Please help a proud owner of a new 6" RC refractor - Forums

Topic starter

Jun 29, 2022

Is there a specific adapter in order to place the camera in the optical train. I was expecting it to be threaded, not a tension connection. I can fit the camera in using a standard spacer that comes with the ZWO camera but I'd feel better if there was something threaded so that at least I'd know that my camera is being placed in the optical train consistently.

Also it come with 3 large spacers. Which combination seems to work best. Or is because RC telescopes don't need correction of the field that it won't really matter which spacers are used as long as the back focus is reached. And if so, does this relate to my first question, in that it won't matter if the camera is not placed consistently because no correction is required?

Thanks again
Blaine

Blaine Gibby

Topic starter

Jun 29, 2022

Oops I mean reflector.

Ben Loftin

Jun 29, 2022

So I will be living this with my 10" RC in the coming days as I start assembly so will be interested too. From the help I got there is this extension

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p368_TS-Optics-30mm-Extension-with-M48---2--Filter-Thread-and-2--Diameter.html

and then something like this, Ill be trying the OAG and EFW

https://stargazerslounge.com/uploads/monthly_2018_12/1848723990_ScreenShot2018-12-30at22_31_07.png.c3b526339ab29c7992a0d4edfa208d5c.png

I would shoot teleskop a question and they can get you correct adapter hopefully.

Ben Loftin

Jun 29, 2022

Oops meant this link too for the 2" attachment

https://www.teleskop-express.de/shop/product_info.php/info/p367_TS-Optics-2--parfocalizing-ring---CCD-locking-ring---for-2--barrels.html

Markus Gorski

Jun 29, 2022

Hello,
in order to be able to screw the camera to the focusser, you need another focuser that allows screw adaptation.
Unfortunately, the focusser in the photo below is no longer available (at least in Germany).
Then a special adapter is needed to connect the camera to the focuser.

I recommend a tilting adapter to be able to adjust the inclination of the focuser to the primary mirror.

Good luck and best regards,

Markus

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Ben Loftin

Jun 29, 2022

At what point we might as well replace focuser…? but I guess there is still hundreds of dollars difference… and I don't know the options there that would allow better connections.

Markus Gorski

Jun 29, 2022

I don't know if I understood that correctly:
The focuser must be changed if the existing one does not have a thread for screwing on the camera, although you want to screw on the camera. For example, an alternative would be:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p6970_TS-Optics-2-5--Zahntrieb-Okularauszug-mit-M90x1-Anschluss-und-360--Rotation.html

An adapter is then required from the camera-side thread of the focuser to the telescope-side connection of the camera. It is best if you ask your dealer.

Many greetings,
Markus

Earle Waghorne

Jun 29, 2022

I have used a 2" to T2 adapter ( https://www.teleskop-express.de/shop/product_info.php/info/p200_TS-Optics-Focal-Adaptor-2-inch-to-T2.html ) and it works fine. It also removes the need for a camera rotator. If you decide to add a focal length reducer it simply replaces the adapter (the same if you add a field flattener).

Without a flattener or reducer, there is no specified back focus for an RC and the large spacers are simply to get to a convenient focus. With my 8" RC I use 1x4cm and 1x2cm spacers at native (f8) but with the x0.67 reducer use only 1x2cm spacer.

Hope this helps but if not I'm happy to add.

CS

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Blaine Gibby

Topic starter

Jun 29, 2022

Thanks for the help everyone. Now I just need to find some collimating supplies but it appears the entire internet is out of stock…

Well Written

Ben Loftin

Jun 29, 2022

Yep waiting on the same

, so it goes….. this is the one they recommend but I have zero experience collimating… so can't really weigh in

Ben Loftin

Jul 2, 2022

Helps if I add a link lol

https://www.teleskop-express.de/shop/product_info.php/info/p14459_TS-Optics-Deluxe-Multi-Collimator-with-integrated-optic-for-all-telescopes.html

SemiPro

IOTD Staff

Jul 4, 2022 · Edited: Jul 4, 2022

Late to the party, but as a RC owner myself I'd stay away from the expensive collimation tools because in my opinion they are not needed. The most expensive diagnostic tool I would invest in would be a Ronchi eyepiece since the mirror spacing for RC scopes is absolutely critical. I doubt it would be off out of the box but you never know. I wouldn't even bother unless you REALLY want to know or your images are too soft. As for the actual collimation, you can get it roughed in with a cheap cheshire and then polish it off under the stars.

For collimation see this: https://www.skydude.me/at8rccoll.html

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Paul MacAree

Jul 21, 2022

Hi folks,

My journey with collimation for my TPO 12" RC has been "interesting". Frankly it looks simple, put a laser in the focuser drawtube, center the laser dot within the secondary' mirror's s center spot, then adjust the secondary so that the laser spot is returning to the laser emitter. Finally, using a laser grid, project out of the front of the scope to ensure the projected grid is symmetrical.

I saw many videos that showed that some of the cheaper lasers were not collimated themselves, this fault would be obvious if the laser was rotated within the focuser drawtube - if the laser spot on the secondary stayed in the same place, then great, but if it described a circle then the laser wasn't worth the money. Okay, so now I'm convinced about the Howie Glatter laser collimator, which has a reputation for being collimated.

Dollars later, the HG collimator arrived and true to expectations did not describe a circle when it was rotated. A few adjustments later and my focus tube was centered with my secondary mirror. Okay, stage 2) adjust the secondary so it sends the laser light back down to the laser emitter… what the heck? how can I see that - the laser is 18 inches down a tube and I'm looking down the side of my scope. Maybe I should buy a 2" Cheshire eyepiece - no luck finding one of them thar gadgets, and wasn't I just introducing another drawtube element that wouldn't be in my final configuration?

Carpet tape to the rescue. I put a piece of carpet tape across the baffle tube with a small hole to let the laser light through, then, adjusting the secondary I was able to see that the laser dot returned to the hole in the carpet tape that it had exited from. Coolness! Onto stage 3) and using the HG laser grid I could adjust the primary to achieve symmetry.

A friend of mine made the excellent suggestion that I replace the carpet tape with a cap with a small hole in the center which he 3D printed, I now use this cap instead of the tape over the RC baffle.

If you have a long baffle tube (even if its removable) on your RC it's pretty difficult to see where the laser light returns to, maybe this idea will work for you.

Paul

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Michele Rainville

Jul 21, 2022

for my 6" RC I used both supplied extenders and multiple extenders on the camera an simply slid it in to correct back focus…. used a simple Cheshire for secondary mirror as my primary was fixed and not able to move. easier with two people but can be done alone. good for a start.