1.14.2015

I'm always curious to see things with my own eyes instead of taking everything I hear or read as objective truth. There's a lot open to taste and interpretation. Like the noise in a GH4...

A Twilight, Handheld Test Run of The GH4. Shot in 4K, edited in 2k. from Kirk Tuck on Vimeo.

If you want to see this in HD you'll have to click through the link to Vimeo (above). And if you hate gratuitous sound effects you should turn off your speakers....

I bought a GH4 last January and I really like the camera, especially when I am using it as a video camera. I did a hand full of major (for me) video projects last year where we used the GH4 as the primary shooting camera and then used one or two GH3s as b-roll or secondary angle cameras. I mixed lenses between the Panasonic X series and my older, manual focus, high speed Pen FT lenses and in every situation I was very happy with the performance. But I'll be the second one (after my wife) to tell you that I am more of a big picture guy and not so focused on the details.

Most of my use of the cameras was in conjunction with decent lighting. If there's one thing I can do pretty well in video or in regular photography it's to light stuff. So I rarely used the cameras at ISOs higher than 640 (except for some of the restaurant footage for Asti Trattoria which was done at ISO 1600...). All of our paid projects last year were also done in 1080p.

So recently when a good and experienced video shooting friend of mine sat down with me over coffee and exclaimed, "I'm over small sensor video!" I paid attention. I'd lent him the GH4 for several commercial projects and while his clients were always happy with the final footage he frequently alluded to the noise in the mid-tones and shadows. And I'm pretty darn sure that my friend knows his stuff, his resumé includes many projects for large, picky corporations and ad agencies. He was also one of the first people in town to throw down for a Red camera...

But here's the deal; some people really care about shadow and mid tone noise and some don't. It's like a sensitivity to wool sweaters or cheap sunglasses. I'm sure you know two groups of photographers: one group that thinks grain adds a lot to images and another group that sees grain as a major failure. It's the same thing. Given my perspective that a certain intolerance or over-tolerance for noise might be highly subjective I felt duty bound to shoot the camera in a dark set of situations and just see for myself.

I grabbed the GH4 with a Leica 25mm f1.4, a fat memory card and an extra battery and went downtown to shoot some minute's worth and check out the noise for myself. And I set up the camera just the way I thought it should be set up by a typical user. I shot at cinematic 4K which is 24 fps. I set the exposure to manual and set the shutter speed to 1/50th while leaving the aperture wide open (it's not a lens performance test, after all).  I used AWB and I varied the ISO sensitivity from somewhere around 640 all the way up to 3200 over the course of my little experiment. I used the "cine-like D" color profile and just to make it real  I hand held that little sucker (also an experiment to see the effects of coffee on small camera holding technique).

I shot with camera movement and with subject movement. Every scene is a veritable symphony of mixed light. I brought everything back into Final Cut Pro X and did not do any grading or noise reduction or color correction at all. As I cut it together I put in some annoying sound effects so you'll probably want to turn your sound off...

So, what did I find? Hmmm. I can see the noise in the deep blue sky areas and in some of the mid tones but it doesn't bother me at all. The highlights seem clean and clear. I'd use the footage as long as the content was good. If the content isn't there the cleanest file in the universe is pretty much a non-started. My overall thoughts?

If you do good lighting and you get enough level to work at ISO 200-800 you can pretty much use the footage for just about anything. Yes, you might hit the noise reduction a bit and you will want to sharpen but at the lower end of the ISO scale you shouldn't have any issues whatsoever. It may be the downsampling from 4K to 2k that helps but the times I've shot these situations originally in 2K yield pretty much the same results. The camera is quite good and the focus peaking, zebras, potential to use a 200 mbs codec are all nice extras. I won't disagree with my pro video friend, I'll chalk it up to different sensibilities.

I know this is not about still photography but the test was, in fact, part of my overall decision making matrix about gear for the year. The Panasonic wins again---at least in the video category. I'm keeping it!

6 comments:

Anonymous said...

"I can see the noise in the deep blue sky areas and in some of the mid tones but it doesn't bother me at all."

If it bothers the viewer, you've already lost them. They are reaching for the remote, or walking out of the theater. Storey trumps technique, every time.

It's hard to do a test without some help, I'd love to have seen someone, backlit by the car headlights, walk through the pool of light in front of the brick building. The GH4 works for me.

As far as the sound, where was that low budget favorite of the low flying chopper ;)

Anonymous said...

Well one could say forget the social media, ignore the enginerds, and take the GH4 for what it is. Just another dSLR-styled mFT camera with 4K capabilities. No more, no less.

It's got a small-ish sensor with small-ish pixels, so obviously there's a limit to its light gathering capabilities. That doesn't make it totally useless, though. Just like you already know.

Have you watched the review, or in fact a review movie done by Philip Bloom? If not, go and watch it. It's somewhat entertaining and less geeky than many of the so called test videos, and he does touch on the low light and noise issue, too, in a rather practical manner.

"As I cut it together I put in some annoying sound effects so you'll probably want to turn your sound off..."

Sorry, but that sentence doesn't seem to make much sense. Why would you want to deliberately annoy your audience? ;)

You're right, though, the sound effects did feel totally out of place and irrelevant to the footage.
Even though I for one like the sound of the classic aircraft engine. At least within any logical context.

Kirk Tuck said...

i

I didn't add the sounds for the audience. I did it for me.

Anonymous said...

Boy, this was an eye opening experience. In the original video, I was unable to determine what the woman exiting the building was carrying on her back. I thought maybe it was a child. In the Vimeo link is was crystal clear that it was an instrument case.

TMJ said...

For ISO from 640 to 3200 in many very challengingly lit scenes, the GH4 did very well and I was not perturbed by the occasional shadow noise.

But then I am more interested in the story (which is probably why I used to shoot Tri-X/HP5 and uprate them in the film days, just to get the images).

Anonymous said...

"I didn't add the sounds for the audience. I did it for me."

Sure you did, and that's perfectly OK.
It's just that when you upload a clip in Vimeo/YouTube and then publish it on your blog, people naturally assume that you did it for the audience.

Just saying, with a friendly smirk, no big deal.
Fortunately the main point was there and no doubt visible. :)