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GH2 color profile and Hacked vs. not Hacked Shootout
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  • In my opinion where the GH2 hack has the most potential for a difference is a clean 422 HDMI output, the ability to hack color profiles, and higher than normal ISO's. Two of these have yet to come, but I sense these two breakthroughs are right on the horizon. Until then the minor differences the current hack allows will not convince me to completely replace my AF100.
  • @Brian202020 any news on your GH2 vs Af100 comparison. From what I saw from the philip bloom shoutout it looked only marginally sharper than the dslr and the worst DR of them all. You can see the worst clipping in the highlight behind the woman. Now it was just highly compressed 1080p and she could be moving also, but it was the worst image http://philipbloom.net/wp-content/uploads/2011/12/3.jpg her skin look like plastic. If he used the same compression in all his jpg http://philipbloom.net/wp-content/uploads/2011/12/9.jpg there just no comparison.
  • @LPowell

    Someone should just block quote your paragraph on preservation in RAW versus AVCHD. This is exactly how we work with RED footage, choosing to light to an 800 ISO interiors and exteriors to achieve the most-balanced base image for a post process.

    The same with my findings with DSLRS, and no different with the GH2. Sticking with a high ISO is most preferred.
  • To be fair @Brian202020 even with those breakthroughs I won't replace my AF101. At least until the GH2 has NDs, XLRs, HDSDI, waveform monitor, peaking etc :) If only Vitaly could be convinced to hack the AF. That really would be a glorious day for me.

    Re; the minimal noise ISO sequence 160, 320, 640 etc. Bloody annoying that the ISO bug affects the same range. Could it be somehow related?
  • It's a $700.00 camera performing like one that's 5-8 times more. I welcome those minor tradeoffs. :-)
  • If you look at all the 1080p example in the Philip bloom shootout, the gh2 only lost to the c300 and f3. very very close in detail and sharpness but they have an edge in dr. so it is more like a $ 10000 plus camera than a $ 5000 one at least in image quality.
  • HA...yeah @danyyyel I was trying my best to be conservative so as not to appear to look like a fanboy. But I agree.
  • @danyyyel
    Yes, the hacked GH2 is like a hot-rodded Nissan Skyline GT-R. While it's not in a league with the Ferrari's and Lamborghini's, it can easily take on the BMW's and Mercedes of the video world.
  • You guys have seen nothing yet... :-)
  • @mpgxsvcd, the test samples you provide:

    1. What was your method and reference point for exposure?
    2. Did you leave original exposure and change profiles, or adjust exposure for each profile and/or shot?
    3. The right side of the roll of toilet paper was over exposed in varying degrees between the profiles. Did exposure appear to be retained at the time you recorded, or was that revealed after footage was acquired?

    Thank you.

  • @driftwood

    Another patch coming soon? Obvious differences between Quantum V2? I hope that the noise pattern is even more finely tuned, so that ETC mode won't be as bad at say 800 ISO, 1000 ISO.

    I'm finding that I'm trying to justify my Super 16mm Lens Set as the prime method, but I know that doing that will mean I have to increase the lighting package to be able to shoot a 160 ISO indoors for the cleanest image possible.

    @LPowell

    Thinking about usable dynamic range, noise floor is going to factor into that, but what about achieving the optimal "cinematic" look? Part of that is using Neutral Density even indoors. I'm thinking that I need to be able to light to a 160 ASA T4 as a baseline (for interiors) and balance my key (or backlight depending on scene) here first, then any ambient spilling through windows as well, and finally drop a 0.6 ND--what I try to use at minimum if possible in any narrative situation, to obtain the right look.

    At 0.6, that's two stops, which forces you up to a 320 ASA T2.1~1.8 if I'm measuring right in my brain (I think I'm a bit off on the T stop). The expense is more noise and wattage, the gain is simply a subjective "look", and the balance of highlights that reach above say an 80-90 range.

    With that line of thinking, it's a check in the column of the impracticality of hand-me-down traditions from large-scale cinema production applied to nano-scale productions. To be able to light a scene to 160 ASA(ISO) on a tiny budget, without the use of sunlight ambiance, requires a decent sized lighting package...

    I don't think 0.3 is strong enough to do the diffusion work I'd want, but perhaps it's time to do more testing for my own eyes. And, even further... why not just light to a 320 T2.1 to begin with then shoot 640 T4 without any ND?

    Or better, light to a 160 ASA T4 (again) and shoot 320? Forget the ND altogether...

    hmm...
  • @kholi
    I'm not sure why you'd use an ND filter indoors, unless you're shooting with the lens wide open @ ISO 160 and still blowing out the highlights?
  • The light temperature you shoot in makes a difference on the profiles I've found (even with matched white balances etc).

    Let's say you are using 1/50th and 25 fps (considering 1.1 here with the future hack or whatever) for simplicities sake.

    At f/2.8 ISO 160, and 1/50th you will need EV8 of illumination, or 640 Lux, it all depends on how you want to light. At 10x10 metre worth of lighting that would require 64,000 Lumens. That's at least a few hundred dollars of LED packages, but it's not tens of thousands anymore with ridiculous power draw. And that is significantly more light than you need indoors too given it's bouncing everywhere, and that rooms are not 10x10m of surface area. to light.

    And you do not need to use ND. That is not how 'diffusion' works. You are blocking out an amount of light with an ND filter, no diffusing anything, and you do not want on-lens diffusion unless you are shooting 80's TV soapies.

    "The ISO setting determines the scaling used when the camera digitizes the intensity levels into 12-bit RAW R, G, and B values"

    The ISO setting drives the amplification circuit, it's not "digital scaling", it's analogue amplification on the analogue electrical signal before it hits the ADC, you -lose- shadow dynamic range every higher ISO you go. The ADC converts a minimum voltage level into bottom end of the image (shadows) after the amplification, at EV8 and ISO 160 the midtone voltage the ADC receives should be the same as at EV10 and ISO 640 etc.

    There comes a point where there is not enough photons to generate a signal voltage for the amplifier to amplify it up to the minimum voltage that the ADC sticks into the bottom end of the range. That's where the dynamic range ends, and with every stop less of exposure, there is half again the amount of photons hitting the sensor photosites, so that bottom end dynamic range is 1 stop less again.

    Go to measurements and dynamic range, and look how dynamic range scales with ISO used.
    http://www.dxomark.com/index.php/Cameras/Camera-Sensor-Database/Panasonic/Lumix-DMC-GH2


    That is out of a RAW image, you cannot get more DR than you can out of your RAW image.

    To put it simply, the GH2 is ISO 160. Period. It is pretty much like pushing film when you raise the ISO, it is done during "development" (amplification) step that expands the latent image (range of small voltages) into a large visible range. In a film camera you can change the film stock to a faster film, on the GH2 you cannot pull out the sensor and change to a faster sensor, you are stuck with pushing only.

    Linear steps/changes are evenly distributed. Hence linear.
  • @LPowell

    Common method for all walks of pre-planned set or location shooting. Either an ND or a Black Pro-mist, both of which do different jobs for specific times. Pro-mists or Magics help to tame highlights, not just blown but the overall tonal shift from dark to light. Of course, Pro-mists are heavier and are used for this purpose less than for the purpose of softening the appearance of make-up, flawed, flesh, etc.

    In this case, I'm specifically talking NDs to smooth over the values between 75 and 100 IRE, where 75 isn't blown out but can be pretty contrasty depending on the situation. It's also pretty common to use an 0.3 exterior night or pro-mist to help with street lamps, stop lights, so on and so forth. However, Ahtiril is right, it isn't "exactly" diffusion which I do not like.

    @Ahtiril

    DO not confuse fact with preference, of course. I still work and train under DPs that shoot modern cinema, at least two of which have had major motion pictures in theaters this year. ND is practice, but the amount is to taste. 80's Soap was never ND, it's mist filters. ND is in no way as strong as Pro_mists, but still offers a level of diffusion for highs that is acceptable. No, it's not EXACTLY diffusion, but it does help with highlights subtly. Some DPs still choose to use Classic Softs for look.

    I do agree about light temperature, I choose not to avoid Tungsten light because anything short of Kino's is hard work to bring back the color in human skin. So that is to be considered, of course. I'd also choose to get as close to a look in-camera (with anything sub RED EPIC) as possible.

    I brought up the scenario because I need to choose my run-n-gun ligthing package for my feature, and I cannot afford to carry large 4x4 Kinos around everywhere. The situation is more than likely to have just one 4x4 Kino with Daylight and Tungsten options, 1 x 4x4 Diva, 1 x 800w Joker, 1 x 200W Arri SunGun, and then a basic kit of Tungsten light:

    2 x 1000w pancake chimeras
    2 x 150w Arri Fresnels
    1 x 1000w Open Face Arri Unit
    1 x 650w Arri Fresnels

    Then augment with LEDs, specifically 4 of the larger lite panels with extra batteries and a Kino Car Kit

    Even now that I list that off, it seems like too many units to carry around in my broken Civic... and I haven't even gotten to the grip gear to support that.
  • @Athiril - "The ISO setting drives the amplification circuit, it's not "digital scaling", it's analogue amplification on the analogue electrical signal before it hits the ADC, you -lose- shadow dynamic range every higher ISO you go. "

    On the GH2 and most other DSLR's the ISO setting scales the image sensor output by a combination of analog and digital factors. The GH2 appears to use only a few discrete analog scale factors - ISO 160, 320, and 640. The intermediate ISO levels and all ISO's beyond 640 are produced by digital scaling.

    As you point out, dynamic range decreases at higher ISO levels. However, below ISO 800, the GH2's noise levels are irregular, with minimum noise at ISO 160, 320, and 640.
  • @kholi
    I like the softening effect of Black Pro-Mist filters in sunlight where you've got more than enough light to work with. But I wouldn't want to sacrifice any indoor light to an ND filter - the more light you can capture in the shadows the better. A quality ND filter shouldn't soften the image; it will just make it darker all around.


  • ND filter doesn't affect shadows more than highlights, you do not sacrifice shadows unless you have to underexpose, the only way it affects shadows more is on film in reciprocity situations (long exposure), where without the ND you would be above reciprocity failure.

    And yes a quality ND filter has no destructive effect on an image generally. You were talking about diffusion, and I said you do not want on lens diffusion unless.. etc.

    The order of placement of filters also has a drastic effect on the image. IE: Place a skylight filter behind a polarising filter, and the polariser behaves like it should, place it in front of the polariser and it turns into a variable warming/cooling filter.
  • @Athiril

    Not meaning shadows, I meant highlights. My phrase might have been off, my bad.

    Even a quality ND (I've got a set of Tiffen and Schneiders, although they have their own effects...) will still have destructive effects once you hit certain stops, namely sharpness. And then, maybe that's more the effect that's happening versus diffusion. Again, though, sorry for the out of place verbiage.

    On order of placement: I've gotten the IR placement wrong a few times... was so glad when we moved to IR/ND combos, and even then it's a right and wrong way.
  • I never thought to use ND filters indoors either, I thought they knocked down light at all values and would do nothing about protecting highlights.

    Another thing I'm apparently ignorant about is ISO values. Thought the debate was settled and that the 200/400/800 values were the way to go. Looks like it's the 160's....
  • @brianluce

    They won't do any serious protection. In fact, the amount of shift is more negligible than the amount of resolution loss; it's almost silly to worry about. It's just become a way to work that satisfies me, but more than likely isn't justifiable enough to continue doing so with smaller cameras. One of those "voodoo" methods unproven that I picked up from other DPs. I wish there was a super light Classic Soft, but even the lightest is too heavy for me.
  • @brianluce

    If you're really terrified of highlights, sometimes a polarizer can help that but at the expensive of light loss of course. I think it's a stop n'a half? I can't remember. You can totally polarize hot concrete, which is weird sounding but true.

    Same thing for certain finishes of walls, etc, and human hair. Just depends on if it's worth it, again.
  • kholi you're talking about indoor shooting and then run and gun shooting.. I got away with indoors with 2 cheap 2K blonde lights indoors bounced off ceilings or corners to fill a good sized room for even lighting extremely well, it was f/4 or f/5.6 I think ISO 250 or 320 (probably 320) and 1/50th back on a HVX variable frame rate camera.

    They aren't that heavy and unportable. And are inexpensive on bulbs etc. I think they're around 15,000-30,000 lumens.


    The 100W LED packages (100x1W LEDs assembled into one unit for your convenience) are about $40 each iirc, they are rated at 8000 lumens. You could get a number of them at the price of one light, they are small and light. Put a small cheap PC HSF on the back, cheapo light stands with a weight at the bottom and a LED driver and power supply and you're mostly good to go depending on how you want to light.

    Plus they'd be easy enough to completely insulated and seal from water, plus can be run off batteries for remote location shooting with no AC power available.

    How do you want to light indoors? Even light coming from everywhere (bounce) is easy, but needs a bit of lighting power, more dramatic direct lighting needs much less. You can use magnifying sheets the ones that are $2 used to enlarge magazines, books, newspapers for reading, theyre fresnel sheets for spotting the light smaller. Or reverse the lights into a bounce card for a bigger light source.


    Everyone needs a good polariser. I use them all the time in still photography in overcast/diffuse situations such as in rain forest, they cut grey off everything (diffuse glare), and increase colour purity, far more useful than the cliche cloud effect.

    Side by side example I shot, both film scans treated equally:



    no pola.jpg
    661 x 800 - 397K
    pola.jpg
    656 x 800 - 436K
  • @Athiril

    I admit, I am terrified of contrasty video images, and I have a stylized preference. haha. You can tell, obviously, from the light sources that I'm going to mainly try to raise the ambient in a room of a fair size, to shoot wides and also not be so afraid of blown out exteriors then, for mediums and close, augment with kino and diva light.

    The other thing, too, is that most of those lights can be powered two to a circuit, never exceeding 1000 Watts or certain amps per circuit because I'll only have one guy with me for the entire duration. You're right, though, say that 800W Joker was my largest light and we're lighting a section of a 20x20 space, creating a box of negative around the unit and blasting it into the ceiling should give us a decent amount of ambient to work with.

    Huge HUGE fan of bounce, as well. Large slabs of bead and Red Heads are a dreamy sort of match, but you're only shooting mediums for stuff like that. Which brings me to your last question, I suppose:

    I want to be able to shoot wide. Outside of the norm for no budget features, but I don't want to have to result to a claustrophobic sort of feel by only being allowed to shoot mediums and close ups. And, of course, being able to stick to the 320 ISO range would be fantastic.

    You have a great point about getting tiny LED packages and stringing them together for a larger source. In a soft box even for exterior night shooting. Do you have a recommendation for any that aren't Lite Panels? I've got four of those bricks, but can't afford anymore.

    Thread derail, my bad guys.

    Also, hell yeah to Polarizer. Circular or Linear, just have one. I plan on living with a 138 in the back of the mattebox as much as possible. THat's probably a better way to roll than to have an ND stuck in at all times...

    Time to change.
  • Image contrast is no problem and is good, what you want is to balance lighting contrast.

    search for 100W LED on ebay, they are $40, they are just the LED package, they are 8000 lumens already wired together for you, so you only need to put a couple together if you want to get a lot of lumens from one source, or split them up and have it coming from multiple sources.

    Like this http://www.ebay.com.au/itm/100W-White-High-Power-6600LM-LED-Lamp-Light-AC-Driver-/330605811498?pt=LH_DefaultDomain_0&hash=item4cf9a4572a#ht_4010wt_952

    Otherwise for spot lights, you can get some LED lenses to put on singular LEDs which can get a very very narrow beam so you can have a small very intense spot from quite some distance. The lenses are cheap since they are so small. They don't add any weight unlike big fresnel lights.

    You dont want to be wiring individual LEDs together, it'll take forever, the above includes driver circuit. You could build a driver circuit of much more power though and keep it with the power supply and run cables to the light. Or attach batteries + small driver to the light stand.

    Obviously you need to investigate before jumping on and buying a bunch of that stuff and not being able to put it together, also PWM circuits allow you to dim LEDs without altering their colour, simple circuits to build if your handy, or can also be bought.


    Ceiling bounce or ceiling corner bounce works very well, I like to use 2 lights per room, opposite ends r corners for nice even coverage.

    You can use hard direct lights in day time to fill nasty shadows, I used to use direct flash no modification to shoot in mid day for photo portraits. Just play with the lighting, you can move the light away from a longer distance to get more coverage around subjects to avoid casting shadows on selves, they shouldn't cast any shadows back in daylight since your fill won't be stronger, so the hardness is generally not a problem.


    I got 40x 1W white LEDs for about $13 delivered too... so for dimmer situations.. outdoors... I might have a rig up on some thin pvc pipes, wooden dowels or something to create four poles connected to the two ones off to the sides and just run strings of LEDs pointing down, a cheap lighting grid from above, you could use white shopping bags as diffusing material but its a PITA and will prolly catch wind like a kite, plus its just going to knock intensity down from reflection, you got so lighting coming from so many points no real need for diffusion I reckon

    You only need some mild active (low power) cooling for the 100W packages that are packed together so tightly etc.

    Obviously it's not buy and go, some time deciding what you need, how much light you want (work this out by determining the exposure level you want, what that is in lux, what area size you want that to be lit like that, convert that to lumens, then get enough lumens and also calculate what distance the lights need to be at to give that coverage size.. covering more.. is a waste of lumens and you'll need more power than what you calculated originally etc.. you can stick lenses on of course), designing it, buying it, waiting for shipping, building it, testing.. etc.



    edit: Have you seen Gabriel? They avoided mostly wide shots, and the sets you saw were all in parking lots, and were the entire sets. They basically had no budget for hardly anything.
  • Absolutely right, I meant lighting contrast.

    Thanks for the heads up on the LEDS, I'm gonna investigate those tonight and see what I can figure out. It would be fantastic to reduce the size of the lighting package.