Ken Strain

Ken Strain

Lives in United Kingdom United Kingdom
Joined on Sep 22, 2012

Ken Strain's recent activity

  • For a start, f/1.4 is 2/3 of a stop larger than f/1.8 (on the standard scale of rounded exposure numbers). Whole stops are factors of about 1.41 apart  - nominally square root of 2, but rounded on ...
  • Rishi: Thank you for the credit. Your article is an interesting overview of Sony technology. It is always nice to see articles of this kind. I certainly learned few things, such as the use of...

  • @ J A C S: no, I did not mean to imply that. E.g. I know that in Olympus IBIS all versions, right from the two-axis one that only corrects pitch and yaw, correct pitch and yaw by moving the...

  • Comments were set in the context of the Euler basis (hopefully you know about that, TheEulerID), in which the motion is separated into pitch, yaw, roll, and three orthogonal translations (one of...

  • Comments were set in the context of the Euler basis (hopefully you know about that, TheEulerID), in which the motion is separated into pitch, yaw, roll, and three orthogonal translations (one of...

  • ps. In the Sony implementation, when a lens with OIS is fitted, it is stated that the lens IS elements move (translate) instead of the sensor, but with a non-OIS lens, the main degrees of freedom...

  • Re slide 3: it is interesting to read that the dd SSM is employed for IBIS. I am impressed that the slew rate is high enough. As the rods (stators) have to move in tubes (see videos showing how...

  • Re slide 2: nobody tilts the sensor - it would have the wrong effect. Think of what that would do in a view camera.

    Displacing the sensor is the appropriate correction. Pitching the lens and...

  • Re slide 2: nobody tilts the sensor for IBIS - it would have the wrong effect. Think of what that would do in a view camera.

    Displacing the sensor is the appropriate correction. Pitching the...

  • Like any other IBIS, pitch and yaw are a) measured as angular motion, b) the result is multiplied by the focal length converting it to a distance and c) the opposite value is applied to displace...

  • and the deconvolution in HiRes reconverts the aliasing back to useful information.  That is the point. Ken
  • I've been wondering that too, since the first mention of 40Mpixels. Ken
  • Hi Anders, I think "voice coil motor" is standard in loudspeaker (drive) design.  There is it assumed to be a linear motor, so sometimes,  in other applications where there could be ambiguity, it ...
  • Hi Anders, which aspect of that surprises you? There are not too many ways to provide electromagnetic coupling, and without prior knowledge, I would have assumed that there would be coils on the ...
  • Hi Anders, I last looked at this several months ago.  I don't have any links/information to hand other than what I mentioned in a post back then.  There were a few more hints in patents, but ...
  • The shutter design for MFT cameras is novel, as it is required to fit in a much smaller space than standard focal plane shutters, they are not just scaled-down copies of mature designs. You can ...
  • The following comments are based on measurements with various instruments and inspection of a dismantled E-PM2 (presumably with a shutter of similar design to your E-PL5). These observations don't ...
  • 1) use the acutance measure(such as in the acutance profiles), noting that while it compensates for sensor size it does not do so for pixel count, and completely disregard the perceptual megapixel ...
  • Replied in problem
    I meant that the measurement should be valid up to 100 Hz, which should be more than enough to work out what is happening with IBIS.  I guess the upper unity gain frequency of the control law is ...
  • Replied in problem
    OK, this is the zeroth version of what I'd do, subject to improvement.  I'd make a tilt table, probably with a loudspeaker-like voice-coil magnet arrangement driving a piece of plywood or some ...
Activity older than 12 months is not displayed.
Ken Strain has not added any gear yet.
Total messages 291
Threads started 11
Last post 1 week ago
Total comments 14
Total likes 26
Last post 1 week ago
Total reviews 0
Entries 0
Votes cast 0
Photos uploaded 0