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Old August 27th, 2007, 02:20 AM   #1
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Lens adapters and 60p recording ...

I remember somewhere over the last few years comments regarding lens adapters not being able to be used when recording at 60p? Anyone have any clarifications on that. Something to do with the spin rate or shake rate of the device, me thinks.
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Old August 27th, 2007, 03:16 AM   #2
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What i heard (if ir remember it well) a rentalhouse advised me not to use the hvx in combination with the mini35 when shooting 60p because you would see the 'grain' of the spinning groundglass. I don't know the exact reasons though..
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Old August 27th, 2007, 07:12 AM   #3
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As framerate increases, so does shutter speed so less motion blur is enacted. Thus the grain is caught in action instead of being blurred. The effective framerate of 60p would be 1/120 (right?) and I've definitely used adapters at this shutter speed with little issue. Spinner-design adapters should have no issue, without question. I'm not as confident about vibrating designs.
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Old August 27th, 2007, 08:14 AM   #4
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thanks much ...

one of the issues with adapters, I've been thinking of going that route but would love some experience with an adapter or at least someone who has one working with an HVX to give me the low down. I agree the vibrating adapter might not work will at that frame rate. I did 24 shutter speed on 24P before and got the gladiator look, more or less. Hmmm, I wonder what 60p at 60 shutter would look like?
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Old August 27th, 2007, 08:43 AM   #5
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Quote:
Originally Posted by Dean Harrington View Post
one of the issues with adapters, I've been thinking of going that route but would love some experience with an adapter or at least someone who has one working with an HVX to give me the low down. I agree the vibrating adapter might not work will at that frame rate. I did 24 shutter speed on 24P before and got the gladiator look, more or less. Hmmm, I wonder what 60p at 60 shutter would look like?
What do you mean 24 shutter? 1/24? that seems really slow...
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Old August 27th, 2007, 08:52 AM   #6
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yes that's right ...

Quote:
Originally Posted by Ben Winter View Post
What do you mean 24 shutter? 1/24? that seems really slow...
choppy but interesting ~ used it in a project.
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Old August 27th, 2007, 11:13 AM   #7
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I concur with Ben on spinning disk designs. I would expect the older Mini35-300 with the disk at higher rpm and the SGPro and possibly the Redrock M2 likewise, to be the most likely to cope of all. There have been operator claims of artifact-free imaging from the Brevis at f11 apertures so it may have some shutter speed latitude at much wider apertures.

On the Letus35 I have tested, whilst there was a fixed pattern artifact present in the lighting conditions I was shooting in, it did not become any worse at 1/150th sec but was quite pronounced at 1/500th sec.

I have run the CD-R sized disk on my own adaptor at approx 1500rpm with a shutter of 1/150th sec. Except for a more strobey look when de-interlaced to 25P it seemed fine otherwise. The Mini35-300 and SGPro use a smaller diameter disk so there may be an artifacted region towards disk centre.

Perhaps avoid clear uniformly bright plain backgrounds such as car bodies or lightly clouded sky in your image if you intend camera moves. In locked off shots any artifact in these areas may be less apparent.

Sticking to wider apertures with f1.8 or wider available-aperture lenses and adjusting for light with camcorder aperture and camcorder ND may help. ND gel in between the SLR lens and the groundglasss may also help avoid flare and possible groundglass artifacts which are seen to disappear with SLR lens aperture and relay or camcorder aperture both wide.

Some lenses also provoke artifacts more than others. You choices may be slightly less. I think you will find you can make it work.

Frame blending back to 30P or 24P is not likely to work as in most cases, even with disk appliances, the artifact will be largely a fixed pattern, shimmering pattern or fixed area on the image. A shimmering artifact could be reduced to something closer to a less vexing burred fixed pattern artifact by frame blending or layer stacking across three to five frames.

Last edited by Bob Hart; August 27th, 2007 at 11:27 AM. Reason: error
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