ok so i did some testing. using my fa 135 2.8, i took six pictures 3 with the tiffen filter and 3 without. i am posting one set of results, but all three sets were basically the same.
with the filter: http://www.xdstech.com/istd/with_filter.jpg without the filter: http://www.xdstech.com/istd/without_filter.jpg i could not believe my eyes. arnie ps the picture were taken handheld, so they are fuzzy. ----- Original Message ----- From: "Scott Nelson" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, December 27, 2003 2:34 PM Subject: Re: another istD issue > On Fri, 2003-12-26 at 04:01, Jostein wrote: > > Quoting Anthony Farr <[EMAIL PROTECTED]>: > > > > > That's a "ghost image", a reflection from the front surface of one of your > > > lens elements onto the rear surface of the filter, and then back through the > > > lens in parallel with the desired image. It is most pronounced when a lens > > > has any uncoated elements, or the filter is uncoated. > > > > I thought ghosting between the front element and a filter would produce a > > reflection with the same orientation as the reflected object? > > No this is definately a ghost image from the filter. The CCD (or film) > doesn't act as a mirror, but diffusely reflects some light back towards > the front of the lens. This light travels back through the lens system > along the same path that it originally did, bounces off the filter > (which is acting as a mirror and creates the inversion of the images) > and is reformed on the CCD after another trip through the lens. In this > case, things are made worse because the lens is wide open, allowing most > of the rays relfected from the filter to be recaptured. > > -Scott >
