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GH4 4K Panasonic video camera, official topic
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  • cinemasteve87cinemasteve87

    Hi everyone, here's a video I shot in Yosemite. Please Enjoy!

  • Vitaliy_KiselevVitaliy_Kiselev

    @apefos

    We have topic in flame about all this, use it, please.

    Otherwise some of the claims are not very accurate as idea to calculate different sensors crop factors by diagonal.

  • apefosapefos

    Crop factors must be calculated using the diagonal of the sensor.

    The full frame film camera sensor is 36x24mm and has a diagonal of 43,26mm It uses all the image circle from the full frame lenses.

    The GH2 multi aspect sensor for 16:9 video is 18.8x10.6mm and has a diagonal of 21.6mm wich is half diagonal of full frame film cameras So the GH2 crop factor for video is 2x and not 1.86x (43.26 / 21.6)

    Considering the GH3 and GH4 uses all the horizontal pixels of the sensor to capture 1080p video:

    The GH3 and GH4 sensor for 16:9 video is 17.3x9.7mm and has a diagonal of 19.85mm So the GH3 and GH4 in 1080p has a crop factor of 2.18x (43.26 / 19.85)

    Considering the GH4 sensor is 4608 pixels in horizontal and C4k is 4096 pixels in horizontal and UHD is 3840 pixels in horizontal:

    The GH4 in C4k mode uses an area of 15.38x8.11mm of the sensor and has a diagonal of 17.39mm So the GH4 in C4k mode has a crop factor of 2.49x (43.26 / 17.39) The GH4 in UHD mode uses an area of 14.42x8.11mm of the sensor and has a diagonal of 16.54mm So the GH4 in UHD mode has a crop factor of 2.616x (43.26 / 16.54)

    This is all without focal reducer.

  • _gl_gl

    yeah well, you get 4:4:4 during the edit, and that can be useful. The catch is that all 'consumer' codecs are also 4:2:0, so you will be throwing the extra chroma data away again when you render to your 1080p delivery format. The only time it is really preserved for a viewer is if they're watching a 4k video which is downscaled live to 1080p.

  • tymeoramatymeorama

    Don't know if this video was previously posted, but I found it very valuable to explain how we can get 1080p 444 from 4K 420 (chroma subsampling)

  • Manu4VendettaManu4Vendetta

  • MRfannyMRfanny

    i don't get that jello argument. its a tool, choose the mode that works best for the shot or in some cases the right camera for the job. 4k for $1600 bucks, theres always going to be compromises, but pretty good ones if you ask me at present.

  • JohnTollwannabeJohnTollwannabe

    So, you need to set the camera on 4k recording and then down-sample to get perfect line for line 1080p, but at the expense of going back to a higher level of jell-o because the processor can't keep up with the extra data.

    Can't win at this lower price point...

  • kurthkurth

    I hope this hasn't already been posted ...adam wilt's review.

    http://www.dvinfo.net/article/acquisition/review-panasonic-dmc-gh4-camera.html/2

    ...says it's got full 1080 lines when 4k is downsampled !

    image

    4K

    image

    test.jpg
    600 x 586 - 62K
    test2.jpg
    599 x 585 - 65K
  • Manu4VendettaManu4Vendetta

  • discomandavisdiscomandavis

    Wow, that's a lot of questions, I'll take a wack at it.

    1- There is no speedbooster for 4/3 lenses, because they are designed to deliver the light necessary to a 4/3 sensor. A speedbooster only works because there is more light going into a full frame lense than a 4/3 sensor needs, so it concentrates that light onto the sensor giving you the extra stop. The good news for you is that a lot of the lenses you can get to use with a speedbooster are dirt cheap, check out the FD lenses on ebay, that's what I use and they look amazing on this camera.

    2-No

    3-Yes I do, when? When I have the mula (money). The workflow is just like any other, it outputs Pro Res, which is a great codec to edit in!

    4-Isn't that the question of the day, a lot of people will say they have, but they then have they faces chewed off by others. I am testing it out currently, whenever I have evidence for either perspective I will happily post it.

    5-Yes it is. I had some ghetto SD cards that I bought a long while ago that fall far below the standard they say it "needs" the GH4, they never had any problems. That being said, I am a sucker and did by the new SD cards, for peace of mind.

    6- I got this bag and I love it. It has this amazing rotating lense holder so I can get to my lenses conveniently without having to open the whole bag. (Edit: Just saw that this company was discontinued (was a branch of Manfrotto), sad thing glad I got it just before.)

    http://www.bhphotovideo.com/c/product/892824-REG/Kata_kt_pl_r_8_Revolver_8_PL_Backpack.html/mode/edu

  • revitdaziorevitdazio

    A couple of quick questions:

    1. Can you use the existing (or upcoming GH4 exclusive) Metabones Speed Booster on the GH3/4 with M43 glass? If not, that sucks for those of use who have invested in M43 glass to be stuck with higher crop factors.

    2. Does anyone have an idea on Amazon GH4 availabilities yet in the US? I placed my order April 1st, and it was supposed to ship by the end of April, but my order status changed from "estimated ship date" to "back-ordered"... They apologized and upgraded my shipping to Next Day delivery, that is whenever they get them back in stock of course. They said they were overwhelmed by the pre-orders. I like ordering from Amazon because they have 4-year Accidental replacement Warranty for $85 (I don't know if that works for cameras bought elsewhere). Any info or suggestions?

    3. Does anyone plan on spending the dough on the Atomos Shogun? If so, how much is it going to be and what would the workflow be like?

    4. Has anyone had any luck transcoding/downsampling the 4k internal 8bit 4:2:0 to 1080p 10bit 4:2:2 or 4:4:4 and color graded it to see it's quality?

    5. Is the Sandisk Extreme Pro 64gb 95MB/s cards sufficient for the internal Cinema 4k video? How about the 1080p 200Mbps setting? What is the reason for those new 280MB/s cards? Are they necessary for anything that the 95MB/s cards can't do?

    6. What types of travel/carry bags do you all use for your GH's? I was looking at the Tenba DNA 11, but I don't know if the GH4 with the battery grip attached and a 13" Macbook Pro will all fit in there width wise. What bags are your favorite and why? I love POCKETS!

    Thanks so much everyone!

    ~Rev

  • MikeLinnMikeLinn

  • mrbillmrbill

    Thanks @tomaso - got it

  • MikeLinnMikeLinn

    GH4 at stock price - http://www.ebay.com/itm/161308410461

  • bwhitzbwhitz

    the 96 fps mode is 720p uprezzed and not true 1080p as others have speculated.

    Well, this is what it looks like, and that's really all that matters in the end, no matter what method they're using. Even the GH2's 60fps in 720p look like more resolution...

  • Kit_LKit_L

    For me, heavily invested in µ4/3rds, the price of the Sony A7s released today makes the GH4 look like a steal.

  • JohnTollwannabeJohnTollwannabe

    It's very possible that in order to save on raw processing power (meaning placing a better and more expensive chip in the camera and having to up the price to keep the GH4 profitable), the 96 fps mode is 720p uprezzed and not true 1080p as others have speculated.

    Anyone do a resolution chart test while shooting at 96 fps??

  • bwhitzbwhitz

    Very nice video! Well done. Still feeling like the 96fps is a huge hit in quality though... I probably can't use it for any portfolio or paid work. Has anyone really tested out the 200mbps 60fps yet? I feel like that's where it's really at for quality slow-motion on the GH4. Plus... the 96fps doesn't feel like it has that really have that much more impact than 60fps. I think the next step of "emotional" slow motion is in the 120-300fps range.

  • SeekingHeartwoodSeekingHeartwood

    on, definitely

  • benjaminreecebenjaminreece

    Quick question guys, am I supposed to have constant preview on or off?

  • benjaminreecebenjaminreece

    @aaronchicago thanks man- my brother owns an Epic/BMPCC, I own a BMCC, my dad owns a MKIII (which I've owned/sold) so I'm hoping to do a family film-out. :)

  • jaksajaksa

    Hi. Did anyone buy GH4 this week through some webshop in Europe? I can't find it anywhere. Thanks in advance

  • aaronchicagoaaronchicago

    @benjaminreece looks good man. The Sigma 18-35 + GH4 is such a killer combo.

  • TomasoTomaso

    @mrbill in the custom menue Page 1 Item on Custo.Set Mem. Page 321 in the advanced manual.

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