GH1/GH2 extensive tests

Uranium City

Pro Member
indiePRO
Now THIS is how you wring out a new camera, in my opinion. My friend and sometimes-producer/DP Benjamin Karl recently upgraded his arsenal with a Panasonic GH1 and GH2 (he had the GH2 on backorder, even before the tsunami, then got sick of waiting and ordered the GH1 as a stopgap. They both arrived on the same day.) Anyway, instead of going out and shooting video of his dog, he devised four short films based on the works of Shakespeare simply for the sake of testing out his new equipment. Below are the results, including Ben's notes:

https://www.youtube.com/watch?v=4OMNubXBy8
(don't know why the YouTube window is blank; here's the link:http://www.youtube.com/watch?v=-4OMNubXBy8

Settings:

DMC-GH1: ISO 800, 1080i AVCHD, Shutter 1/50, f2.5, Lens Panasonic 14 mm (2x crop factor)

DMC-GH2: ISO 800, 1080i AVCHD, Shutter 1/50, F2.0, Lens Voigtländer 50mm (2x crop) with 1:1 Crop Mode enabled (additional 1.8x crop)

Memory: RAW Class 10 SDHC 16GB

Lighting: 4 candles.

Audio: AT815b Shotgun Microphone connected to an H4N digital audio recorder.

Conclusions:

While both cameras handled admirably under extremely low lighting conditions, the 1:1 Crop Mode on the GH2 introduced a tremendous amount of noise, suggesting that it is an unusable feature in low light.

As a videographer I have been accustomed to 'push-white balance' and found it difficult to achieve in camera. Short of enabling the automatic feature, it has to eye-balled while adjusting the kelvin reading. This seems to be the case with most, if not all, DSLR Hybrid Video Cameras.

Using Apple's Final Cut Studio, I was able to reverse telecine the 1080i AVCHD to 23.97fps Apple Pro Res 422 for a beautiful filmic sense of movement. I used Color simply to push the highlights and crush out blacks, no additional color correction was performed. The footage with the 1:1 Crop Mode suffered a fair amount from pushing the levels, though the footage without the 1:1 Crop Mode stayed crisp even with extreme leveling.

Both lenses were beautiful and I was able to achieve some really nice bokeh without having the depth of field too narrow for ANY movement.

I had no issues with recording time limits, data write speeds or overheating despite leaving the cameras running for long periods while setting up shots and doing multiple takes with the large viewfinder fully lit the entire time (in previous tests with the Canon 5dMkII, I had a number of overheating issues under less taxing conditions).

The big take-away was not to use the 1:1 Crop Mode in low light. Otherwise, both cameras were very user friendly, easy to intermix, and produce a nice filmic image.

https://www.youtube.com/watch?v=5WXGe8h1ygg

Settings:

DMC-GH2: ISO 160, 1080i AVCHD, Shutter 1/50

Lenses: Panasonic 14 mm f2.5, Voigtländer 35 mm f1.4 , Voigtländer 50mm f1.5

Memory: RAW Class 10 SDHC 16GB

Lighting: Natural light only

Audio: AT815b Shotgun Microphone connected to an H4N digital audio recorder

Conclusions:

Having really fast lenses is great (except when you're shooting outside in daylight)! If you're going to use super fast lenses, you just have to get ND filters to shoot outdoors in daylight. We set the ISO as low as the GH2 would go and closed up the lenses as far as we could. After that, we were just careful about what direction we were shooting so as not to get blowout where we didn't want it. On a still camera you can increase the shutter speed to darken things a bit, but when you're shooting a motion picture the result would be the impression of fast movement even though the film is playing back at normal speed (i.e. the opening battle in Gladiator (2000)). Fortunately the day was quite overcast and the deeply muted tones lent themselves nicely to color correction for a colder wetter day than it actually was.

Both the Voigtländer 50mm and Panasonic 14 mm (remember, this translates to 100 mm and 28 mm respectively in 35mm format) performed admirably as usual. Very easy to focus, adjust aperture and so on (though switching m43 adapters gets tiresome and is made more difficult in cold and rainy conditions). The Voigtländer 35 mm is just too difficult to focus, particularly in very bright situations, due to a very limited range of motion on the focus ring. It produces a great picture, but I won't be using it in the wild again.

The extreme small size micro four-thirds format cameras makes them easy to get into super tight spaces, though it can be very jittery looking any time that the camera is physically very close to an onscreen element. The physically further the element is from the camera, the easier it is too avoid that "shake." Interestingly, because the camera itself is so small and weighs next to nothing, I found that by extending the legs of the tripod, closing the center spreader and then holding it from underneath, by the spreader's center fulcrum, created a kind of steadicam effect. The legs counterbalanced the top weight easily and the whole thing is no heavier than just carrying a tripod, so it was easy to execute one handed and generate a nice float without seeing the operator's footfalls.

Audio was a challenge because we had so many natural noises from the birds, the creek, wind and distant sounds of cars or airplanes, but ultimately it worked for the type of story / editing we'd set out to for. At one point, I'm afraid the H4n was dropped and it began to record a sort of high pitched squeal. I was able to isolate the frequency using Apple's Soundtrack and pull it out without noticeably affecting the remaining audio. Similarly, the car sequence needed work to remove the din of the aging engine without loosing the whole bottom end of the actor's voice. Again, Soundtrack gave me the flexibility to isolate a range of frequencies that the actor wasn't using too much and pull them out.



The big take-aways from this shoot were: (1) If you're going to shoot outside, get some ND filters or slower lenses. Fast lenses are fast even at their slowest. (2) Test your equipment thoroughly as soon as you acquire it. The Voigtländer 35 mm is beautiful when it works, but frankly too much of a hassle due to its focus range. I love the other lenses. (3) m43 cameras have tiny bodies, sometime weighing a lot less than the lenses you're putting on them, so tripod those shots (even if you have to cary the tripod) so it doesn't look like it was shot on a cell phone. (4) Don't drop your equipment. It will get you back.

https://www.youtube.com/watch?v=H5zCmuvbkK8

Settings:

DMC-GH1: ISO 200, 1080i AVCHD, Shutter 1/50

DMC-GH2: ISO 200, 1080i AVCHD, Shutter 1/50

Lenses: Panasonic 14 mm f2.5, Voigtländer 35 mm f1.4 , Voigtländer 50mm f1.5

Memory: RAW Class 10 SDHC 16GB

Lighting: 3 100-watt open-face reflectors, 1 bounce board.

Audio: AT815b Shotgun Microphone connected to an H4N digital audio recorder.

Conclusions:

3oo watts was more than enough light to easily shoot the scene at a low ISO (200 is the lowest that both cameras go) in order to reduce grain and maximize bokeh. I was even able to stop the lenses down just a touch to open the depth-of-field enough to give the actor room to move.

Both cameras resolved the dark and/or black areas of the image with little-to-no noise, which was great. Even when the 1:1 crop mode was enabled on the GH2 (this nearly doubles the focal length of the lens), there was no notable increase in noise as there had been in the candle light test, previously. It would seem to be a valuable feature so long as you have reasonable lighting. In poor lighting it is unacceptable.

Both cameras produced surprisingly saturated images. I found that I had to reduce the overall saturation by about 20% and another 15% was pulled out of the red hues in particular.

It should be noted that the GH1 imports natively to FCP7 at 1080i / 29.97fps ProRes 422 whereas the GH2 imports natively at 1080i / 23.98fps ProRes 422. While they can be edited in the same timeline with no noticeable issues, they need to be transcoded to the same fps before you can make them into multiclips. Both cameras maintain high data rates sustained over 18Mb/s which means that transcoding takes a substantial amount of time.

Some conclusions, some observations.

Big takeaways were that I'll have to watch saturation closely in post, 1:1 crop isn't a total loss as long as there's a lot of light and a lot more time needs to be allocated per project for transcoding.

https://www.youtube.com/watch?v=BXA1NcKg1po

Settings:

DMC-GH2: ISO 160, 1080i AVCHD, Shutter 1/50

DMC-GH1: ISO 160, 1080i AVCHD, Shutter 1/50

Lenses: Panasonic 14 mm f2.5, Voigtländer 35 mm f1.4 , Voigtländer 50mm f1.5

Memory: RAW Class 10 SDHC 16GB

Lighting for Green Screen: (8) 100 Watt Open Face Reflectors.

Lighting for Talent: (3) 100 Watt Open Face Reflectors.

Audio: AT815b Shotgun Microphone connected to an H4N digital audio recorder

Conclusions:

First and foremost, Green Screen requires a lot of light which produces a tremendous amount of heat. If you're planning on turning your garage into a small Green Screen studio, don't do it on the cusp of summer, but rather early Spring or late Fall. The actors will appreciate it greatly.

The primary purpose of this episode was simply to test DMC-GH1 and DMC-GH2 for Green Screen conditions. Can they resolve the necessary color space to pull a good key without tearing the subject to pieces? This is notoriously difficult in most video formats because of chroma-subsampling in consumer and prosumer cameras which reduces the amount of color information available when trying to isolate and remove a specific value. While I wouldn't say it was 'easier' to do with these cameras, the end results were better than I've gotten with other cameras. Part of that seems due to the cameras themselves and part of it due to the keying filter that I was using.

I started out using the color key filters in Final Cut Pro and Motion, but found them woefully inadequate. I had stair-stepping issues all over the subject; it looked like he was assembled from a child's building blocks. An old friend of mine that I used to shoot with put me onto Keylight from The Foundry. While pricier than I was looking for at this time, it turned out to be an amazing keying filter with many controls and features that you can use to fineness your key in ways that I had never considered. Bottom line; awesome filter and easily worth a few hundred dollars if you want to do Chroma Key and keep your hairline.

A word about setting up and lighting your Green Screen. You can use 'actual' green screen material or paint, but if you light properly, then you can get away with almost anything. I have no plans to do extensive Chroma Key work so I picked up a roll of green paper from a local teacher supply store and hung it from the rafters in my garage. The major problem with paper is that it creases easily and, worse than that, it is highly reflective. You can't light it directly, but rather you have to light it off-angle to keep it even. Lighting off-angle means moving your subject even farther from the screen (to avoid both your screen lights and green spill hitting your subject), which means you need to hang more paper which means you'll need even more l lights...you can see where this is going. Plan on doing a lot of Chroma Key; Get real lights (watch your color temperatures to make sure everything is matching) and get a real cloth Green Screen (keep it clean and nicely folded when not used). You can find some decent ones online or go to a fabric store and pick up a bolt of green fabric (non reflective).

Some big take-aways; Avoid summertime Chroma Keys indoors and there's no cheap way through a good Key. You can spend on the lights and screen or you can spend on the filter, but you're going to spend somewhere.
 
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Do you mean presets or manual like on my cannon DSLR? how odd... (please pick up the sarcasm before I pop!)

XHA1 is a ROCKING cam. Stick on a redroc M2 or letus ultimate and your good to go.
 
My first thought was - Wow, good actors...

Second though, DSLR's are a pain in the ass to work with if you ask me.. I am still very new but between me and my mate (Basically my whole crew) we have two DSLR's. (7D and 5DM2) Plus my Canon XH A1s. I would rather use the XH and spend more time in post production fixing the coloring and stuff up then use a DSLR and have to mess with that stupid thing they call white balance.

sorry, I think we were making fun about that last bit..

hope you have a sense of humor.. :)
 
Why shoot in 1080i?
Were you in Creative Movie Mode? the 24p in the Cinema setting gives the highest bitrate and best 1080p image.
True about noise in ETC mode, 200 ISO is more or less the limit. It's great for outdoors though.
Sensor output from the GH2 is progressive, but the .MTS wrapper flips it to interlaced (an unnecessary step, except perhaps to make you go buy the AF100). Even though the manual and most of the literature out there calls it 1080p, the reality is that most every time you see p, it really should be an i (for any camera). Some how or other, the industry seems to have accepted that 24p and 23.98 are the same in the digital world, though if I had a film camera that didn't expose whole frames, I think I would have a fit *grin*.

According to the menu, I was in 24p Cinema with Rec Quality set to 24H (24Mb/s off the sensor, but again lower in actual output though the .MTS wrapper). Last I'd read, Tester 13 was getting close to removing these inconsistencies from the GH2s software.

All that said, I found greater latitude in editing, effects and color correction with the results of the GH2 than I had in footage from the 7D, T2i or 5DM2 so I'm a happy camper.
 
. Even though the manual and most of the literature out there calls it 1080p, the reality is that most every time you see p, it really should be an i (for any camera). .

This is the first time I've heard this. The GH1 shot in an interlaced wrapper which had to be dealt with by the respective NLE, but the GH2 has always been touted as progressive. GSPOT reads GH2 files as progressive so does Sony Vegas. Anyway, I don't think "re-wrapping in interlaced" makes the file interlaced, it's just a designation for the container. But here you're saying all video cams are in reality interlaced despite multiple manufacturer claims that it's progressive. This is an emperor has no clothes claim and it's dubious.s
 
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