As far as I understand how (sensor-based) shake reduction works is that
the sensor is moved to compensate for the motion of the camera - but only
for the object that are in the focal plane (or close to it).
Things that are closer or farther also benefit from that, but to a lesser
degree.
That place has no fence or anything behind. It has the rest of the tree
behind: I was shooting somewhat against the light. I do not think this
aperture images are due to multiple light sources from the back.
I do not have a complete picture (in my head) of how the aperture images
show up in this case, and, especially why they are all aligned along one
straight [!] line. I suspect that they might be due to a reflection from
the sensor.
In that case, I could imagine how the sensor motion alone one line (around
one axis) could create multiple aperture images.
Igor
Larry Colen Fri, Apr 15, 2022 9:42 PM:
On Fri, 15 Apr 2022, Igor PDML-StR wrote:
Larry,
You are probably right about the light coming from the background.
What I am not understanding completely is why all the aperture
images are perfectly aligned along a straight line.
If my assumption is correct that it is a SR that creates that motion,
projecting this aperture images onto different portions of the sensor, - then
why is it in a straight line? I'd assume my shaking hands to be moving less
linearly.
If it was due to SR then you would get all sorts of linear blur all over
the place.
I would guess that part of what ever was mostly blocking the light was
pretty much a straight boundary, like a fence or a tree trunk.
Going back, I’d say holes in a fence. No way would shake reduction make
that much of a blur.
Were those taken someplace you could go back to? Do you have any other
photos of the site? Do you have geotagging so you can look at it on google
streetview or something?
Igor
Larry Colen Fri, 15 Apr 2022 11:25:02 -0700 wrote:
On Fri, 15 Apr 2022, Igor PDML-StR wrote:
I thought some people here might find this curious:
It is interesting to see 5[!] images of the aperture.
Pentax D FA 100 mm F2.8 Macro (not "WR") @ f/5.6
(The lens has 9 elements in 8 groups.)
Some other images from this setting showed only 4.
Never mind the central part of the photo - this is one of the images to be
deleted. I did not crop it out just to show the context of how the image
was taken:
http://42graphy.org/misc/ApertureImages/ApertureImage_IR09244.jpg
I cannot say that I _fully_ understand how all these images are formed, -
especially after looking at this photo:
http://42graphy.org/misc/ApertureImages/ApertureImage_IR09238.jpg
This has up to 8-9 aperture spots, but some of them are motion-blured.
The camera was hand-held, with the motion reduction enabled.
I am guessing that the motion-blur comes from the camera shake, not
compensated by the sensor. But it also makes me wondering if all these
aperture images are effectively just the same single image - due to a
reflection from the sensor that moves as the sensor compensates for the
camera shake.
Any thoughts?
I suspect that if you had stopped the camera down you would see points of
light
coming through the foliage in the background.
I think it’s just standard bokeh of point light sources in the background,
especially since I see a bunch of other vaguely MG logos in other portions of
the image.
--
Larry Colen
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