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Flip mirror setup???


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Hi all:

I tried to set up my flip mirror on the sct the other night (have never used it yet).  Jupiter was centered in the reticle and when I flipped the mirror up and looked down the tube (to camera) I could see the bright image in the center....however could not see the image on screen when I put the camera in.  Should I be using a barlow first to get closer to focus on the camera train?

Thanks again for your help :confused:

Cheers

Roger

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Just because the object is in the centre of the fov in the eyepiece tube, doesn't necessarily mean it will be smack bang in the centre in the other tube unfortunately. What i do is again in day light, centre something very distant in the camera tube on the chip, then look through the eye piece tube (with a barlow and eyepiece) and just make a note of where the object is - often not bang in he middle. Then at night place the target in that position in the eye piece tube, then look with the camera tube. You also need to work out how much focus difference you nee to make when using either tube - again a day light job.

The canera likely has a very small sensor so can be hard to get the target on the sensor. Plus if it is out of focus, even if it is on the sensor, you won't see a thing.

James

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To add to what jambouk has explained on some flip mirrors there is an adjustment screw underneath which acts as a mirror stop. This can be used to make sure the centre of the image to the camera is the same as the one to the eyepiece.  Also the eyepiece holder can be adjusted so that when the camera is in focus the eyepiece is also in focus.  This is known as "parfocal".  The way to do this is as previously suggested, is in daylight get the camera focused on a distant object.  Then adjust the eyepiece so it is in focus as well and then adjust the mirror stop so everything is central.  

Note that even if you have to focus to something closer than optimal in daylight the focus for both eyepiece and camera will remain the same even if you have to refocus.

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To add to what jambouk and gkec have said about testing in the daytime:


Buy a 1.25" Parfocal Ring and use it on the camera nosepiece or on the eyepiece, to get them both in focus when you flip the mirror.


If you can't adjust the mirror to get the centres the same, an eyepiece with cross-hairs will help you to judge which "quadrant" to aim for.


Ideally a cross-hair eyepiece with X-Y adjustment, so that when the object is central on the camera, you can adjust the coss-hairs to be on the object when you flip to the eyyepiece.

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Thanks gentlemen....your advice is much appreciated. :smiley:

The eyepiece holder does have a helical focuser/lock mechanism.  There is a mirror stop on the bottom and there are also adjustment allen screws on both sides to adjust the mirror itself apparently.

I'll try set it up in the daytime on a distant object. 

Again thanks so much

Cheers

Roger

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