observing with diagonal

[25585]

Painfully pricey. Same vein as Mk 5 bino viewers. https://www.rothervalleyoptics.co.uk/baader-2-90-degree-amici-erecting-prism.html

More reasonable https://www.365astronomy.com/lacerta-2-90-degree-erecting-amici-prism-diagonal.html

[LukeSkywatcher]

54 minutes ago, 25585 said:

Painfully pricey. Same vein as Mk 5 bino viewers. https://www.rothervalleyoptics.co.uk/baader-2-90-degree-amici-erecting-prism.html

More reasonable https://www.365astronomy.com/lacerta-2-90-degree-erecting-amici-prism-diagonal.html

Out of my reach. The WO is still a tad pricey. There is another WO for about 50 quid, but I like the shape of the round one I linked to earlier. 

[Ruud]

5 minutes ago, Doc said:

Have you used the APM or Zeiss models Ruud? 

I cannot see no degrading at all.

 

Hi Doc, 

no, haven't used those. The ones I have were either bad or due to low magnification no degrading was noticeable. 

There are of course these considerations:

No prism or diagonal means no degradation at all. The viewing angle may get very uncomfortable though.

• Just a diagonal means one surface that has to be made to exacting standards: flat, smooth and with a good coating.
• A simple prism means the same for three surfaces, two with transmission coatings, surfaces which must be positioned at very precise angles.
• An Amici prism involves four surfaces, two of which meet at a roof edge which is in the middle of the light beam from the objective. Now you need four very flat surfaces placed at precisely the right angles, and you still need good coatings.

No wonder that a diagonal has the advantage.

Televue puts it like this: Their 45° Erecting Prism "works best at moderate magnifications".

 

[Paz]

Interestingly Newtonian views don't bother me at all because although the image is rotated it is fundamentally faithful.

[Stu]

10 hours ago, 25585 said:

What is so confusing is moving from an atlas to eyepiece, whether Newtonian

With a Newt you can just turn the atlas upside down

[25585]

2 hours ago, Stu said:

With a Newt you can just turn the atlas upside down

Ideal for southern hemisphere observers using Newts. Right way up through a Newt. Maybe a Heritage should be my travel scope ?

[LukeSkywatcher]

1 hour ago, 25585 said:

Ideal for southern hemisphere observers using Newts. Right way up through a Newt. Maybe a Heritage should be my travel scope ?

Love my heritage. Focuser is a bit of a pain.