Re: Interesting artifact
> On Apr 15, 2022, at 2:24 PM, 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 > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-le...@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- Larry Colen l...@red4est.com. sent from ret4est -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Interesting artifact
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. 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 -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Interesting artifact
> On Apr 15, 2022, at 11:15 AM, 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 l...@red4est.com. sent from ret4est -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Interesting artifact
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? Cheers, Igor -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: My journey down the slippery slope continues ...
> On Apr 15, 2022, at 12:06 AM, John Francis wrote: > > > you know, I might have one of those (and a K-mount to u4/3 adapter) lying > around. > I've definitely got an A50mm/f1.4, an A50mm/f1.7, and an M28mm/f2.8; I'm just > not > entirely sure whether or not I hung on to an M50mm/1.4 to keep my MX company. I think I’ve got a couple of supertak 50/1.4s lying around. -- Larry Colen l...@red4est.com -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: My journey down the slippery slope continues ...
you know, I might have one of those (and a K-mount to u4/3 adapter) lying around. I've definitely got an A50mm/f1.4, an A50mm/f1.7, and an M28mm/f2.8; I'm just not entirely sure whether or not I hung on to an M50mm/1.4 to keep my MX company. On Thu, Apr 14, 2022 at 11:18:44PM +0100, Steve Cottrell wrote: > I???ll just leave this here??. > > http://www.seeingeye.tv/pages/pen.html > > Cheers > > Cotty > > > On 7 Apr 2022, at 18:13, Larry Colen wrote: > > that still leaves the question of glass > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-le...@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to pdml-le...@pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
