reflector telescope image corrector

[space4me]

very basic question, if already answered somewhere, apologies- is there a optical image corrector for a reflector telescope I just was given, its easier to see and find objects with a right side up image, have found several for refractor telescopes, not for reflectors

[John Baars]

Welcome to TSS!
Most erecting correctors for refractors have a diameter of 0.965 inch, not the standard 1.25 inch. Moreover their quality is questionable.
Prismatic correctors are used in refractors and catadioptric ( Maksutovs, Cassegrains) reflecting telescopes, they cost a lot of in-and out travel of the focusser, many instruments still can't handle it.
There is no corrector for Newton telescopes as far as I know, Newtons can't handle the increased travel path of the focuser. If you want an upright image in a Newton, make sure you have the eyepiece pointing straight up during your observation. Easy viewing is still not possible then, because you actually have to be right behind it. And that's where the tube gets in the way. Moreover, left and right still remain misrepresented.

Get used to seeing observations left/right wrong and / or top and bottom wrong as soon as possible. We all do that and we too could get used to it. After all, in the universe there is also no above / below / left / right. Succes!

[Piet Le Roux]

Good day space4me,
I think this is something we novices should learn to cope with, The image will always be reversed depending on how many mirrors it is reflecting off, My SCT with a diagonal has 3 mirros, so the view is reversed left to right, a Newtonian has 2 mirrors and its view is upside-down. I think a SCT with a 45° diagonal has a "normal" view but I have not tried it. here are some information on the subject:
https://www.skyatnightmagazine.com/advi ... ar8UtxmSgE

[JayTee]

Those of us who've been using reflector telescopes for awhile understand that there is no "UP" in space.

[WilliamPaolini]

Good day space4me,
I think this is something we novices should learn to cope with...

Ahhh...yes and no. I think that generally there is too many no longer valid characterizations that are carried from the past for some things, like Barlows and AMICI Prisms for correct views with refractors. For 55+ years I have been as you say, coping with the image disorientation. About a year or so ago though I had a chance to use both an inexpensive Astromania 1.25" AMICI as well as the premium (and very expensive) Baader 2" AMICI prism. With either they produce very sharp views at typical magnifications and for the premium unit even at very high magnifications (the Baader unit I tested up to 600x). Similarly, for DSO while there was a very slight loss of transmission with the AMICI compared to a top shelf prism or mirror star diagonal, it was so slight even for dim DSO that not worth the mention IMO. Of course, since the AMICI prism is split one does get a diffraction spike on brighter stars so there is that cost to using them, but for most targets was not any issue (unless a double star since the spike might be across the companion). What was amazing though was how much more intuitive the entire observing process became as I hopped across the night sky from object to object as there was no translation needed from naked eye to through the eyepiece. And on the Moon it was simply wonderful to be able to see some feature up in the far right of the FOV and to be able to move the scope in the same direction to center it. Felt like a great burdon I never completely realized had just vanished. So IMO beginners should not shy away from getting an AMICI prism diagonal for their refractors, even an inexpensive one, as it can be quite a nice experience using them!

[AstroBee]

very basic question, if already answered somewhere, apologies- is there a optical image corrector for a reflector telescope I just was given, its easier to see and find objects with a right side up image, have found several for refractor telescopes, not for reflectors

Rather than add an unnecessary piece of glass (or mirror) into your imaging train, it's best to get used to as others have stated, there is no "up" in space.
Remember, anytime you add another piece of glass or mirror into the line, your image quality degrades a slight bit. The cheaper the item, the worse it degrades.
I'd suggest a Telrad or similar zero power red-dot finder for easier pointing and then get used to when you want to go "left" you push "right" or whatever the direction might be.
Of course, with a GEM mount that left and right is going to flip when you cross the meridian. You really do get used to it all after a while.

[Lady Fraktor]

very basic question, if already answered somewhere, apologies- is there a optical image corrector for a reflector telescope I just was given, its easier to see and find objects with a right side up image, have found several for refractor telescopes, not for reflectors

No they do not make a optical corrector for a reflector. There are some image erect eyepieces but they work poorly and usually just a waste of money.
If you are using a planetarium program to plan a observing session you can flip the image and print a map with the correct view for your telescope.
With a little bit of practice the movements become automatic.

[Piet Le Roux]

Orientation of the image is somthing we have to get use to but as the article I shared the link of stated, it is something we do daily when looking in the mirror or reversing your car. I use Stellarium software to help me with this by setting it up for the specific scope and eyepiece I would be using to find a difficult object like proxima centauri, it would then give me an exact view, of what I would see in my eyepiece on that specific date and time, even rotated correctly for my Az/Alt mount.......without it I would never be able to pinpoint proxima centauri. I then print the image in reversed black and white and use it as a map.

[Richard]

Many years ago I had an Astromaster 130mm reflector that came with an image correct eyepiece but as mention was only really suitable for terrestrial use and poor quality , If I recall the eyepiece has 2 small prisms inside , I think the only reason for this was to advertise it for both Astronomy and terrestrial use

[WilliamPaolini]

Here's the premium AMICI correct view prism I now keep on my TSA-102 as it makes observing more effortless allowing the equipment to get more out of the way while observing...

https://www.baader-planetarium.com/en/a ... ating.html

Here's my testing notes from August 2020...

DAYTIME --

Baader AMICI prism in the Vixen 81s. Using the 40XW it was a beautiful view. Razor sharp field stop. Was so nice doing daytime spotting with the scope now as everything correct view. Everything about the image was perfect. Moving to the 3.5xw which produces 55x/in in the Vixen the day view was still very good, but the prism was inducing just a little CA as some brightly lit objects were showing a slight color cast compared to the neutral view using the Zeiss T2 1.25 prism. View appeared slightly less etched also probably due to the slight CA that was induced. But other than for that more extreme magnification was quite excellent. Will have to see how the high mag behavior is on Moon and Sirius. Hopefully tonight if it stays clear. Will also be interesting to see how behaves on the 4" ED doublet I have.

NIGHTTIME --

Very impressed with the Baader AMICI prism. Compared it to my 2” Zeiss prism in 6” Apo. Basically on stars like Rigel the single diffraction spike from the split in the prism was visible across most of the FOV. But it was so very thin and non obtrusive that even if Rigel’s companion was on the spike would still be visible. So no where near as fat as what a Dob produces. On the Orion Belt stars the spike barely to be seen. So all but invisible. Took the scope up to 300x and double splits were just as clean and color rendition just as good as Zeiss. When I was up at 400x on Sirius though, my ED scope was showing a little blue tightly around the star point a little more in the AMICI than the Zeiss. But that is over 50x/in. On Nebula the Zeiss showed them just a tad more so greater extent on wings of M42 and M1 looked slightly larger. M42 also showed mottled structure just a tad better in Zeiss. But that was it. Dimmest stars just as visible in either diagonal and things like Trap E and F just as visible in either. Was so much more intuitive with the AMICI moving around star fields than with the conventional Diagonal. So really enjoyed the AMICI and showed good clean color saturated star points right to the field stop in the ES24 as example. Really nice to use. Heavier than the Zeiss 2” prism though. Overall I loved it. And want one now!

Using the TSA and AMICI prism on Moon. Used Tak LEs and Barlow to get to 326x which is over 80x/in. Moon was just as sharp and etched in the AMICI as in the 2” Zeiss prism. I felt the Zeiss was a gnat hair crisper but after 6 flips between the 2 diagonals could not nail it down positively. Finding best focus was a bit easier in Zeiss though. Probably why felt it might have been a tiny bit crisper just because had more precise focus. So cool having Moon in correct view. Enjoyable difference.

Final high power test in Moon with AMICI prism. Used the 152ED and cycled thru with two other diagonals, the Zeiss 2” prism and the BBHS Silver mirror. Went up to 480x then 600x. No sharpness difference. No induced SA or CA that I could detect between them. Was an incredibly stable and clear evening with the Moon near the zenith. Views were jaw dropping. Felt like I was landing the LEM in the Moon!

[Richard]

Yes they are great for Refractors and ( SCT and even a Mak which are reflectors of some sort) but for pure newtonian reflector no as mention by LF, I only think its modifies eyepieces , which as mentioned are not very good for astronomy
I thought of adding this as the OP only mentioned a Reflector , so could be a SCT of a Mak

[WilliamPaolini]

Here are products to get erect view from Newtonian. Unfortunately they also gives 1.5x magnification so it is a Barlow of sorts.

www.amazon.com/Datyson-Rectifier-Newton ... B0768YB6L8

www.amazon.com/1-25-Erecting-Barlow-Uni ... 8C7J&psc=1