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  1. Member
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    I have mostly canon lens and was wonder if there was a mount out there that would let you auto focus with the canon alot of my work will be underwater, so manual focus can be very problematic. I know the Black Magic cinema camera can come ready for EF lens (the style I have ) but I really need to keep weight and size down. Any input would be helpful.
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    Nope you cannot auto focus your Canon lens with a BM camera.
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    Is there any lens out there that you can use auto focus with. From the post above it look like you can not use auto focus even with the EF mount on the BMCC
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  4. https://www.blackmagicdesign.com/press/pressdetails?releaseID=61126

    Money quote:

    New features in this update include enhanced lens control support for EF lens mount cameras such as the original Blackmagic Cinema Camera EF and the Blackmagic Production Camera 4K models. This means customers can now get auto focus when pushing the focus button on active EF based lenses and the cameras will mathematically analyze the center of the image and optimize the focus for maximum sharpness.

    (edit: Nevermind, you knew this.)
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    Thnaks for the input I was not sure that the BMCC with EF mount would auto-focus, I would really like it if I could find a BMPC after market adapter that would let you Auto-Focus with the EF lens. Weight is a factor, in traveling to remote places as will as cost.
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  6. Member Cornucopia's Avatar
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    From their forum, it looks like some EFs can autofocus and some can't.

    Personally, I would think that autofocus underwater would be very problematic on its own (index of refraction depending upon depth/salinity, etc), so it would make more sense to manually rack focus (either visually or via measuring or via laser/sonar).

    Scott
    Last edited by Cornucopia; 16th Nov 2014 at 02:03.
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    One would think that if you have a tripod manual focus would work, but most of the time you do not a tripod. Your hand is not fast enough to stay with the ever changing condition you are talking about. Also you need to have a much bigger depth of field then you would general have with land based filming so when a surge moves you unexpectedly your subject stays in focus. At the same time you need to stay with in 3 feet of your subject (if you are use a video light) to stop them from blueing out.
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    Originally Posted by Dano718 View Post
    One would think that if you have a tripod manual focus would work, but most of the time you do not a tripod. Your hand is not fast enough to stay with the ever changing condition you are talking about. Also you need to have a much bigger depth of field then you would general have with land based filming so when a surge moves you unexpectedly your subject stays in focus. At the same time you need to stay with in 3 feet of your subject (if you are use a video light) to stop them from blueing out.
    I fear you do not like to hear this but I think the Blackmagic pocket camera may not be the right camera for you.

    If you want full automatic cameras there are better choices, for instance the Sony mirror less (very light) DSLR or the new Panasonic camcorder. They do not have the quality level of Blackmagic but the Blackmagic pocket camera is not your "instant shoot" kind of camera.

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  9. Member Cornucopia's Avatar
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    Think about it this way: you don't want or need to focus on distant or infinity stuff, because of the BLUE (whether using a light or not). So your area of importance for focus is close, medium-close and medium distance. That's it. You seem to already know this.
    Then you've got the fact that you want to get a wide-angle, both to compensate for the narrowing of perspective (increased focal length) due to water refraction and to cover the surge changes and "unpredictability". So it make sense to use a very wide angle lens.
    And very wide angle lenses at medium distances have a HUGE DOF!* So, unless you are trying to shoot real close-up/macro stuff, it really shouldn't matter WHERE you set the focus because everything visible in that range should also be in focus. Though, for typical good photography physics reasons, it makes sense to set the focus nearer rather than farther.

    So, set it and forget it.

    Example: BMPCC (micro 4/3 sensor) with 12mm lens at f5.6 with focus set at 5 meters - DOF = 1.2m->Infinity. With focus set at 1.5m - DOF = 0.78m->20.2m

    Scott

    *Yeah, I know DOF isn't really dependent upon focal length - but it is dependent upon aperture, distance & magnification. In this instance, very WA lenses used at medium distances and medium apertures, there is much less magnification than a longer focal length lens and thus greater DOF.
    Last edited by Cornucopia; 16th Nov 2014 at 13:39.
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  10. Member racer-x's Avatar
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    I never shot underwater, but I wonder if there is enough available light to support a f5.6 aperture, without resorting to high ISO settings?
    Got my retirement plans all set. Looks like I only have to work another 5 years after I die........
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  11. Member Cornucopia's Avatar
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    Maybe not, but we don't know the depth, ISO, etc. It's just an example.

    Scott
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    everything you said is true, but I do a lot of surge work so I need one hand to hold the camera one hand to hold my location, so far I have not found the third hand to focus with. LOL I guest I just have to stick with the prosumer handcam style for my recording. Cause it looks like there is nothing else out there that would fix my needs.
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  13. Member Cornucopia's Avatar
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    Gell pulled around alot, huh? Wow.

    Well, the 2nd part about using very WA, setting the focus to near and leaving it, wouldn't that work for you?

    BTW, do you use a red filter?

    Scott
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    Originally Posted by Dano718 View Post
    everything you said is true, but I do a lot of surge work so I need one hand to hold the camera one hand to hold my location, so far I have not found the third hand to focus with. LOL I guest I just have to stick with the prosumer handcam style for my recording. Cause it looks like there is nothing else out there that would fix my needs.
    You might want to look at the Panasonic LX 100, does not look like a bad thing especially if you record live through HDMI.

    http://www.panasonic.com/uk/consumer/cameras-camcorders/lumix-digital-cameras---point-...dmc-lx100.html

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  15. Member Cornucopia's Avatar
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    Tethered recording is a bitch underwater though. Much harder to keep airtight and less mobile.

    Scott
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    Originally Posted by racer-x View Post
    I never shot underwater, but I wonder if there is enough available light to support a f5.6 aperture, without resorting to high ISO settings?
    You could limit the ISO in the main settings, and use Av mode to see what shutter speed is selected. If too slow, then switch to Tv mode. If it's then too fast, you're hosed.
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