BW-Optik 30mm 80˚ Ultrawide


 Info  Votes  Messages  More Stats  Up One Level
Switch to Subject View
Post Message



Page 1 of 1


Subject: BW-Optik 30mm
By: Anonymous (xxx.xxx.202.201)
Date: 06/25/2003 12:20:24 pm PDT
I too got mine from Anacortes. It comes in a plastic bolt-type container (a bit cheap -- feels like it's made from a recycled milk jug). Overall fit and finish of the eyepiece was very good. I tested it on both 120ST and C102 refractors. Views were remarkably sharp and generously wide with both 'scopes (actually, verging on the stunning with the 120ST). Stars did not focus to complete pinpoints (as they did when I did a quick swap with a 35mm Panoptic). Still, for $95, this eyepiece is hard to beat. It also got several nods of approval from others who took a peek during a group viewing session.


Reply
Post Un-related Message


Subject: Moved Message
By: Anonymous (xxx.xxx.1.184)
Date: 01/12/2004 03:20:12 pm PDT
I wanted a PowerMate to allow my inexpensive 30mm BW Optik eyepiece to operate at a high power without vignetting. Also, surprisingly to me , my newly acquired 20mm TeleVue Plossl vignetted badly when used with my barlow.
Not wanting to spend the $$$, I came up with an alternative solution that some may wish to explore. I remembered reading that the PowerMate was a combination of the Panoptic Barlow interrface lens and a (Tele-Vue) barlow. I was able to find the interface lens on closeout for $40 and decided to give it a try. To get to the point - the combination of the interface lens and my 1.25" Ultima barlow makes a wonderful 4x (more like 3.8x) unit. My 2" 80degree 30mm
eyepiece gives about 150X and is VERY sharp to the edge - stars are close to absolute pinpoints (10" f/5 newtonian). No vignetting either ! Last night with seeing conditions rated around 7-8 out of 10, in quiet moments between undulations of the atmosphere, Saturn appeared in wonderful detail at 150x, 240X and 400x. I could make out multiple bands on the globe and the crepe ring, Cassini's division and just a hint of the Enke division (at 400x). I love this thing ! - Herb


Reply
Post Un-related Message


Subject: Re: Moved Message
By: Anonymous (xxx.xxx.238.146)
In Reply to: Anonymous (xxx.xxx.1.184) (Original Message)
Date: 05/11/2004 06:20:24 am PDT
Can you detail me the combination between the Barlow and the Barlow interface?

Thank You!


Reply
Post Un-related Message


Subject: Re: vote by ckw1astro
By: SCT8Swanson
Date: 09/16/2010 02:36:23 pm PDT
>Overall a fairly respectable eyepiece for the money. I was quite surprised. The throughput is very good, coatings seemed good, comfortable to use, and very nice for daytime use too.
>
>However at night, it's very obvious that it doesn't come close to the 31 Nagler in performance (or the UO 40mm MK-70), especially at the edges, and in faster scopes. While very sharp on axis (I was impressed there), the BW starts to exhibit softness around 50% out from center and continues to get worse towards the field stop. The last 7%-10% is almost unacceptable, and shows astigmatism too, even in an f/7 scope. The eyepiece also suffers from quite a bit of curvature, and there's just no way to make the stars appear to be anywhere close to in focus all the way across the field.
>
>One thing I did notice is that the eyepiece appeared to be more like a 32mm-35mm rather than 30mm. Several objects appeared to have smaller angular size than in the 31mm Nagler, and I'm not sure the AFOV is really 80* either. The difference between the 82* of the 31 Nag and the supposed 80* of the BW is significantly more than what I expected, and I'd say mine is probably closer to 75* - not much larger than the AFOV on the MK-70. I have not verified this with star timings, but objects just appear to be less magnified than in the 31.
>
>It's a good value no doubt, and I'd say it's worth it even for daytime use only, where I think it is better suited. But I think there's other eyepieces out there that aren't too much more expensive that will perform noticeably better for astronomical use. I'll be selling mine very soon.


Reply
Post Un-related Message


Subject: Re: vote by ckw1astro
By: SCT8Swanson
In Reply to: SCT8Swanson (Original Message)
Date: 09/16/2010 02:42:01 pm PDT
>>Overall a fairly respectable eyepiece for the money. I was quite surprised. The throughput is very good, coatings seemed good, comfortable to use, and very nice for daytime use too.
>>
>>However at night, it's very obvious that it doesn't come close to the 31 Nagler in performance (or the UO 40mm MK-70), especially at the edges, and in faster scopes. While very sharp on axis (I was impressed there), the BW starts to exhibit softness around 50% out from center and continues to get worse towards the field stop. The last 7%-10% is almost unacceptable, and shows astigmatism too, even in an f/7 scope. The eyepiece also suffers from quite a bit of curvature, and there's just no way to make the stars appear to be anywhere close to in focus all the way across the field.
>>
>>One thing I did notice is that the eyepiece appeared to be more like a 32mm-35mm rather than 30mm. Several objects appeared to have smaller angular size than in the 31mm Nagler, and I'm not sure the AFOV is really 80* either. The difference between the 82* of the 31 Nag and the supposed 80* of the BW is significantly more than what I expected, and I'd say mine is probably closer to 75* - not much larger than the AFOV on the MK-70. I have not verified this with star timings, but objects just appear to be less magnified than in the 31.
>>
>>It's a good value no doubt, and I'd say it's worth it even for daytime use only, where I think it is better suited. But I think there's other eyepieces out there that aren't too much more expensive that will perform noticeably better for astronomical use. I'll be selling mine very soon.

The BW- Optic is the eyepiece with the correct stated focal length of 30mm. The 31mm Nagler has alot of pincushion distortion which is basically uneven magnification across the field. It is like looking into a bowl.

Why you would assume that the Televue focal length would be accurate and not the BW is not surprising to me because everyone would assume that Al Nagler could not be wrong about anything. Not me.

Mark


Reply
Post Un-related Message


Page 1 of 1

[Click Here to Login]
Don't have a login? Register!