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-   -   Brevis35 Flip Footage (https://www.dvinfo.net/forum/alternative-imaging-methods/106654-brevis35-flip-footage.html)

Dennis Wood October 27th, 2007 02:58 PM

Brevis35 Flip Footage
 
We spent a few days this week shooting with the Canon XH-A1 and the Brevis35 + flip module. It's the cleanest, sharpest footage we've ever squeaked out of the system. We've also been able to clean up a great deal of the XH-A1 lens inherent chromatic issues with the combination of the flip unit and optics.

35MB 360x640 Quicktime H264 (right click and save)

174MB 720P Quicktime H264 (right click and save)

Dennis Hingsberg November 5th, 2007 08:47 PM

Nice footage! How will the flip version work with rails, what do you recommend, will they be standard distance from rod center to lens center? (forget what that is, 60mm I think but am not sure)

Dennis Hingsberg November 6th, 2007 08:47 AM

Two more questions, what will the total light loss be through the flip adapter and when will the unit be shipping?

cheers.

Dennis Wood November 6th, 2007 09:52 PM

Dennis, we did some very interesting tests using the Brevis and XH-A1 (large cam) and HV20 (small cam) tethered to a laptop running Adobe's OnLocation. The waveform monitor and split screen functions allow efficient analysis of light loss and edge falloff (very important!) with the various setups. We discovered a few interesting things about the adapter and the cameras too.

1. We quantified our previous light loss measurements done on the camera. The Brevis with a 50mm f1.4 lens attached loses less light than stopping the bare camera down one f stop. Compared to our bare camera base-line tests, we measured .6 stops.

2. Adding the flip unit loses so little light that it's hard to accurately measure. A good predicton is 1/5 f stops, and a lot less then we had modelled optically.

3. Using CF1L, CF1Le, or CF1, stopping down the 35mm lens from f1.4 to f2.8 is nearly lossless, and pushing on to f4, light loss starts to become measurable. This is hard to believe given that the aperture is closing by a factor of 8, but is supported by Phil Blooms review showing the Brevis as much as 4 stops more efficient when the 35mm lens in his tests was set to f8. What this means is that you can stop down your 35mm lens to its sweet spot, and lose little to no light doing it!

The flip module is in full production, so expect to see units shipping later this month. The CNC shop has managed to lighten the housing another 15% or so by machining every bit of superfluous material away. There's another few surprises coming, but we're keeping those under wraps for now.

I answered your rails question in your other thread...

David Delaney November 6th, 2007 10:09 PM

wow Dennis, that is very impressive. There is some great sharpness on that video. Is that Thunderbay?

Dennis Wood November 6th, 2007 11:06 PM

Yes, all shot in Thunder Bay in one day at three locations:

1. Hillcrest park (sunset, war memorial)
2. Kakabeka falls
3. Marina park

Fall is a brief but very special time here. We try and enjoy it as it's followed by 5 months of some pretty serious winter!


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