Hyperion 36mm Lens

[Tinker1947]

Anybody have or know any thing about this lens i'm thinking i need something about this size and price, would be used in the 2" mode.

First Light Optics - Baader Hyperion Aspheric

[Ags]

Be aware it only really has a 2" mode - in 1.25" mode you lose half the FOV.

[John]

A 36mm eyepiece used in the 250P scope produces an exit pupil of 7.7mm which is probably a bit large and will mean that some of the light being collected by the mirror will not get into your eye. A 30mm eyepiece, or therabouts is a better bet, in my opinion.

[Tinker1947]

Thanks for the info, not sure if its worth a new lens just for 6mm..??

[Mr Spock]

The other thing to consider is with this kind of eyepiece is the aberrations you get. This added to the rampant coma of a 250P means only half the field will be sharp.

To get decent wide views from a 250P you need a good coma corrector and a quality wide field eyepiece - all very expensive.

[Tinker1947]

The other thing to consider is with this kind of eyepiece is the aberrations you get. This added to the rampant coma of a 250P means only half the field will be sharp.

To get decent wide views from a 250P you need a good coma corrector and a quality wide field eyepiece - all very expensive.

Anybody want to name, names the CC is about £100, what type of EP would suit..

[cs1cjc]

This eyepiece will give you the widest possible field, and brightest image in a 2" format. Some light will be wasted because of the large exit pupil but that does not seem to be a major issue with the 38mm SWA that I use. The central obstruction does not intrude once my eyes are fully dark adapted. Coma will be the same as any other eyepiece with 72* apparent field of view.

However, if you are prepared to lose a small amount of true field of view, the 31mm might be a better bet.

[Charon]

The 36mm works well with my CPC800, it is my most used eyepiece.

[Tinker1947]

John, may come along with the formula to show why it will work in your scope but not so well in mine...

[faulksy]

The 36mm works well with my CPC800, it is my most used eyepiece.

you changed your avitar again lol