Which baader click lock for 11" SCT?

[the_laughing_crow]

Hi

I've got a 11" celestron and have decided to get a 2" baader click lock. It seems I have two options: the standard 2" baader click lock which would screw onto my existing visual back:

https://www.firstlightoptics.com/adapters/baader-click-lock-2-for-celestron-meade-sct.html

 OR the click lock which would replace my existing visual back:

https://www.firstlightoptics.com/adapters/baader-planetarium-2-clicklock-adapter-for-large-325-sct-thread.html

So as I see it the first option which screws onto the existing visual back has the benefit that if I want to use my focal reducer I just unscrew the click lock and screw on the focal reducer. The second option which replaces the visual back would mean id have to unscrew the click lock, put on the old visual back and then screw on the focal reducer. So one more step.

Any one have any thoughts?

[the_laughing_crow]

Having thought about it I'm feeling fairly confident that the best option is actually the standard 2" click lock as it avoids having to change the visual back to use the focal reducer. I actually cant see any advantages of the 3.25" click lock, only disadvantages.

Anyone out there using these on an 11" SCT?

 

[PeterCPC]

The first one is for 8" or 9.25" SCT. The second is the correct one for 11" SCT.

Peter

[the_laughing_crow]

Yeah but the one for the 8"/9.25" will fit onto an 11" SCT. 11" SCTs have a stock back on them which is 2" across... eg this is what you screw the standard focal reducer onto.

 

The one specifically for the 11" requires removing this stock back. That means you no longer have threads to screw a focal reducer onto. That means using a focal reducer requires removal of the 3.25", replacing the stock back, screwing on focal reducer and then screwing on something else other than the 3.25" click lock - which is incompatible with a focal reducer.

 

The smaller click lock which does fit onto an 11" SCT is however compatible with the focal reducer. You screw on the focal reducer first, then the click lock.

[alanjgreen]

I use the 3.25 on my C11. It opens up the full aperture to the eyepiece. Fitting the smaller one has these disadvantages 

1. You are not getting the full aperture

2. You are fitting adapters to adapters instead of straight to the back of the tube

3. You are pushing eyepieces (weight) further back where it will have more effect on the back end total weight

 

i have never used focal reducers so I did not reply as I have no idea what you are trying to do.

Baader state the 3.25 is the one you need.

 

Edited January 20, 2017 by alanjgreen

[alanjgreen]

here is some info

http://www.cloudynights.com/topic/229977-what-is-best-focal-reducer-for-c11/

http://www.cloudynights.com/topic/494063-celestron-f63-focal-reducer-with-baader-click-lock-for-c11/

There is a picture in the last (C11 visual back 3.25") link...

Edited January 20, 2017 by alanjgreen

[the_laughing_crow]

Thanks for the responses!

I don't think this affects aperture at all. Both versions of the baader clicklock have at one end an opening of 2" in diameter where the 2" diagonal will go. At the other end one clicklock is 2" and the other is 3.25". So regardless they both limit aperture to 2".

I've borrowed a non 3.25" click lock to check the system works and it does:

With reducer and diagonal:

The disk at the top of the first image is the standard adapter that ships with the scope. Essentially the 3.25" clicklock seems to be a 2" clicklock combined with the baader version of that adapter in a single unit. The drawback being that the 3.25" clicklock has no threads.

So if I to want to use a focal reducer with a click lock these are my options:

1. Telescope>adapter>focal reducer>2" clicklock>diagonal/camera

2. Telescope>3.25" clicklock: No threads!!!

So have to remove 3.25" clicklock replace original adapter, screw on focal reducer screw on a 2" click lock (!!!!), the insert diagonal/camera

 

[ngwillym]

Alternatively,

get one of these:-

http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Imagers-Opticstar.asp?p=0_10_5_0_3_105

the leave the 3.25 clicklock attached and screw this adapter onto the reducer and push it in to the clicklock?

Neil

 

 

[the_laughing_crow]

Thanks Neil, 

Using this adapter, I would insert it into the 3.25" click lock, then screw on focal reducer, then......  I'd then need another 2" click lock to insert the diagonal/camera into. So two click locks, instead of one.

I just don't see what the 3.25" clicklock brings to the party except for limitations.

 

[ngwillym]

good point - I attach my camera (not a dslr) directly from the reducer (I've got the f3.3 version - can't use for visual) with another type of adapter (T2 to c mount) - so I don't need the second click lock. - don't do visual that much and wouldn't attempt it with the reducer in place. (I've got a 127mm APO for visual use  )