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Collimation and Focal reducers - LX200 SCT's

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#1 tommax

tommax

    Vostok 1

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Posted 07 April 2013 - 11:18 PM

Hi all...

Wondering what best practice is when it comes to this...

I have my scope collimated fine with no focal reducer, but when I add my 6.3 reducer the collimation is off, I use the 26mm eyepiece usually.

I like to image planets usually, then I switch to dso's normally using the 6.3 reducer... I have read you should collimate to your most used setup, but if you bounce back and forth which should you choose? I also in a package recently got a 3.3 reducer I would like to try if it works with my scope because for something's according to CCD calc I would get a very nice wide field with it, but maybe the 3.3 is just not a match? Anyways with wanting to webcam planets w/o a reducer and possibly 2 reducers what is collimation best practice? or is more than 1 scope required?

I assume this topic would be of interest to many LX200 users in the more beginning of imaging...

#2 Rayh

Rayh

    Mariner 2

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Posted 27 April 2013 - 08:02 PM

Hi Tommax,
I would do my final collimation with no reducer and a short focal length eyepiece to be able to see the donut and finally just the stellar diffraction pattern at high mag. You want your scope to be correctly collimated by itself without trying to get in other optics that could change each time you use it.

The 3.3 focal reducer was designed for the older small-chip cameras like the DSI-1 It only produces a good image in the central part of its image plane. On a large-chip camera like a modern DSLR you would experience horrible vignetting.
Ray






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