Will the Metabones speed booster for M43 be a NEX cast-off?

Started Feb 1, 2013 | Discussions thread
brian Senior Member • Posts: 1,176
Re: Will the Metabones speed booster for M43 be a NEX cast-off?

don_van_vliet wrote:

What I mean by this is, does anyone know if the M43 speed booster will simply be the NEX design with a different register distance, or if it will actually be optimised to the M43 sensor size?

The Metabones speed booster effectively reduces FL by a factor of ~0.73 (I think), and increases aperture by approximately 1 stop. Because M43 has a smaller image circle than NEX, a speed booster could be made to reduce the FL by a larger amount, and increase aperture by a large amount, surely?

The  M43 version of the Speed Booster will have the same 0.71x reduction factor as the NEX version, so it will boost the aperture by one full stop.  I wanted (and tried) to do a version with significantly more reduction for the 4/3 format, but there just wasn't enough space to do a good job.

What I found was that the 0.7x factor was at the edge of an aberration "cliff".  At 0.7x I could do a good job of aberration correction, but even if I tried dropping down to 0.68x or 0.69x the aberrations increased dramatically.

The M43 version does use its own unique optical formula optimized for the smaller format.  As a result, the corners are significantly sharper than if we had simply "re-cycled" the NEX optics.

-- hide signature --

J. Brian Caldwell www.caldwellphotographic.com

Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow