{ illuma·blogspot·com }

Sunday, May 24, 2015

••◊ How To Setup A Lavaliere Microphone

My friend Tommy inspired me to make a tutorial for Video Gear on how to setup a lav mic after he started talking about buying his own audio package.  You know the old saying about "necessity is the mother of all invention.?"  Tommy is s corporate shooter and I knew it was either making a tutorial for Video Gear or taking a call mid-day at work with a last minute panic in his voice as he wonders if he can save the audio from his last gig.  So thanks for the inspiration Tommy.  We tried to keep to the 3 minute format, but this one runs a bit long at 5 minutes just because of so many details you need to know how to get right before pressing record.

Tuesday, May 19, 2015

••◊ Using S-log3 with the Sony FS-7

This last Thursday I received a call from the rental shop I do video blog work for.  Dominique tells me that the brand new FS-7 is suddenly free Saturday and I can shoot with it.  Woohoo!  Breaking in a new camera is a challenge that I readily accept.  The problem is that I get to spend zero time with the camera before the shoot.  So that night I read through (the important parts) of the user manual and study up online.  Lucky for me, there's lots of great user advice out there.

Then in the middle of the night (yes, I know that's weird...I'm a camera guy) I get the idea that I should try out S-log3.  I'm not really a log shooter for blog videos.  I'd rather just shoot with the final look baked in for these short projects that go straight to Vimeo/YouTube.  However, S-log3 is it's own work flow and I figured I'd better learn it sometime.  This was going to be a glorious success or an absolute A-bomb disaster.  What the hell...you only live once.  What could go wrong?

So I got to the shop about 10am on Saturday and had about 30 minutes to do camera prep, which involved setting at least 20 parameters in the camera.  I'm trying to read the PDF of the manual and figure out the menu system at the same time.  Cameras pretty much all do the same fundamental stuff.  It's usually a case of where did the engineers hide it?!

The first problem I needed to resolve is with exposure.  The battery on my Sekonic meter died the morning of the shoot, however I had a DSC ChromaMatch Lt. chart that the kind folks at DSC gave to me during NAB.  As far as I can tell, the chart has an 18% neutral gray background.  S-log3 needs middle gray be exposed at 41 IRE for proper exposure.  So I was in luck.  You can't exposure S-log3 by eye since it will look too dark while recording in camera - see the picture below.  Even while using the rec.709 monitor LUT, the exposure was a bit touchy for "eyeballing-it."  On the Atomos Samurai I had connected I looked at the gray surround and exposed it at exactly 41 IRE using their luma scope.  In the second picture below I cropped the first picture to just the right edge of the card so you can clearly see the exposure level.  The other advantage I had here is that the card has a number of neutral patches, any of which could act as a white balance reference in post.

This brings me to my second point...In S-log3 you only get three white balances: 5600K, 3200K, and 4300K (I think).  So if you need another white balance for a tricky lighting situation or effect, then you'll need to take a few seconds of video with a white balance chart.  The plasma lights I was using were pretty close to 5600K and a good CRI rating, so I chose 5600K and didn't have to do any re-balancing in post.  Even when I tried to white balance using the DSC chart in post, the color wheel barely moved - not enough to bother.

What I still don't completely understand are the SGamut3 and SGamut3.Cine color gamuts.  Did I mention that I only got 30 minutes of camera prep?  Sony has an excellent tutorial posted on their web site.  Essentially SGamut3 is a super wide gamut meant for ultra-HD TV (i.e. UHD rec.2020), and ACES work flows.  SGamut3.Cine is meant for film print emulation and DCI-P3 work flows.  Which works better for rec.709/sRGB displays?  I'm not that far yet.  Sony says they have a .cube file to convert SGamut3.Cine to 709, so that might be the way to go until I learn more.  The Sony Community Forum posts also suggest this from a few users.

So...how about the color grade.  Well, let me tell you - it's a whole different world having a professional 10-bit codec.  No more suffering the limitations of 8-bit banding and artifacts.  You don't have to be gentle during color correction.  The first picture below is of the uncorrected image.  In the second picture I started by raising the recorded middle gray (41 IRE) to 55 IRE for rec.709/sRGB displays,  then I applied the toe and knee to the curve to add back in highlights and shadows.  The third picture below shows that I added about 40% saturation to the image, which is what Sony seems to recommend for S-Gamut3.Cine.  This make the skin tones about perfect for Dominique.


You can use S-log3 in "Custom" or "Cine EI" modes on the Sony FS-7.  In custom mode you can tweak the image parameters, but in Cine EI mode the list of parameters you can change decreases, more like a film stock.  Most notably, in Cine EI mode there is no in-camera noise reduction.  For those used to standard video cameras that do noise reduction, having no noise reduction by default can be a bit discerning at first.  Cine-EI is meant for people that will have a definite post production work flow and treats the image more like a digital negative than image processed video.

One thing I noticed is very slight red noise in Dominique's black shirt.  However the noise was so minor that it didn't really warrant any post noise reduction.  Members of the Sony Community forms suggested that you're OK up to about ISO4000 with noise, but until I can test it for myself I won't know for certain.  If you can't see it in the picture below, then it's probably not going to be an issue.  Other members suggested recording at a lower ISO sensitivity to reduce noise further.  At a native ISO of ISO2000 there's certainly room to do so.

Which brings me to my last topic: ISO sensitivity in Cine-EI mode.  By design, S-log3 has six stops above middle gray when you use the native ISO rating.  If you reduce the ISO sensitivity in Cine-EI mode you lose 1 stop of highlight range for every 1 stop decrease in sensitivity.  For instance, if you were wanting to record at ISO1000 to reduce noise in a dark scene you would only have five stops of highlight range.  Conversely, if you increased the sensitivity to ISO4000 you would have seven stops of highlight range, but a hella-ND filter to put in the matte box! 

The sensitivity in Cine-EI mode is just like push and pull processing with film.  The digital negative has a set sensitivity that does not change in Cine-EI mode; in this case ISO2000.  If you set the ISO setting one stop lower in Cine-EI mode (i.e. ISO1000) and expose properly for that, your digital negative will be one stop over-exposed and you'll have to effectively do pull processing in post production.  The good thing about this feature with a digital camera is that the monitors can be compensated look like the ISO sensitivity you choose, which gives you immediate feedback on what you're about to record.  Also, in Cine-EI your dynamic range doesn't change.  It's always 14-stops with S-log3.  You only trade off highlights for shadows and vice versa if you diverge from the camera's native ISO2000.

I personally found that the full six stops of highlight range was more than enough.  When I viewed the white walls at the left of the frame with a rec.709 monitor LUT I was worried that they were going to be greatly over-exposed - and even went to the extent of flagging some light off of them.  However, when I got in post I saw that the walls were nowhere near over-exposed - not even close to nowhere near.

It's been a wonderful camera so far and I look forward to using it again.  Now if only I could afford one!

Sunday, April 26, 2015

••◊ Lavaliere Versus Shotgun Microphones

A colleague and I were talking about the what should go in his production kit next.  He suggested a Sennheiser 416 shotgun microphone, to which I replied that he should really get a wireless lav kit.  The reason being is that he's a one man band corporate video guy and doesn't have a sound mixer with him.  Shotgun mics really need to be used in an echo-free environment with the little or no background noise.  A lavalier microphone isolates a speaker from the background and doesn't require a sound mixer to follow the speaker with the boom pole.
Two weeks ago I was at NAB and recorded a number of interviews for Video Gear.  I had my friend's suggested combo: Channel 1 = lav, Channel 2 = shotgun microphone thinking the same thing he was.  I would try to use the shotgun a backup if something went wrong with the lav, because wireless audio isn't perfect either.  Below is a short video with the results


As you can hear, the shotgun microphone audio was pretty much worthless at 6 feet from the subject.  Now this isn't to say that a shotgun microphone is worthless.  It just says that there are optimal tools for different situations.  If I would have had a sound mixer with a boom pole we could have gotten really good results by placing the shotgun microphone much closer.  The lavaliere microphone already has this advantage because it's pinned to his collar.

My guess is that my friend will pickup a used wireless lav kit off Ebay and be much better off. 

Friday, April 17, 2015

••◊ The Color Rendering Index and Video Lights

There seems to be a lot of confusion about what lights actually produce good color now days, along with a lot of marketing un-"truthiness" from vendors.  So Dom and I set out to make a video that talks about how video lights actually render color with supporting measurements.  The color rendering index is really a comparison between how colors are rendered by natural sources versus the video light.  We could have gone into black body radiators and Planckian Locus, but I think that would have muddied our intent. 

There is one huge caveat to making a video like this: You can't assume that a certain technology always performs good or bad.  For instance, we measured Fiilex LED lights and they consistently have good color rendering, in measurement and real world use (yes, we actually use them too).  I would personally trust them to produce nice color on camera in most situations.  Another un-named brand of LED light that's in the shop has horrible color rendering and I wouldn't use it if someone held a gun to my head.  I would advise you to do your own evaluation before trusting the marketing numbers.  However, some vendors are very truthful.  Using a C-700 spectrometer I had on loan from Sekonic, we measured great performance on the Cineo TruColor HS at NAB earlier this week and it measured exactly as the vendor stated.  The point of all this is don't make assumptions based on one brand.  We didn't intend the video to make that statement.

I also made this video because I certain number of my friends don't understand why video lights cost any more than hardware store bulbs...then they wonder why they have to constantly tweak color in post to make it look "good enough."  The video delves into that too.  Needless to say, when it comes to LED and fluorescent lights, my advice is to stick to the professional products. 

Sunday, April 12, 2015

••◊ Video Lighting Diffusion Tutorial

I've been meaning to post this for a while now, but I've been lazy/too busy.  Dom and I produced a video showing the various attributes of video lighting diffusion.  I hope you find this useful.  It seems to be one of our more popular videos.

Monday, March 23, 2015

••◊ Review of the Sekonic C-700 Spectrometer

Sekonic sent me a demo unit of the new C-700 Spectrometer.  This meter is meant to help cinematographers, photographers, and gaffers understand where lighting issues occur and help correct them.  What it doesn't do is act as a scientific development tool with download-able spectrum spreadsheets and CIExyz plots, which is more a task for the UPRTek MK350N.  That said, what the Sekonic meter does it does much better than any other color meter tool I've seen before.

The meter is laid out like you would expect from a Sekonic product with the rotating integrating sphere at the top of the unit.  Like their new exposure meters the C-700 features a touch screen that will feel familiar to anyone with a smart phone.  On the left side of the unit there are two buttons: On and Memory.  To turn off the meter you have to press the On button for more than one second.  The memory button can save a measurement to a named file if you press it directly after taking a measurement.  This allows you to save the measurement data to a PC later via the C-700 Utility software.

As with any of the Sekonic meters, the measurement button is on the right side; appropriate for right-hander's thumbs. (second picture below)

As you may notice in the third picture below, the integrating sphere has three click-stop settings: dark calibration (bottom), ambient light (middle), and bright light/flash (top).  When you turn on the meter it has to be set in the dark calibration click stop so the meter can calibrate.  In most cases you'll use the ambient light setting when taking measurements.  If you use the bright setting with video lights it will take significantly longer to do the measurement.  The bright setting is mainly for flash photography.

Speaking of flash photography, there are two ports on the bottom of the unit.  The PC sync port can be used to take measurements with photographic flashes and the USB port is used to connect to a PC and download spectral measurements, perform firmware updates, and change meter settings.

The "hidden" black button at the bottom front of the unit is the home button, just like on a smart phone.

There is a wide range of lighting analysis tools built into the C-700 with the main focus being to help you diagnose color problems and correct them.  I didn't show the home screen below, but you'll be able to access any of these tools by tapping on the appropriate icon on the home screen.  The icon is shown the upper right corner of each of the tools.

In the first picture below you'll see a text analysis of the light.  Here I measured a light that measured a CCT of 3247K, 121 foot-candles, and a color rendering average of 95.8.  This was measured from late day golden sun entering my living room window.

In the second picture below from the spectrum analysis tool you see most of the same data, but with the spectrum plotted.  This can tell you about any problems due to missing parts of the spectrum, as common with fluorescent and LED lights.

The third picture shows how you can actually compare spectrums from a previously saved measurement.  So if you really want to fine tune a gel or match light intensity you can with this tool.

The fourth picture below shows the color rendering rating of 15 colors.  This measurement is generally associated with a CRI rating for the light.  Because this graph shows the rendering rating of each of the colors it's easy to spot problems with the color rendering of a light fixture.  We'll see an example of that later in this article.

As I mentioned previously, the real power of this meter is the ability to find and correct lighting problems.  The fifth and sixth picture below show the tools for adding a camera filter or lighting filter, respectively.  In the camera filter correction tool you can see that the light is measuring 3247K and I input a target color temperature of 5000K.  The meter is recommending that I use a Lee 80C and 82A camera correction filters to get the color temperature back to 5000K in the camera.  This would have been a more common method in the days of shooting actual film that is only available in "tungsten" or "daylight" balance. 

Likewise, in the lighting filter tool I measured a CCT of 5548K and set a target CCT of 3200K.  The tool is recommending that I use a Lee 3/4 CTO to get the light to be 3200K - which makes sense.  No more second guessing or messing around the experimental filter and gel combinations.  That's the huge advantage of this meter over an old fashioned color meter that only gives you CCT and +/-green ratings.

The final picture in this series shows the color shift of the samples relative to the target.  This helps you easily identify green/magenta shifts in the light.  The blue/amber axis basically correlates to the CCT difference, so you get that information from all the tools.  In this example it's saying that the target is much, much more blue (5000K) than the measurement (3247K) and has a magenta bias.


I'm not going to dwell over all the settings since that's essentially a user manual.  There are three pages of settings, but I want to cover the two most basic features.  First, you can change the LCD back light brightness.  Under normal video lighting I found the "Normal" setting to be adequate.  However if you're out in the sun you won't be able to see the display with this setting.  You'll need to use the "Bright" setting.  Obviously you want to keep the back light setting as low as possible.  The meter is powered off of 2 AA batteries.

The second feature is that you can choose between Lee and Fujifilm camera filters when the meter recommends correction filters.  Having this database built into the meter makes the meter far more advanced than other options.

Here's a measurement example from 3pm sun just outside my house.  I had to take a picture of the meter in the shade since the LCD wouldn't photograph well in the sun.  The color temperature of 5700K and Ra of 98 seems about right. 

The three graphs below are all output from the included C-700 Utility software.  The first graph shows that my target (5000K) is more amber than what I measured (5700K) - makes sense.  The next graph shows the actual spectrum of the sunshine.  The last graph shows how well the sun renders all 15 colors in the CRI plus special colors.  A very high quality light indeed!

Here's another example from early afternoon (2pm) shade.  Ambient sky light is very, very blue and in this case it's more than 9000K, but still is able to render colors well with an Ra of 98+.  The second graph below shows again that the target (5000K) is much more amber and slightly more green than the ambient sky light measurement.

In this last example I wanted to show an LED bulb, since using LED lights has been somewhat problematic for cinematographers.  Instead of showing a picture of the meter here I wanted to show a screen shot of the C-700 Utility software while viewing the "text" tab.  The LED bulb in my living room is rated for 3000K and a claimed CRI of 92.  In the Text tab we can see that the CCT is measuring 2983K, which correlates well.  However the Ra rating is about 83, which is more like what I would expect from a cheap LED bulb. 

The first graph shows that with a CCT of 2900K we aren't seeing any significant green or magenta bias, which is surprising given that this is a common problem with cheap LED bulbs.

The spectrum shows this light as a common blue LED with a phosphor coating, just as we would expect.  Notice how cyan and deep red are missing from the spectrum, unlike a real tungsten bulb.

Now this is where things get interesting.  A lot of lighting vendors make claims about the wonderful nature of "their" LED technology (everyone purchases from the same 4-5 companies).  The last graph below shows the individual rendering ratings for each of the 15 colors.  Notice how the red patch is 21.5?  You sure wouldn't want to do any product shots for a red Ferrari under these lights.  The color of the car would be WAY off.  Notice how violet has a rating of 65.2?  That means no photography of Barney dinosaur toys under these lights.  Using this graph alone you can see where color rendering problems are going to occur.  Even with orange at 77.1 you probably wouldn't want to use these lights for a cooking show that involved carrots and oranges.   ...You get the drift.


I'm dreading giving this meter back to Sekonic. It's a good tool to have in my bag for fixing problems.  I'll be directing a video for Video Gear showing the differences in video lights using this meter, so stay tuned for that on their blog.  I hope this overview of features was helpful.  If you have any questions please feel free to leave a comment.

Sunday, March 15, 2015

••◊ Refocus

I've had a lot of foreign experiences lately in film making and this seemed like the appropriate place to share them.  As we all know, Southern California is well known in other parts of the nation for narcissism.  When you get in the groove here you don't notice it as much, because it unfortunately almost becomes a familiar state of being; more so if you're in the film business.

For example, if you tell anyone that's trying to make it in the film/video business you're from San Diego, they won't talk to you.  The reason being is that they can't use you as a connection to forward their career toward greatness.  The person may swear up and down that they'll call you, email you, or whatever...but it will never happen.  You simply aren't someone they can immediately use as a stepping stone into the film business.  I've seen certain filmmakers go as far as putting in big bold letters on their business card, "based in L.A."

The other problematic behavior I commonly encounter is with social media and disingenuous personalities.  It's quite common for people to becomes Facebook friends simply to use as a reference for someone they really want to talk to.  The person may be a smiling, happy friend to your face but they're really thinking how they can get posts about themselves on your Facebook feed so "Producer X" sees it - and, of course, immediately falls in love with them (to quote Mike Myers, "Yeah!  Sure! ...and monkeys might coming flying out of my butt!).  It's like a game of Frogger to try to gather as many high level Facebook friends and social media followers as they can - A game I happily don't participate in.  You know someone is small-time when they still care about such things.

This is the state of being for a large community of insecure people who are still trying to figure out a way to "make it" - whatever that means.  My alternative proposal is to actually do good work.  People love great content.  I see way too may people chasing nepotism when they should be polishing their skills and doing hard work.  Malcolm Gladwell's 10,000 hour rule still applies.

So this led me to some thoughts on how to refocus myself so I don't become one of the dream chasing, fake personality, L.A. Borg.
  • Try to work with people I enjoy spending time with.  These are people I know in real life and I know they have my back when things don't go as planned.
  • Have adventures that I wouldn't normally have if I wasn't a filmmaker.
  • Chase better art.  Concentrate on the skills, craft, and doing good work; work I can be proud of.
...but if that doesn't work out, feel free to still follow my blog.