# B Optical eyepieces for star observations

1. Nov 14, 2017 at 11:55 AM

### bruha

Hello, can I ask you if you have some experience with hyperion modular eyepiece adapter? I would like to know what is its main advantages compare to standard eyepiece ( as it is about ten times more expensive..)

thank ou....

2. Nov 14, 2017 at 2:53 PM

### davenn

Hi Tomas,

is this what you are talking about ? ....

the left part is a Hyperion Eyepiece with a 2" barrel
the right part is an adaptor that screws into the end of the eyepiece to reduce the 2" barrel down to a 1.25" barrel
this is for telescopes that don't have a 2" eyepiece holder

Is that what you wanted to know ?

Dave

3. Nov 14, 2017 at 3:17 PM

### davenn

4. Nov 15, 2017 at 5:20 AM

### bruha

Hi , yes it is exactly what I am talking about... I have just 1,25" eyep. holder. Do you have some experience with this one,...?

thank you

5. Nov 15, 2017 at 12:08 PM

### Staff: Mentor

Hi bruha. Can you elaborate on what you're asking? Do you currently have an eyepiece that you want to use with an adapter, are you wanting to buy an eyepiece with adapter to use in your 1.25" focuser, or something else?

6. Nov 15, 2017 at 12:35 PM

### NFuller

Yes, I have a few of these.
What do you consider to be a "standard eyepiece"? Are you referring to a cheap Plössl here?

7. Nov 15, 2017 at 1:00 PM

### bruha

Hi ,
yes I plan to buy these eyepiece with adapter as I have just 1,25" telescope (or thinkink about it) but concerning high price I would like to know if it is really importantly advantageous compared standard eyepiece ?...

Thank you,...

8. Nov 16, 2017 at 5:51 AM

### lomidrevo

I cannot say anything about the Hyperion Aspheric eyepiece, but I do have Hyperion Zoom Mark IV, and I like it a lot..

There are also 68° modular eyepieces in Baader hyperion series. And as far as I know, all of them (except 24mm) can be adapted to 2" or 1.25" focuser. The focal length should be variable by removing first group of lens or by adding the extensions - that's why it is called modular. Maybe you want to check more about them at this link...

By standard eyepiece, you mean that it is not modular?

9. Nov 16, 2017 at 12:56 PM

### bruha

Thank you, for answer and link... Yes I have just not modular simple eyepiece 20,12, 6, 2,5 mm (telescope 130 *600 mm) . I will check it....

10. Nov 16, 2017 at 1:02 PM

### bruha

ANd yes I mean for example Plössl ones -my question in fact was how much and by which way I improve quality of image (what I can see) by using Hyperion compare these standard cheap ones

11. Nov 16, 2017 at 3:29 PM

### davenn

which standard cheap ones ?
you haven't given any specific brand name examples

Plossl is a type of eyepiece, not a brand, many companies make plossl's along with other types

12. Nov 16, 2017 at 11:25 PM

### NFuller

The two major differences will be the apparent field of view and optical aberrations.

More expensive eyepieces, like the Hyperions, are designed using multiple lens groups to give a much wider field of view. The Hyperions have a field of view of ${68}^{\circ}$ while a Plössl is around ${50}^{\circ}$.

Cheaper eyepieces often have inferior optics which cause issues like chromatic aberration, ghost images, and even distortion of the image.

The optical issues are often most noticeable when observing bright objects like the moon, planets, or stars.

13. Nov 17, 2017 at 5:00 AM