With PK-NEX speedbooster adapter my fast F1.4 lenses that I use on my full frame Sony NEX-VG900 like my 24mm will work like F1.0 lens !
While the Lens Turbo isn't the perfect alternative to a full-frame mirrorless camera, it's a step in the right direction in terms of achieving that aesthetic look. The results, even wide open on older Pentax glass, are satisfactory enough for most circumstances, and I'd even feel comfortable using it on paid client projects under the right scenarios. It succeeds in widening the field of view to nearly the same as what you'd receive on a full-frame body, and it does seem to marginally increase the exposure as well. Yes, the edges do soften up a bit, and it does seem to smudge and swirl the bokeh a bit. But it creates a unique look, and opens up the option to use manual glass in either their original focal lengths (with the Lens Turbo), or at cropped focal lengths (with a "normal" adapter).
Because I already had the full frame Sony NEX-VG900 along with the new 16-50mm OSS power zoom and 55-210mm OSS lenses and seen a new NEX-3N body only on ebay last week for $180 + $5 shipping so I thought getting that would be a no brainier since Sony sells the NEX-3NY kit with both lenses for $700. The NEX-3N is also the first NEX interchangeable lens camera from Sony that offers support for new “TRILUMINOS Colour” that is on their new 4K UHDTVs and the only one with zoom control for the new power zoom OSS lenses like the 16-50. I purchased the new PK-NEX Lens Turbo adapter to use with my fast F1.4 full frame like the 24mm, 50mm and 85mm that I use on my VG900 and Pentax DSLRs that converts them into F1.0 eqiv. APS-C lenses that I could use on the 3N or VG900 in APS-C mode. It also looks shorter than the normal PK-NEX adapters that I use on my Pentax mount lenses like my SMC Pentax-M* 300mm F4.
I just received the PK-NEX Lens Turbo adapter and it looks like a great deal if you have a bunch of PK mount lenses like I have. Here it is on my NEX-3N that turns the full frame Pentax 50mm F1.4 into a 36mm F1.0 APS-C E mount lens:
BTW it will also work on my NEX-VG900 in APS-C mode.