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Thursday, August 22, 2013

••◊ Visiting the ASC Clubhouse

I foolishly made another death defying trip up Interstate 5 to visit Hollywood today.  The ASC was hosting a talk by cinematographer Dan Mindel.  The ASC club house is just opposite Hollywood and Highland in north Hollywood, which makes for a lively neighborhood.  Usually when I get there in the morning the tourists and tour guides are just starting to wake up.  The Spider-Man/Superman/whatever-man's are just putting on their masks.  In fact, as I was exiting the parking garage stairs I came upon an unmasked Spider-Man...oh no, I now hold his secret identity!

After about 9-10am, the place turns into a nut-so tourist trap with street hustlers busking on every other walk of fame star.  It's like a game of outdoor checkers!  For $20 you can invade the privacy of many of Hollywood's stars through bus tours, walking tours, and street maps.  Alternately, there's Madame Tussaud's wax museum on the corner of Hollywood and Orange.  I'm over the celebrity thing, so in the first few minutes I'm looking for a retreat and a restroom - not necessarily in that order.

Below is a panorama shot of the ASC club house this morning.  This is clearly a welcome oasis from the opposite side of the block.

But...before we get much further, I had an hour to kill so I decided to take some photos of the early morning neighborhood so you can get a feel for the flavor...  Yes Aunt, that Star Trek group impression was just for you.  This picture also relates to the guest speaker I was about to see.




Back to the oasis...  Today's talk was given by Dan Mindel, ASC.  Dan has worked with many well established directors, such as the late Tony Scott, Oliver Stone, and most recently JJ Abrams.  Dan shot MI:3, as well as the last two Star Trek films with JJ.  Beautiful work.  Now for the BIG news.  Dan is scheduled to shoot the next STAR WARS film for JJ!  I was in the presence of greatness!  It was my destiny!  I would scrub toilets to be on that set.

Dan, ever the film guy, proudly announced that he will be shooting on Kodak 5219 film stock and knowing him it will be anamorphic too. 

I heard one great quote from Dan when discussing working with directors who are impatient with lighting a set.  He asks the director, "Do you know the difference between art and pornography?  ...Back lighting."  That usually shuts up the director for a bit.

On "Domino" he and Tony used 35mm film, a 7D, and older-than-the-hills hand crank cameras...Talk about mixed mediums.  I also learned about his use of lens flairs in the Star Trek movie.  They actually rent special Xenon flashlights from Mole-Richardson to ping the lens and create semi-random flares.  Only in Hollywood would high end rental houses have special purpose lens pinging flashlights (I am so out of touch with that world).

The ASC club house contains a number of historical cameras and pictures of an earlier adventurous era in film making.  If you look carefully at the group shot of pictures below you'll see a very young Shirley Temple taking a picture of the director of her film.

Further down there's a picture of the Akeley Audio Camera with the original headphones.  The headphones look like they came from a disassembled 1970's telephone.



Here's Thomas Edison's very early idea of home theater, which looks like a hand crank projector with belt drive.  I'm sure if some hipster technologist sees this there will soon be a kickstarter campaign to develop an updated one so their home theaters can be "different".

Lastly, here's an original Edison Kinetoscope.  Because the picture is a bit small, I'll copy the sign's text here..."The customer dropped a penny in the slot to view fifty feet of film.  Each machine ran a different subject.  The film was photographed at forty frames per second and ran at the same speed."  The machine still works, but now takes $0.05.  That's inflation.

Sunday, August 18, 2013

••◊ C100 AVCHD versus Atomos Samura Prores for Green Screen Work

Scott, Eva, and I went over to Video Gear to do some green screen tests with the C100, the initial results of which are published over on their blog.  Surprisingly I was able to pull a reasonable key with the AVCHD native codec on the C100.  What we initially intended to do was to compare the C100 footage to the Atomos Samurai footage to see the difference between codec quality.  The Atomos Samurai encodes to Prores HQ 4:2:2, which should obviously be "better" for green screen work, but we wanted to find out how much better is "better", really?

To compare the keyed footage I recommend you click on the photo below and view it on a full HD monitor.  The image is 1920x1080.  Immediately I see a difference in Eva's hair flying in the wind.  Notice how the key breaks up just to the right of her neck on the C100 footage?  The left side body outline is a bit less defined on the C100 footage as well.  Is this really a deal breaker?  Dunno.  Depends on who is paying the crew and what they want.

The AVCHD codec is 8-bit 4:2:0 24Mbit/s and the Prores footage is 8-bit (because the camera only outputs 8-bits) 4:2:2 at about 146Mb/s.  The doubling of chroma sub-sampling along with the 6x increase in bit rate should pay off with a better key, and it does.

An issue I ran into, which we are still working on solving is trying to make the Samurai do 3:2 pull down on the Canon's 60i output.  I was working on a production with a Canon rep yesterday and he suggested using 24PF mode in the camera.  There is also some talk of a technique in section 10 of the Atomos manual on how to enable 24p 3:2 pull down from a 60i camera.  I have yet to get this to work, but hopefully we can figure it out by next weekend.

Until then, I recorded the C100 output at 29.97p into the Atomos Samurai.  This means that three of every five frames are encoded properly as 23.976p (24p) frames.  We have to reconstruct that fourth 23.976p frame from two adjacent 29.97p frames using pull down.  For that, I employed After Effects and the "Interpret Footage" menu item - you can Google how to get to it.

I selected 23.976 as the frame rate, clicked on "Guess 3:2 Pulldown" and chose a square pixel aspect ratio.  After Effects was then able to do the final 3:2 pull down and reconstruct the fourth frame from two of the adjacent 29.97p frames.  I obviously want the recorder to do this automatically, so we're still working on making that happen.

Hope this information helps others out there.  If you have any experience with the C100 and Samurai in conjunction with 24p recording I would like to hear about it.  

Monday, August 12, 2013

••◊ Exposure to Foot-Candle Conversion

I saw an interesting formula posted on Roger Deakins' forums yesterday and decided to store it on my blog for future reference.  The formula converts exposure parameters (aperture, ISO, shutter speed) to required foot-candles - a common parameter of professional lighting fixtures.

foot-candles = 25 x (T-stop)^2 / (ISO * shutter time)

So if I'm running at T4, ISO 800, and 1/48th shutter, then I require 25 foot-candles of light to get standard exposure.  For me, this really helps to know which lights I need to drag onto set to get exposure.

Credit goes out to David Mullen, ASC for posting this formula.

Saturday, August 3, 2013

••◊ Photos from the San Diego 48 hour film project screening

No, I didn't participate in the San Diego 48 hour filmmaking contest.  However I did attend their screenings this past Thursday and I wanted to share a few photos from the event.  It's good to support friends and colleagues, especially those who go through the torment of making a complete project in 2 days.  Caffeine, Metallica, nails on a chalkboard, sometimes all three simultaneously...whatever keeps you awake until the final video export!

This event worked out well for me.  I showed up to see Clarence's film and met Jeff from Video Gear out in the lobby after the first screening group.  I didn't have a ticket to the second screening group, but Jeff had an all-event pass since Video Gear is a sponsor.  The night went longer than I expected, but the second set of films were even better (purely by the number of good films). "Van Buren", which was shot exclusively on GoPro cameras, was a favorite.  "Chirp Chirp, Buzz Buzz" was great.  Clarence would have loved "Captain Hand" (Die evil puppets of the world, die!) and "Effective Weapon" (Russian accent - "You Americans die so easily!").  4120 produced the most striking visuals of the night with "Thin Places".  On with the photos... 

Most of the Amalgamated Grommets.  Sorry your head got cut off Bill.  Sometimes you get what you get when you turn around and have 5 seconds to take a photo and the stupid point and shoot camera takes 2 seconds to focus.  The other photo had Elsa's head cut off.
Marianne Bates, writer for the Amalgamated Grommets, and her friends.
Most of the Palomar GC cast and crew, including Clarence mugging for the camera on the far right.

The producer line up after the group E screenings.  Robin, the co-producer, picked the screen grabs - some of which are funny just on their own.
Robin and a puppet from Captain Hand.  The audience went in laughter when the puppet asked Duane (paraphrasing) "why is Robin *still* only your *girlfriend* after five years?"  Oh...the things I could get away with if only I had a puppet.

Duane Trammel - the local 48 hour film project producer doing his duties as host and emcee.

Mike Breuggemeyer, director of the Amalgamated Grommets, being interviewed post screening by Duane and Robin.  His group won their screening class...yes, *again*, but for good reason, with "Inmate 14658".
Jeff Merrill from Video Gear being interviewed by Duane after the group F screenings.

Jeff and his producing partner after the screening.  A screenshot from his film "Busking for Love", staring local musician Gregory Page, can be seen as #6 in the background.