Simon Shasha Posted June 24, 2014 Share Posted June 24, 2014 Hey guys, I was watching Dave Dugdale's GH4 review, and I noticed some strange "onion-like" bokeh - if you fast-forward to 14:15 you can see it: Is this common among Speed Boosters? Does the x0.58 BMPCC specific Speed Booster suffer from this too when the lens is wide-open? Would love to know what experiences you guys have had with Speed Boosters and bokeh rendition :) Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted June 24, 2014 Administrators Share Posted June 24, 2014 All lenses with aspherical lenses have onion bokeh, although Panasonic tried new technology to reduce it recently with the 42.5mm F1.2. The onion bokeh is there with the aspherical lenses on my 5D Mark III without Speed Booster. Samyang 35mm F1.4 is especially bad for it. But 99% of the time I don't notice it. I like older lenses like the Canon FD 35mm F2.0 for the bokeh... no aspherical elements... smooth as hell. Quote Link to comment Share on other sites More sharing options...
JohnBarlow Posted June 24, 2014 Share Posted June 24, 2014 The major cause of onion rings in the bokeh is the use of aspherical elements, in this case most likely in the host lens. These elements are made in a mould which if not polished out leave small ridges in the glass. Quote Link to comment Share on other sites More sharing options...
JohnBarlow Posted June 24, 2014 Share Posted June 24, 2014 SNAP!!! Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted June 24, 2014 Administrators Share Posted June 24, 2014 Speed Booster doesn't make bokeh taste of onions... This was shot on my BMCC Speed Booster modified to fit Canon EF mount Speed Booster on GH4 (bit of a mouth full I know!) Quote Link to comment Share on other sites More sharing options...
Simon Shasha Posted June 24, 2014 Author Share Posted June 24, 2014 Thanks for posting that shot, Andrew! Is that with the lens wide-open all the way? Quote Link to comment Share on other sites More sharing options...
Perplex Posted June 25, 2014 Share Posted June 25, 2014 Speed Booster doesn't make bokeh taste of onions... This was shot on my BMCC Speed Booster modified to fit Canon EF mount Speed Booster on GH4 (bit of a mouth full I know!) hold on hold on. How do you modify the BMCC speedbooster to make it fit the GH4? Can you provide explanation!? Quote Link to comment Share on other sites More sharing options...
Simon Shasha Posted June 26, 2014 Author Share Posted June 26, 2014 I don't think its physically modified, rather, electronic shutter is switched on in order to stop the shutter from coliding with the Speed Booster. However, people have reported increased rolling-shutter when electronic shutter is activated, not sure how true that is though... Quote Link to comment Share on other sites More sharing options...
Guest Ebrahim Saadawi Posted June 26, 2014 Share Posted June 26, 2014 However, people have reported increased rolling-shutter when electronic shutter is activated, not sure how true that is though... Only in stills yes. Rolling shutter is incresed when using electronic shutter. With mechanical shutter you don't get any rolling shutter. That's only for stills. Video is electronic shutter anyway, Quote Link to comment Share on other sites More sharing options...
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