Stop obsessing about camera specs!

Dear aspiring filmmaker, here’s a tip to avoid being lost forever in the ocean of mediocrity that swallows 99.99% of you.

Stop obsessing about camera specs, in fact, forget about the damn camera and learn to craft a story, learn to write, learn to direct, find your voice. Your camera is a tiny, forever changing spec of insignificance.

If you want to be a cinematographer, again, forget about the camera and learn to light, compose and frame, learn about the subtlety of the visual language, emotion, movement. Shoot stills everywhere you can, become an excellent photographer, practice with your iphone if that’s all you’ve got, it will teach you a ton about balance and composition, light and shadow.

Download a good light meter app on your phone if you don’t have a proper light meter and play with it, understand contrast and lighting ratio.

The camera you have, no matter how high the dynamic range or ISO, will not make you a better filmmaker or cinematographer.

For the low-light obsessed, a real cinematographer doesn’t shoot at ISO 6400, they light everything carefully and intentionally, that’s the art. ISO 400 is plenty, you need to learn how to use and craft light, those skills are rare and getting rarer every day.

Your camera will not set you apart. Everybody has a good camera now and they cost almost nothing.

Possessing and mastering these rare and ever-diminishing skills are what will put you in the top because these skills are the secret behind the true art of visual storytelling.

Obsessing about camera specs is easy; blaming camera specs for not making up for poor or non-existent skills is easy. Actually learning those skills is difficult and time consuming, requiring patience and humility to learn from others.

Of course I love the cameras, don’t get me wrong, that’s what this blog is all about, and that’s how I make my living, but the camera you buy won’t make you a better storyteller or make up for a lack of lighting or cinematography fundamentals.

Okay that’s enough of that, there’s a new multi cam comparison shootout video on youtube I need to watch :)

“Film Look” – More on Linear / Log Gamma Curves

I’ve written before on this subject here: Demystifying color bit depth, dynamic range and linear/logarithmic scales but here’s a few more notes on light, and log vs linear gamma curves, as it is one of the most important things you can understand in digital cinema acquisition and post, and it can be confusing for the uninitiated.

Why Light is Linear

Basically if you double the energy emitted from a light source, and the distance from that light source stays constant, the light intensity at that point will also double. Easy right?

Why Light is Not Linear – The Inverse Square Rule

Imagine a single light source in a massive dark room. Standing right next to the light, you’ll experience the highest light intensity possible. Moving to the far end of the room, you’ll experience the least intensity in the room, because the light intensity diminishes over distance.

However, it doesn’t diminish linearly as distance increases. If you stand half way between the light source and the far end of the room, the light won’t be half as bright; it will actually be approximately a quarter as intense. The light intensity is inversely proportional to the square of the distance from the light source.

In photography and cinematography brightness or light intensity is often measured in f-stops as it relates to exposure. F-stops are a unit used to quantify ratios of light, or exposure. Each added stop represents an increase in light intensity by a factor of two, each increased stop is a doubling of light intensity, or exposure. A decrease of one stop is a halving of light intensity or exposure.

From Wikipedia:

The f-stop scale is an approximately geometric sequence of numbers that corresponds to the sequence of the powers of the square root of 2:   f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, f/90, f/128, etc.

You don’t need to understand the math, just what it means. So f/2 represents double the light intensity of f/2.8 but half the the light intensity of f/1.4.

Human Perception is Not Linear

This is the real world physics of light. However, our perception of luminance is quite different and that is important when it comes to how we map real world linear luminance values to perceived brightness. We are more sensitive to small changes in luminance at the low end of the scale than the high end.

The Gamma Curve – Linear vs Log

I found the below descriptions from RyanJuckett.com very useful, he’s speaking in the context of color science as it relates to computer graphics and coding for games but it is a good explanation of the gamma curve nonetheless:

The gamma correction curve is used to convert pixel luminance from a linear scale to an exponential scale. When encoding the final pixel value, the curve is used to gamma compress linear luminance to a gamma corrected value. When decoding a pixel value, the inverse curve is used to gamma expand the value back to linear units.

We don’t perceive the luminance of a color on a linear scale, so this gamma compression actually helps us store more useful information in a limited number of bits per pixel. This nonlinear relationship between linear luminance and the perceived brightness of a color (also known as lightness) is shown below.

Linear Luminance

If we were to store image values on a linear scale, single steps in value would correspond to large steps in lightness on the lower end of the scale and minor steps in lightness at the higher end of the scale. As a result, we would lose a lot of lightness fidelity in dark colors.

Now let’s look at luminance using the sRGB gamma corrected curve.

Gamma Luminance

We now get consistent steps of lightness across all values letting us encode lightness with more fidelity across the entire scale. While this image does show linear lightness (human perception), it should be stressed that we are no longer working with linear luminance (physics).

To go through this one more time, lets use 10 bit values as an example; you have 1024 possible values (including 0) to map input luminosity levels to output values from black to white. So your output range is between 0 (black) and 1023 (white).

A normal idealized gamma curve is actually almost a straight line, and this linear mapping will divide values perfectly evenly between 0 and 1023 across the scale of linear luminance, so the mid point of 512 will be exactly half way between black and white, which is 50% grey right?

Wrong. A value of 512 will actually be about 75% grey. There will be far fewer values mapped to the dark end of the scale than the bright end with linear mapped values.

If you have 1023 possible values to map to luminosity levels, it is a waste of valuable data to spread them perfectly evenly because our perception is not linear, we are more sensitive to changes in the shadows and mid-tones than in highlights.

A logarithmic gamma curve also serves to better assign data to expanded highlight information from high dynamic range imaging sensors.

This is why a log image viewed without gamma correction will look very flat and washed out.

In the context of the Blackmagic cameras “Film” and “Video” modes, simply put, “Video” mode applies a more linear gamma curve to the image and “Film” mode applies a logarithmic gamma curve preserving the shadows and midtones and expanding the highlights.

Video example

Above, a more linear gamma curve. Video mode.

RAW exampleAbove, a log gamma curve (without gamma correction). Film mode.

I highly recommend reading Understanding Gamma, CineGamma, HyperGamma and S-Log by Alistair Chapman on dvinfo.net

Pimp Your Pocket Cinema Camera – Pt 3 – Canon EF SpeedBooster!

Following on from the last of my Pocket Cinema Camera posts (Pimp Your BMD Pocket Cinema Camera – Pt 2 – Super 35mm in Your Pocket!) where I introduced the Metabones Nikon G to BMPCC SpeedBooster, I now want to introduce the long awaited Canon EF version.

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It’s absolutely brilliant. Everybody needs one of these.

Here’s some test shots showing the huge difference the Metabones SpeedBooster makes to the field of view by reducing the sensor crop factor from 3.02 to 1.75 on the Pocket Cinema Camera. Notice the exposure is also brighter using the Speedbooster. The aperture on the lens was T2.8 and wasn’t changed, so the brighter exposure (technically +1 2/3 stops) is from the Speedbooster only.

NOTE: The Metabones SpeedBooster BMPCC – Canon EF adaptor does not work with Canon EF-S lenses, only EF lenses. It does however provide electronic aperture control from the camera to Canon EF lenses.

Below: Without SpeedBooster – using Redrock Micro Livelens MFT to EF adaptor. Lens is a Samyang 24mm at T2.8, 400ASA on Pocket Cinema Camera.

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Below: with Metabones SpeedBooster BMPCC – Canon EF – Lens is the same Samyang 24mm at T2.8, 400ASA on Pocket Cinema Camera.Metabone_Speedbooster_CanonEF

 

The subject for these test shots by the way is the lovely Avid S6 Control Surface which just happened to be laying around :P

Check out the previous posts:

Pimp Your Pocket Cinema Camera – Pt1 – Power in Your Pocket!
Pimp Your Pocket Cinema Camera – Pt2 – Super 35mm in Your Pocket!

Blackmagic Camera References – Data Rates, Recording Times, Shutter Angle

Below you’ll find some useful references I compiled as part of a larger FAQ reference I am working on for the cameras. I have not listed data rates for all the frame rates, just for 25fps to give a rough idea.

Data Rates – Comparative data rates for Prores are given below. (Mb = Megabit, not Megabyte (MB)… there are 8 bits in a byte, so divide these numbers by 8 if you want MB/sec)

1920 x 1080 @25fps 3840 x 2160 @25fps
ProRes 422 HQ 184Mb/sec 737Mb/sec
ProRes 422 122Mb/sec 492Mb/sec
ProRes 422 LT 85Mb/sec 342Mb/sec
ProRes 422 Proxy 38Mb/sec 151Mb/sec 

Recording Times – Below you can find recording times for each camera and format.

For the Cinema Camera:
–       480 GB SSD, recording RAW = approximately 65 minutes
–       480 GB SSD, recording ProRes 422 HQ = approximately 5.9 hours
–       480 GB SSD, recording ProRes 422 = approximately 9 hours
–       480 GB SSD, recording ProRes 422 LT = approximately 12.8 hours
–       480 GB SSD, recording ProRes 422 Proxy = approximately 28.8 hours

For the Production Camera 4K:
–       480 GB SSD, recording CinemaDNG RAW = approximately 35 minutes
–       480 GB SSD, recording ProRes 422 HQ = approximately 89 minutes
–       480 GB SSD, recording ProRes 422 = approximately 2.2 hours
–       480 GB SSD, recording ProRes 422 LT = approximately 3.2 hours
–       480 GB SSD, recording ProRes 422 Proxy = approximately 7.2 hours

For the Pocket Cinema Camera:
–       64 GB card, recording RAW = approximately 15 minutes
–       64 GB card, recording ProRes 422 HQ = approximately 35-40 minutes
–       64 GB card, recording ProRes 422 = approximately 70 minutes
–       64 GB card, recording ProRes 422 LT = approximately 1.7 hours
–       64 GB card, recording ProRes 422 Proxy = approximately 3.3 hours

Native ISO – Below you can find the native ISO for each camera.

Pocket Cinema Camera – ISO 800
Cinema Camera – ISO 800
Production Camera 4K – ISO 400

Shutter Angle to Shutter Speed Conversion – Below you can find the shutter speed in 1/x sec. For example… 25 frames per second (fps) on 180 degree shutter angle = 1/50th sec shutter speed.

Shutter Speed (1/x sec) at the below frame rates (fps)
Shutter Angle (Degrees) 23.98fps 24fps 25fps 29.97fps 30fps
45 191.84 192 200 239.76 240
90 95.92 96 100 119.88 120
108 79.93 80 83.33 99.90 100
144 59.95 60 62.50 74.93 75
172.8 49.96 50 52.08 62.44 62.50
180 47.96 48 50 59.94 60
216 39.97 40 41.67 49.95 50
270 31.97 32 33.30 39.96 40
324 26.64 26.67 27.78 33.30 33.33
360 23.98 24 25 29.97 30

 

Unboxing the Blackmagic Studio Camera

Today was unboxing day and since yesterday’s post had no images, I thought I’d share these with you today.

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Very impressed with the finish and build quality, the body is die-cast magnesium alloy and is really almost feather light. The four pin XLR power is a great move on this camera but what blows me away is a studio camera with fiber connectivity at this price point. It’s just nuts.

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Look! XLR’s! :D

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Big backlit buttons for key functions and menu navigation.

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Not at all a studio lens, but to throw a image on the sensor the Voightlander Nokton 25mm f/0.95 was what I had laying around. I look forward to testing with an active Panasonic Lumix zoom lens also.

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The 10″ full HD viewfinder is very crisp and clear, very bright. After seeing it I actually wish the Cinema Camera had this screen, even if it meant a bigger body… well, URSA does! It is very reflective though which may bother some users.

So far, very impressed with this camera. I think we will see much more coming for this camera in the months ahead, including possibly a viable powered and active B4 adaptor. MTF Services already make a powered B4 to Sony EX3 adaptor, as well as a B4 to MFT adaptor for super 16mm sensors. I wonder what it would take to combine the two. Such a solution would take this camera to a whole new level with real support for ENG zoom lenses and remote control.

More to come! Watch this space!

Blackmagic Design – Rebels with a Cause

Today the first Blackmagic Studio Cameras landed in Dubai. In my research leading up to this day, and the inevitable need to support and answer a ton of pre-sales questions about this new animal, I’ve discovered a few important “limitations” with the much anticipated Blackmagic Studio Camera.

Whether these “limitations” are perceived or real is the question that is really on my mind. I believe Blackmagic are breaking new ground here and that will always be met with resistance from the guardians and defenders of the established norms.

This is a camera that is not likely to please everyone in the professional broadcast and studio establishment, but may appeal to new and open-minded low budget users crossing over that are willing to overlook a few things, or more likely than not won’t miss them in the first place.

1. The only way to mount a proper ENG zoom lens is with a dumb MFT to B4 adaptor. That means no remote lens control is possible through the camera. Full stop.

Due to the sensor size being larger than that of a 2/3” broadcast camera sensor, only ENG zoom lenses with a 2x extender engaged can be used. This has always been the case, as with the Cinema Camera and a MFT to B4 adaptor, but I don’t consider this a problem necessarily, it’s just a fact.

Remote color balancing and adjustment is of course still possible through the ATEM, just no remote iris / zoom / focus control with a ENG lens.

For many established studios wishing to use a Blackmagic Studio Camera / ATEM combination with professional ENG zoom lenses to replace their current setup, this lack of remote lens control will be a complete deal breaker.

2. So it seems that if full remote lens control is desired, only an active MFT lens with servo zoom will work. That’s basically only one lens. The Panasonic LUMIX® G X VARIO PZ 45-175mm / F4.0-5.6 ASPH. However I don’t think it is a perfectly parfocal lens (able to maintain focus throughout zoom range) although if you know better, please correct me if I’m wrong, and it is not constant aperture. http://shop.panasonic.com/shop/model/H-PS45175K

The hardened old-school professionals who haven’t switched off at point 1, will have left the room whispering (or shouting) four letter expletives at point 2.

I just don’t think those people are the intended target market.

3. Apparently the “interlaced” outputs are not really interlaced but somehow pseudo interlaced from an internally progressive source. Now I haven’t had a chance to look into this yet and am happy to be wrong, but it would make sense seeing as the read-out from the sensor is most likely progressive as with all the other Blackmagic cameras. I anticipate this may be problematic for some expecting a true interlaced output. I don’t know whether this is technically then PsF (Progressive Segmented Frame) or what.

4. The software color and camera control will not be familiar for anyone used to hardware CCU controls. God forbid anyone try anything new.

Therefore my initial thoughts are that this was never intended to be a replacement solution for the established broadcast market. It’s a new system, a new way of running a multi-cam live production and a extremely cost effective entry point for a brand new market.

Some accuse Blackmagic of completely ignoring the established existing requirements of studio production, arguing that if they hadn’t they would have made a Studio Camera with a 2/3” sensor, B4 mount and lens control… which they did… the URSA Broadcast Camera. However I don’t believe this is the case. I see a lot of innovation here and in my opinion they are going after a less experienced, new market of crossover DSLR shooters and cinematographers that are happy to control their own lens at the camera, and were simply wishing for a way to feed multiple sources to a switcher and color balance multiple cameras centrally. That makes sense to me and for that Blackmagic have provided a excellent beginning to end solution at a ridiculously affordable price.

I’m not sure they ever intended to make the ENG purists happy with the Studio Camera… Blackmagic are doing something new here, and I see a deepening blend between EFP / Cinema and ENG / live production.

Pimp Your BMD Pocket Cinema Camera – Pt 2 – Super 35mm in Your Pocket!

In my previous post last week I set out to introduce you to the minimalist approach to equipping the Blackmagic Pocket Cinema Camera for shooting from the hip in any situation as quickly as you can grab your camera, frame your shot and hit record.

Many would love it if Blackmagic had shoehorned a larger super 35mm sensor into the pocket camera, but for whatever reasons they didn’t, and it’s a lovely super 16mm format camera. No amount of wishing can change that fact. However, for those intending to shoot with 35mm format lenses and for lovers of the 35mm ultra shallow depth of field that is considered de-facto standard for any respectable digital cinema camera, Metabones has come to your rescue with the latest Speedbooster for Nikon F lenses.

Metabones have released two versions each with optics tailored to reduce the sensor crop as much as possible for the BMC and BMPCC respectively. By optically reducing the image circle of the larger 35mm format lens to better match the smaller sensor, the light is also intensified giving you 1 2/3 extra stops (on the BMPCC version) on any given lens.

This actually turns the pocket camera’s smaller sensor from what some might consider a disadvantage into a huge advantage over full frame cinema cameras in that you’ve got more than a stop and a half brighter exposure plus a 35mm aesthetic which is closer to the un-cropped field of view using 35mm lenses.

So the BMD Pocket Cinema Camera with the Metabones Speedbooster – BMPCC Version gives you the smallest (close-to) 35mm digital cinema camera solution available. The adaptor reduces sensor crop factor from 2.88x to 1.75x and makes any lens 0.58x wider. A 50mm f/1.2 becomes a 29mm f/0.74!

This can get confusing. To put this back into terms of 35mm equivalency… a straight-up Nikon F to MFT lens mount adaptor with no reduction in sensor crop will mean a 50mm lens with the BMPCC’s 2.88x sensor crop gives you the equivalent field of view of 144mm in the full frame 35mm sensor world. With the BMPCC Speedbooster, the crop factor reduces to 1.75x so your 50mm lens looks like what you’d expect of a 87.5mm on a full frame camera… or from a 29mm lens on a straight mount adaptor… only 1 2/3 stops faster :) Got it? Good!

F0.74 – The new Metabones Speed Booster – BMCC & BMPCC versions from Andrew Reid on Vimeo.