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Flip (in) Mirror


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Always looking to make life easier I thought that I would use a Flip Mirror to assist with planetary imaging.

I tried setting it up last night and, so far, I am not impressed with it over what I was previously doing.

Previously I made sure that the finder was well aligned so that I am on target and then get the target centered using an EP before changing it for  the camera. When using a high power Barlow there is always an element of searching because of the tiny FOV of the camera (ASI120) but it does not take long to find and centre the target.

I tried with the Flipping Mirror last night and found that it does not really make the process much easier. It's fine if you do not use a Barlow but I wanted to use a 3X Televue so the installation was visual back-flip mirror-barlow-camera. What I found is that with the 3X Barlow I could not match the focus of the camera with the EP unless I used a 40mm EP which is not ideal due to high FOV. This was because there was insufficient back focus possible with the flip mirror EP holder which you can adjust but not nearly enough for a high power EP. So, after collimating the FM, I could centre the target (Venus in this case) in the flip mirror EP but still had a bit of searching to do because it was not centered in the camera. 

The problem is that the use of a Barlow with a flip mirror will greatly reduce your FOV with the camera but not with the EP which is before the Barlow.

So the conclusion is that I am not convinced that a Flip Mirror helps very much when using a high power Barlow as part of the image train.

I'd be interested in any views by Flip Mirror users and if there is any way to the make the process easier.

Peter

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I use one and i love it. I also put a barlow of similar in the eyepiece so both channels are magnified. Often the target isn't central in both, so it's a case of remembering where it needs to be in the eye piece for it to also be on he sensor.

Damian Peach doesn't use a flip mirror.

James

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I used a Vixen Flip mirror set-up on the early Spectra-L200 spectroscopes.

I also used the freeware "Al's reticule" to present a moveable crosswire on the guide image. Once this was set to match the centre of the camera FOV there was NEVER an issue in positioning the target star exactly onto the 20 micron entrance slit.

Highly recommended.

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I don't care if the image isn't focused when I use an eyepiece.  As long as I can see a round blob to centre on the reticle that's sufficient.

James

Hi James...you're right on, as I found out tonight!

I finally set up my Meade flip-mirror on my 9.25SCT, after receiving some excellent advice from other members in a previousw post.  Yesterday I set it up in the daytime on a telephone pole insulator (fairly far away).  I put a 2x Barlow and a reticle eyepiece in the camera train to centre the insulator.  Then I put the reticle eyepiece in the eyepiece...only had to adjust the mirror stop a bit to centre it.

Tonight I went out to do some imaging and (while not absolutely perfectly aligned) I was able to get Jupiter on the chip pretty well right away....the other night I had no luck at all getting Jupiter on the camera chip, swapping out the reticle eyepiece for the camera.  I think (for me) this flip mirror is an indispensible aid...don't know how I got along without it, and I'm sure my neighbour appreciates the lack of cussing on my part.

Cheers

Roger

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I shall try again using a 2X Barlow, as this should be easier, so that I can ensure that it's all centered ok. Learning process I guess. Interesting that Damian Peach does not use a flip mirror.

Thanks for the input all.

Peter

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Had another go last night and used a 2X barlow and didn't worry about getting the EP to focus and it all worked brilliantly. Went from Jupiter to Venus several times and the image was on the laptop screen each time. So I think that this could well make life a bit easier. 

Peter

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That's great Peter!

My next project (now that the frost has quit heaving my scope around) is to get a good drigt alignment so Jupiter stays exactly in the center of the screen,,,if such a thing is possible. If I recall I had it like that a couple of times.

Cheers

Roger

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