• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Recent content by John A Roberts

  1. John A Roberts

    Nikon EII general question- Zeiss or B&L framed bino?

    Hi Norm (post #8), That was also my thought. As an example, a diagram from Frank of the SarD 6x42’s optics perhaps helps to make things clearer: John
  2. John A Roberts

    Swarovski Habicht 8x30 SLC

    Hi Rene, In terms of dating, the serial number includes the date of manufacture - both the year and the week. The Neu version (which has a later version of the rubber armour to that on yours), was introduced in 2005. The earliest 8x30 Neu unit that I've seen is #D7506 94925. To determine the...
  3. John A Roberts

    The OG Leather Wrapped Bausch & Lomb Elite

    For those interested in more information on and images of the Bausch & Lomb Elites (and the Browning 7x35 - a rebadged B&L 7x35), see: Early Elite's John
  4. John A Roberts

    Swarovski NL Pure 8x32 vs CL Companion 8x30

    Hi Dr. K, Did you measure the total focuser travel from lock-to-lock, or from closest focus to infinity? The two can differ substantially, depending on the brand and model. For example, Canip (aka Pinac elsewhere) measured the excess travel beyond infinity as equivalent to around: 5 diopters...
  5. John A Roberts

    Baby S

    In shops from 15th May, or you can pre-order now Overnight my time, this showed up in my email: The same info is also on the front page of the Swarovski site: SWAROVSKI OPTIK John
  6. John A Roberts

    Internal-focusing Porros (Leuopold, Minox) - anyone still using them?

    Hi Miguel, To give others an idea . . . The same binoculars were marketed under various brands, including Leupold (North America), Minox (Germany), Bynolt (Holland) and Opticron (UK). An image of the Bynolt (from Allbinos): Details from Opticron's 2018 catalogue (when they last listed...
  7. John A Roberts

    Broken focusknob Swarovski EL, more people having this?

    It's certainly not common, though I've seen two used EL SV’s for sale with the focuser cover missing (one had a white plastic screw cap as a replacement!). As can be seen the focuser cover (along with the marked end cap) slides on over the complex underlying mechanism, though it's not clear how...
  8. John A Roberts

    Sticky Focus Wheels

    Hi Ignatius, Also from the 2007 catalogue: another image showing the main body of the focuser more clearly; along with accompanying text referring to 'almost no lubrication': John
  9. John A Roberts

    Sticky Focus Wheels

    . . . and on occasion there's also been problems with the NL e.g. see: NL Focus Wheel Problems After Washing Perhaps aggravated by the unusually enclosed focus wheel? Images from Roger’s review at: Swarovski 8x42 NL Pure Review John
  10. John A Roberts

    Sticky Focus Wheels

    Typically with centre focus binoculars . . . Due to mechanical needs, external focus designs require heavy grease on the focuser shaft * But in contrast, internal focus designs are able to largely dispense with lubrication. By way of comparison: a) Zeiss Jena 8x30 Deltrintem from a 2016...
  11. John A Roberts

    Will Swarovski upgrade lenses on older 7x42 B SLC?

    Hi coolhand, When SONA (Swarovski Optik North America) receives the binocular they’ll examine it to see what needs repair, and then proceed accordingly e.g. see a work sheet from late 2022 for a 7x42, where various parts including the prisms were replaced: It’s from an ebay listing in early...
  12. John A Roberts

    CZJ T3M

    Anti-Reflective Lens Coatings For an historical overview see: Development of Anti-Reflective Lens Coatings In brief . . . There was awareness by some going back to at least the early 19th century (Fraunhofer) and again late in that century (Taylor), that modifying the reflectivity of a lens...
  13. John A Roberts

    Nikon SE

    And a reminder . . . Stephen's reviews from the old BVD site can be found at: https://www.cloudynights.com/BVD/reviews.php John
  14. John A Roberts

    Einblickverhalten/ease of view FL 7x42 vs FL 8x32

    Hi tenex, It seems that only recently there’s been discussion here on BF about the eyebox in relation to binoculars, and I’m not sure how relevant the concept is. It’s long been significant in relation to telescopic sights, e.g. From: Large eyebox for comfortable oberservation. To address...
  15. John A Roberts

    Einblickverhalten/ease of view FL 7x42 vs FL 8x32

    Hi Ignatius, I’d expect a big difference in the ease of view of the FL 7x42 compared to the 8x32, due to the significant difference in the exit pupil sizes. We often fail to appreciate EP size differences, due to the convention of expressing them in terms of diameter (from the expedient of...
See more
Back
Top