B4 Lens

greeches

greeches

Veteran
Anyone else have any out there?

I have a J15x9.5B4 Lens on a B4 -> m4/3 adapter.

IMG_5692 (Large).jpgIMG_5696 (Large).jpg

143mm vignettes slightly, but the rest of the range has an image circle.

Once telecine mode is on, the full range is useable. (~43 - 650mm) (2x m4/3 * 2.6x telecine)B

 
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Got my eye on this exact lens and am very curious how it looks. Theoretically with ETC mode, that should be the only lens you'll ever need :)
 
I haven't used it in a real-world situation yet (I've had the GH2 less than a week) but it seems to be a very useful range. Its much sharper stopped down to 2.8 or 4. You will see some this when the my upload goes live.
 
Thanks for posting that video. How much of that was shot wide open? The wide shot of the stove looked a little soft but all the other shots weren't too bad. Are you planning on doing any low light tests with the lens?
 
It was mostly wide open. Towards the end, when you see it get lighter then darker, I'm going from F4 to F1.8 and back to around F4. There are no clicks, so all a guesstimate.

Its pretty useable at F4, and at certain focal lengths good at F1.8/2.8.

I'll do some more tests in daylight. It'll have to be over the weekend.
 
How fun! I used B4 lenses on Sony DXC-M7 cameras for years. These cameras were tripod mounted, and had the typical TV style focus and zoom adjustment controls mounted to each tripod arm.

Do you have the remote focus and zoom controls for that lens? It wouldn't be practical handheld, but you could definitely use them on a tripod.

Cool stuff :)
 
Yeah it looks like it shows signs of CA on the wide end and not so much at the telephoto end. It might also have to do with the lens hitting a light source head on and getting sensor reflection. I'd be curious to see how it performs in a downtown setting or a cocktail party. Looking forward to more testing.
 
Thanks for your quick test.
Wide open, around f1.8, images are clearly too soft; at f2.8 are still somewhat soft but it's a useable aperture for low-light shooting.
Adapters from ebayer seller ciecio7 seem offer quite good uniformity from center to edge.
 
there are no optics in the adapter. Is simple a hollow tube w/ a female B4 adapter on one end and a male micro 4/3 on the other.
 
Here is a test done during daylight.


Canon J15x9.5B4 on a B4 to micro four-thirds adapter.

-You have to stop down to f4 for a useable image. It is kinda foggy from f1.8-~f3..

-You can shoot at 143mm without turning on telecine mode. For the rest of the range you must use telecine to avoid severe vignetting.

I think it will be quite useable. I'd like to test it on a narrative and see how it handles. Its easy to hold, because you can just grab the lens grip and hold it like a shoulder mount cam.
 
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