B4 Mount Question

[Ziad Oakes]

Hi All,

Looking for some advice here on the B4 Mount. Have a client coming in to shoot with my RED ONE from abroad and they want to use a B4 mount with their digi lenses.

I don't currently own the B4 Mount adapter that you can buy at the red Store, but wanted to enquire to those that own it if there is anything I need to be aware of.

Is it as simple as plug in and play?

Any feedback/advice would be really appreciated.

Thanks in advance,

Z

 

[Mitch Gross]

The mount adapter is simple and works fine. Lenses will only cover in 2K mode. You will also want to have a cable made that will give power and run/stop control from the lens servo control to the camera. This is a simple item that we can make you as can others. It plugs into one of the Lemo4 jacks on the back of the camera.

 

[Carl Larsen]

Does the mount loose significant light? I thought I heard that in another thread, but I've never found specific numbers.

 

[Ziad Oakes]

thanks for the info Mitch. I will PM you in concerns with getting one of these cables.

thanks again,

z

 

[Mitch Gross]

There are two types of adapters. The one from RED projects to just the 2K image area, so there is no significant loss of light. The other type (not offered by RED) projects the image to the full 4K area but with a loss of two stops of light.

 

[Mick van Rossum NSC]

Had a little time to spend with Red's B4 mount. Two observations; There is some change in FOV ; when swapping a 20mm Standard with a Digiprime 20 on the B4 mount, the Digiprime gave a wider FOV. My thought is that it has to do with a lens element in the adapter, but was surprides because I was just explaining to the rental house owner that a 20mm is a 20mm. In this case , NOT. Second test; I put the HJ40x10B on the B4 adapter, flipped in the 2x extender and it covered the 4kHD setting. Did not have time to test how the quality is, it would be intersting to compare the 400mm on 2k compared to the 800mm on 4kHD with extender (same FOV), and see what wins...

 

[Cail Young]

Did not have time to test how the quality is, it would be intersting to compare the 400mm on 2k compared to the 800mm on 4kHD with extender (same FOV), and see what wins...

The extenders are generally not the greatest elements in a zoom; every time we've used one it fringes much worse then when it isn't in the way...

 

[Shane Kelly]

I used to use the optex B4 to PL adapter with a canon j15x8.5b4 lens on my aaton and it changed the shortest focal length to an 11.5 and I think lost about half a stop. This is, I believe, the same adapter that is offered by red and still available from ZGC. I tried it out with a B4 HD lens and it looked great.

 

[Shane Kelly]

BTW, I could rent it out cheaply if anyone would like to try it. I just don't have the cable to run the zoom. I do have the aaton cable though.(not that that's any use on the red)

Shane.

 

[Darren Orange]

Hey Mitch

How do you think the Zeiss DIGI Primes would look with the other adaptors that project on to the full sensor? I guess its not really worth it with the light loss, but I figure if lit correctly it should be fairly sharp?

 

[Mitch Gross]

I personally don't think it would be worth it. Better to get regular 35mm format glass at that point.