• 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 goshawk

  1. J

    What purpose does this have?

    Hi All, I came across this on an old velbon tripod. What purpose does it have, a spacer? What are the two screws for? Many thanks John
  2. J

    Prism size in spotting scopes.

    It's ok , I worked it out! Thanks again, John
  3. J

    Prism size in spotting scopes.

    Great info. I understood all, apart from 'The last disadvantage of the Schmidt Pechan prism pair used in binoculars, the need for a mirror coating does not apply to to a single Schmidt prism.' I thought a single Schmidt would still need/is usually coated?
  4. J

    Prism size in spotting scopes.

    Thanks Joachim, Any idea about the link I posted above regarding opticron binos?
  5. J

    More contrast with ED scopes?

    This 'discussion' is reminiscent of Charlton Heston in Planet of the Apes. The self elected high priests are terrified of even discussing what can be seen with their naked eye - and become very aggressive, suspicious and hostile to anything that challenges their beliefs. I didn't realise optics...
  6. J

    More contrast with ED scopes?

    Yes agreed. Today I did same test with opticron HD66 and HD66ED. Whites appear 'whiter' and darks darker. Don't understand the science behind it fully. I know that is heresy for many people on here. But for others who trust there eyes (and other people's eyes!) it seems pretty obvious beacon...
  7. J

    More contrast with ED scopes?

    I've given up with this website. There is some clever people here that could help me with developments of my theory. And I could help you. However as soon as you engage in an indepth discussion you get your intelligence insulted straight off. Or something jumps down your throat with a wild...
  8. J

    More contrast with ED scopes?

    I can't understand what you said here or how it applies, which makes me fairly sure that you don't either Why you being so rude? Would you say that if you sat opposite me?
  9. J

    More contrast with ED scopes?

    My friend is letting me borrow his opticron HD66. Exact model/year as my own HD66 ED. There is a white wall opposite my house. I will do some comparisons on this and other locations. Like I say I have an open mind. There is a likelihood that the final image at the focal plane of a spotting scope...
  10. J

    More contrast with ED scopes?

    Furthermore I find a recent private message I come home to by someone above quite disturbing . A horrible thing to receive after spending most of the day birdwatching, with a very dear friend who has very poor health due to advanced dementia. Just trying to have an interesting discussion. I...
  11. J

    More contrast with ED scopes?

    I arrive at my opinion through observation and experience. In the same way I can easily tell the difference between a chiffchaff and a willow warbler.
  12. J

    Prism size in spotting scopes.

    Here is another example of the 'larger prism' puzzle! Does this mean other binos are vignetting. In which case why not just reduce the aperture? Appreciate any help with this! https://www.opticron.co.uk/our-products/binoculars/marine-binoculars/marine-2-7x50-ic-
  13. J

    More contrast with ED scopes?

    In my opinion a slight blurring of image boundaries isn't the biggest cause of contrast lost, especially not at low magnifications. That is just my opinion and the real answer to contrast loss with non ED glass may lie in quantum physics. Believe it or not, I do have a right to my own opinion.
  14. J

    More contrast with ED scopes?

    Agree with above. I wouldn't association colour fringing too much with contrast loss. I would perhaps associate that more with a loss of sharpness. ED scopes have more colour saturation and therefore whites are whiter in my experience. More colour saturation means more contrast. Newtonians do...
  15. J

    More contrast with ED scopes?

    I would have thought better contrast, means better colour saturation, which means purer colour. I'm with Nethero on this one :)
See more
Back
Top