amanieux

​i know there is a tax in europe but it is a 5% tax, any customer in europe would be happy to pay 5% more and have no time limit, the camera makers know that but i think they are just protecting their high end pricy market cameras at world level by applying the linit to the world. when there are no longer technical arguments to differentiate these markets they need to add artificial restrictions, like lower bitrate, time limits, remove a 50cts headphone jack etc ... the problem is that hardware R&D is driven by mass market components so progress will come from low end hardware, they will have more and more problem defending their high end market because there will no more be high end sensors . this already happend in cpu and in 3d graphic cards because there is 100x more R&D investment on these chips. camera sensor makers invest much more r&d on smartphone camera sized sensors and not on full frame sensors because they sell 10000x more smartphone sensors than full frame sensors. the other incentive to use smaller sensor is the rejection yield is so much greater on bigger sensors, i bet we will see in the next 5 years see bigger sensors replaced by multiple smaller sensors recreating better images at a lower cost with computational photography (http://linximaging.com/).

​you are right there is a heat issue but i notice that a tiny gopro4 enclosed in a waterproof plastic shell that is not good at dissipating heat can still record 4k for hours. even if a full frame sensor dissipates more heat than a gopro size sensor, there are obviously ways to dissipate heat in such a bigger camera body, they already have fans on pricier camera, a fan costs tens of cents.

why the hell do they put a 30 minutes limit on video recording on their high end 3k$ prosumer camera ? (the gh4 is half the price and has no time limit, are the gh4 and the 2 blackmagic 4k the only three sub $3000 interchangeable lens camera to be free of this 30 min limit in 4k?)

​i agree, we are still in the first gen 4k, the next step for 4k camera is to put more computing power in order to have better algorithms to scale down from full sensor information and do more real time processing for image improvement such as noise reduction.(nx1 is leading this trend with 6.5k downsampled to 4k in real time). just an idea but why don't they put a m2 format ssd (the size of 3 sd card) to write raw 4k at the required 500MB/s and post process the information in camera afterward this will not only improve quality but also solve overheating issues (you can process 1 min of footage in 5 minutes with a lot of heat but if you do it in 10 minutes, it will be 4x less heat as thermal dissipation vs mips is exponential. why cant filmakers go and have lunch after shooting something or let it process during the night in the camera (though we will need bigger batteries ) ?

​and in aps-c crop it may be worse than the aps-c nx1 also BSI (we will see the comparisons i am sure) as there will less information before compression (downsampling 5k vs 6.5k) and after compression (100Mbits/s vs 160Mbits equivalent in h264)

general answer to this question : https://www.youtube.com/watch?v=_KYvp8PrCFc

​why dont they put a heat sensor and stop the recording based on heat and not on time ? (so we have the option to cool it down from the outside with $5 heatsink and fan (http://www.newegg.com/Product/Product.aspx?Item=9SIA45H22W1786 )or a $50 water cooler (http://www.newegg.com/Product/Product.aspx?Item=N82E16835103195)

very ​true, it is not the same segment - it is as if you compared a ford focus MK.II to a rolls roys because they both had the same maximum speed.(by the way about pure specs sheet 4k are not made equal , don't you remember the 5d mark 3 1080p that was equivalent to a gh2 in 720p)

impressive amount of information to start from as 4k is downsampled from full frame 42Mpixels, but only 100Mbit/s h264 at the output (nx1 has a 160Mbits/s equivalent in h264)

is there a sub $1000 camera that has no 4k recording time limit ? (can a smartphone do that after a rom update, or is there a heat issue on such compact devices ?) thank you

vulgatron, if you hesitate between nx1 and gh4 remember that nx1 has 30 min recording time limit , gh4 has no time limit

very good idea, but it should also say on the lens "24Mpix on full frame, 18 Mpix on aps-c and 12Mpix on micro4/3" because it is what is really happening !

is there a 30 minutes limit for video recording as on the nx1 ?

a uhd 1:1 crop on a 28mpix apsc sensor make a 3.6um photosite size for the nx500 vs 4.2um for the lx100 so we'll see in the tests if the samsung bsi technology can compensate for a 17% smaller photosite that will bring more noise by catching less light than the lx100

it was obvious they would cripple it in term of features (no peaking, no advanced video settings) and in term of quality (no downsampling from the 6.5k and lower bitrate) to not canibalise their own nx1, they just wanted a position in the entry 4k camera price range at an entry 4k quality that will be i guess much closer to the lx100 rather than the nx1.

yes nx1 is much better in low light than the lx100, even though they have same photosite area (better bsi technology and noise is reduced by scaling down the croped 23,6Mpix down to 8,8mpix, the lx100 is just a 8,8mpix crop) : same night scene iso 800 (already too much noise for the lx100) lx100 : https://www.youtube.com/watch?v=WVaA0840d3M nx1 (+samyang 24mm f1.5) : https://www.youtube.com/watch?v=4gdrFX2oFDw guess who wins i am in also to buy nx500 but i'll wait to see samples first because samsung should in all logic limit video quality on purpose to avoid stepping on the toes of the nx1 warning: 800 is the sweet spot for nx1 above that it falls appart and 3200 is terribly bad for a unknown reason

why don't you mention there is a 30 minutes recording limit, deal breaker for many !

you say in 4k there is a crop factor of 4.0 (37mm/9.1mm) so must we also multiply the aperture by the crop factor to get the full frame equivalent as i read in many articles ? so is the lens a f11.2-f16 equivalent ? (how bad is it going to be in low light ?, i don't understand if this "full frame aperture equivalency" is just good for the depth of field equivalency or is it also applying for the quantity of light going onto the sensor ? if so f11.2 is going to be really dark for indoor shooting ) if it makes it really bad choice for indoor shooting and this camera is only good for outdoor bright sunlight shooting, then why no wait for the gopro4 that will also do 4k (>15fps) it will be cheaper, smaller and water proof (but lack the zoom). it is supposed to be out within 2 weeks.

they give a solution using another software here : http://forum.doom9.org/showthread.php?t=166368 , i am suprised to see it is not possible in premiere using the default effects tools

if you have 10bit per channel to convert to 8bit per channel, noise dithering is not the best algorithm, diffusion dithering is better the typical algorithm is Floyd–Steinberg - look at the difference with the noise or "random" algorithm it is day and night : http://en.wikipedia.org/wiki/Dither vs

it is because when you downsample 4k 4:2:0 8 bits to 1080p you get 4:4:4 but with only 10 bit for y and 8 bits for u and v , as your sky does not change its luma but just the shade of blue your are still in 8 bits for the shades of blue so the banding is still there, if you had shot in black and white then your banding thickness would have been /4 (going from 8 bit to 10 bit in the Y channel). or record the 4k externally in 4:2:2 when the new atomos recorder will be available, you will get 11 bit for the chroma (blue banding size /8) if you downscale to 1080p (4:2:2 10 bit 4k, downsampled to 1080p will give you 4:4:4 in 12:11:11 bits. and by the way, with your present test, even if you still get your 5 bands of blue, the border of the bands should be less pixelated by a factor of 2 as chroma precision is still 8 bit but chroma resolution is doubled.

i don't understand the maths when you downsample a 4:2:0 8 bits by a factor of 2 (4 pixels to 1 pixel) , you get 4:4:4 but with 10 bits only for the Y, and you still only get 8 bits for U and the V so it is 4:4:4 in 10:8:8 bits, no ?

i am just saying that 4k in h264 is not future proof. when you step up the resolution you must also step up the codec to avoid an explosion in size it happened in the past it will happen again (as a reminder h264 is more than 10 years old). - 4k will go with h265, as HD now goes with h264 and HDV went with h262(mpeg2) and before that DV went with JPEG-DCT. - and i also bet you that it will not be in 5 to 10 years but rather in 2 to 3 years because 4k screens are already out, they will be mainstream/low cost in 2 to 3 years.

what about h265 ? the gh4 it is the most expensive mirrorless camera from mid 2014 and it is stuck with hardware h264 compression without any hope for getting the h265 codec with a firmware upgrade ?