Erecting Prism quality?

[Guest]

I have a bog standard erecting prism.My question is ,are the varying qualities of glass.I s one erecting prism costing three times the cost of a bog standard going to give a clearer sharper view?

Williams Optics are £59 and others are considerably less or more.

Martin.

[michael.h.f.wilkinson]

I have a few erecting prisms: two 45 deg 1.25" jobs, one of which is Meade branded, one of which came with the 70mm F/5 scope I transformed into a RACI finder. The build quality of the Meade is better, the other is very flimsy and plasticky. Both have about the same optical quality; but neither are very good. They are OK at low magnification, but do not hold up well under high mag. I also have a SkyWatcher (I think, might also be a TS branded one) 90 deg 1.25" version. Build quality like the Meade, or a touch better, optically a bit better I would say, but not much. Works well in my RACI finder. My best Amici prims by far is an Orion Optics 2" 90 deg version; clearly built by WO, very good build quality (MILES ahead of the cheap ones), and optically very good. I could go to 137x with my 80mm scope, although the out of focus behaviour is odd, the in focus image is very sharp. My review can be found here:

http://stargazerslounge.com/topic/185261-proper-first-light-of-the-orion-2-90-deg-amici-prism-plus-the-home-brew-mount/

[RichM63]

I have a WO Amici prism, but so far have only mainly used it on the EQ5 mounted 200P for looking at distant tall ships out to sea. Seems to work great, but I look like a Pratt surrounded by all the 'real' TS watchers standing straight.

My conclusion with optics, is that you get what you pay for, but adding a £300 EP to a £50 Telescope is like fitting Alloys to a Lada. "pointless"

[John]

;;;;;My conclusion with optics, is that you get what you pay for, but adding a £300 EP to a £50 Telescope is like fitting Alloys to a Lada. "pointless"

What price scope is "worthy" of a £300 eyepiece then ?

[John]

What price scope is "worthy" of a £300 eyepiece then ?

Actually, no need to answer that - it's off topic. Sorry Martin

[Guest]

I have seen the WO for sale at FLO.Might give it a whirl.

[Mr Bond]

I bought the 1.25" WO prism at first, to watch birds in the garden on my TV85 (mainly to allow me to sell a Pentax spotter scope).

This was quite good but would not let itself be pushed too far before becoming soft. Excellent at birdtable-ish 20-30x.

I used a Swarovski (Meade branded) zoom EP.

My logic was then to go to 2" as it must be better, right?

Wrong.

Noticeably softer at high mag although a little brighter (not much imho). I concluded that the smaller clear aperture in the 1.25" version must act like "stopping down" a lense diaphragm, increasing the image quality. It was not the scope or EP at fault.

After much gnashing of teeth I bought the Baader/Zeiss T2 prism. Simply transparrent, stunning. You don't know it's there, and it's easier to stand as your wallet is much lighter.

It's not 45 degrees though, it's set at 90. This may be problematic for some. I use a red dot finder on high in daylight without issue, or with a zoom set wide and zoom onto target.

The moral, as usual, buy cheap, cry every time you use it, buy good, cry only once when yo pay for it.