Celestron F6.3 focal reducer

[Vince1963]

Hi Guys... Its been awhile since i last posted or left comments on here for that matter. Truth is the weather as been getting me down and on the odd occasion where its been clear i've been at work So between work and having beer thats been it for me. But i have been buying a bit of gear in between said stuff, one being a Celestron F6.3 focal reducer which i managed to test drive last night and i can thoroughly recommend it to anyone with the C11 SCT (or suitable SCT). I think the reducer is aimed more at astro-photographers to increase contrast issues and reduce exposure times with long focal length SCT, (which is what i hope to get into someday soon). But that said i think i remember reading somewhere that its also great for your viewing pleasure too.... And it gets a big thumbs up from me even with the gibbous moon detail was improved, I am looking forward to using it on a dark sky. So anyway just wanted to share that with you and anyone thinking of getting one. I'm no expert but i think its a must buy and essential part of your kit.

[scarp15]

Hi I have one of these with my C8, which is also used for visual. I think that it works best under dark sky conditions with 1.25" eyepieces. I have used it at Kielder, with my high power naglers on open and globular clusters. In these circumstances, making the most fo the sllghtly wider and flatter field, it performs quite well.

[ollypenrice]

It is primarily a photographic device but if you only have 1.25 eyepieces then it can widen the field of view. However, if you do have a widefield 2 inch EP you can get a wider field than in any 1.25 EP with reducer.

If you use the reducer with a 2 inch widefield, though, you will not gain in FOV because you'll be limited by the baffle tube.

Olly

[paulastro]

Good point re no advantage when using a 2inch widefield Olly. So with the C11, what combination of 1.25 eyepiece with reducer will give the largest visual field?

[Dunkster]

Pretty much anything that reaches the maximum field stop for a 1.25" eyepiece (27mm) will give you the widest field of view with the reducer. As Olly said, you can go wider still with a C11 by using longer focal length 2" eyepieces without the reducer... Something like the LVW 42mm or Panoptic 41mm or a 55mm plossl.

[sgazer]

I used one of these with a C8 a few years ago and found it excellent for imaging with a DSLR, much reduced imaging times, wider field and sharp stars to the edges. After tying a couple of other brands, I found none performed as good as the Celestron reducer.

[Vince1963]

Thanks for the comments Guys... I totally agree with your comments.. But just to add... I found the reducer sharpened up the image for general viewing with my 1.25" EPs.. and yes i know it wouldn't be necessary with the 2" EPs. that said my main EPs are 1.25" and i tried it with and without reducer..Clear skies guys

[baggywrinkle]

I use one with my 6SE, particularly for wider field, sun and lunar work. Gives nice sharp images, the other thing is that it acts a a rear baffle preventing ingress of outside dust etc into the OTA.

[magnahrl]

Hello!

I use the Celestron f/6.3 f/r with my old (1973) deforked Orange C8 Pacific together with a 1.25" diagonal for visual. Very pleased with the views. In fact I never take the f/r off!! At "Cloudy Nights" there have been some intressting discussions regarding f/6.3 f/r and as far as I understand you loose aperture if you use f/r + 2" diagonal.

Maybe someone knows more about that here?

Clear Skies!

Magnus 57N.

Sweden

[Chris Rowland]

As I see it the choice should be between 2" EPs with no FR and 1.25" EPs with a FR.

If you do some measuring and sums you find that the maximum image circle the FR will illuminate is about 25mm.  That's almost exactly the same as the maximum image circle you can get in a 1.25" EP.  A wide field 2" EP will have a field width of more like 45mm and only the inner 25mm will be illuminated so you get vignetting.

The larger size of a 2" diagonal also makes a difference. The FR needs 105mm between the reducer and the focal plane to operate correctly.

This is achieved with the normal 1.25" visual back, 1.25" diagonal and 1.25" EP.

A 2" diagonal is bigger and that makes it longer, especially the ones with a 2" connector because they also need a SCT to 2" visual back.  The ones which are designed for SCTs and screw on directly may be OK.

I took the discussion on CN with a pinch of salt because no one explained why the presence of fresh air round the optical path made any difference.

I guess that what may be happening is that using a 2" diagonal gives a greater FR to focal plane spacing and that means that the scope focus needs to be changed by so much that its optical design is changed and something other than the corrector limits the light.

Chris

[hobsey]

I'm confused.

So are we saying a f/r is ok for 1.25 eyepieces for wider field visual?

As a reducer is cheaper than forking out for 2" eyepieces.

[Chris Rowland]

That's the way I see it, a FR with 1.25" EPs will give about the same maximum field as a 2" EP without.  More or less. And the 2" with a FR won't give more field.  As you say a FR is probably cheaper than 2" EPs.

Chris

[hobsey]

Thanks Chris.

[Martinbracken]

Help with Focal Reducer

I am a newbie and having trouble with the limited field of view I get on AP using a Canon 450D DSLR attached to a T-Ring and Celestron 6SE so using prime focus

My question is does a Celestron F6.3 focal reducer fit between the T adaptor and the Scope and will it increase the field of view?

Hope someone can help

Martin

[NosyTrader]

Hi Martin,

I have the same issue as you and ordered a focal reducer last night. As soon as it arrives I will let you know!

Firoze

[ollypenrice]

Help with Focal Reducer

I am a newbie and having trouble with the limited field of view I get on AP using a Canon 450D DSLR attached to a T-Ring and Celestron 6SE so using prime focus

My question is does a Celestron F6.3 focal reducer fit between the T adaptor and the Scope and will it increase the field of view?

Hope someone can help

Martin

I think the answer is yes.

Olly

[Tinker1947]

I think the answer is yes.

Olly

The F6.3 does need to be placed at the right distance from the Camera sensor, this is 105mm from the rear of the F6.3 it will work with less than 105mm but how this affects the image i don't know......

[redfox1971]

The F6.3 does need to be placed at the right distance from the Camera sensor, this is 105mm from the rear of the F6.3 it will work with less than 105mm but how this affects the image i don't know......

Hi Tinker1947 is the rear of the focal reducer the thread that screws on the telescope or the focal reducer glass side faceing the camera?.

[Tinker1947]

Its the camera end of the reducer the space is taken from....

[redfox1971]

Thanks Tinker1947.

[Tinker1947]

Thanks Tinker1947.

My solution, a Baader Click-Lock with a small extension going into the T-Ring......from memory the Click-Lock attached to the F6.3 with a extension tube attached to the T-Ring, this allowed the F6.3 to be removed and the DSLR attached to the Click-lock on the back of the SCT...