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ZZ VISUAL

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  1. We do not speak about bining to 1K here (there is no bining in the 4K mode on GH4) - otherwise there would be no x2.3 crop (instead of the native x2.0). The ISO advantage between the 16MP and 12MP sensor pixel densities is rather small (~1/3 step) - that is not ISO what makes 16MP less fit for 4K than 12+MP (see item 1 in the post). But for the continuous shooting reduction 30% in the file size does matter (item 2).
  2. A "tech geek's" comment inspired by the Sony A7S release... I appreciate the quality of codec/bitrates of the new Panasonic GH4 (there are several first examples available online), the maturity and all-round versatility of the system, as well as its plethora of great improvements (like the “depth-for-defocus†contrast-detection AF). However, there is one thing on GH4 I have never found to be the most elegant technical solution. Namely, it is rather high megapixel score (16MP). I do suppose for a motion-stills/video oriented micro 43 camera the optimal resolution would be 12+MP. The arguments are straightforward: 1. 12+MP on a micro 43 sensor is a “native†resolution for the academy DCI 4K standard (4096×2160 pixels). On GH4, DCI 4K is supported in the crop mode (x2 vs x2.3), owing to the higher horizontal resolution of its 16MP sensor (4608 pixels). To note: x2 vs. x2.3 crop is noticeably less pleasant for a video maker (!). 2. Higher continuous shooting rates for stills: 30% speed-up in the continuous shooting does matter (!). 3. Slightly lower ISO noise (and slightly higher dynamic range) in the video and pictures’ modes. For the motion-stills/video-oriented cameras (1) and (2) is much more important than extra 4 MP in stills. B.t.w, I lived a quite happy stills’ live with my G2 – just be thorough with composition and no need to crop :). There are well-known successful examples of the strategy (“less MP = more speed/IQâ€) in the DSLR world (Nikon D4 (16MP/FF), Canon 1D (18MP/FF)… And now – “suddenly†appeared at NAB, the first 4K mirrorless full-frame Sony A7S. As compared to the GH4, A7S has lower bandwidth/processing power (50 Mbps vs. 200 Mpbs for 1K, UHD (3840×2160) vs. DCI resolution, 4:2:2/8 bits vs. 4:2:2/10 bits etc.) with the advantage in the high ISO of course. Note that A7s has also 14 bit RAW for stills. However I would rather applaud Sony for limiting the sensor resolution by 12MP. It is a very harmonic engineering solution for the motion-oriented hybrid camera. Dreaming forward about 4K on micro 43… I would like to see two lines of Panasonic sensors: 16MP for the stills-oriented cameras and 12MP for the motion-oriented ones. For that I would gladly pay extra. Apparently, Panasonic thought about it more than me. Sadly, they do not follow this path likely due to the high financial burden for maintaining the two lines of the "perfect" sensors on one consumer’s products line. This is in contrast to Sony which always seem to have enough cash to sit on several sits (e.g. A7, A7R, A7S, NEX, ... )… PS I do not intend to compare 4K/micro 43 vs. 4K/mirrorless-FF as systems themselves here: the pro/cons are be basically the same as for the stills’ counterparts. Stay tuned, ZZ VISUAL
  3. There is a (very reasonable) opinion around that the cameras operating with such high bit rates at the moment cannot provide IBIS, since they need a solid connection to the heat sink. However, I do agree that the still-oriented cameras from Panasonic (GM1, GH3, GX7 ...) must incorporate 24p/25p/30p at least, mic/head jacks and of course a competitive IBIS (except perhaps GM, for which it probably would not make much sense due to the size limitation).
  4. I just pointed "Messerjocke" that GH4 (1500€) is not the first camera "cinema quality camera" below 2K. Sure, I would say a "reliable cinema quality" is somewhat above 4:2:0 and 8 bit/color at 1080p :).
  5. It is a naive idea, but nevertheless... If 4K/8bit/4:2:0 from the GH4 card converts to 1080p/10bit/4:4:4, can 4K/10bit/4:2:2 (grabbed by YAGH) be converted to something like 1080p/12bit/4:4:4 etc. ? PS I suppose a good idea would be to contact Panasonic directly to answer if all these manipulations are feasible.
  6. I am not sure it is a hardware rather than the firmware (=marketing, in their understanding) problem...
  7. One should not forget that it is not sampling (4:2:2 vs 4:2:0) alone but also the color representation (10 bit vs 8 bit) is important for the overall quality, isn't it ? Just the same as jpeg vs. raw.
  8. If you want more analogy with the past you should add more blacks and highlights :).
  9. Andrew, let me enter your discussion with Tim 1. It is really difficult to estimate how much 1080p 4:2:2 10 bit on board would affect the cost of the camera (which price is estimated by 1500€ - not so much for this speed monster), but I bet if it was available on GH4 it would generate a lot of profits from both camps (enthusiasts/indies/small studions/photographers and broadcast volks). Thinking in analogy with all our previous experience with the GH line I am pretty sure that the lack of 4:2:2/10 bit is rather the "marketing segmentation" problem ((in)famous for the Japanese manufacturers) than the technical one. Perhaps they reserved it for an upgrade of AF100 (?) 2. The argument: "4:2:2 is not given to support more compact files" is not serious to advocate its lack - if you need to save the space just set lower sampling, resolution, rates etc. - this is already there. 3. Overall, despite the camera did not give us everything we dreamed (since the GH2) in one pack, it is the great tool with many features beyond the competition. One of the strongest points of the camera is its capability to assist AF (which is now DFD(!)) via the touch screen what is indispensable for the dynamic shooting/tracking with the CD-based AF. I suppose that the value of the latter is not yet well realized by the filmmakers due to their binging to MF. 4. In view of the pros/cons of both cameras, I would suggest that if one is on a lower budget, then the combination of GH4 alone [1500€] (dynamic scenes/tracking, low light) plus BM Pocket CC (DR, color, "film looking") [1000€ plus accessories] would be a very practical solution.
  10. My guess guess is that IBIS is not feasible with high bit rates sensors at this point since the latter shall require solid attachment to the heat sink. But maybe I am wrong...
  11. Besides of your arguments, I guess the ultimate advantage of 444/10 bit can be recognized only with the 10 bit screens.
  12. Hi Andrew, according to the specs the camera seems capable of the 2K 12 bit RAW 24 fps bitrates out of the sensor (its output rates are 594 mbps), do you have any comments on it ? Regards, ZZ
  13. A great pedagogical article for those who fail to accept ABC of imaging. My couple of pennies: 1) In principle one could bring much of the message just comparing two still jpegs - one from e.g. a Panasonic camera and another from the RAW of the same camera. For anyone who ever made RAW processing for stills all this is obvious, but it seems many video makers (or those pretending to be, esp. from the 43rumors crowd) never made it... 2) The difference between 8 bit vs 14 bit (for whatever photo or video) will be more severe when we go from the present 8 bit screens (where we watch this post) to the higher bit ones.
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