Typically, in photography you struggle with not enough light . Nevertheless, if using Blackmagic Pocket Cinema Camera you can easily run into a „too much light“ problem. As the camera offers the minimum of ISO 200 and a shutter of 1/200s you are forced to use very small aperture, which affects image quality. Typically, this problem is counteracted with a ND filter. However, we have mounted the Panasonic 7-14mm lens, which has no filter thread due to its bulby front lens. As there is no alternative for the exceptional focal length range of the Panasonic 7-14mm paired with its superior image quality we need to find solution for the ND filter mount.

Several approaches for mounting ND filters to Panasonic 7-14mm lens have been discussed in http://www.mu-43.com/showthread.php?t=28762 . But none of these seems reliable and light enough for our flying BMPCC.

The solution I want to present is made for 77mm filters. There is no vignetting present even with 7mm focal length. The only thing you need is a 72 – 77mm filter adapter (e.g. like this adapter).

First, I shortened the built-in hood of the lens by ~2mm on the left and right side and ~7-8mm at the top and bottom. With 7mm focal length the front lens has approximately the same height as the hood. The important thing is that the remaining hood has the same height all around. I used a Dremel for cutting the hood and sand paper for smoothing.

Cover the lens when working on the hood

Cover the lens when working on the hood

Black Magic Pocket Cinema Camera Lens Modification 

The 72-77mm filter adapter fits exactly over the hood. Even though it holds quite well on the hood, I fixed it with silicone to make sure it doesn’t depart during flights: I applied some silicone and moved the adapter over it. Move the adapter down as far as possible so that the filter is as close to the lense as possible, but without touching it. Finally, remove the excessive silicone.

Black Magic Pocket Cinema Camera

Black Magic Pocket Cinema Camera with modified lens casingMount a filter for checking the correct position of the adapter before the silicone hardens.

7 comments

  • Good day,

    Thank you for this solution. I am about to proceed cutting the built in hood of my lense too. Ok when you use ND filter on but how the lense perform without the ND filter on? Any reflections because of the missing hood?

    Thanks

    • Hi Dimitris,
      we use the ND filter basically when we operate in very bright conditions like snow during the winter season. Without the ND filter we would have to close the iris too much, resulting in poor image quality. We try not to exceed aperture values above 11 in order to get sharp images.
      So far we haven’t had any reflection issues due to the modified hood.

      What are you going to use the ND filter for? Are you filming in snow?
      Cheers
      Sven

      • Hi Sven,

        Thanks for your response. I always try to keep apperture values at max 11 too in order to get sharp images. My intention is to use ND filters for long exposure shots at bright light but I want to take full advantage of the 7mm of this great lense. Up to date I have only managed to take shots from 9mm and so on with no vignetting with various pattents. I guess, cutting the petal hood as you did is the only way to go to completely eliminate vignetting at 7mm. My concerns weight only on possible flare issues because of the hood shortening.

        Also, it doesnt seem that the 72-77 adapter fits exactly on lense as I bought this adapter among other items. The petal hood is 69mm so the 72mm of the adapter is loose…

  • Hello Dr. Schmid,

    BMCC MFT sensor size is slightly smaller than standard MFT sensor, so I wonder if this design will vignette at 7mm on MFT photo cameras. I will appreciate if you can share any info about that.

    Thank you!

    • Hi Michael,

      the smaller the chip the less vignetting you get with a given lens. Also distortion will be lower, as the smaller chip uses only smaller (center) part of the lens which has typically less distortion.
      With the described filter mount we don’t get any vignetting using one or even two slim filters.

      Best regards,
      Thomas

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