Skymax 127 Image Orientation

[procky1845]

Hi,

Posting in the beginner forum as I didn't know the answer and may be useful for somebody considering a first scope.

I've been into astronomy for the past 5 years, for the most part using a Skyliner 200p which I absolutely love. However, after moving house a year ago I am now aware that my current location isn't conducive to doing any kind of planetary observing due to the north facing garden, hill to the South and general obstruction of views where I need to be looking.

I have no intention of parting with my beloved 200p but would like something lightweight I can carry to the top of a hill easily to do some planetary.

Anyway, more or less set at this point on a Skymax 127 which ticks all the boxes for me but having only used a Newtonian I don't know much about Maks.

So my question is, what is the image orientation when looking through the Mak both with and without the star diagonal? (I'm assuming you can use it with and without?) My 200p is as I would describe it rotated 180° but assume it will be different for the mak?

Thanks.

[johninderby]

With a mak the image is the right way up but reversed left to right using a diagonal. Without a diagonal the image is inverted but Maks are nornaly used with a diagonal,

https://www.telescope.com/Image-Orientation/p/99816.uts

Edited October 13, 2019 by johninderby

[Stu]

For Maks and refractors the view without a diagonal is inverted, and with it is upright but left-right reversed.

[procky1845]

So without the diagonal it would effectively be the same as my 200p? I assume that it's just too difficult to use without hence the diagonal. Can you get diagonals that don't flip the image left to right? Presumably this would involve extra mirrors and loss of light transmission?

[Stu]

20 minutes ago, procky1845 said:

So without the diagonal it would effectively be the same as my 200p? I assume that it's just too difficult to use without hence the diagonal. Can you get diagonals that don't flip the image left to right? Presumably this would involve extra mirrors and loss of light transmission?

No, that's not correct. The dob image is upside down ie rotated 180 degrees, but the Mak image would just be inverted top to bottom. The mirror then corrects the vertical inversion but introduces the left right reversal.

You can get erecting prisms (Amici prisms) which show a correct image. Unless you buy a very high end one you can end up with spikes off bright stars and a reduction in quality. I have always preferred either mirrors or standard prisms which offer the least degradation of the image.

[procky1845]

Ah right I see, so the left right is reversed in both scenarios. The diagonal simply "fixes" the up down.

Thanks that's very helpful.

[Alan64]

Your 127mm Maksutov may function as a daytime/terrestrial spotter, for birds in trees, ships at sea, that sort of thing, and where you'd want the image to be upright and corrected for left and right.  For that, you would need a 45° Amici erect-image diagonal; for examples...

https://www.firstlightoptics.com/diagonals/skywatcher-45-erecting-prism.html

https://www.365astronomy.com/Baader-Amici-Prism-45-degree-1.25-inch-with-24mm-free-aperture.html

However, when the telescope is aimed at the sky, it doesn't matter if the image is upside-down or whatever, for which a star-diagonal will serve, unless you want the view to match what you see on a chart, map or app.  In that event, you'd want a 90° Amici erect-image; for example...

https://www.rothervalleyoptics.co.uk/antares-90-erecting-prism-125.html

With any Amici erect-image diagonal, you will see the "Amici line" illuminated when viewing smaller, brighter objects...