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B4 adaptor for BM Micro Studio 4K Camera

PostPosted: Tue Oct 02, 2018 4:15 pm
by Allan Stevenson
I am seeking advice on a lens mount adaptor to mount a B4 lens onto the MFT mount of the BM Micro Studio 4K Camera. Could anyone offer their findings regarding this matter? Apparently the MFT mount or sensor on this camera and the BM studio camera are not the same??

Also, has anyone used a Canon J55X box lens on an URSA broadcast camera successfully?

Thanks for your insight.


Re: B4 adaptor for BM Micro Studio 4K Camera

PostPosted: Tue Oct 02, 2018 6:32 pm
by Denny Smith
The MFT mount in the Micro Studio is the same as the regular Studio MFT Mount. The sensor however is slightly different in has it is used in the camera, to get 60fps. Your best bet, is either the MTF Services 2/3rds B4 to MFT optically corrected adapter, or the Abel Cine version of the same. These are optically corrected adapters, that allow use of the max f/stops, 1.4-5.6, and get a good sharp image. The drawback, is these are expensive adapters, due to small batch runs, and are $1500-2500 for each one.

Both companies also make a nice non optically corrected adapter ($200-500), but this adapter requires you to stop down the lens to f5.6 or f/8 to get a sharp image, because of rhe CA and fringing caused by the lens when used on a single sensor camera. If you plan to use the camera/B4 lens outdoors or in good lighting where you can use f/5.6-8, then the non optically corrected less expensive adapter will work.

B4 ENG lenses were designed to be used on TV cameras that had three CCD sensors, and the camera used a prism to split the image by three color wavelengths to the three sensors. When used on a single sensor, this throws the blue and red wavelengths off to focus short or behind the single sensor, causing a soft looking image until you stop the lens down to at least f/5.6.

B&H sells the MTF adapters. AbelCine sells theirs directly. A Google learch will being them up.
I would avoid the cheap adapters often found on EBay or other auction sites, as they do not fit well, and the FFD is not as accurate, which is very important, to get the lens to adjust its back focus correctly.

Re: B4 adaptor for BM Micro Studio 4K Camera

PostPosted: Thu Oct 11, 2018 7:06 pm
by Xtreemtec
On a ursa broadcast it should work as intended. Marc Colemont also has 55x on Ursa mini 4K pro with B4 adapter..

I have a 66x Fuji.. >> viewtopic.php?f=4&t=74203

On the MFT i won't recommend it.. Due too the nature of the MFT mount you need to put in the Doubler.. And if not a HD lens the doubler will get it quite soft image..