If you have a UV canopy they are useless, tested that…... Agree an article would be good, can go in the coaching article archives as well
> On 24 May 2016, at 7:59 PM, James Cooper <[email protected]> wrote: > > Two comments. > Photo Chromatic are no good in a car as they require direct sunlight to make > them change. > So in a glider they may be ok gliding. But not driving. > > As pointed out in an earlier email the SunTiger have this strange effect of > being better when light is low, in comparison to clear lenses, don’t know > why. And they are not so dark as to open up the iris and thus giving you a > better depth of vision. > > David’s comments were much more precise. > > I think we should make a comprehensive article in AG. I think David would be > the best but I am happy to add comments? > Are you in for it David or anybody else for some personal comments. > > James Cooper > 042 999 2468 > Po Box 6254 > East Perth > Western Australia 6892 > > From: Skysurferau [mailto:[email protected] > <mailto:[email protected]>] > Sent: Tuesday, 24 May 2016 12:27 PM > To: Gliding Australia Forum > Cc: Mike Henderson; David Wilson; Dafydd Llewellyn; Colin Collum > Subject: Re: [gfaforum] Article on human eyesight limitations > > Are we comparing apples with apples? You can go to a well advertised > optometrist chain and they advertise 2 pair for $200; my most recent new > glasses (purchases in the past 3 months) the lens alone for one pair were > $500.00; do we have someone with industry experience who is willing to > comment product quality? > > My experience is that modern high quality photo-chromatic lenses change tint > very quickly and go almost totally clear, a far cry from the product that > were about when these recommendations were made 30 or so years ago. Yes you > would be able to tell they are photo-chromatic on a veranda on a sunny > afternoon but not once they have been completely away from UV for about 90 > seconds. What I have found is that photo-chromatic do not provide enough > protection when flying or driving and I have invested in a set of full > sunglasses too. > > Skysurferau > [email protected] <mailto:[email protected]> > > > >> On 23 May 2016, at 19:07, Colin Collum <[email protected] >> <mailto:[email protected]>> wrote: >> >> This makes interesting reading. >> >> Both polarising and photochromatic lenses are, to say the least, strongly >> recommend against. In particular the photochromatic lenses can be slow to “ >> lighten up” as the ambient light decreases, and they never go fully clear. I >> believe that photochromatic lenses that are adjusted by battery power and >> are therefore much quicker to respond are, or, will become available. >> >> Something to keep in mind should you be worried about having to make an >> insurance claim? >> >> Colin >> >> From: Mike Henderson [mailto:[email protected] <mailto:[email protected]>] >> Sent: Monday, 23 May 2016 1:07 PM >> To: 'David Wilson'; 'Dafydd Llewellyn'; [email protected] >> <mailto:[email protected]> >> Subject: RE: [gfaforum] Article on human eyesight limitations >> >> If anyone’s interested, the Designated Aviation Medical Examiner’s section >> on vision is here: >> http://www.oaansw.com.au/visionstds/CASA_Handbook_Vision_Section.pdf >> <http://www.oaansw.com.au/visionstds/CASA_Handbook_Vision_Section.pdf> >> The section relating to sunglasses is 2.1.13 >> Salient points are that the glasses shouldn’t be too dark, (recommended tint >> ND 15) and should NOT be polarised. Lenses should be large enough to provide >> good eye coverage and frames thin, so as not to obstruct. (Which is how the >> “aviator” style evolved.) >> >> Mike >> >> From: David Wilson [mailto:[email protected] >> <mailto:[email protected]>] >> Sent: Monday, May 23, 2016 12:40 PM >> To: Dafydd Llewellyn <[email protected] <mailto:[email protected]>>; >> [email protected] <mailto:[email protected]> >> Subject: RE: [gfaforum] Article on human eyesight limitations >> >> James is absolutely right about sunglasses not being too dark. >> Unfortunately the market caters for peoples beliefs, and most people believe >> that sunglasses need to be dark to blot out the suns light. The Iris just >> opens to let in the same amount of light, with no gain at all. In fact the >> vision becomes much worse with a much smaller depth of field so that many >> more people would find they miss seeing any small object against a blue sky >> background. >> >> I have found it impossible recently to get polarised multifocal sunglasses >> without very dark tint. We used to be able to order the suntigers from US, >> but they are no longer available with multifocal prescription lenses. >> Anyone know a source? >> >> Polarised lenses are in my opinion a very definite advantage for pilots, >> because there is a lot of polarised glare coming from the sky, which is cut >> out by the polarising. They do cut out 50% of the incoming light, so there >> is some opening of the iris, but losing the glare more than compensates. >> >> If Richard finds that his instruments with LCD screens go black when using >> polarised sunglasses he should return the instruments to the manufacturer >> and ask them to change the direction of polarisation. LCD screens do emit >> polarised light, and if the direction of polarisation is wrong, then you >> would need to turn your head 90 degrees sideways to read them. >> >> I have never had a problem with the windscreen using polarised sunglasses. >> >> >> >> David M. Wilson >> 0407 825 706 >> >> From: Dafydd Llewellyn <mailto:[email protected]> >> Sent: Monday, 23 May 2016 10:39 AM >> To: [email protected] <mailto:[email protected]> >> Subject: [gfaforum] Article on human eyesight limitations >> >> I don't profess full knowledge on this subject - perhaps somebody can >> enlarge: Sunglasses for flying should probably NOT be polarising type. >> Polaroids are of considerable advantage when the angle of the windscreen to >> your line of sight is close to the "Brewster's angle" - see >> https://en.wikipedia.org/wiki/Brewster%27s_angle >> <https://en.wikipedia.org/wiki/Brewster%27s_angle> - about 56 degrees for a >> glass windscreen, which is common in modern cars. This can be easily >> demonstrated by placing something bright on top of the glareshield; with >> polaroids, its reflection in the windscreen disappears. However, polaroids >> can make LCD screens very difficult to read. >> I don't know what the Brewster's angle is for Acrylic - and it may vary >> according to the forming process - but I suspect most glider windscreens are >> set at about half the optimum angle for polaroids. >> >> >> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> >> >> Virus-free. www.avast.com >> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> >> -- >> You received this message because you are subscribed to the Google Groups >> "Gliding Australia Forum" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at >> https://groups.google.com/a/glidingaustralia.org/group/gfaforum/ >> <https://groups.google.com/a/glidingaustralia.org/group/gfaforum/>. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Gliding Australia Forum" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at >> https://groups.google.com/a/glidingaustralia.org/group/gfaforum/ >> <https://groups.google.com/a/glidingaustralia.org/group/gfaforum/>. >> -- >> You received this message because you are subscribed to the Google Groups >> "Gliding Australia Forum" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at >> https://groups.google.com/a/glidingaustralia.org/group/gfaforum/ >> <https://groups.google.com/a/glidingaustralia.org/group/gfaforum/>. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Gliding Australia Forum" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at >> https://groups.google.com/a/glidingaustralia.org/group/gfaforum/ >> <https://groups.google.com/a/glidingaustralia.org/group/gfaforum/>. > > > -- > You received this message because you are subscribed to the Google Groups > "Gliding Australia Forum" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > Visit this group at > https://groups.google.com/a/glidingaustralia.org/group/gfaforum/ > <https://groups.google.com/a/glidingaustralia.org/group/gfaforum/>. > > -- > You received this message because you are subscribed to the Google Groups > "Gliding Australia Forum" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > Visit this group at > https://groups.google.com/a/glidingaustralia.org/group/gfaforum/ > <https://groups.google.com/a/glidingaustralia.org/group/gfaforum/>.
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