Hi Ken - I think the image was in focus, though slightly degraded due to
the long shutter speed (0.4 second). I tested the setup at that shutter
speed using a dollar bill as a subject and found that the detail was
very good, but the resolution of some of the individual fibers in the
paper was not as sharp as it could have been.
I think there is just something odd about the iridescent reflection and
how the stacking software constructs the image. At full size, some of
the patterns in the gold area resolve into whorls and swirls that look
more like something in motion than something solid. Using a 10x loupe I
cannot see any of the patterns present in the gold areas, so I was
surprised to see them emerge in the 4x photos. But then, at some angles
the crystal is dull gray with no color at all, so the patterns of the
reflections probably come into play. Larry's comment about bokeh
stacking might be a good explanation.
I need to get a simple manual ring flash and try again - I was using an
LED ring light that was woefully inadequate for lighting the subject.
The crystals are are like stair step pyramids and I was shooting into
the cavity - only a straight on light would work.
Mark
On 12/16/2015 12:37 PM, Ken Waller wrote:
Mark, beautiful and colorful image. I've looked several times and come
away feeling its slightly out of focus but I don't believe you'd post
an OOF image.
Your thoughts ?
Kenneth Waller
http://www.pentaxphotogallery.com/kennethwaller
----- Original Message ----- From: "Paul Stenquist"
<[email protected]>
Subject: Re: PESO - Bismuth Crystal
Finally was able to take a minute off work to look at this.
Absolutely gorgeous. It is certainly a worth subject.
Paul
On Dec 16, 2015, at 11:00 AM, Mark C <[email protected]> wrote:
Thanks, Rick! I am hoping this will open up a new line of macro
work. Insects and spiders can be interesting but they are not too
appealing.
On 12/15/2015 9:01 PM, Rick Womer wrote:
All punning aside, Mark (at least for a minute or two), both of the
fossil and mineral photos are gorgeous. They're well worth printing
LARGE and framing.
Rick
On Dec 15, 2015, at 11:33 AM, Mark C wrote:
Continuing experiments with minerals - this is a 4x lifesized
close up of a bismuth crystal:
http://www.markcassino.com/b2evolution/index.php/bismuth-crystal
or
https://www.flickr.com/photos/markcassino/23671905071/
K01 with reverse mounted SMC K 24 f3.5, 70 stacked images. I could
not position a flash well to shoot into the crystal (it is very 3
dimensional) so I used ambient light which resulted in a shutter
speed of 0.4 seconds per shot. I would prefer to use the flash to
counter any vibration related blur, but the long exposures came
out OK.
Comments welcome.
Mark
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