Harry Siebert Optics Premium 21mm, 1.25 inch

Ratings:Top:Astronomy:Equipment Reviews:Eyepiece Reviews:Harry Siebert Optics Premium 21mm, 1.25 inch

 Info  Votes  Messages  More Stats  Up One Level
Brand and Model:Harry Siebert Optics Premium 21mm, 1.25 inch
Price ($USD):$79.00
Type:Misc Wide Angle
Focal Length:21 mm
Barrel Size:1.25 in
Apparent FOV:75.0 degrees
Field Stop Dia.:0.0 mm
Eye Relief:12 mm
Elements:3
Weight (lbs):
Description:

Vote Highlights Vote
Harry Siebert Optics Premium 21mm, 1.25 inch
I have a Discovery EQ 8 inch reflector that is an F/5, which I like very much. After much research trying out different eyepieces I decided to purchase an entire line on Siebert Eyepieces as I felt that they would give me the most for my eyepiece dollar. I have the 3.4mm, 4.9mm, 7mm, and 10mm 1.25” standard series; the 15mm, 21mm 1.25” Premium deep sky series; and the 32 Ultra Plus 2” eyepiece. Harry has been a pleasure to deal with and in the many times that I have spoken with him he has given me excellent advice as to which eyepieces would benefit me the most given my telescope and what I like to observe. He truly took the time to tailor my eyepiece selections to me and I don’t think that you can get that service easily anywhere else.

21mm premium review --> For the $79 price it is unbeatable. It is sharp almost to the very edge and it's excellent light throughput and brightness make it perfect for hunting the faint fuzzies. It is my workhorse deepsky eyepiece and it is what I use when I am searching for a galaxy or nebula. Found the Leo triplet with it for the first time. Again, nothing even close to this for 2-3 times the price.

Overall Rating: 10
Optics:10 Value:10
Weight: 10 (Trustworthy Vote)
Date:
By:
Link to this vote: http://excelsis.com/1.0/displayvote.php?voteid=111449

Harry Siebert Optics Premium 21mm, 1.25 inch
I've used this eyepiece on two f/6 scopes: an Orion XT8 and a Stellarvue AT1010.

Cosmetically, this is a definite improvement over some of Harry's older eyepieces. Much nicer fit/finish, metal barrel that's threaded for filters, stamped focal length and a better quality rubber eyecup. However, shining a light at the lens reveals that there is very little in the way of coatings on there. Instead of the rich green color of every other eyepiece in my collection (even lower-cost ones such as Sirius plossls) this lens shines back a bluish-white reflection that is much brighter.

Optically, the eyepiece needs to be upgraded in my opinion. It begins to show aberrations about 70% of the way out, they become quite bad about 85%, and become multi-colored comets at 90% and further. I should balance this by saying that everything is crisp and sharp inside that 70% figure.

I noticed that any star brighter than about mag 4 would show a very noticeable reflection (I characterize it as finding previously-undiscovered little planetary nebulas!). To Harry's credit, this is fully disclosed on his website, but it was more severe than I'd expected. I anticipated seeing reflections on the moon/planets and maybe the brightest handful of stars (and those weren't the intended uses of this eyepiece anyway, so I wasn't concerned about that). But this eyepiece will show a reflection on so many open clusters that it loses its usefulness for me.

This eyepiece does seem to have better contrast than the 32mm Sirius plossl that it replaced, but I suspect that's due primarily to the magnification. I haven't had a chance to compare it to another 21mm eyepiece to see how it stacks up against a better-coated eyepiece, but I suspect I'll sell this one once I do.

It's a shame...this is an eyepiece that I *really* wanted to like, since there's very little in the way of eyepieces in the 20-23mm range that maximize the FOV within the 1.25" format. But I wish I'd returned it and saved up for a Meade SWA 24.5.

Chris Nicholl

Overall Rating: 5
Optics:3 Value:6
Weight: 7 (Veritable Vote)
Date:
By:
Link to this vote: http://excelsis.com/1.0/displayvote.php?voteid=145707

Harry Siebert Optics Premium 21mm, 1.25 inch
Not the best eyepiece in the Siebert line - suffers from ghosting, seagulls, and internal reflections. I like the Siebert 7mm much better.

Overall Rating: 2
Optics:2 Value:3
Weight: 6 (Veritable Vote)
Date:
By:
Link to this vote: http://excelsis.com/1.0/displayvote.php?voteid=429063

Harry Siebert Optics Premium 21mm, 1.25 inch
I agree with the last vote. They did have some ghosting on bright objects. But the performance was so close to the Denk 21mm's that it was hard to see a difference. On deepsky objects they were flawless down to f\6. With the price difference I decided to keep the the Siebert 21mm's. I say try before you buy and make up your own mind.


Gary Franks

Overall Rating: 9
Optics:9 Value:9
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://excelsis.com/1.0/displayvote.php?voteid=429433

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

Jay Freeman's Eyepiece Primer
Starting out in Amateur Astronomy
 
How to use This Site
Why Register?
Voting Guide