Mounting B4 zooms on the BMPCC MFT mount

 

Blackmagic Pocket Cinema Camera

We have a Blackmagic Pocket Cinema Camera on demo, and are experimenting with various (older) lenses, including building a rig to use 2/3" B4 zoom lenses with the BMPCC. The tables below show frame-grabs from our tests to assess vignetting and focus at different focal lengths and apertures (F4, F2.8 and wide open), with and without using a doubler (where the lens has one).

BMPCC - A demo unit of the Pocket Cinema Camera

This video (above) contains a few shots of Salford taken on my way home, using a Canon J11x4.5 B4 lens on a BMPCC. It's intended just to show the range of shot sizes that can be obtained from a single lens, from very wide to telephoto, so there was no planning and not much finesse to it, no power to the zoom servo (ie jerky zooms), etc.

Fujinon A7x7 (used) - 80.00

This is a used Fujinon A7x7 SD 2/3" broadcast B4 wide-angle servo-zoom lens, pictured and tested below. The lens has a focal length of 7-50mm and a minimum focusing distance of .3M (1ft).  Lens hood and front cap included.     

Fujinon A7x7 BRM-28

Fujinon 7x7 B4 lens    Fujinon A7x7 B RM-28 lens

This SD B4 wide-angle lens has a focal length of 7-50mm and a maximum aperture of F1.7. It neither includes a x2 doubler, nor does not feature internal focusing, and is probably from the 1990s(?). However, it does seem to produce an above-average circle of light so scores well in terms of not vignetting.

Focal length Doubler used? at F4 at F2.8 at F1.7
10 mm N/A
20 mm N/A
50 mm N/A
    F4 F2.8 F1.7
OK for:-
  • Use at F4+ and from ~10mm upwards
  • Use at all focal lengths when cropping in post. Allows a clean 1280x720 to be extracted from the native 1920x1080 on the BMPCC.
Not so good for:-
  • Use as a telephoto, as max focal length is 50mm

 

Fujinon A10x4.8 BERM-28

Fujinon A10x4.8 BERM-28    Fujinon A10x4.8 BERM-28

This broadcast SD B4 wide-angle lens has a focal length of 4.8-48mm and a maximum aperture of F1.8. It includes a x2 doubler, and features internal focusing. This lens also has a macro mode.  

Focal length Doubler used? at F4 at F2.8 at F1.8
4.8 mm No
9 mm No
15 mm No
24 mm No
48 mm No
96 mm Yes (x2)
50 mm Yes (x2)
20 mm Yes (x2)
9.6 mm Yes (x2)
    F4 F2.8 F1.8
OK for:-
  • Use without the doubler at F4+ and above ~24mm
  • Use at all focal lengths when cropping in post. Allows a clean 1280x720 to be extracted from the native 1920x1080 on the BMPCC.
  • Cropped super-wide-angle shots
Not so good for:-
  • Use in low light (when using the doubler)
  • Extreme telephoto, but goes to 96mm with doubler
 

 

Fujinon A14x9 BERM-28 Pegasus

Fujinon A14x9 BERM-28 Pegasus lens    Fujinon A14x9 BERM-28 Pegasus lens

This SD B4 standard lens has a focal length of 9-126mm and a maximum aperture of F1.7. It includes a x2 doubler, but does not feature internal focusing, which gives some indication of its age (1990s). This lens also has a macro mode.

Focal length Doubler used? at F4 at F2.8 at F1.7
9 mm No
20 mm No
40 mm No
80 mm No
126 mm No
160 mm Yes (x2)
80 mm Yes (x2)
40 mm Yes (x2)
18 mm Yes (x2)
    F4 F2.8 F1.7
OK for:-
  • Use without the doubler at F4+ and above ~60mm
  • Use at all focal lengths when cropping in post. Allows a clean 1280x720 to be extracted from the native 1920x1080 on the BMPCC.
Not so good for:-
  • Use in low light (when using the doubler)
  • Getting wider angles that don't vignette
 

 

Canon J14x8 B4 IRS

Canon J14x8 B4 IRS lens    Canon J14x8 B4 IRS (shown on Sony DSR130)

This SD B4 standard lens has a focal length of 8-112mm and a maximum aperture of F1.7. It includes a x2 doubler, but does not feature internal focusing, which gives some indication of its age (1980s/90s). This lens also has a macro mode.

Focal length Doubler used? at F4 at F2.8 at F1.7
8 mm No
20 mm No
40 mm No
80 mm No
112 mm No
80 mm Yes (x2)
40 mm Yes (x2)
20 mm Yes (x2)
16 mm Yes (x2)  
    F4 F2.8 F1.7
OK for:-
  • Use without the doubler at F4+ and above ~60mm
  • Use at all focal lengths when cropping in post. Allows a clean 1280x720 to be extracted from the native 1920x1080 on the BMPCC.
Not so good for:-
  • Use in low light (when using the doubler)
  • Getting wider angles that don't vignette
  • Getting a totally vignette-free image without the doubler -  even at longer focal lengths slight edge shading still persists.

 

Canon J15x9.5B4 KRS

Canon J15x9.5B4 KRS lens    Canon J15x9.5B4 KRS lens

This SD B4 standard lens has a focal length of 9.5-143mm and a maximum aperture of F1.8. It neither includes a x2 doubler, nor does not feature internal focusing, and is probably from the 1990s(?). Some versions of this lens also have a macro mode, although this particular lens doesn't.

Focal length Doubler used? at F4 at F2.8 at F1.8
9.5 mm N/A
20 mm N/A
40 mm N/A
60 mm N/A    
80 mm N/A
143 mm N/A
    F4 F2.8 F1.8
OK for:-
  • Use at F4+ and from ~60mm upwards
  • Use at all focal lengths when cropping in post. Allows a clean 1280x720 to be extracted from the native 1920x1080 on the BMPCC.
Not so good for:-
  • Use in non-cropped mode, as it vignettes at most focal lengths in the bottom half of its range

A short video about lighting in modern office buildings   

Lighting in modern office buildings

Inspired by the techniques shown at the IOV Videoskills Roadshows, in this short video Martin talks about, and demonstrates, the benefits of using lighting when filming in modern office buildings. With modern cameras able to get a well exposed picture in fairly low light, it's easy to forget what a difference lighting can make.

 Watch the video here

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