Overall Rating: 7 Optics:7 Value:10 Weight: 20 (Notable Vote) Date: 02/23/2002 07:01:57 am PST By: Thompson Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=69708
My last post escaped before I began typing. I am holding back on voting on this EP. I have owned the 7mm for several months and am less than happy with it. While I find the 34mm Observatory to be great, the 7mm appears to have problems in both my Nighthawk and 14" dob (f/4.7). The star images are less than pinpoint across the fov. My Orthos of the same fl have no problems. Still, the weather in my region has been horrible, and I am holding back on passing judgement. My overall satisfaction with Seibert products has been good, and I still suspect the problems might be somewhere other than the EP. >I took the time the other night to A-B the 7mm Siebert against my 14mm Pentax XL with the Orion Ultrascopic 2X Barlow. That's a pretty tough contest for the Siebert, given that the Pentax XL sells for five times the price. But I figured some people might like to know just how well or how badly the Siebert compares against premium glass. I used both eyepieces in our 10" f/5 Dob and our 90mm f/11 refractor. Here's what I found out: > >f/5 Dob >------- > >The Siebert 7mm is worlds ahead of the typical 9mm Ploessl or Kellner bundled with inexpensive scopes. It provides about the same true field but with significantly higher power, which results in a darker sky background and better contrast. At about 7mm, the Siebert's eye relief is somewhat better than the 9mm Ploessl. Despite the Siebert's lack of multicoating, contrast is excellent. Sharpness is at least as good as the Ploessl on-axis, although the Siebert becomes slightly soft in the outer 10 degrees or so of its apparent field. The eye lens is much larger than the tiny eye lens of the 9mm Ploessl, which makes the Siebert more comfortable to use. > >As expected, when I compared the Siebert to the Pentax XL, it wasn't even a contest. The Pentax XL provides 20mm of eye relief, which makes it usable by someone who wears glasses. The Pentax image was sharp to the edge of its field. Although the Pentax XL and the Siebert are both rated at 65 degrees apparent field, the Pentax feels noticeably wider. It also has noticeably better contrast, as you'd expect from an ocular with world-class multicoatings. Stars that were visible with direct vision in the Pentax XL required averted vision with the Siebert. The long eye relief, huge eye lens, and eye cup of the Pentax XL made it much more comfortable to use than the Siebert. > >f/11 refractor >------------- > >Here the optical differences were much smaller, particularly in terms of edge performance. The Pentax XL still performed superbly, but the Siebert was only a step or two behind. At the edge, the Siebert still showed a bit of softness, but I really had to look for it. Once again, the Pentax had noticeably better contrast, and of course the advantage of better eye relief. It remained a lot more comfortable to use. But, given the price difference, the Siebert gave up surprisingly little to the Pentax. > >Summary >-------- > >I own four Siebert eyepieces, the 4.9mm, 7mm, 12.5mm, and 21mm, and have had a chance to compare them against standard Ploessls and premium eyepieces of similar focal length. There's no question in my mind that the Siebert eyepieces offer higher bang-for-the-buck than any other eyepiece available. Recognize, though, that the Siebert eyepieces simply can't compete with premium eyepieces, not that any reasonable person would expect them to. > >If you have a fast scope like an f/5 or f/6 Dob or a short-tube refractor, the Siebert 7mm will beat your bundled Ploessl hands-down as a high-power eyepiece. If budget limits you to eyepieces in the $50 range, I don't think you can do better than a Siebert 7mm. The main drawbacks are noticeable edge softness and eye relief that's too short for eyeglass wearers. If you're certain that you will remain in the hobby and you can possibly afford it, I'd recommend spending the extra money to buy a 7mm Pentax XL. > >If you have an f/8 or slower scope, such as a small Dob, long-tube refractor, or Mak-Cass, you'll find that the Siebert 7mm gives you most of what a premium eyepiece does, other than multicoating and long eye relief. The Pentax XL is still a better eyepiece, noticeably so, but the difference is less significant than with faster scopes. > >I've retired my four Siebert eyepieces for use with our slow refractor, at public observations, and so on. Although I don't regret buying them, in retrospect I would have been better off spending $225 on one Pentax XL than $175 on four Sieberts. But that's not a slam against the Sieberts, because they remain the best value per dollar spent of any eyepiece line I know. If you're on a tight budget, don't hesitate to buy the 7mm Siebert. You'll like it a lot.
>I took the time the other night to A-B the 7mm Siebert against my 14mm Pentax XL with the Orion Ultrascopic 2X Barlow. That's a pretty tough contest for the Siebert, given that the Pentax XL sells for five times the price. But I figured some people might like to know just how well or how badly the Siebert compares against premium glass. I used both eyepieces in our 10" f/5 Dob and our 90mm f/11 refractor. Here's what I found out: > >f/5 Dob >------- > >The Siebert 7mm is worlds ahead of the typical 9mm Ploessl or Kellner bundled with inexpensive scopes. It provides about the same true field but with significantly higher power, which results in a darker sky background and better contrast. At about 7mm, the Siebert's eye relief is somewhat better than the 9mm Ploessl. Despite the Siebert's lack of multicoating, contrast is excellent. Sharpness is at least as good as the Ploessl on-axis, although the Siebert becomes slightly soft in the outer 10 degrees or so of its apparent field. The eye lens is much larger than the tiny eye lens of the 9mm Ploessl, which makes the Siebert more comfortable to use. > >As expected, when I compared the Siebert to the Pentax XL, it wasn't even a contest. The Pentax XL provides 20mm of eye relief, which makes it usable by someone who wears glasses. The Pentax image was sharp to the edge of its field. Although the Pentax XL and the Siebert are both rated at 65 degrees apparent field, the Pentax feels noticeably wider. It also has noticeably better contrast, as you'd expect from an ocular with world-class multicoatings. Stars that were visible with direct vision in the Pentax XL required averted vision with the Siebert. The long eye relief, huge eye lens, and eye cup of the Pentax XL made it much more comfortable to use than the Siebert. > >f/11 refractor >------------- > >Here the optical differences were much smaller, particularly in terms of edge performance. The Pentax XL still performed superbly, but the Siebert was only a step or two behind. At the edge, the Siebert still showed a bit of softness, but I really had to look for it. Once again, the Pentax had noticeably better contrast, and of course the advantage of better eye relief. It remained a lot more comfortable to use. But, given the price difference, the Siebert gave up surprisingly little to the Pentax. > >Summary >-------- > >I own four Siebert eyepieces, the 4.9mm, 7mm, 12.5mm, and 21mm, and have had a chance to compare them against standard Ploessls and premium eyepieces of similar focal length. There's no question in my mind that the Siebert eyepieces offer higher bang-for-the-buck than any other eyepiece available. Recognize, though, that the Siebert eyepieces simply can't compete with premium eyepieces, not that any reasonable person would expect them to. > >If you have a fast scope like an f/5 or f/6 Dob or a short-tube refractor, the Siebert 7mm will beat your bundled Ploessl hands-down as a high-power eyepiece. If budget limits you to eyepieces in the $50 range, I don't think you can do better than a Siebert 7mm. The main drawbacks are noticeable edge softness and eye relief that's too short for eyeglass wearers. If you're certain that you will remain in the hobby and you can possibly afford it, I'd recommend spending the extra money to buy a 7mm Pentax XL. > >If you have an f/8 or slower scope, such as a small Dob, long-tube refractor, or Mak-Cass, you'll find that the Siebert 7mm gives you most of what a premium eyepiece does, other than multicoating and long eye relief. The Pentax XL is still a better eyepiece, noticeably so, but the difference is less significant than with faster scopes. > >I've retired my four Siebert eyepieces for use with our slow refractor, at public observations, and so on. Although I don't regret buying them, in retrospect I would have been better off spending $225 on one Pentax XL than $175 on four Sieberts. But that's not a slam against the Sieberts, because they remain the best value per dollar spent of any eyepiece line I know. If you're on a tight budget, don't hesitate to buy the 7mm Siebert. You'll like it a lot.
I would have to disagree with the better off spending $225 on 1, then $175 on four. The compairson with a $225 eyepiece seems a little tough on Harry also. Here is a person working out of his own shop building eyepieces for $49 that someone is compairing to a $225 eyepeice. The reviewer says in his review " Siebert gave up surprisingly little to the Pentax." Then says but you should spend $175 more on the Pentax, would you spend $175 to get a "suprisingly little" more? Point being for a 3 element economy eyepiece the is increadable. I use my Siebert eyepiece to this day for planetary viewing. Great for star parties, public viewings, and personal viewing. Show me another eyepiece with 65 degree AFOV for $49! >I took the time the other night to A-B the 7mm Siebert against my 14mm Pentax XL with the Orion Ultrascopic 2X Barlow. That's a pretty tough contest for the Siebert, given that the Pentax XL sells for five times the price. But I figured some people might like to know just how well or how badly the Siebert compares against premium glass. I used both eyepieces in our 10" f/5 Dob and our 90mm f/11 refractor. Here's what I found out: > >f/5 Dob >------- > >The Siebert 7mm is worlds ahead of the typical 9mm Ploessl or Kellner bundled with inexpensive scopes. It provides about the same true field but with significantly higher power, which results in a darker sky background and better contrast. At about 7mm, the Siebert's eye relief is somewhat better than the 9mm Ploessl. Despite the Siebert's lack of multicoating, contrast is excellent. Sharpness is at least as good as the Ploessl on-axis, although the Siebert becomes slightly soft in the outer 10 degrees or so of its apparent field. The eye lens is much larger than the tiny eye lens of the 9mm Ploessl, which makes the Siebert more comfortable to use. > >As expected, when I compared the Siebert to the Pentax XL, it wasn't even a contest. The Pentax XL provides 20mm of eye relief, which makes it usable by someone who wears glasses. The Pentax image was sharp to the edge of its field. Although the Pentax XL and the Siebert are both rated at 65 degrees apparent field, the Pentax feels noticeably wider. It also has noticeably better contrast, as you'd expect from an ocular with world-class multicoatings. Stars that were visible with direct vision in the Pentax XL required averted vision with the Siebert. The long eye relief, huge eye lens, and eye cup of the Pentax XL made it much more comfortable to use than the Siebert. > >f/11 refractor >------------- > >Here the optical differences were much smaller, particularly in terms of edge performance. The Pentax XL still performed superbly, but the Siebert was only a step or two behind. At the edge, the Siebert still showed a bit of softness, but I really had to look for it. Once again, the Pentax had noticeably better contrast, and of course the advantage of better eye relief. It remained a lot more comfortable to use. But, given the price difference, the Siebert gave up surprisingly little to the Pentax. > >Summary >-------- > >I own four Siebert eyepieces, the 4.9mm, 7mm, 12.5mm, and 21mm, and have had a chance to compare them against standard Ploessls and premium eyepieces of similar focal length. There's no question in my mind that the Siebert eyepieces offer higher bang-for-the-buck than any other eyepiece available. Recognize, though, that the Siebert eyepieces simply can't compete with premium eyepieces, not that any reasonable person would expect them to. > >If you have a fast scope like an f/5 or f/6 Dob or a short-tube refractor, the Siebert 7mm will beat your bundled Ploessl hands-down as a high-power eyepiece. If budget limits you to eyepieces in the $50 range, I don't think you can do better than a Siebert 7mm. The main drawbacks are noticeable edge softness and eye relief that's too short for eyeglass wearers. If you're certain that you will remain in the hobby and you can possibly afford it, I'd recommend spending the extra money to buy a 7mm Pentax XL. > >If you have an f/8 or slower scope, such as a small Dob, long-tube refractor, or Mak-Cass, you'll find that the Siebert 7mm gives you most of what a premium eyepiece does, other than multicoating and long eye relief. The Pentax XL is still a better eyepiece, noticeably so, but the difference is less significant than with faster scopes. > >I've retired my four Siebert eyepieces for use with our slow refractor, at public observations, and so on. Although I don't regret buying them, in retrospect I would have been better off spending $225 on one Pentax XL than $175 on four Sieberts. But that's not a slam against the Sieberts, because they remain the best value per dollar spent of any eyepiece line I know. If you're on a tight budget, don't hesitate to buy the 7mm Siebert. You'll like it a lot.
Overall Rating: 9 Optics:9 Value:10 Weight: 15 (Trustworthy Vote) Date: 02/05/2002 10:25:27 pm PST By: anttler Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=65012
Overall Rating: 10 Optics:9 Value:10 Weight: 9 (Veritable Vote) Date: 02/13/2002 07:50:10 pm PST By: Anonymous (xxx.xxx.34.219) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=67271
Overall Rating: 10 Weight: 9 (Veritable Vote) Date: 07/29/2001 12:31:51 am PST By: Anonymous (xxx.xxx.111.201) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44157
Overall Rating: 10 Weight: 9 (Veritable Vote) Date: 07/27/2001 03:10:12 am PST By: Anonymous (xxx.xxx.30.199) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44156
Overall Rating: 10 Optics:10 Value:10 Weight: 6 (Veritable Vote) Date: 01/13/2002 07:03:59 am PST By: Anonymous (xxx.xxx.161.126) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=55494
Overall Rating: 10 Weight: 6 (Veritable Vote) Date: 10/31/2001 01:03:44 am PST By: Anonymous (xxx.xxx.82.19) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44162
Overall Rating: 10 Weight: 6 (Veritable Vote) Date: 10/10/2001 10:07:49 am PST By: Anonymous (xxx.xxx.210.148) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44161
Overall Rating: 10 Weight: 6 (Veritable Vote) Date: 08/04/2001 08:27:08 pm PST By: Anonymous (xxx.xxx.176.249) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44159
Overall Rating: 10 Weight: 6 (Veritable Vote) Date: 07/29/2001 11:37:39 pm PST By: Anonymous (xxx.xxx.137.222) Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44158
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