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Genesis shutter angles


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#1 Dave Perkal ASC

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Posted 01 March 2007 - 09:33 PM

I am currently in prep on a pilot. The studio has made a decision to use the genesis(before I was hired-this seems to almost be a trend for tv). One of the things that I am concerned with is that video's sharpness looks so plastic. Video seems to have an artificial sharpness to the edges that, even while having a depth of field closely matching 35mm, seems to give it away. It is almost as if visually depth of field is treated as a binary, i.e. 0 or 1, on or off, rather than a more organic gradual fall off as with film. It almost looks as if at 180 degrees, it is actually a shorter shutter. One thing I will test is using a longer shutter 220 or 270 to extend that persistence of vision. Hopefully that will begin to add an element to help visually make a compromise. I know the dangers of a 360 visual smear and hope to avoid this. The monitors panavision gives you are interlaced instead of progressive. So on set it will be difficult to discern the effect of shutter correctly.

Has anyone tested this with different shutter angles?

Also what is everyones asa rating for this camera? Dean S. rates at 640 while others rate at 400. This will also be tested but just searching for opinions.

thanks
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#2 Michael Nash

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Posted 03 March 2007 - 06:33 PM

Hi Dave,

Since no one has responded yet I'll offer a couple thoughts. But my experience with the Genesis is very limited, so take it with a grain of salt...

In general I find that shutterangles larger than 180 on any kind of 24P video (including HDCAM) make motion blur look even more like video, and less like film. Depending on the subject and look, I'll often shoot with a 144 degree shutter (or electronic equivalent) just to avoid that "video" look.

The "artificial sharpness to the edges" of course can be adjusted in camera, either by turning the detail enhancement "off," or have a DIT assist you in adjusting the detail frequency and limiters. Keep in mind that what you often see in standard def is detail enhancement added to the image during downconversion, since HD detail is generally too fine to see at standard def resolution. It's worth doing some tests with the proposed workflow all the way through post, to see the difference between your in-camera footage and the final release version.

As for the falloff of focus and perception of depth of field, you of course can experiment with diffusion filters to smooth out the look of fine detail and focus. It's a subtle thing, but sometimes this can give some "grace" to the depth of field. But again test it all the way through, since HD colorspace and resolution is already less than what you get with 35mm.
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#3 Douglas Hunter

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Posted 07 March 2007 - 01:34 AM

Dave,

I was discussing some of these exact topics today. I second what Michael was saying, specifically about the DIT. But I also think you may find that the fall off in the DOF of the Genisis is more pleasing to you then other HD cameras.
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#4 Roberto Schaefer asc aic

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Posted 25 April 2007 - 09:52 AM

I recently shot a pilot with the Genesis and ended up almost exclusively at 360 deg shutter. I found that the camera was giving me a relative ASA of 200 when I was at T2.4. I needed the extra stop from the shutter in order to get my exposure. I have heard varying opinions and wonder where you stand on this. I was told that the sensor is rated at 2.8 so anything open from that would change your effective ASA rating. Do you know anything about this? I din't notice any odd blur effects from the 360 shutter and didn't have any other negative artifacts like strobing. And it didn't seem to add to a video feel. I also used Classic Soft filters on all the Primo lenses to help the film look.
Roberto Schaefer, ASC
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#5 Max Jacoby

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Posted 26 April 2007 - 12:18 AM

Hi Roberto

I find your experience on the ASA interesting as other people have rated it faster. Dean Semler rated it at 640 ASA for instance, but his film had visible noise. From what I understand digital sensors don't have a fixed ASA, it all comes down to how much noise you can tolerate. Unlike film where you have to print up when you underexpose and thereby lose the blacks, in digital grading getting the desired level of black is not related to the speed you expose at. Personally I liked the more noisy scenes in 'Apocalypto' because I felt it added texture and character to an otherwise very cold digital image.

How was your experience of the Primos btw. Did you use zooms as well to intercut with primes?
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#6 Stephen Williams

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Posted 26 April 2007 - 02:42 AM

I recently shot a pilot with the Genesis and ended up almost exclusively at 360 deg shutter. I found that the camera was giving me a relative ASA of 200 when I was at T2.4. I needed the extra stop from the shutter in order to get my exposure. I have heard varying opinions and wonder where you stand on this. I was told that the sensor is rated at 2.8 so anything open from that would change your effective ASA rating. Do you know anything about this? I din't notice any odd blur effects from the 360 shutter and didn't have any other negative artifacts like strobing. And it didn't seem to add to a video feel. I also used Classic Soft filters on all the Primo lenses to help the film look.
Roberto Schaefer, ASC


Hi Robert,

Deciding how much headroom you require for highlights above normal white, is the reason IMHO that people quote wide ranges of relative ASA's on digital cameras.

Stephen
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#7 Roberto Schaefer asc aic

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Posted 26 April 2007 - 07:51 AM

I did use a zoom along with the Primos. Panavisions terrible little rehoused Canon lightweight zoom. I think it is 28-64mm, t 2.6. The good thing was that I didn't need to use Classic Soft filters on it to match the Primos with the filters! I was hoping to get their new LWZ, but it wasn't available.
I am an ARRI guy. I love the choices available- Angenieux Optimo zooms, Arri Master Primes, Cooke S4's, etc. AND, I love the Arri cameras. As an operator and DP. I will try the D20 next Digital job because of the optical viewfinder. And if the slow relative ASA rating is true, it might be closer to what I got on the Genesis when I really needed the speed!
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