Friday, November 16, 2012

Our next movie - what camera to use - Part 2

Part 1 is down 3 posts from this one, or if you are seeing posts separately then the direct link is:

In brief, we think it is now possible to shoot an experimental no-budget feature in a borrowed classroom with a green screen setup.  The big enabler is the improvements in video editing software, eg the "Keylight" compositing plugin in "Adobe After Effects".  Sharing some thoughts from further reading, asking questions and running some more tests.

We have run tests with borrowed Canon HV20, Canon HF R20 and Sanyo VPC-HD2000.  This opened a whole new issue in that we discover we like the 60p (60 full frames per second) high frame rate of the Sanyo.  So now we gotta go 60p, or maybe 50p because we are in PAL territory New Zealand.  Further details.

Sanyo VPC-HD2000 - We were able to test this briefly.  We kept it simple and set it to preset "sports" following advice that a high shutter speed is a good idea.  Clear winner for a clean key result including movement at 60p and we like the 60p look.  Colours were warm and over-saturated but if we had more time with this we could probably explore its settings and do better.  The Sanyo dates from 2009 and was a cutting-edge camera then.  We and other bloggers note that Panasonic have now bought Sanyo and 60p has since been appearing on Panasonic cameras so we are guessing that Panasonics with 60p are the children of this Sanyo and worth further investigation.

Canon HV20 - an "old" as in over 5 years old cam.  HD 1920 x 1080 on tape using MPEG-2.  The attraction was that this has more manual control than the other cams we have access to.  We ran this at 25p.  Very good keying results until we do subject movement then we do not like what happens.  Staccato quality of movement and on reversing direction subject heads seem to have a ghost image that shows up by lagging a little behind the main image.  We ran trials at shutter speeds of 1/50sec and 1/250sec following some theory that 1/250 would be good but we can see no significant difference.  Our all-green-screen short film "Laputa" shot with an HV20 is now online at:

Canon HF R20 - amazingly good camera for its low price of USD 280.  We tried 24p, 30p and 60i frame rates.  30p was best with 24p a close second - both were good for keying but some of our viewers did not like the subject movement especially motion blur on human subjects.  Best keying with "cine" setting.  Could be used for a green screen epic which is low on subject movement - and that may be the case with our possible literature-based drama.

What others are saying about green screen work - with my personal comments

"Compression is bad - you need very high bit rate technology" - eg Blackmagic HDMI capture, Panasonic GH3.  I disagree on this and I suggest that the AVCHD-2 standard of 60p at 28 Mbps is a viable, low cost accessible way to go. 
Argument from theory - AVCHD temporal compression works by recycling non-moving background elements and is going to work at its best efficiency with a simple background ie a green screen. 
Argument from experiment - with the Canon HF R20 we have done trials at bit rates of 5Mbps and 24Mbps and 5Mbps looks remarkably good and not much different to 24 Mbps.

"Cine setting is good" - Agree

"Use 'hard colour' setting in Keylight rather than the default 'soft colour' setting" - Agree, has made a good improvement to our trials and also in re-working some older shorts.  Thanks to the Dastoli Brothers website for this advice.

So the continuing question of what camera?

Top of the desirable list is the soon to be released Panasonic GH3.  Testing website names this in their 2012 awards article as the best system camera for video.  Too expensive for us and we will need to go more modest for our quickie experimental feature.  Top priorities for our spending are likely to be food and transportation.   Maybe we can find someone who has bought this or similar to join the co-op as guest camera operator even for some of the shooting?  We have done this kind of thing before! 

Candidates are 1080p60 capable cameras and we would like to go digital large sensor lens-interchangable.  Some models we are investigating are:

Panasonic G5 - Some impressive sample videos on Youtube but conflicting opinions expressed on the web about possible limitation of manual control of settings for video.  Trying to find out more.

Sony NEX-5N, Sony A-57 - Mostly good reviews but with some warnings about "moire" effect and I have seen this in sample videos on Youtube eg when tiled roofs get into shot.  Trying to find out more.  Maybe a green screen production is less likely to hit moire situations than shooting in the wider world?

Interesting Web links:

"Dastoli Digital - Simple Tricks and Nonsense"

"Sony NEX-5R vs Panasonic G5: Four Reasons to Buy the Sony NEX-5R OVER the Panasonic G5"

Sony Alpha NEX-5N Review with lab testing including video capabilities testing.

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