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Pentax sensor shift and swirly bokeh
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PostPosted: Thu Sep 10, 2015 1:58 pm    Post subject: Pentax sensor shift and swirly bokeh Reply with quote

We know that the swirly bokeh of a lens like Helios 44 is more noticeable on the corners of a picture (and considering the background pattern and distance, the focus distance, etc). For those who still do not have (or want) a full frame camera, and use a aps-c sensor, this is a limitation for getting more noticiable swirly bokeh because were aren't seeing the corners that a full frame sensor is capable of capturing. But, with some work and a shifting sensor, we can get some more swirly bokeh and also take advantage of the center resolution of helios lenses (or similar) to move this center to another place in the final picture, by moving the sensor (for example, we can avoid to center the subject in the picture and move it somewhere else now that we can modify the position of the center of the image proyected by the lens using the best part of it). Well, these are some test I've done and may be usefull for practical uses.

1# full image, no sensor shift


2# full image, down left sensor shift


3# full image, upper right sensor shift


4# from left to right: (100% crops from extreme upper right corner of the image)
down left corner shift - no shift - upper right corner shift


5# from left to right: (100% crops from not that extreme upper right corner of the image)
down left corner shift - no shift - upper right corner shift


6# from left to right: (100% crops from center of the image)
down left corner shift - no shift - upper right corner shift


I hope this will be usefull for someone, and sorry for my bad english.


PostPosted: Sat Jan 14, 2017 4:31 am    Post subject: Reply with quote

Interesting!


PostPosted: Tue Feb 21, 2017 12:25 am    Post subject: Reply with quote

Can you explain the method of sensor shifting? Didn't quite get it...


PostPosted: Tue Feb 21, 2017 2:49 am    Post subject: Reply with quote

AlexKV wrote:
Can you explain the method of sensor shifting? Didn't quite get it...


Count me in. Didn't get it either.
Meself very curious.


PostPosted: Tue Feb 21, 2017 8:51 am    Post subject: Reply with quote

Probably push the lens around with some shift adapter on APS-C similar to what you can do with medium format lenses on FF?


PostPosted: Tue Feb 21, 2017 9:10 am    Post subject: Reply with quote

Nordentro wrote:
Probably push the lens around with some shift adapter on APS-C similar to what you can do with medium format lenses on FF?

Given the thread title, I'd imagine it's using the sensor shift composition fine tuning feature Pentax cameras have.
IBIS is not used while the camera is on a tripod, so the sensor movement can be utilized for other things.