CN FORUMS ARCHIVE Telescope Reviews: Barska vs. Oberwerk

Last night I was able to perform a cursory comparison between my brand new, but cheap, 15X70mm Barskas and my 1-1/2 year old Oberwerk 15X70's. Superficially they are very similar with the Oberwerks displaying a nice green coloured lens coating, the Barskas had a light metalic blue.

Looking at star fields with the aid of a tripod they seem to show about the same. I didn't try to count stars in a cluster or check for stars with averted vision (this was to be a quick, in the light polluted back yard, gross differences kinda test). Jupiter looked good with several moons showing (May 5th about 9PM MST).

The moon was a different story. The Barskas showed two strong ghost images, at 10:00 and 4:00. If I moved off target about six more much smaller ghost images appeared (the first ones were full size). I had the impression I was looking thru a vaseline covered lens.

The moon its' self looked pretty good, a little colour, in focus but with mushy details. The limb was in focus but the lit area was hard to see details in. It was not quite a half moon.

The Oberwerks took the moon with out any ghosting. At times I could make out one very faint ghost around 9:00 or 10:00 and it was not there all the time. The limb was in focus, slight colour and surface details where very easy to make out. Checking out the Barskas this morning in the smogging early morning light from the 18th floor of city hall did not show any defects. These will be daylight bino's.

When I received the Barskas they were way out of collimation with a cats eye light cone on the right tube. With the help of a couple collimantion articles from this site I was able to recollimate them but I can't help but think the ghosting may yet be an artifact of mis-collimation instead of just a coatings issue. Although it's my opinion the difference in coatings is the main reason for the superior image in the Oberwerks.

I don't feel so bad paying twice as much for the Oberwerks as the Barskas now.

Ron

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Ron

NS11GPS
Pronto
16" dob
15X70 Obies

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