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SCT 6.3 reducer


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I'm sure this has been discussed on SGL but I'm a newbie and couldn't find an answer when I searched .......

I want to get a 6.3 focal reducer for my 6" SCT. There seem to be 4 options

  1. Celestron.
  2. Meade
  3. Antares
  4. Unbadged versions.

From what I can glean off the net, the Celestron is most expensive and works well, the Meade is OK but not quite as good as the Celestron, the Antares is cheaper and as good as the Celestron but the coating is delicate and the cheap unbranded ones are a bit of pot luck.

Has anyone got first hand experience of these?

Thanks, Jim.

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I have recently bought the Celestron, which I am very pleased with. However, depending on your reasons for getting one, regardless of make, it may be less useful in a 6" SCT because of the smaller baffle size.

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I'm not bothered much by the reduced focal length, it's the reduction in exposure times that I want. I don't have an auto-guider yet, I want to get my basic AP work as good as I can with what I've got before having to learn another "skill" :-)

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I also have the Celestron. At one time it was recommended over the Meade for having more accurate threads, if I remember well, so that it screws on and off with more ease.

I like it. It reduces exposure time and field curvature.

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And now throw this into the mix.....

http://www.mallincam.net/optical-accessories.html#oa06

And where would civilization be without.....? -

http://www.mallincam.net/uploads/2/6/9/1/26913006/focal_reduction_for_dummies.pdf

If you don't do anything else this year - do download a copy of the last link. And read it! :icon_eek: 

Ciao,

Dave

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+1 for the Celestron FR I use it with my 9.25 helps get the moon and the sun in a low powered eyepiece! I've not used it for AP other than solar snaps. Great observing tool for everything but planets! Cannot vouch for the AP though as I've not used it for that purpose. 

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These "Reducers" are advertised as eg "Meade SCT Focal Reducer - Field Flattener", and "Celestron Reducer-Corrector"

So regarding Dave in Vermont's 2nd Mallincam link.

It shows how to get a range of reductions by using spacers with the Reducer.

But as I understand it, on an SCT at least, if you alter the spacing from the recommended spacing, the coma inherent in SCT's gets worse instead of better - do you want that?

Mallincam don't seem to appreciate that, so read it - with care.

Michael

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I've got the Meade 6.3,  It's descibed as a Field flattener/Focal reducer.   Basically it's supposed to do both jobs.    I've never used it for imaging work though - that's something I'm going to be trying this season.  Hoping to get lots of scope time this year.

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Then, by proxy, any focal-reducer would cause coma in one's image/view. If this were an intolerable amount, I doubt they'd be on the market. 

Meade also had a 3.3 FR some years ago. People tried these and found them to be terrible. So Meade took them off the market. But the problem was that those complaining had tried to employ them for visual astronomy. For imaging, they worked as advertised. And imagers' were out in the cold. Now there is a steady market of people trying to find one in the used marketplace.This is partly the reason I posted the link to "Focal Reducers For Dummies." Though it uses the MallinCam as it's referenced camera, the principles are the same for others as well. Apparently they work just fine for their intended purpose. I haven't personally used one yet - but have one tucked away for a nice, clear night next summer.

I will send off an email to Rock Mallin later and get his take on the problem (if there is one) of coma with imaging on video. I'm a member of a slew <koff> of Yahoo Astro forums that relate to this subject. I'll also poke around in these. Anyone who is planning on doing video-astrophotography would do well to check them out as well. Drop me a pm and I'll gladly send you the links/titles.

"There's a place. A far, far place. In outer-space. I'll wait for you. I'll wait for you,"

Dave

PS: Here's another one to look at:

http://www.antaresoptical.com/new.htm

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The Celestron reducers used to be made in Japan, and the glass was very nicely finished. If you should be buying used, worth looking out for an early version, it will say on it where it was made.

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Still waiting for Olly to jump in and explain that the 6.3 SCT focal reducer DOES NOT increase the field of view.

AFAIK the Meade 3.3 reducer was only any use on early very small CCDs and once CCDs got bigger it became redundant.

Dave 

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Is there any benefit to these for visual observing other than a wider field of view?

A reducer does not give a wider field of view. The field of view in an SCT is limited by the size of the baffle tube. In some cases , a reducer will have a smaller aperture than that.

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Thanks for all the pointers folks. I've managed to find a used one on UK Astro buy n sell. Have yet to receive it but it's said to be in fine condition and the seller is a genuine guy.

Looking forward to getting a couple of extra stops for my imaging :smiley:

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