first light C14 Helix and Sculptor

[spearo]

Hello,

First real light.
Still working out sweet spots for balancing and guiding etc
5 min subs on the Helix and Sculptor
better than what I could do before on these same subjects but i think I can do better still with better guiding and longer subs eventually
anyways, here goes
cheers
frank

[iceman]

Very nice indeed, Frank! Great first lights!

More exposures will help next time. Did you calibrate with any flats or darks?

[spearo]

Thanks Mike,
I only used darks, never got around to using flats yet.
It's been so long i kind of forgot how to process images!
:]
frank

[iceman]

Flats will make a big difference too and allow you to stretch the image more.

I know what you mean about processing - I've got a couple from Nambucca that I need to process up, but it's been months since I've processed a deep sky image.

[Dennis]

Hi Frank

Impressive images, especially for first light at 2.2 metres focal length.

Cheers

Dennis

[spearo]

Thanks Dennis,
I still don't know what I should say about the focal length: The C14 is an F11 so when I put the the 6.3 focal reducer on does it make it 6.3 or 7.3 ?
????
anyways,
i've had a quick try of 1 min shots at F11 and cant wait to try that seriously, that'll be a focal length of 3.5 meters and promises to reveal nice stuff a few small and fuzzies I want to image
gotta work out balancing/guiding etc first
i'll keep everyone posted
cheers
frank

[strongmanmike]

Two nice images those :thumbsup:

The guiding looks pretty good to me..?

Mike

[Dennis]

Whoops – thanks Frank, I did my calculations based on F10 so at F11, you are closer to 2500mm!

I think an x0.63 reducer will make an F11 system an F6.93 system?

Cheers

Dennis

[AlexN]

They look awesome to me mate!

Well done.

[Ric]

Very nice Frank, two great looking images but I really enjoyed the Helix.

I'm looking forward to more images with the C14.

Cheers

[rogerg]

In theory... but I suspect it'd be quite different, depends what's in the image train. My F/6.3 takes my F/10 scope to about F/7.3 :)



Nice images for a first night. Perhaps a bit high on the contrast for NGC 253 as viewed on my screen, would prefer that backed off a little. Looks like you have quite a nice flat field there, I would've expected a lot more curvature. I only ever tried my 350D on my 12" LX once and had some curvature visible around the corners.

:thumbsup:

[jase]

Great work on the 14" Frank. More data will certainly provide pleasing results - @ F11 you'll need longer subs or a higher ISO. A focal reducer would be beneficial if you find it hard to keep stars round when imaging at such long "tear your hair out" focal lengths. Look forward to seeing more.

[spearo]

Thanks everyone,
really appreciate the feedback
Roger, there's a very slight croping done mainly to center the target in the final frame but also to remove some of the stars on the edges which are inevitably suffering from curvature, not much cropping though.

Dennis and Roger, thanks for the info re F ratio, I think I can probably say with clear conscience that the F ratio with the focal reducer and imaging train (focal reducer, 10-1 focusser, Canon) if F/7 ? just never really saw that anywhere else.

Alex and Ric thanks for the encouragement

Jase and Strongmanmike, very pleased with your kind words. On the full res images i notice a very slight elongation in the stars so the guiding isn't perfect yet. I also had to discard 10 min shots which all showed some trailling so I haven't got it licked yet bu i know I'll get to it at some point...just need more time at the scope!
or a self guided SBIG which would reduce overall weight issues, neutralise the issue of differential focal length between the imaging and guiding setups
maybe when the bankbook allows ...the better half is already supportive (what can I say...she's a keeper!)
:]
thanks everyone
it's good to be back!
frank

[GCO]

Dear Frank,

The exact focal length with the "standard" Meade or Celestron "f.6.3" focal reducers, is 2,370mm. This is taken from using the standard Celestron 1.25" visual back. The resulting f/ratio is f/6.88. However, the FURTHER you are back from the focal reducer, the longer the focal length (and the more coma being introduced) but they are less senstive to distance than the Optec focal reducers and this is why we prefer them. We have run our C14 with filter wheels and flip mirrors using them up to f/7.2, without any problems with CCD chip sizes up to a ST-10.

Trust this helps you.

If you have any Celeston C14 questions, please feel free to ask me - Grove Creek has the 2nd C14 ever made by Celestron and it has undergone a lot of modifications and different configirations. We have a movie on YouTube about our C14. Just go to www.youtube.com (http://www.youtube.com) and search for "C14 Grove Creek". More details about our C14 is at:
www.gco.org.au/scopes/ (http://www.gco.org.au/scopes/)

Our C14 has recently been moved out of our fork mount to a Astro-Physics GTO-1200 mount. The previous fork mount had a Agro Navis and DEC & RA stepping motor tracking system that I built and designed. The fork, motors, controller, Agro Navis and encoders are now all packed away, where we may possibly sell it in the future. The fork only had a PEC of 9.75^sec peak-to-peak, which was very good for its time - 1972.

Steven Williams,
Managing Astronomer
Grove Creek Observatory
www.gco.org.au (http://www.gco.org.au)

[Ian Robinson]

.... green with envy , got some great gear there.

[Ian Robinson]

those images ---not too shabby .... love the galaxy shot.

[Rigel003]

Very nice first images, Frank. How well does the G11 handle the weight of the C14 plus guidescope?

[peeb61]

Great images Frank,
Just got to love the helix...and I do!

Paul

[seeker372011]

oooo impressive and for first light at that

[Hagar]

Nice images Frank... Looks good for focus and colour. Longer subs is the way to go. Keep at it.

[spearo]

Thanks everyone,
It's been a bit of a hassle getting to the observatory so I haven't had much of a chance to try anything else out.
Had a go last weekend but clouds moved in...
I realized that the trailing i was getting past 5 min was probably my alignment and sure enough it was all out of whack so i spent the entire night fixing that (i'm a bit rusty...)
will test it out this weekend.
Thanks for the info Stephen,
i have still much to learn!
At this point all tests suggest it works fine on the G11. I tested a preferred mode of setting up the guidescope using the base plate for C14 and putting the guidescope underside it but I could only image to the East because it didnt have quite enough clearance to move around ...the best would be if the Losmandy base plate could be extended say 6 inches or so
having the guidescope allows it to be right close to the center of gravity and requires fewer counterweights.
Of course, ultimately, i'll be getting a self guided SBIG (anyone got a good one they want to donate? hahahaha)

hope to have a few shots from this weekend but may not get much of a chance to process for a few weeks and duty calls and I'll be on the road a bit.

I cant wait to start really using this beast. It does show coma (way more than i ever saw with the C9.25 but the center is very nice and that's what I want it for, I'll be cropping images without a doubt
Thanks for all the replies
look forward to posting some pics soon!
frank

[Peter Ward]

Frank!

I would have (in fact I think I did) advised against a C14 and G-11.

But hey...perfectly round stars! ..... pretty cool.

The C14 is probably one of the *best* planetary scopes available. You might
want to consider going there as well.

cheers
Peter

[spearo]

Thanks Peter,
Yes I did see your advice, so while I proceeded, I did so with caution if it's any consolation...
It seems to work ok but as I said i ned to get my polar align etc just right and haven't had a chance to test things out (i soooo long for more time at the scope)
I really think that the very best soluton would be an extended base plate so the amount of counterveights can be kept to a minimum.

Anyways, I did think of moving into planetary imaging at some time but I want to aim it at some very small faint and fuzzies first.

Planetary will come though!

by the way, grounding Gemini and a cold start seems to have resolved the issues we discussed but havent had time to give it a full night test yet.
will do this weekend!
frank

[Dr Nick]

Very nice nice, I love the Helix, always have... ;)