Results 1 to 4 of 4
Like Tree15Likes
  • 6 Post By j.gardavsky
  • 4 Post By John Baars
  • 4 Post By j.gardavsky
  • 1 Post By Don Quixote

Thread: Docter Nobilem 7x50 Porro against Jenoptem, Leica Ultravid, and Swarovski EL Sv

  1. #1
    j.gardavsky's Avatar
    j.gardavsky is online now Super Moderator
    Points: 110,910, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 99.6%
    Achievements:
    Ghost Achievement! Averaging 5+ posts a day!200+ Posts Achievement!400+ Posts AchievementFirst 1000 Experience Points365 Days+ Registered Achievement!
    Awards:
    3rd Most Active Award
    Join Date
    Feb 2011
    Location
    Germany
    Posts
    14,398
    Points
    110,910
    Level
    100
    Thanks
    14,394
    Thanked 8,785x 5,719 Posts

    Default Docter Nobilem 7x50 Porro against Jenoptem, Leica Ultravid, and Swarovski EL Sv



    Hello all,

    the Docter Optic binoculars, made in the former Zeiss Jena plant in Eisfeld, belong to the “Big Seven” of Leica, Minox, Optolyth, Steiner, Swarovski and Zeiss, most of them still manufactured in Germany, Swarovski in Austria.

    Thanks to our annual trip to Mr. Schilling’s Foto in Berlin-Charlottenburg https://www.foto-schilling.berlin/pages/ausstellung.php , I have added a pair of one of these remarkable Bernhard Docter’s Nobilem 7x50 B (GA) Porro prisms binoculars to my collection.

    The first light on the dark clear night skies in the woods close to the Scharmützelsee lake on the 8th September have revealed through these Docter Nobilem the large Wolf-Rayet Sh2-132 nebula crossing the border between Lacerta and Cepheus.
    Should you ask me when I have seen the last time this nebula, then it has been on the 3rd September 2016 through the big 15x85 with the UHC filters.
    And this is now the reason to compare these Docter Nobilem 7x50 binoculars with the other small binoculars in my arsenal.


    The Docter Nobilem 7x50 B, discontinued in 2014, are the classic Porro prism binoculars, reminding the Carl Zeiss Jena Octarem binoculars, and to some extent also the Jenoptem binoculars.

    Hence, I have decided to take for the primary comparison the Jenoptem 7x50 W from the last production batches of Carl Zeiss Jena in 1989/90, before discontinued.
    As it is always of interest how the Porro prisms classics compare with the modern roof prisms binoculars, the other two binoculars for the comparison are the Leica Ultravid 7x42, and the Swarovski EL Swarovision (from the first production batch) 8.5x42, see the first attached picture.

    Nobilem Jenoptem Leica Swarovski.jpg

    The choice of this row of binoculars covers a wide range of prices for which these binoculars are traded on the 2nd hand markets in Germany:
    The Jenoptems are offered for typically less than 200 EUR, the Docter Nobilem for around 500 EUR, the Leica Ultravids and the Swarovski EL Swarovision change the hands in the range 1,000 – 1,300 EUR.

    The First Impressions

    The Docter Nobilem, with their thick GA rubber armour around the light weight magnesium body, feel very rugged and comfortable in my hands, better than the Swarovski, and much better than the Jenoptem. The ergonomics comfort is comparable to that of the Leica Ultravid, even if the concepts of the both binoculars are totally different, and even if comparing something big with another one small.

    The small threaded hole on the bridge front is for an adapter to a tripod, unfortunately not matched to the standard “L” adapters, as offered for the binoculars coming from China.

    Surprising are the flimsy front lens caps if compared with those rugged on the Swarovski, and the undersized and too soft rubber eyeguards, if compared with the Leica robust eyecups.
    To prevent some stray light incidence on the eye lenses of the Docter Nobilem eyepieces, I have mounted larger and winged eyeguards, as shown in the attached picture,

    Nobilem with winged eyecups.jpg

    The 1.25” filters find enough place to be inserted and DIY fastened on the eyepieces of the Docter Nobilem, similarly as on the Leica Ultravid, but unlike on the Jenoptem and Swarovski.

    The focusing of the Docter Nobilem has a precise and smooth CF mechanics, similarly to the Jenoptems. This makes a difference to the hard focusing mechanics of the Leica and Swarovski. However as always, someone likes it smooth, others may like it ‘hard and stop’.

    Optics, so far revealed without dissecting

    Coatings

    The Docter Nobilem look like fully multicoated.

    The front lenses on the Docter Nobilem reflect an amber color plus a nearly color-neutral reflection for a wide range spectral balance of the transmitted light, similarly but not identically to the Jenoptem. According to the Carl Zeiss Jena manual, the Jenoptems have the ‘new’ T3M Zeiss multicoatings.

    The eyepiece coatings in the Docter Nobilem are multicoated, reflecting blue, orange and violet colors.
    The eyepieces in the Jenoptem reflect just amber.

    The attached picture shows the reflections on the front lenses and eyepieces of the Docter Nobilem and Jenoptem,

    Front lenses and eyepieces Docter Nobilem 7x50 and Jenoptem 7x50 W.jpg

    Lenses inside

    There is no Linsensalat (lenses salad) inside, Mr. Schilling would comment.
    The front lenses in the Docter Nobilem and Jenoptem are very similarly looking cemented doublets, with a high precision polish leaving just faint scattered green laser beam traces. The cements in the both show the similar impact spots, see the attached picture of the raytracing,

    Raytracing with the green laser pointer.jpg

    The green laser beam through the eyepieces reveals the eye lens as a cemented doublet followed by the third lens in the Docter Nobilem. Expected are in the Docter Nobilem five lenses in three groups (2-1-2), a sort of the Zeiss Astroplanar classic ocular redesigned for the fast achromatic optics. Similar Zeiss Astroplanar eyepieces have been used in the Jenoptems, and in the Dialyt binoculars with the roof prisms, among other binoculars from Jena.

    As the field in Docter Nobilem is much better corrected than in the Jenoptem, I would not exclude an aspheric surface inside the eyepiece, as Docter Optic has designed an OEM series manufacturing facility for the aspheric lenses.

    Day Light Tests

    Sharpness, contrast and aberrations

    All four binoculars are very sharp with very high contrast in the central field.
    The chimney test reveals the chromatic aberration and the field aberrations as follows:
    Swarovski EL Swarovision: 90% of the field of view free, blue/green fringe and a very small blur towards edge of the field of view.
    Docter Nobilem: 80% of the field of view free from the aberrations, blue/green fringe and a very small blur towards edge of the field of view.
    Leica Ultravid: 70% of the field of view free from the aberrations, blue/red fringe and a very small blur towards edge of the field of view. A very small astigmatism emerges due to the diffraction on the roof prisms.
    Jenoptem: 50% of the field of view free, blue/red fringe and a very small blur towards edge of the field of view.

    Distortion

    The Swarovski EL Swarovision is the only one distortion free in the tested group of binoculars.
    Docter Nobilem shows a small pincushion distortion, but still acceptable.
    Leica Ultravid and Jenoptem show a well pronounced pincushion distortion.

    Color rendition and color contrast

    Docter Nobilem and Jenoptem reveal a warm color tone.
    Swarovski EL Swarovision and Leica Ultravid are fairly neutral, the brightness of green increases in the near field.

    Docter Nobilem and Jenoptem show the highest color contrast, both in the near field and in long ranging. The Leica Ultravid is very close, followed by still a decent but lower color contrast through the Swarovski EL Swarovision.

    Thanks to the increased brightness of the red and green colors, the Docter Nobilem is well suited for the long range viewing.

    Visually perceived transmissivity differences

    These visual tests have been made holding the binoculars and watching the brightness of the exit pupils.

    Against the sun lit white matt surface:
    Leica Ultravid shows the maximum brightness but closely followed by Swarovski EL Swarovision, the Docter Nobilem closely follows Swarovski, and finally the Jenoptem follows at some distance Docter Nobilem.
    Through the blue(RGB)CCD filter (400nm – 505nm):
    Swarovski EL Swarovision shows the maximum brightness followed by Leica Ultravid, then Docter Nobilem, and finally Jenoptem.
    These results meet my intuitive expectations.

    The so far published spectral photometric curves are here:
    Swarovski EL 8.5x42 Swarovision: https://www.allbinos.com/251-binocul...arovision.html
    Docter Nobilem 7x50: https://www.allbinos.com/234-binocul...7x50_B_GA.html
    Carl Zeiss Jena Jenoptem 7x50: https://www.allbinos.com/276-binocul...ptem_7x50.html

    The photometric transmissivity is best corrected for the visual spectral range on the Swarovski EL Swarovision with 80% and more in a wide spectral range 415nm – 680nm, covering about 75% of the visible RGB spectrum. The UV/violet cut is close to 415nm. This flat spectral characteristic explains the increasing popularity of the Swarovski EL Swarovision binoculars among the birders, when the true colors rendition is required.

    I don’t have a reported test for the Leica Ultravid 7x42.


    The Docter Nobilem 7x50 has the widest spectral range of 460nm (close to the H-Beta spectral line 456nm) up to 830nm in the near infrared, with the transmissivity above 80%,
    and a remarkably wide spectral range of 500nm (green OIII doublet in nebulae) up to 700nm (red bricks, Miras and Carbon stars) with the fairly flat transmissivity above 93%.
    From my point of view, I would rate it as ultimatively ultrawide spectral transmissivity corrected optics. And at 900nm, already in the deep near infrared and away from the RGB, the transmissivity is still above 70%.

    The Jenoptem 7x50 with the transmissivity of 80% and more in the spectral range of 500nm – 670nm, and peaking at 570nm with 85%, is behind the other three binoculars, even if still good enough for the casual use, and a very good choice for its price.

    Tests during sunset and early evening hours

    Scattered and stray light

    The scattered and stray light arises due to an insufficient baffling in the optics tubes, due to the prisms, and in the eyepieces.
    The old school way to check the scattered and the stray light in the telescopes and binoculars is to aim the optics at a bush in shadow against the bright skies with the Sun low above the horizon.
    And we have such a bush in the NW corner of the backyard.

    A minimum of the scattered and stray light shows the Docter Nobilem, closely followed by the Jenoptem.

    Swarovski EL Swarovision and Leica Ultravid are noticeably behind, revealing a veil of scattered and stray light rays across the bush in the field of view. This is the price you pay for the comfort of using the short built binoculars with the roof prisms.

    Ghosting

    Tested against a nearby street lamp, I have seen ghosting only in the Jenoptems. Hence, the Docter Nobilem is expected to have more precise collimation of the prisms and better multicoatings than the Jenoptem.

    Colors visibility after the sunset

    Whereas most of the differences between the premium binoculars are small during the bright daylight, the differences eventually increase when using the binoculars after the sunset.

    The tests objects have been the red roofs on the nearby houses and down in the valley, and two big blue Provencal canisters with flowers in the garden, offering the RGB colors.
    The visibility of the colors has been checked as the colors have turned into dark grey or black.

    Wheres the green has been slowly fading into the grey and dark grey through all binoculars,
    The Jenoptem has been the first to loose the blue and red colors visibility, followed by Swarovski EL Swarovision and Leica Ultravid loosing the colors visibility later. Docter Nobilem has been keeping the visibility of red and blue still over 1 hour after the sunset.

    Tests on the selected Nebulae in Cygnus – Cepheus – Cassiopeia

    The binoculars have been tested on the 11th and 12th September under the NELM 5 skies over our backyard, to find the differentiators in performance for the astronomy use.

    The first impression is, the Swarovski EL Swarovision show the stars (OB associations) and the sky background brighter, but the Milky Way clouds have lower contrast.

    The Docter Nobilem shows the stars clusters fainter, the sky background is darker, and the Milky Way clouds have high contrast. The difference is especially pronounced on the dark nebulae. Moreover, the orange color and the red color stars pop up.

    Dark nebulae:

    B144 Fish on the Platter in Cygnus: Docter – dark and structured, Swarovski – grey and no structures
    B168 Dark Cigar in Cygnus: Docter – well visible, Swarovski – not seen
    Le Gentil 3 “The Northern Ink Spot” in Cygnus: Docter – well visible and structured, Swarovski – not seen
    B170, B169/171 in Cepheus: Docter just visible, Swarovski not seen.

    Bright nebulae:

    IC 1396 in Cepheus: Docter and Swarovski nearly equally bright
    NGC 7380 (Sh2-142) Clamshell Nebula in Cepheus: Docter hardly seen, Swarovski well visible
    Sh2-137 in Cassiopeia: Docter well visible, Swarovski slightly brighter
    NGC 7822 in Cassiopeia: Docter faint visible with averted vision, Swarovski not seen
    IC 1805 Valentin’s Heart in Cassiopeia: Docter shows extended glow around the Mel 15 ionizing cluster, Swarovski shows just the core of the nebula.

    The differences in observing the dark nebulae are traceable to the high transmissivity of the long wavelengths of light through the Docter Nobilem and to the cut of the sky glow due to the short blue/violet wavelengths. This difference in the contrast performance is quite important under the suburban-to-country skies, and whenever the sky glow interferes.

    On the other hand, the Docter Nobilem dims the H-Beta spectral line, and even more the H-Gamma. Hence, under the very dark clear skies, the Swarovski EL Swarovision due to its higher transmissivity on the H-Beta and H-Gamma, is expected to perform better on the bright nebulae.

    The total number of the deep skies objects I have checked out through the Docter Nobilem and Swarovski EL Swarovision has been 52.

    All in all, the unfortunately discontinued Porro prism Docter Nobilem 7x50 binoculars can be regarded as a very nicely performing companion to the premium roof prism binoculars.
    On budget reasons, the Porro prism Docter Nobilem binoculars may advance to the first choice, whenever the magnification of 7x, and the aperture of 50mm is enough.

    Thank you for reading,

    JG
    Binoculars: Leica Ultravid 7x42, 8x42HD; Swarovski EL 8.5x42 Swarovision; Nikon 10x70 Astroluxe; Docter Nobilem 7x50 Porro; Jenoptem 7x50W, 10x50W; BA8: 10.5x70, 15x85; 25x100FB, AsahiPentax 8x40, Refractors: Sky-Watcher 150mm/750mm; Leica APO Televid 82mm (25x-50x WW ASPH); EPs:Baader Classic Orthos; Fujiyama ortho, Leica B WW, ultrawide zoom ASPH, Periplan GF, HC Plan S, L; DOCTER UWA; Wild UW mil; Tele Vue Delos, Nagler Zoom, Plössls; Swarovski SW; Pentax XW; ZEISS diascope B WW T*, Carl Zeiss E-Pl; Hensoldt mil; Filters: Astrodon, Astronomik, Baader (CCD), TS; Astrophotography: AstroTrac; Leica R7: Leica 2/50, 2/90mm, 2.8/180mm lenses
    Astronomy Forum Rules and Terms of Service
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  2. The Following 3 Users Say Thank You to j.gardavsky For This Useful Post:

    bladekeeper (09-23-2018),Gabby76 (09-24-2018),John Baars (09-24-2018)

  3. #2
    John Baars's Avatar
    John Baars is online now Bronze Supporter
    Points: 17,634, Level: 91
    Level completed: 84%, Points required for next Level: 66
    Overall activity: 99.5%
    Achievements:
    20 Posts Achievement!2 Posts AchievementGallery Achievement!Album Achievement!5 Threads Achievement!
    Join Date
    Sep 2017
    Location
    Schiedam, Netherlands
    Posts
    1,376
    Points
    17,634
    Level
    91
    Thanks
    1,373
    Thanked 1,205x 706 Posts
    Blog Entries
    7

    Default Re: Docter Nobilem 7x50 Porro against Jenoptem, Leica Ultravid, and Swarovski EL Sv

    Thanks for this extended comparison!
    Well written and so very much to learn!
    Being a Jenoptem-owner my wife heard me saying: aahhhrg... and Oh! while reading. ( more "aahrgs" though) And I saw my favorite 30 year old binocular-girl quietly sneaking away for the modern high-tech giants, although she did well on some parts.

    Very learn-full to see the connection between the spectral photometric curves and the actual visual performance on DSO's. I had never realised that.
    And another proof of the fact that roof prisms are behind on scattered and straylight, even in top-models. For that reason I always use roof-binoculars in backlight situations (sea for instance).

    A very nice, rich and full comparison, well thought over, with all information one would like to know. This is article-worthy, even for in a magazine!

    Thanks very much!!
    Telescopes in Schiedam : SW Evostar 120ED F/7.5, Vixen 102ED F/9, OMC140 maksutov F/14.3, SW 102MAK F/13 on Vixen GPDX.
    Binoculars: AusJena 10X50 Jenoptem, Swarovski Habicht 7X42, Celestron Skymaster 15X70, Swift Observation 20X80.
    Astronomical Rijswijk observatory telescopes: Astro-Physics Starfire 130 f/8 on NEQ6, C8 on NEQ6, Meade 14 inch SCT on EQ8, Lunt.
    Amateur since 1970.

  4. #3
    j.gardavsky's Avatar
    j.gardavsky is online now Super Moderator
    Points: 110,910, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 99.6%
    Achievements:
    Ghost Achievement! Averaging 5+ posts a day!200+ Posts Achievement!400+ Posts AchievementFirst 1000 Experience Points365 Days+ Registered Achievement!
    Awards:
    3rd Most Active Award
    Join Date
    Feb 2011
    Location
    Germany
    Posts
    14,398
    Points
    110,910
    Level
    100
    Thanks
    14,394
    Thanked 8,785x 5,719 Posts

    Default Re: Docter Nobilem 7x50 Porro against Jenoptem, Leica Ultravid, and Swarovski EL Sv

    Hello John,

    and thank you for your comments!

    At the vendor's shop, I have got the Swarovski EL 8.5x42 for comparison on the street views.
    Some days later at another vendor's shop, I was allowed to take the Swarovski Habicht 7x50 roof prism binoculars in my hands, and to do a short inspection of their performance.

    Basically, it has been my curiosity how Docter continues in the tradition of the Carl Zeiss Jena binoculars,
    as our generation grew into the hobby astronomy with the binoculars.

    Now, I am feeling very happy to have added these 7x50 Docter Nobilem Porro binoculars to my arsenal.

    Clear skies,

    JG
    Binoculars: Leica Ultravid 7x42, 8x42HD; Swarovski EL 8.5x42 Swarovision; Nikon 10x70 Astroluxe; Docter Nobilem 7x50 Porro; Jenoptem 7x50W, 10x50W; BA8: 10.5x70, 15x85; 25x100FB, AsahiPentax 8x40, Refractors: Sky-Watcher 150mm/750mm; Leica APO Televid 82mm (25x-50x WW ASPH); EPs:Baader Classic Orthos; Fujiyama ortho, Leica B WW, ultrawide zoom ASPH, Periplan GF, HC Plan S, L; DOCTER UWA; Wild UW mil; Tele Vue Delos, Nagler Zoom, Plössls; Swarovski SW; Pentax XW; ZEISS diascope B WW T*, Carl Zeiss E-Pl; Hensoldt mil; Filters: Astrodon, Astronomik, Baader (CCD), TS; Astrophotography: AstroTrac; Leica R7: Leica 2/50, 2/90mm, 2.8/180mm lenses
    Astronomy Forum Rules and Terms of Service
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  5. The Following User Says Thank You to j.gardavsky For This Useful Post:

    John Baars (09-24-2018)

  6. #4
    Don Quixote's Avatar
    Don Quixote is online now HYPER GIANT
    Points: 10,196, Level: 69
    Level completed: 82%, Points required for next Level: 54
    Overall activity: 21.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!Ghost Achievement! Averaging 5+ posts a day!5 Threads Achievement!
    Join Date
    Jun 2018
    Location
    Illinois.
    Posts
    1,568
    Points
    10,196
    Level
    69
    Thanks
    1,279
    Thanked 841x 611 Posts

    Default Re: Docter Nobilem 7x50 Porro against Jenoptem, Leica Ultravid, and Swarovski EL Sv

    Ditto, what John said JG.

    You have done another very fine write up which I appreciate !

    Thank you.
    j.gardavsky likes this.
    Telescope: Mak; 127, Meade 8 LXD75, Fracs; ES127mmFcd100,ES80Essential, SW 100ED Evostar, Skychief 60mmF15. Mount: cg4, az/eq5, slt, lxd75, farpoint Para. EP: Doctor 12.5 UWA, Pentax 7-14XW, KK Ortho 4-25, Meade Plossl x3, TV 22Panoptic, Leitz 10X,12.5X, Leica 10X25 HC, Bits of other glass. Binoculars: 8x43 Pentax, 10X30 Swarovski, 25X100 Oberwerk.Cam;Nikon d90, Nikon d810.
    "The pendulum of the mind oscillates between sense and nonsense"
    "Gratuitus affermations of a dominant theory can mesmerize the unwary."

  7. The Following User Says Thank You to Don Quixote For This Useful Post:

    j.gardavsky (09-25-2018)

 

 

Similar Threads

  1. Nikon EX 7x50 vs. Buschnell Marine 7x50
    By Baruch in forum Binoculars Forum
    Replies: 8
    Last Post: 08-11-2014, 06:24 PM
  2. Replies: 8
    Last Post: 07-18-2014, 01:40 PM
  3. Leica Ultravid 7x42 price reduction
    By j.gardavsky in forum Binoculars Forum
    Replies: 0
    Last Post: 01-09-2013, 01:04 PM
  4. Nobilem 8 x 56 B/IF - your thoughts?
    By Skyscanner in forum Binoculars Forum
    Replies: 2
    Last Post: 12-27-2012, 10:02 PM
  5. FS: Jenoptem Zeiss 7x50 binoculars - perfect for low light observations
    By Curious_Orange in forum UK Astronomy Forum
    Replies: 1
    Last Post: 01-28-2006, 01:57 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 10:11 PM.