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The Panasonic GH4: An Analysis (Part 1 of 2)

DSLR enthusiasts and 4K adopters alike have all been talking nonstop about the new Panasonic GH4; the tiny camera that can do 4K internally, high speeds up to 96fps, and some very high bit rates. Panasonic has taken the queues from its users who have in the past hacked and modded the GH series cameras to suit their needs. The GH4 does everything they’ve asked for, and Panasonic has come out strong with a very interesting 4K camera – but how does it perform in the real world? Size The GH4 is small. Real small. As you can see in the photo above, even with some rigging it maintains a small profile. Compared to the Canon 5D Mark III at around 2lbs, the GH4 squeaks in at a svelte 1.2lbs. The additional YAGH bottom unit will add a bit of heft to the camera, but at the end of the day it is one of the smaller DSLR’s out there. This can be a good or bad thing, all depending on your situation. For me, the flip out screen and small form factor are fantastic for run and gun situations, specifically in crowded areas or in public. It’s small and lightweight, but packs a punch with its recording quality. The small size will lend itself nicely to stabilizers of all types – including the new Movi M5 (available to buy or rent here at Rule!). Imager and Recording The GH4 is another camera in a long line of Micro Four Thirds (MFT) size sensors. MFT is an interesting sensor size. Compared to the Full Frame Canon DSLRs, the crop factor can be intimidating (2.1x, thereabouts). Those of us familiar with shooting with the Blackmagic Cinema Cameras won’t be too surprised, but it can be a shock to some. When using S35 glass, like our beautiful Zeiss Super Speeds, the crop shrinks down to a manageable 1.4x – making the field of view on a 50mm look more like the field of view of a 70mm. Something shooters of the C100, C300 and other APS-C canon cameras will be very familiar with. Aside from the crop, the image produced by the GH4 is impressive. It’s no low-light monster like the Canon 1DC – I don’t find ISO values higher than 1600 usable without heavy noise reduction and post work, compared to the 10,000 ISO on the 1DC that I’ve filmed with comfortably in the past. I find the standard ISO 800 values to be pleasing, but find that the shadows can still present some blocky looking noise artifacts. This can usually be graded out easily, but it’s important to remember that this isn’t a 1DC, and you’re going to have to take care when shooting dim scenes. The GH4 does not have an official “Log” setting, as the 1DC does – but I find one can get very close when using the Cinelike D profile. I’ve altered my settings slightly to present a slightly more flat and dynamic range friendly profile. By lowering the in camera noise reduction, sharpening, and saturation, I find you can squeeze a bit more information into the recording. I also use the master pedestal setting to raise the blacks up (+15 in camera menu). I find this to be very near to a proper log setting. In DaVinci Resolve, using the Arri Alexa LUTs shows just how close it can be – though you should bump the saturation down a bit more before applying. Below is a very quick test I did here at the Rule office. Shot in very bright mid-day sunlight, I tried to see how well the camera would capture detail and dynamic range. You can see it holds up well. The camera loves daylight, far more than tungsten. Though the 4K is only recorded at a variable bitrate, maxing at 100Mbps, it seems to handle detail and movement well. It is able to capture the bright blue sky, as well as plenty of shadow detail. It’s not RAW, like the Blackmagic counterparts, but you can record around 80 minutes of 4K video on a 64GB card – compared to the Blackmagic Pocket Camera that can give you around 20-30 minutes of Prores, or 15 or so minutes of RAW 1080p. Puts it all into perspective, doesn’t it? Click here for “Panasonic GH4: First Tests” on Vimeo. The GH4 is also capable of outputting a 10bit 4:2:2 signal via HDMI. This disables the internal recording, but allows for very high quality Prores recordings with the Odyssey 7Q. While it can be a bit of a runaround getting from Micro-HDMI to Mini-HDMI, the image quality is striking. The Odyssey 7Q’s monitor is also a miracle when shooting, and a welcomed respite from using the small 3” flip out LCD screen. The added focus peaking, zebra, and histogram functions also make shooting life easier. The GH4 does internally offer peaking, zebra, and histogram – but none perform quite as nicely as that of the 7Q. Stay tuned for a follow up blog post with some more footage and examples, as well as the GH4 Learning Lab I’ll be presenting June 25th here at Rule Boston Camera! Alex Enman, Engineer, enman@rule.com

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Production LEDs in a New Light with Zylight’s F8

UPDATE ON 5/12/14:  Since my original post below, I’ve learned that the F8’s bellows are actually made from silicone which should last significantly longer than rubber and that a redesigned yoke was already shown at NAB.  Zylight’s on the ball! We’ve all heard about the merits of LED lighting (low power draw, low heat, no bulb changing, etc.), but for the reality of production work, there were always major trade-offs. The throw of an LED light was useless unless you were right up on the talent, their color rendition was poor and their tell-tale multi-shadows were garbage.  LEDs were rightly relegated to being just an easy fill option or kick light.  Even their flicker free qualities were limited by their low output which is not what you need for high frame rate shooting.  Despite a larger power draw and the heat, you were always better off using tungsten or HMI. Zylight’s F8, though, finally spoils us. This is a focusable fresnel LED fixture (70° flood and 16° spot) that is lightweight, can be powered for over an hour with a standard camera battery, and has the equivalent throw of a traditional 650w tungsten head. I had to break out a light meter to see the proof in lux for myself.  Not to be overlooked is the distinct, single shadow you get from this instrument. You can order the F8 as 5600K or 3200K.

Admittedly, the F8 is a little pricey at $2,400.00 but remember that tungsten replacement bulbs aren’t cheap and neither is your electric bill if you have a studio.  The fact that you can just slap a dionic on the back and you’re good to go anywhere is amazing.  Save yourself from that heavy sack pack of stingers and dimmers.  I appreciate the retracting bellows design that squeezes this unit down to just a few inches thick.  The bellows are rubber, though, so there is the concern of hardening and cracks over time.  The yoke definitely needs a redesign.  Rosettes are for tripods and handles, not lights.  Having two separate rosette mounts to deal with every time you need to make adjustments is annoying.  Flicker free dimming from 0-100% from a small knob in the back or through DMX is a nice feature.  Zylight is very proud of their “Zylink” wireless control control capability but in practice, I could take or leave that feature.  I noticed a USB 3.0 port behind the fresnel lens so who knows what else is to come through firmware.  All things considered, the F8 is already a staple in our lighting inventory here at Rule and once you try it, you’ll be asking for it again and again.

– Jason Potz, Engineering, j.potz@rule.com