Again, I'm very interested to have others try my Photoshop experiment,
to see if my results are duplicated. This experiment eliminates all
other factors - it is solely the eye looking at a flat image field
simulating the image field at focus.

Interestingly, last night, I perused the seemingly myriad animations now
available of this transit and noticed that some clearly show the effect
and some do not. Notice that I use the word 'effect' as opposed to
'phenomenon'.

FWIW,

Bart Fried

Pete Lawrence wrote:

On Wed, 09 Jun 2004 19:03:45 GMT, nobody wrote:


For my money, the black drop appears to be substantially caused by the
eye's own optical illusion, and is dependant upon the image scale of the
eyepiece (the effect was more pronounced at what experience tells me is
medium magnification and wasn't noticable when the Venus image was very
small (zooming out the Photoshop image greatly) or very large (highly
zoomed in.)

Thus, in addition to the eye playing tricks, the magnification, quality
of the optics and the seeing most likely contribute to the effect,
positively or negatively.


The problem is that for all theories at the moment, I'm hearing
examples of images taken with equipment/conditions that counter each
theory.

Despite the massive number of images taken of the event, I've had very
few equipment/conditions/black-drop (y/n) reports sent in yet [HINT
HINT!].

Unless there's data to back it up, theories will simply stay as
theories.

For my part, I believe it's caused by equipment quality and the
contrast of the image that is being observed. However, I'd dearly
like to gte some proof.