SCT and Focal reducer

[Donkeiller]

Looking to maximise the number of targets for my 6SE SCT.

Looks like a focal reducer would provide a wider field of view.

Question is

1) how does a reducer work?

2) how do you fit it?

3) how easy to take on and off?

[riklaunim]

It can help, but for 1,25" eyepieces in general. You screw the f/6.3 reducer/corrector to the SCT end and to that you can screw in a SCT-threaded diagonal.

[Merlin66]

Yes, you just remove the visual back and scew the reducer in place...

Note for the x0.63 reducer there's a "design" back focus distance of 110mm from the reducer to the ccd or eyepiece.

[Donkeiller]

It can help, but for 1,25" eyepieces in general. You screw the f/6.3 reducer/corrector to the SCT end and to that you can screw in a SCT-threaded diagonal.

So I need a special "SCT-threaded diagonal" as well:icon_scratch:

[CGolder]

no you can use the adapter that is on already

it just fits between the one u have and the ota

[nightfisher]

just an idea, what about the antares style of 0.5 reducer that screws to the filter thread of the choosen eyepiece

[GazOC]

Nice in theory NF but a bit of a PITA in practice. I've tried it to try and save money!

[red dwalf]

the f 6.3 reducers work very well also for visual, the f 3.3 for smaller ccd cameras,

i have the Antares f6.3 reducer, made in Canada, cheaper than the Meade or Celestron models but just as good from reviews i`ve read.

i wouldn`t sell it.

very easy to use, just take off the visual back and screw the reducer on.

[Donkeiller]

the f 6.3 reducers work very well also for visual, the f 3.3 for smaller ccd cameras,

i have the Antares f6.3 reducer, made in Canada, cheaper than the Meade or Celestron models but just as good from reviews i`ve read.

i wouldn`t sell it.

very easy to use, just take off the visual back and screw the reducer on.

Thanks for this- I take it you then just insert your diagonal in the same way as you do normally?

Forgive me this "visual back" thing is still bugging me:icon_scratch:

Is it, or is it not what normally accepts the diagonal?

[mallorcasaint]

Yep. The visual back is the bit that accepts the diagonal.

[red dwalf]

it is indeed, lots of names in this hobby for small unasumming items L.O.L.

it screws off the rear of the scope, focal reducer then screws on the visual back screws back onto the reducer, then you can either use a diagonal or just a webcam or camera stright into the visual back as normal.

[Merlin66]

Just remember the standard x0.63 reducer is designed for a fixed back focus of 110mm.....

[RobH]

If it's for visual use, then why would you want to use a focal reducer?

If you use a 15mm eyepiece and a 0.5x reducer for example, this is precisely the same as using a 30mm eyepiece.

Focal reducers come into their own for imaging, but are completely unnecesary for visual astronomy.

If you try to use a long FL eyepice with a focal reducer, you won't widen the useable FOV, you'll just have a smaller image surrounded by lots of vignetting.

Save yourself some money and just get some longer FL eyepieces.

Rob

[Donkeiller]

Yep. The visual back is the bit that accepts the diagonal.

Thanx- sorted!

[michael.h.f.wilkinson]

I still have my 0.63x Celestron reducer, but it has not been used in a month of Mondays. I used it when I only had 1.25" EPs, but since I replaced the 1.25" visual back with a 2", and inserted my first 2" EP (the Paragon 40mm), I have not used it visually at all. You can do the same with a C6. For travel use, when you do not want to carry heavy 2" EPs the focal reducer may be handy. I might one day start using it for imaging again.

[Mr Spock]

When I got my C9.25 I already owned a 42mm LVW so a focal reducer for visual was never needed (or wanted). I already get the maximum FOV from the C9.25, a focal reducer would mean using shorter focal length 1.25" eyepieces. A 42mm LVW (and 2" diagonal) is quite expensive though and a focal reducer could be a cheaper option.

For viewing faint objects though, all that extra glass is not a good idea.

[Charon]

it is indeed, lots of names in this hobby for small unasumming items L.O.L.

it screws off the rear of the scope, focal reducer then screws on the visual back screws back onto the reducer, then you can either use a diagonal or just a webcam or camera stright into the visual back as normal.

Not hi-jacking the thread sorry, but thank you for solving that mystery for me.