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Celestron f6 focal reducer


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Hi guys rob here again just another question for yous am kind off new to this game as you know ? Only into looking up for about 18 months I have my c11 with some great eyepices but was thinking about getting a f6 celestron focal reducer is this good for planet viewing or is it great for nebulas and star clusters would like good advice before buying cheers guys??

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Hi Virgo man, I own a CPC 1100 and the Celestron f6.3 reducer. I recently tried the reducer with a 36mm Baader Aspheric and felt the combination was not good. There was significant distortion in the outer 1/4 field of view. I have generally not liked using the reducer for visual.

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For planetary viewing, you want high magnification so a focal reducer would not be useful. Eyepieces in the 16 to 12mm range will probably be useful, ie x175 to x233 although in good conditions I'm sure you could go higher.

It's generally accepted that focal reducers are not much use for visual on SCTs, so for larger objects such as open clusters and nebulae, you need the longest focal length eyepiece such as a 41mm Panoptic or 42mm Vixen LVW. The 55mm Plossl doesn't give any wider a field, but does bring the mag down more if that is needed.

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Sorry I have to disagree with the above to some extent.  The f/6.3 makes a difference to visual.  Obviously you can't go above the limiting field stop and some eyepieces will react worse because they are designed for use with with longer focal lengths.

For planetary you should stick to f/10 but for DSOs it's not just about the FOV (you're limited to the 2" baffle tube diameter no matter what the f ratio is)  - however it's about getting to a reasonable magnification without using ridiculously large eyepieces and it's much easier to step up in levels of reasonable magnification at f/6.3 i.e from 50x to 75x to 100x than at f/10 (I do this using a 22mm, 17mm and 13mm for example) which is important for DSO viewing as small increments in magnification can make large differences to how the DSO will be visible as the exit pupil approaches the optimal (approx 2mm) for DSOs it becomes ever more critical.

Regardless, I find the view improved using the focal reducer for example it does correct the field somewhat with the correct eyepieces and you get sharper stars imo.

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8 minutes ago, Davesellars said:

Sorry I have to disagree with the above to some extent.  The f/6.3 makes a difference to visual.  Obviously you can't go above the limiting field stop and some eyepieces will react worse because they are designed for use with with longer focal lengths.

For planetary you should stick to f/10 but for DSOs it's not just about the FOV (you're limited to the 2" baffle tube diameter no matter what the f ratio is)  - however it's about getting to a reasonable magnification without using ridiculously large eyepieces and it's much easier to step up in levels of reasonable magnification at f/6.3 i.e from 50x to 75x to 100x than at f/10 (I do this using a 22mm, 17mm and 13mm for example) which is important for DSO viewing as small increments in magnification can make large differences to how the DSO will be visible as the exit pupil approaches the optimal (approx 2mm) for DSOs it becomes ever more critical.

Regardless, I find the view improved using the focal reducer for example it does correct the field somewhat with the correct eyepieces and you get sharper stars imo.

Second that. Even though reducers are much more useful for imaging, I do believe they make a difference for visual as well.

The reducer will flatten the field - which does make a difference for visual observing. Also, it does improve visibility of dim objects. However, as mentioned before - for planetary observation a focal reducer is probably not a good idea.

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On 16 July 2016 at 10:49, Davesellars said:

Sorry I have to disagree with the above to some extent.  The f/6.3 makes a difference to visual.  Obviously you can't go above the limiting field stop and some eyepieces will react worse because they are designed for use with with longer focal lengths.

For planetary you should stick to f/10 but for DSOs it's not just about the FOV (you're limited to the 2" baffle tube diameter no matter what the f ratio is)  - however it's about getting to a reasonable magnification without using ridiculously large eyepieces and it's much easier to step up in levels of reasonable magnification at f/6.3 i.e from 50x to 75x to 100x than at f/10 (I do this using a 22mm, 17mm and 13mm for example) which is important for DSO viewing as small increments in magnification can make large differences to how the DSO will be visible as the exit pupil approaches the optimal (approx 2mm) for DSOs it becomes ever more critical.

Regardless, I find the view improved using the focal reducer for example it does correct the field somewhat with the correct eyepieces and you get sharper stars imo.

Seems like quite a complex picture from the searching I have done, as much to do with varying field curvature on different eyepieces and whether they cancel or increase the scopes field curvature as the reducer itself.

Having said that, if you get better views with the reducer then, well it's got to be doing something right :) 

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Slightly off topic, (may or may not be relevant to the OP question), I read read a review somewhere in an a magazine or i'net and the Celestron 6.3 focal reducer was 'best overall' in a comparison with other focal reducer brands*.

 

* just to clarify, the reviewer was comparing the 6.3's not the 3.3's.

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On July 16, 2016 at 09:32, beka said:

Hi Virgo man, I own a CPC 1100 and the Celestron f6.3 reducer. I recently tried the reducer with a 36mm Baader Aspheric and felt the combination was not good. There was significant distortion in the outer 1/4 field of view. I have generally not liked using the reducer for visual.

Cheers Beka I may give the reducer a miss save some cash for ??

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3 hours ago, Louis D said:

They're cheap enough used (about $75 here in the states), that I'd say go ahead and get one to play with to see what it does well and what it doesn't and report back.

Will do Louis will buy a used one and keep you posted will spend spare cash on ? Cheers 

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