On Fri, 28 Jan 2000, TRUCCO Martin TENCO wrote:
> > I'll give you an example. I used to own the 35-70/3.6 Zuiko. i once took
> a shot of a glass-sided building at sunset with a golden gloaing cityscape
> at sunset reflecting on the side of the building. the glass mirror building
> was actually a grid of rectangles of the mirror/glass siding, with some sort
> of metal beams forming frames around the rectangles throughout. I didn't
> notice the sun reflecting off of a tiny corner of one of these beams, and it
> was enough to flare the image with a ghost image of the diapragm, ruining
> what otherwise would have been a superlative shot. I don't think this would
> have happened with a prime lens. Point a zoom at the sun and it will flare.
Ghosting is a kind of (extreme) flare. There's always flare present,
even if most of the time you can't discern it.
> The primes also suffer from flare effect, specially wide angles. Of
> course, as the flare is due to internal reflections, the more elements a
> lens have (and this happens with zooms and wide angles) the more prone to
> flare the lens is. Of course this is only a general rule and two lens with
> the same quantity of elements than other can perform worse (regarding flare)
> than other because of worse quality coating, less effective design, etc.
Martin, it is the glass-air surfaces that scatter the light most, so
it is the number of groups, not elements, that is more significant.
If you have a group of three elements, you have 2 air-glass surfaces.
If you have 3 elements in 3 groups, you have 6, for example.
*= Doris Fang =*
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|