GS400's Pro-Cinema or do it in post?

[Brian Andrews]

I'm making a short film with my GS400. I want this to look good and to look like a real film, not a home video. We will be doing our best to light properly (on a budget).

Should I use the GS400's Pro-Cinema frame mode or should I just shoot in the wide mode (16:9) and then attempt to get the film look in Post?

[Guy Bruner]

Wide mode would be best. You have more editing options and better resolution. If you are not going to change the look of the video from procinema and want to save some time, then shoot in procinema.

[Paul Kepen]

Guy, Could you please expand on "You have more editing options and better resolution." What are these options that you don't have in procinema, and Is the resolution really better in Wide? Why is that.

I have a GS-400 and can't seem to make my mind up between the two. Somethings ProCinema seems to handle better - strong contrasty light, while wide certainly is superior with fast motion.

This brings me to another question; outdoors going from strong sunlight to shade, white balance and exposure don't seem to handle the change as well as my old Canon Optura 200. Any Tips would be appreciated. Thanks, PK

[Guy Bruner]

Procinema, because it uses frame mode, results in a loss of vertical resolution to around 320 lines versus 360 lines in interlaced mode and a loss in color information due to the way the two fields are combined by the camcorder's processing engine. You can't get those back in post. Also, the cam adjusts exposure and gamma settings to give the "film" look. Those can be done in post (although the increased latitude due to the changed gamma in the cam may not be possible in post). I would start with the highest color and resolution as possible which is achieved in interlaced mode. That being said, Procinema mode can look very good and is an easy way to get the "film" look without having to manipulate things in post. If that is the look you are going for and don't intend to change it, then it is certainly useful.

The best thing when going from one source of light to another is to put the cam in manual so the change is not abrupt. You will notice the color balance shift going from shade to bright sunlight and vice versa when auto makes the change.

[Dennis Wood]

The increased latitude is something that bears some testing. I just read (and Guy did too :-) a good article on Panasonics "Cinne Gamma" technology that describes how Panasonic has stretched the exposure range of DV. Although there should theoretically be a drop in resolution in frame mode, no one has demonstrated that there is...in fact my tests have shown no resolution loss that I can detect on an EIA1956. For that matter, I can't confirm that cinne gamma is even incorportated into the GS400's pro-cinema mode...although logically you would think that it is.

So I'd recommend trying pro-cinema with colour correction in post. If the article is correct, and cinne gamma is actually incorporated into the GS400, you should see increased exposure range in the pro-cinema footage.

[Joshua Provost]

You can get lots more latitude from a GS400 by simply turning the CONTRAST PICTURE ADJUSTMENT down (see my article). You don't need to use PROCINEMA mode for that.

Beware of the term "gamma." The DVX100A has CineGamma controls that manipulate the entire gamma curve with multiple adjustments to the knee, middle, and shoulder, and manipulate clipping in highlights and shadows. A more basic gamma adjustment would be simply lowering or raising the gamma at its midpoint, resulting in an overall lighter or darker image.

I have a feeling the GS400 PROCINEMA mode simply raises the gamma midpoint, resulting in a slightly darker, richer image. We'd need someone to shoot a grayscale chart in NORMAL and PROCINEMA modes and analyze the images to find out.

[Dennis Wood]

Therein lay the the question...is it Cinne Gamma, or just Panasonic fiddling with contrast? We've all kind of dismissed pro cinema mode as a bit gimmicky, but to date, no one has taken the trouble to test it. If I understood this article http://www.hpaonline.com/i4a/pages/index.cfm?pageid=236 correctly, it would seem that Panasonic is actually taking advantage of increased exposure range from the CCD with Cinne Gamma rather than just adjusting knee and stretch. Bergeron explains in his article that a contrast ratio of 1000:1 is achieved in this mode, and that a 2 f/stop decrease in apparent exposure is evident when viewing the footage on a monitor. Presumably if you brighten this footage up, there should be more detail in the shadows. This sounds to me quite different from just adjusting contrast.

Joshua, what's your take on this? What would you suggest for methodology?

[Paul Kepen]

Thanks Guy, you sure know a lot more about this then I do. I do agree with some of the other posts here though, that in extremely contrasty lighting, procinema seems to have a wider range of latitude. However, in other lighting it can be terribly dull or flat, and deffinitely dark. In post you can change this ofcourse. However if in extreme contrast, its hard to get the blownout highlights back. I live on a lake, so with lots of reflections it can get intense. I'll have to try playing with the contrast adjustment in Wide mode to see if I can get the same amount of lattitude. While at an airshow this summer, I noticed in procinema it looked as if the propellers were turning backward, must be the 30fps versus the 60 field interlaced, but it sure looks weird. However, the brightly polished, shinny aluminum in sunlight did hold well in procinema.

[Guy Bruner]

Paul,
In bright reflective conditions, using a polarizer filter should help. If you want to see a good video shot in Procinema, take at look (click) here. This video was shot in auto and without a polarizer. It still looks very good.

When in manual on the GS400, you have control over exposure, contrast, color saturation but not gamma. It would be nice if Panasonic made that adjustable, too.

[Dennis Wood]

Paul I just finished shooting about 6 hours of footage (over 3 events) of yacht racing. I used pro cinema with two of the events so I could have lots of footage to test. A things that will help with water and sun. Forgive me if I'm stating what is already obvious to you...

1. Get a circular polarizer as Guy has suggested. This will bring your exposure levels down about 2 f/stops and help with the blowouts, particuarly reflected glare. In auto mode the cam will not advance beyond 1/60s shutter speed and therefore beyond F/16, everything will be "blown" out. Alternatively switch to manual and up the shutter speed to bring your F/stop down to the F/5 to F/8 range.

2. Enable the zebra stripes to remind you of when an area is likely to be blown out.

3. Try a shot with both dark and very bright elements (like an object in front of a window, or an object with the lake in the background). Use wide, frame mode with contrast dropped, shoot a bit, then switch to pro cinema for a minute. In post, brighten your pro-cinema footage 1 or 2 f/stops. What looks better? I'd be curious to hear your observations.

[Paul Kepen]

Thanks Dennis & Guy. I purchased my GS400 at the end of Jan. They threw in a filter set, and I've had the UV filter on ever since. Last spring I went skiing in Colorado. Got beautiful shots in the mountains using the polarizer. I tried a still shot 1st and saw the vignetting problem in the corners when stacking filters, so I was changing back and forth UV-Polorizer during that trip. Yup, you guessed it, some how I've lost the polarizer.

In the summer we like to waterski. Obviously, procinema would not be good for speedy action. I found that the programed Sports mode did seem to clear up the water spray vs standard auto. I think sport mode ups it to 100sec. Anyways cause were rapidly going from side/front/back lighting, not to mention the boat bouncing, manual control and adjusting a polarizer would be difficult. Don't get me wrong, I love the gs400, it produces the best image I've ever had from a camcorder, I'm just trying to get the best results I can :) Thanks again for your help - Paul

[Paul Kepen]

Sorry, another stupid question. When using the zebra bars, is the idea to not have ANY showing, or just in the strongest highlights. I.E. Where the zebra's show, is this normal "spectral hilighting, or overblown, you don't want to go there territory!

[Dennis Wood]

Normally the zebra stripe areas will end up looking overexposed. Given your issue in the boat, just slide the switch to manual and up the shutter speed until the zebra stripes disappear. I kind of like the "Gladiator look" you get at 1/250s. Using frame mode with the higher shutter speed can give an interesting effect too. Interlaced mode however is definitely better if you plan to use slomo in your NLE.

[Joshua Provost]

That article was interesting, but it references some mostly the Varicam, and only very briefly the DVX100A. I'm going to be very skeptical that Panny would include such an advanced function into the GS series, but it's possible. The question would remain, if it is like the Varicam FilmRec feature, then what is the threshold (200%, 300%, etc.)?

One thing to note is that miniDV is an 8-bit format. Conveniently, bits correspond well to stops, since each additional bit double the range of the number and each additional stop doubles the light. Theoretically, miniDV has an 8 stop capability. You have to shave off some of that because the legal range is 16-235. So, it's more like 7 3/4 stops. Without going to a 10bit or Log format, that's the most you can get. I want to make sure we maximize what we are getting out of this camera.

Obviously, there is zero information from Panasonic on how this works. The manual is a joke. Sadly, even if it is a great feature, it's in combo with FRAME mode and some other adjustments that you may not want.

OK, methodology. There are a couple of tests I would like to see. First, a gray scale chart, 3 ways: properly exposed, under-exposed, and over-exposed. Shoot that in NORMAL, PROCINEMA, and in MANUAL w/ CONTRAST picture adjustments. We'll want to analyze the resulting images so we can plot the gamma curve in those modes.

Next, shoot an image half indoors, half outdoors through a window with daylight. This is a classic test of latitude, film or video. There should be varying levels of light, both on the inside and outside sections of the frame. Shoot this in all three modes and analyze the images to see how much detail was captured.

Ideally, we would meter various areas of the image, so we would know that outdoors, for instance, we had areas of the image that were F8, F11, F64, etc., and indoors there were areas that were F1.4, F2, etc., and we could get a good feel for exactly how many stops of exposure the camera has in various modes. Without metering, we can only know that one mode is better or worse than another, without exactly quantifying it.

Maybe I can run some of these tests tomorrow. I won't be home today with enough daylight to make the camera really work.

[Dennis Wood]

I was hoping you would volunteer. I'll have to do some reading on the bit thing as I've never delved into DV at that level. Truthfully, you're the best man for the job :-)