my backyard: 9 x 10minute subs @ iso400.

And another 253: 17 x 15minute subs @ iso400.

No light pollution filters on these but no moon either :)

[AlexN]

Not bad.. Not bad at all!! theres a little bit of trailing in them, but the 253 mist have made you happy!!! Thats been eluding you for a while, but now... Now you've hit the nail right square on the head!

Why are you shooting at ISO400 by the way? If you're shooting darks (and im pretty sure you do) you should shoot ISO800.. the amount of detail you'd get in a 15min ISO800 shot would be intense.! :)

Just a suggestion also, the top and right hand edges of the 253 shot show the rotation and movement between subs, the image would look a lot better with those darker areas cropped out....


A Job well done mate... Now go get some sleep :P

[spearo]

well done Robin,
you'd be pleased with these.

I can tell you must have spent quite some time making sure your polar alignment was dead on
A tad darker for the black point is my personal preference.
well done
frank

[Tandum]

Cheers guys. Was checking out how long to expose without the CLS filter. Kicking up the iso brings up the noise and the gradients. Got a Ha filter in the mail for when he moon comes back ;)

[Ric]

Well done Robin, great images. The Helix looks very natural with the right blend of colour.

Cheers

[Tandum]

Thanks Ric but there's more of it there I'm sure. If I stretch the image to hell I can see what appear to be spirals coming from it. Might have to spend more exposure time on it to see, they are pretty faint.

[Craig_L]

Nice shots Robin, particularly with no filters. Lots of detail in NGC 253.

[Tandum]

Craig, still not happy with 253. I've shot it so many times now and there does not seem to be a definate edge to the galaxy. It seems to just dissolve into dust. I always thought it was an imaging problem and so I have shot it over and over again and get the same result every time. This one is 4 hours with really long exposures and I got the same result so I guess the galaxy just disolves into dust on it's boundaries :)

[Craig_L]

Know what you mean and can't get as much detail as you. Lack of focal length among other things.

[Tandum]

I think it's more to do with mirror power. I aquired a 12" dob last week and am trying to get it onto the mount with a camera down the tube to see if it gives more detail.

It's really hard to get 355mm tube rings :)

[edit] the Vixen has the reducer in so it's about 1200 F/L @ F6.3 similar to an 8" dob. I imagine the detail difference between an 8" dob and a 12" dob will also show up in the photos.

[AlexN]

Robin, You can get rings for your 12" from the UK... Orion Optics UK can do them up for ya!

[Tandum]

Yes I know Alex, but I'm not paying them in AU pesos for them at the moment.

I have a set of 303mm rings coming which I hope to modify to fit :thumbsup:

[AlexN]

you might get 303mm rings to fit, but I think the OD on a GSO12" is more like 325mm.. not sure. Its been a while since I checked...

[Tandum]

Think 355mm. It's not small at all ... :(

[AlexN]

yeah... a 12" scope is where you can really start calling yourself an apertureoholic! :)

[Tandum]

I can see detail through the eyepiece on that 12" dob that I can not see at all through any of the 8" scopes I've owned. That C11 of yours would be similar, if you could get the sucker on target. What is it, a 3 meter F/L?

[AlexN]

2790 @ F/10 and yeah, the visual detail it gets in the helix / globs & faint fuzzys destroys my old 8" I've got it all set now too.. mirror lock installed.. and judging by tonights 20minute exposures I've been getting, I reckon I can get the C11 out for some DEEP sky imaging!! :D

[Tandum]

Go for it, only problem I see Is getting some of the stuff up there to fit into your scope down here :)

[AlexN]

:) Helix will NEARLY fit at F10... at 6.3 I easily fit M20, M8, any gobular you like.. faint fuzzies!! :) At F/6.3 its just a touch shorter than your 200L @ f/9... 1750mm