What to expect from a C11?

[multiweb (Marc)]

I'm not much of a visual observer and rarely peeked through my scopes, only imaging. I had a look through some of my mate's dobs though. I'm in the process of aligning the optics of my C11. I did a couple of star tests then the other night, I think it was Saturday or Sunday night, can't remember, I had a look at the moon with a 2x Barlow and a 6mm eye piece then a quick peek at jupiter. The moon was sharp enough but wobbly from the seeing. On Jupiter I could see 4 moons in line and one dark spot on the surface that I assume must have been one of the moons shadows. The colors were quite washed out, not much contrast althhough I could clearly make out the bands and a bit of twirl on the edges of one of them.

My question: does this sound like the level of details I got is ok and it's as good as it gets or should I expect much more at this FL and further tweaking is needed. Thanks for any feedback.

[astro744]

Sounds about right for 'wobbly' seeing. A lack of contrast is from the large secondary obstruction; not much can be tweeked there.

Good collimation and long cool down time is all you need the rest is up to the sky, your eye and the eyepieces.

[sheeny (Al)]

It sounds about right to me, Marc.

Long focal lengths are great for seeing seeing.

Ah I see astro744 has beaten me to it... what he said!

Al.

[multiweb (Marc)]

Cool - sounds good then. I'm heading in the right direction - thanks for the feedback guys.

[asimov (John)]

Sounds about right mate. I have the C11 also & that pretty well sums up my visual views. You might want to look at cooling the OTA before using it. It'll help.

[sjastro]

Marc,

Like any mass produced scope quality can be variable, but if you are fortunate enough to have a good quality scope the performance is excellent under good seeing conditions.

My best memories of my C11 was the spectacular views of Jupiter.

Regards

Steven

[supanova (Wayne)]

Unfortunately with Celestron manufacturing offshore,the quality became variable and so did the image quality.Some of the newer ones seem to give quite good images,others quite bad images.Some are reasonably sharp,some give images that appear washed out with poor contrast.I have only come across 1 of the newer type ie Black metal or carbon fibre tube C11's that give an image anywhere near as good as my old Orange tube C11.And have not come across any that have as little mirror shift.The price we pay for mass production I guess.And oh yes ,my old scope still gives fantastic images of Jupiter.

Wayne

[coldspace]

Originally Posted by multiweb

I'm not much of a visual observer and rarely peeked through my scopes, only imaging. I had a look through some of my mate's dobs though. I'm in the process of aligning the optics of my C11. I did a couple of star tests then the other night, I think it was Saturday or Sunday night, can't remember, I had a look at the moon with a 2x Barlow and a 6mm eye piece then a quick peek at jupiter. The moon was sharp enough but wobbly from the seeing. On Jupiter I could see 4 moons in line and one dark spot on the surface that I assume must have been one of the moons shadows. The colors were quite washed out, not much contrast althhough I could clearly make out the bands and a bit of twirl on the edges of one of them.

My question: does this sound like the level of details I got is ok and it's as good as it gets or should I expect much more at this FL and further tweaking is needed. Thanks for any feedback.

, Mark step that magnification back, 6mm with 2 X barlow will give over 900 magnification, I am suprised you got any detail at all and the images would have just been plain big shimmering blobs and impossible to focus.
Very,very,very rarley do I push my 12R past 400X.

Try about 200 you will see a remarkable difference only image scale will be alot smaller.
I get comparatable views with my cooled down Meade 12R,and 17mm Ethos at about 180X to some of the good solar system images you see on good steady nights only with alot less image scale.
Better to have a nice crisp/small image in the eyepiece than a big blurry blob.
Your C11 should perform well at lower magnifications, I can not see why your optics will be any different to mine except that from my experience the ACF optics are a tad sharper visually but I have seen excellent visual views through a new C11 and C9.25 on planets and deep sky from dark skies. Try again with alot lower magnification you will be suprised.

Regards Matt.

[multiweb (Marc)]

Originally Posted by asimov

Sounds about right mate. I have the C11 also & that pretty well sums up my visual views. You might want to look at cooling the OTA before using it. It'll help.

Yep. Cooling makes a huge different. I have modded the primary cell a while back to install fans and get rid of tube currents. They are an image killer.

Originally Posted by sjastro

Marc,

Like any mass produced scope quality can be variable, but if you are fortunate enough to have a good quality scope the performance is excellent under good seeing conditions.

My best memories of my C11 was the spectacular views of Jupiter.

Regards

Steven

I have no problem believing that Steven. They perform extremely well when properly aligned.

Originally Posted by supanova

Unfortunately with Celestron manufacturing offshore,the quality became variable and so did the image quality.Some of the newer ones seem to give quite good images,others quite bad images.Some are reasonably sharp,some give images that appear washed out with poor contrast.I have only come across 1 of the newer type ie Black metal or carbon fibre tube C11's that give an image anywhere near as good as my old Orange tube C11.And have not come across any that have as little mirror shift.The price we pay for mass production I guess.And oh yes ,my old scope still gives fantastic images of Jupiter.

Wayne

It's all about aligning and collimating I guess.

Originally Posted by coldspace

, Mark step that magnification back, 6mm with 2 X barlow will give over 900 magnification, I am suprised you got any detail at all and the images would have just been plain big shimmering blobs and impossible to focus.
Very,very,very rarley do I push my 12R past 400X.

Try about 200 you will see a remarkable difference only image scale will be alot smaller.
I get comparatable views with my cooled down Meade 12R,and 17mm Ethos at about 180X to some of the good solar system images you see on good steady nights only with alot less image scale.
Better to have a nice crisp/small image in the eyepiece than a big blurry blob.
Your C11 should perform well at lower magnifications, I can not see why your optics will be any different to mine except that from my experience the ACF optics are a tad sharper visually but I have seen excellent visual views through a new C11 and C9.25 on planets and deep sky from dark skies. Try again with alot lower magnification you will be suprised.

Regards Matt.

Thanks Matt. Pushing magnification is the only way to see if alignment or collimation holds. At low magnification anything looks good