Tele Lens and Black Magic Micro Cinema Camera

Hi Guys,

I shoot a surf movie with the BM Micro, i just chose it for the Crop ( for long lenses shots )and the 60p Prores. So i'm filming with a 100-300mm Lumix, everything ok but if a add a ND filter, the image gets slightly blurry. I tried ND 2 4 6 an variable, same problem. Same problem with other lenses, 400/300mm nikon, s16 lenses ...
I Suppose this is because of the huge crop factor but i wanted to share my experience and asking if anyone could have a solution/idea.

Thanks a lot

Cheers from France.

Jean

What exact ND filter are you using and is the ND filter the only filter being used? Is the 100-300mm zoom blurry at all focal lengths with the ND filter on and clear without the ND filter at all focal lengths.

300mm on that sensor is a long lens. What are you using to stabilize the camera? When you are recording, do you have hands on the camera or controls? Your pulse can make the image have micro jitters with that length of lens on your camera.


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Jean, I have the Micro camera and S16 lenses, including the Angenieux 17.5-70mm zoom, and use znD filters on them without any issue. What ND filters are you trying to use? With heavy NDs above 1.0, you really need to have an IR cut filter also. Firecrest IR/ND, and Tiffen IR/NDs both work well in the Micro camera. Also quality filters like the Lee Pro glass NDs and the SLR Magic VND work well also. You should also have a good lens hood on these long lenses when at the beach, reflective light is bouncing all over the place. The SLR Magic VND also acts like a polarizing filter, removing some of the glare from the water.

If you are mixing a traditional polarizing filter with the NDs could cause some issues, if the ND is in front the polarizing filter you may get some issues, not sure on this.
Cheers

Test the lens without any filter so to rule filters out as the culprit.
Some filters apparently give us a softer image the longer the focal length.
Rather than using an ND filter you can use a smaller shutter angle to get a number of benefits including less blur from shaking (then stabilize in post).

From my experience with that equivalent focal length you need a super sturdy tripod and rig in general.
If we even breathe near the camera it can shake and hence blur.

Also: According to reviews Ive read that lens isn't the sharpest to begin with, so you don't want to soften it further with filters.

Hi Rick !

thanks for answering the 100-300 blurs at all lengths withe NDs, it is not a motion blur problem, i've a pretty stable tripod. I tried different types of NDs, i wonder if someone tried with kind of high quality NDs ...

Thanks for the update, Jean. What brand of ND filters have you used on that lens? Did you also use a Vari-ND or a traditional ND filter?


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Ok thanks guys, i'll try some other filters. i still find the 100-300 pretty sharp

This sounds like a ND filter issue. I suggest that you buy a high quality ND filter to test. If it works or not, you always have 30 days to get a full refund. It sounds crazy but I buy, test and return all the time. Saves me a lot of money. Your also putting a ND filter on a focal length of 288mm-864mm. I don't expect that a focal length greater than 300mm to be really sharp unless it's a canon prime lens that costs over 3K. I have a Lumix 12-35mm and 35-100mm on my BMMCC.

Good points Keith, but the Micro Camera does Not change the focal length of a lens when you use a full frame lens in it -- only the field of view is changed. So the lens interaction with a fitter will be the same if it is used on a Canon or the Micro camera. A 300mm lens is a 300mm lens regardless of the camera it is used on -- only the filed of view changes with the different size film gates or sensors, not the focal length.