P.J.,
My inquiry was whether the ghost images in the original ("sunny") image
were due to the reflections (possibly multiple reflections) from the
lens elements' surfaces. Mark and Bill suggested an alternative
explanation that those could've been caused by dust/mist particles.
My argument (in the most recent response just below yours) was that
if the ghost images of the aperture in the original ("sunny") image
were due to dust/mist, they would've looked differently.
The two images taken with a flash are just an illustration why
I think that would've produced a differently looking ghost images in
the sunny photo.
I am wondering if this argument is correct or not.
I cannot seem to see if your response helps discerning this; you just
suggest that the mechanism of those ghost images is different in the
"sunny" and the "flashy" images. (Did I get you right?)
Thanks,
Igor
Tue Sep 16 23:27:49 EDT 2014 P.J. Alling wrote:
Igor, if by ghost image you are referring to the round brightish spot in
the upper right corner of the second image, and the left side of the
first. I don't think you're seeing an internal lens issue, well not
exactly. What you have recorded are orbs.
Those who believe in the paranormal, think they're recorded spirits or
ghosts, in the supernatural sense, but what they really seem to be is an
artifact of direct flash off a sufficiently shiny object suspended in
the air or resting on a surface, that reflects back some of the direct
flash you're using back to cause a ghostly image on the capture
surface. I'll see if I can find an example. I know I've got a pair of
images somewhere taken with the *ist-Ds and 43mm limited of exactly the
same subject, taken from exactly the same location, the only difference
being the direct flash from the camera. In the flash shot there's
clearly an orb, (which looks like the supposed reflection in your second
photo), and without the flash there is none.
The first image you showed in your quest for information with the sun in
the image was clearly flair from the sun, in that particular case any
lens would be hard pressed to suppress all flair, but the last two,
(below(, are a different issue.
On 9/16/2014 11:11 PM, Igor PDML-StR wrote:
Mark, this argument got me thinking even more (after I somewhat
thoughtfully dismissed Bill's suggestion).
My argument in defense of the non-aligned reflections was that
those were due to multiple reflections from non-parallel surfaces of
the elements (or, rather groups) on the sides where the element's
curvature makes it more non-parallel to others'.
This is plausible, since the lense had to be at a large (from the
normal) incidence angle for this to happen.
If the ghost aperture images were due to dust/mist, I would expect
them to show at smaller incidence angles as well.
Once or twice, I observed this type of phenomenon in a dusty
environment.
The main difference is that in those cases is that the size of the
ghost images was different, and those ghost images were not images of
the aperture (as in the present case).
See, e.g. these photos:
https://picasaweb.google.com/janyap/LastDance#4983773194748100626
https://picasaweb.google.com/janyap/LastDance#4983773188523687954
What do you think?
Igor
Mon Sep 15 14:50:43 EDT 2014
Mark C wrote:
Interesting experiment... Intuitively, it would seem that reflections
off the lens surfaces would align with the angle at which the light was
entering the lens. You can see that in the alignment of the two bright
flare spots in the lower left corner with the sun (light source,
obviously.) So - I wonder if the halo of small light spots circling the
sun are the result of lens flare or, as Bill Robb suggested, water
droplets or even dust specs on the front element. If they were
reflections off the different lens element then wouldn't they be in a
line, diagonal up towards the light source?
Like in this photo:
http://www.markcassino.com/newsite/portfolios/landscapes/pages/IMGP2837.htm
- Mark
On 9/12/2014 10:11 PM, Igor PDML-StR wrote:
How many surfaces does this lens have?
http://42graphy.org/misc/Baikal/_IR29947.jpg
(for those ready to cheat: it's Pentax 17-70/4 at f/22)
I didn't expect to see so many reflections from all the surfaces.
That's what I assume was the reason for all those spots. Right?
Igor
