ORION Edge On - any good??????

[StarLane]

I noticed Bintel are selling the new Orion "Edge On" EP's.

Has anyone bought one or had any experience with these? Do they perform as stated??, minimal field curvature???

Cheers.

[Scoper]

Hi Paul, I emailed Bintel about the 16mm edge on eyepiece. Don from Bintel stated that he had tried one of these eyepieces terrestrially in an ED80 scope and that the edge of field was crisp. He also stated, however that he has yet to try one under a dark sky. Here is a cloudy Nights review of the Smart Astronomy EF eyepieces which appear to be the same as the Orion Edge On's. http://www.cloudynights.com/item.php?item_id=1684
Having only five elements should make these eyepieces produce sharp, bright and well contrasted images on -axis though i would imagine the edge of field will be astigmatic to some degree. Hope this all helps.

Cheers
Malcolm

[Scoper]

By-the-way, how does your 7mm TMB/Burgess Planetary eyepiece perform in your 10 inch Newt? Does it compare with a 7mm Orthoscopic as far as contrast and detail go? I'm interested in the 7mm Burgess myself mainly for good eye relief.

Cheers again

Malcolm

[MortonH]

The 27mm model has a disappointing AFOV of only 53 degrees, but the 16mm and 19mm models look attractive.

Morton

[StarLane]

Hi Malcolm,

Thanks for the info.
For the money, my 7mm BO/TMB performs very well in my scope. It's well corrected for a reasonably fast scope. It's my favourite TMB. I haven't tried any Ortho's so can't give you a comparison there. The throughput and sharpness with the 7mm TMB is pretty good, although my 10mm XW has more contrast, with a much larger price tag of course. I bought the BO/TMB planetaries for the ER and the twist up eye cups. They work well and are comfortable with extended viewing sessions. I am surprised at the performance for the money.

Cheers,
Paul.

[StarLane]

Thats interesting.
They state they are all 60 degrees AFOV. Thanks for that Morton. It goes to show, don't believe all you read from the makers.

Cheers,
Paul.

[MortonH]

I took that from the Bintel website. Maybe it's wrong?

Bintel also says that the 19mm is 65 degrees, not 60. Sounds a bit fishy. Maybe more research is required...

Morton

[MortonH]

This is from Orion's own website:

Available in 27mm 19mm, and 16mm focal lengths, with apparent fields of view of 53°, 65°, and 60° respectively, and eye relief of 21mm, 17mm, and 17mm, respectively.

[StarLane]

Yeah, You're right Morton, my mistake.:doh:
I only looked at the 16mm on the Bintel web-site and assumed they were all 60 degrees. Strange to have different AFOV for different focal lengths.

Cheers.

[MortonH]

I guess to keep the price the same for all three, and achieve the flat field they claim, they had to mess around with the field of view.

Morton