Doctor/Zeiss Misc. 12.5mm

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Brand and Model:Doctor/Zeiss Misc. 12.5mm
Price ($USD):$350.00
Type:Ultra Wide Angle
Focal Length:12.5 mm
Barrel Size:Dual
Apparent FOV:90.0 degrees
Field Stop Dia.:0.0 mm
Eye Relief:10 mm
Elements:7
Weight (lbs):0.0
Description:

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Doctor/Zeiss Misc. 12.5mm
He's the bestdocter ever

Overall Rating: 10
Optics:10 Value:10
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=83358

Doctor/Zeiss Misc. 12.5mm
This is the eyepiece that spends the most time in my 12.5", f/6 scope. One rater noticed coma in an f/5 scope, but the only thing I notice in the f/6 is a bit of softness at the edge - also some yellow when looking at the moon. I also have a 12mm Nagler 4, which used to be my favorite, but the Z/D has permanently replaced it. The 2 main reasons are 1) blackout is eliminated in the Z/D, and 2) internal reflections are greatly reduced. If I forgot my external baffle, the 12mm Nagler was very good at picking up external lights - annoyingly so - but the Z/D is very forgiving. This probably explains why it has better contrast when comparing both of them with the baffle in place. The third reason is the field of view - it is incredible how noticeable the difference is. I should also point out that mine is the Astroversion, which has been quite modified from the original. The problem with too much in-focus required has been solved, and it now focuses in a "normal" range. The barrel design was changed into a 1.25" with a 2" skirt, and the built-in focuser was removed. This reduced the weight and it is now advertised as being 327 grams (.72 lbs.). I haven't actually weighed them, but this would make it more than .5 lbs. lighter than the 12mm Nagler 4. The modifications also increased the price to $350. As of 10/6/01, the original is still available for $290, but I would highly recommend paying the extra $60 for the Astroversion. With all the modifications this eyepiece rates an 11.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=43842

Doctor/Zeiss Misc. 12.5mm
Just got mine and compared it to the Nagler 12T4 I also own. The Docter has better color, is brighter, sharper and has better contrast. On the negative side it exhibits significant coma at the edge of field in my f/5 scope. Coma starts at about 30% out from the center of FOV. It gets progressively worse to the edge. On axis it is very sharp. I compared M13 with the Nagler and Docter. The Nagler is higher in power but not higher in contrast. This implies the Docter is the contrast winner. Faint core stars were resolved in the Docter but just smudges in the Nagler. Stars in general are very tight pinpoints in the Docter on-axis and the background is black. Very little light scatter. I saw no ghosting or internal reflections. I tried to get the EP to blackout or kidney bean and it would not. Overall a great EP. I may try a Parcorr to tame the coma. This would be unbeatable in a slower f-ratio scope. A real keeper.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=43840

Doctor/Zeiss Misc. 12.5mm
As a first impression I was greatly impressed. In a Takahashi resolved M13's core while still showing outer edges. Only viewed through one night but would recommend. Due to the difficulty of obtaining one of these, from what I've read, you may be better off going for a 12mm Nag. If you do find one at a good price, jump on it like flies on a turd.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=43839

Doctor/Zeiss Misc. 12.5mm
Great eyepiece. Very sharp on center with pleasing views to the edge. Remarkable contrast. Very lightweight and a pleasure to use. It's the eyepiece I reach for most often. A real performer and a keeper.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=43838

Doctor/Zeiss Misc. 12.5mm
By far my favorite eyepiece. Incredibly sharp views, incredibly wide. It fades on sharpness at the VERY edge but the edge is so far out there, it is of no consequence. I haven't seen any better. I had it AND an excellent Teleview Nagler 20mm. I sold the Nagler because it sat unused. Now THAT'S saying something! I really liked the 20mm but the 12.5mm Docter had almost the same field of view, better contrast, better sharpness, much lighter. This eyepiece is the ultimate for core resolution on globular clusters while STILL getting the entire object in. It's a WOW factor of 10 and I've found no better. When I find it, I'll buy it! This is my only 10 rated eyepiece out of dozens that I've tried.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=43836

Doctor/Zeiss Misc. 12.5mm
Just curious,
If you have an 10" f/5 (hypothetically), the difference in magnification between the two eyepieces would be 4X. An f/5 5" would be 2X etc. So this minimal difference in mag accounts for the difference in contrast?

Take care,
john

Overall Rating: No Vote
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