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Celestron C6 for planetary imaging?

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#1 joelimite

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Posted 03 November 2012 - 11:18 AM

I've been dabbling in planetary imaging for the last year or two and have mainly been using small refractors (first an Explore Scientific 80mm and now a TMB 92L). I now want something with a little more aperture. I wouldn't dream of selling the TMB; I just want a compact scope with a little more aperture and a longer focal length for planetary imaging. Would the Celestron C6 SCT fit the bill? I have no intention of using it visually. I just want to capture a bit more detail on the moon, Jupiter, Saturn, and so on. Whatever I get, it needs to ride comfortably on a Celestron CG-4 mount. I suspect a C8 would be undermounted on the CG-4.

#2 oldstargazer

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Posted 03 November 2012 - 10:11 PM

Last winter I tried using my C8 with the neximage I had then and was never really satisfied with the results. I then found a used 10 inch Orion dob with mounting rings for EQ rig. I had to use barlows to get image size of the C8 but the results were better. I had tried using my refractor that had the same FL as the dob but was only 6 inch diameter and results were not even close to the 10 inch dob ota. It really seems that the bigger the scope is the better the image is on the planets. I now have a CPC1100 and I have seen another improvement in resolution with that one inch larger ota.

Not sure of the weight difference between the C6 and C8. I do have to use two 11 pound counter weights on the CG5 when mounting the C8 if that helps narrow down the weight issue for you. One thing for sure I will be glad when I can get a place that has room for me to put up an observatory and put a C14 in it. I think that size ota gives very good planetary resolution from all the pictures I have seen this year and last year from those that have that size ota.

Good luck with your decision.

#3 rg55

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Posted 04 November 2012 - 12:16 PM

Check out the Jupiter image at this post:
#5494173
"Jupiter for the rest of us with smaller scopes"

#4 old_frankland

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Posted 04 November 2012 - 01:17 PM

I've been dabbling in planetary imaging for the last year or two and have mainly been using small refractors (first an Explore Scientific 80mm and now a TMB 92L). I now want something with a little more aperture. I wouldn't dream of selling the TMB; I just want a compact scope with a little more aperture and a longer focal length for planetary imaging. Would the Celestron C6 SCT fit the bill? I have no intention of using it visually. I just want to capture a bit more detail on the moon, Jupiter, Saturn, and so on. Whatever I get, it needs to ride comfortably on a Celestron CG-4 mount. I suspect a C8 would be undermounted on the CG-4.


Might also consider the 4" and 5" Maksutovs offered by Meade, Orion. The only down side to them is a longer cool down time due to thicker corrector and mirror than the 6" SCT. However, the Maks have the edge in terms of contrast which is precisely what you need for lunar and planetary.

My two cents...

#5 oldstargazer

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Posted 04 November 2012 - 02:06 PM

That was a very nice image. Question is what was the entry level color camera used for the image? My avatar came from one of the best I ever got using the original neximage and the 10 inch dob tube.

#6 flava

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Posted 04 November 2012 - 05:25 PM

I got all the captures from this image with my former 6" Meade LS6 ACF a 2x barlow and a PLA-C camera which is a USB2 (up to 30fps) camera with the good old Sony ICX098BQ chip.

For some reason the image is dispayed in a reduced size, here is the link to the full size : http://i40.photobuck...upiter_2011.jpg

Posted Image

On this one from 3 october 2011 there was detail on Ganymede

Posted Image

A 6" scope is definitely capable of delivering nice data. It will have less resolution compared to bigger scopes (8", 10" ...) but is also more forgiving with the seeing conditions.

#7 Chris_H

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Posted 04 November 2012 - 05:30 PM

Wow, you even got detail on Ganymede! Never thought you could do that with a 6"!

#8 flava

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Posted 04 November 2012 - 05:39 PM

Seeing was very good and that LS6 tube excellent. On collimation tests it produced an Airy disk like those simulated by software.
Anyway, a 8" will beat the 6" that's no contest, but the 6" are no toy scopes either.

#9 Kokatha man

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Posted 04 November 2012 - 06:02 PM

Seeing was very good and that LS6 tube excellent. On collimation tests it produced an Airy disk like those simulated by software.
Anyway, a 8" will beat the 6" that's no contest, but the 6" are no toy scopes either.


.....I think your images demonstrate that pretty conclusively Flava....! :waytogo: :waytogo: :waytogo:

#10 oldstargazer

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Posted 04 November 2012 - 06:05 PM

Well I guess if you consider a 6 inch scope small then you can call that imager entry level. Very nice images from a very nice imager! I think if I was in europe I would have to get one of those cameras. I saw where they used it to capture an image of the bubble nebula, very versatile imager, not your average webcam by any means.

#11 flava

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Posted 05 November 2012 - 04:23 AM

It is a good camera, but far from the performance of ICX618 chips especially the monochrome ones.
It is indeed versatile, it does long shutter. I used it to image the ring nebula with the 6", and it worked.

#12 rg55

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Posted 05 November 2012 - 11:51 AM

Flava, did you use filters/filter wheel for your Jupiter? These are probably the best examples for the aperture I've seen, right up there with Zambonii's.

#13 flava

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Posted 05 November 2012 - 12:49 PM

Thank you! No filters, it was a color (bayer matrix) camera.
Here is a sample of the captured avi (it's lower quality than the original because of compression)


Posted Image

#14 rg55

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Posted 05 November 2012 - 05:12 PM

Flava,

I would love to hear about your capturing and processing routines! Whenever you're ready.

thanks!

#15 flava

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Posted 05 November 2012 - 05:39 PM

Well, capturing and processing were not that hard when seeing is good and the scope collimated just right.
Before capturing I pay a lot of attention to focusing. I had replaced the stock focus knob with a Feathertouch microfocuser. Makes a BIG difference.
While capturing the trick was not to burn the green color, as the camera was most sensitive in green.
Processing is quite standard, at this small size any align method works about the same, even "center of gravity" or single point with Registax.
Auto RGB balance in Registax gets rid of the green dominant.
Wavlets with the first slider, just up to when the noise starts to show get the details out.
A courbe in Photoshop or Gimp to get the contrast up a bit, and that's all.

When the seeing was bad though, noting worked right :)
These pics are all from nights with good seeing.






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