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philipd

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Everything posted by philipd

  1. Hi I suppose a lot depends on the hardware in the camera and how the firmware might be optimized specifically for different cards. The Canon may also have a much larger buffer allowing it ride over dips in the card write speed. For example the GH5 has been tested to really only work with the newer standard for V60/V90 type cards and newer recording protocols and I suspect they've pretty much ignored all other older cards on the market, anything else that works is a lucky accident, whereas the Canon may not support this new standard (I don't know if it does or not) so might be optimised to recognise popular SD cards and the firmware knows about their characteristics to write more reliably. Regards Phil
  2. Hi Taken from https://superuser.com/questions/847016/performance-difference-between-sd-and-microsd-cards What I mean is, we might be lucky and have a card that whilst it isn't rated V90, seems to perform okay, we then buy 4 others the same and find they don't work reliably if at all. If it doesn't have V90 on it's label, then it isn't a V90 card, so whether it works or not is somewhat down to luck of the draw. The card could also be so borderline, that it will work for the first couple of shoots, then fail consistently on the third. The only way to have a V90 card is to buy one. A card that isn't V90 is a different beast and is written too like a file system, whereas a V90 card switches the camera to recording in a more efficient and reliable way, probably why you have to have a least one of these to allow the camera to work fast enough to write a backup to both cards if that mode is selected. Regards Phil
  3. Hi Just because they are identical doesn't mean they are of course. A lot of manufactures will buy in NAND memory from wherever is cheapest, and even if the same they will be differing quality. In the same way Intel CPUs are mostly the same with the best off the production line running and sold at higher clock speeds, NAND works in a similar way. Also as the NAND is used and bad blocks are mapped out, the speed and reliability will vary. If it works and it isn't a V60/V90 card, it's a lucky find, buying the exact same again you may not be so lucky. V90 cards are using the cream of NAND memory and a different recording protocol to achieve a guaranteed minimum write speed regardless if the card is fresh out of the packaging or on it's 100 use. This is why they are more expensive and harder to come by. Regards Phil Hi Me neither, and the likely hood of the final output being All-Intra is next to none, even if there was a visible benefit, it wouldn't be delivered that way. Also IPB in the GH5 codec isn't really that long of a GOP, as usually just 24 or 60 group of pictures is used in the GH5 for a group, in comparison internet streams or higher compression rates will see 200 or more before a clean I frame. So cameras like the GH5 don't really suffer from motion issues caused by the compression anyway. Regards Phil
  4. Hi Good news, thanks for reporting back, and I've seen successes and failures reported on non V90 cards even if the speed rating suggests it would be okay, so it might be a luck of the draw a little bit. (My Sandisk V30 cards work fine with FHD at 200Mbits/sec but failed after 20 or 30 seconds at 400Mbits/sec for 4K but that was expected). I'd be inclined not to trust anything important to a non V90 card, but otherwise if it works it works. In terms of backup to two cards, Panasonic have stated in their manual insert update for firmware 2.0 that at least one card must be a V60 or better for the back up function to two cards. Good on Panasonic for not blocking non rated V60 or 90 cards which I thought they might have done, so the camera at least can have a best effort attempt at any card. Regards Phil
  5. Hi Have you tried it out elsewhere? That could be some interference it is picking up and it might be very local? I've heard similar noises from DECT cordless phones. On my H1 though I've not heard any noise like that. It could just be faulty? Regards Phil
  6. Yes, it is in the white paper published by the SD Association, its a new protocol and hardware specification specifically for real-time video recording, so cards of certain age could never have this addition anyway as it wasn't invented :-) It isn't just another way of advertising the speed of the card, it denotes the card supports the new video recording protocol that is optimised for video recording. The card enters a different mode of operation for video recording on cameras that also support this standard. Other cards may work absolutely fine but unlikely, the problem is cards not using the new video recording method very quickly in use get to a point they cannot sustain a fast write data-rate without pausing to do other things. This happens all the time today in the cameras, and it's fine with VBR files not going much more than 150Mbits/sec for short bursts as the cards are faster enough to catch up and buffers big enough in the cameras to ride these drops in writing performance. When you are needing to push 400Mbits/sec constantly (not VBR) no matter how fast modern cards are at the moment, any pause in accepting data gives rise to a situation that the card can't run ahead and catch up quick enough, and very quickly the camera is going to have a buffer overflow and quit recording either within seconds are randomly as you try and use it. Cards with the V moniker, like V90, enter a different operating mode that allows them to sustain the minimum data-rate required. The reason why V90 cards are not readily available (same for V60), is that it isn't just a new sticker on the same old cards, but actually something very challenging and expensive to produce, i.e. it requires the best NAND memory and fast controller hardware and good firmware on the card with a low yield rate no doubt further increasing the cost and lack of availability. We will find out soon enough who is right, I hope I'm wrong as I don't want to pay a premium and replace good memory cards if I don't need to either.. However it was Panasonic instrumental in introducing this new protocol in SD version 5.0 or higher specifically to allow cameras like the GH5 to run at very high bit-rates to SDXC memory cards, as it couldn't be done otherwise. Regards Phil
  7. Hi Of course it depends if the final GH5 restricts use to V60/90 cards only or attempts to write to any card on a best effort basis as to whether we have a chance with any fast card. We know already that a Sandisk 95MB/sec UHS-I card, so that is a 760Mbits/sec data-rate, almost double that actually required for 400Mbits/sec All-Intra, failed, that was tested by this site. So there is a world of difference between the marketing of these cards and what they achieve in reality. It may well be a V60 card isn't even enough or 100% reliable as that is 480Mbits/sec, so not much headroom, and explains why it seems those testing the firmware 2.0 update were all given Panasonic V90 rated cards to use. Panasonic only confirm tested with a V90 card so far. Regards Phil
  8. Hi Copying files are not a true test to see if a card has a sustained data-rate suitable for high bit rate video, for example the copy may dip to almost zero bps then burst a lot higher, giving a high overall average but would break when writing real-time video that can't be halted or would see a buffer overflow. This is why they've introduced a new standard so we know the card will work at a sustained minimum. File copies are different to different to real-time streaming. Some details are in the white paper https://www.sdcard.org/downloads/pls/latest_whitepapers/Video_Speed_Class-The_new_capture_protocol_of_SD_5.0.pdf it is part of the SD 5.0 specification, from page 7 onwards it goes into more technical details, and as explained it requires a card and hardware to understand the new protocol to enable it. If the card doesn't show V30/V60/V90 it doesn't have support for SD 5.0 and real-time video recording, this of course hasn't mattered previously but does now where 400Mbps constant writing speeds are required. I bet there is no current SDXC that will work in the GH5 on 400Mbps intra recording, unless it is has V60 or V90 on the label, regardless of how much it costs or how high a speed it is advertised at. I also wouldn't be surprised if on the released firmware the camera refuses to do anything unless the card reports it is V60 or better to avoid complaints of 'it isn't working'. Regards Phil
  9. Hi That is the footnote they put to that statement. It's basically something SandDisk has made up for marketing, as that card doesn't show a V rating, we know it doesn't support the new real-time recording protocol and there is no guaranteed minimum write speed. There are 2 problems with using cards that don't support the new Video (V) protocol. 1) The GH5 may not be able to reach or sustain the required bit-rates full stop unless the camera can switch to using the Video protocol mode with a supported card. The new protocol changes completely how the camera writes to the card in order to ensure high speed writes that are sustained and never drop below the guaranteed minimum. The GH5 firmware may even block the use of cards that aren't rated at V60 or better. 2) All-Intra is a sustained constant (more or less) write speed, the card and hardware have to sustain the write speed without any hiccups. IPB used in cameras is a variable bit rate that allows borderline cards chance to catch up and buffers to empty as the write bit-rate ebbed and flowed so we got away without needing to worry too much about guaranteed minimum write speeds, this is not the case with All-Intra at these high recording rates, it is much less forgiving. The V moniker shows a guaranteed minimum write speed, achieved using new hardware in the camera and card (for example a memory card with the V rating reports to the camera about itself so the best writing scheme can be negotiated and both card and camera can switch to a new real-time streaming recording protocol). Bench mark tests are also going to be something we should be wary of as new V type cards arrive and are tested and reviewed. The reason being a card may benchmark much slower than it's V60 or V90 rating suggests it should and so look a poor choice for cameras like the GH5, but this is simply because the benchmark software/hardware will not engage the Video recording protocol, so isn't testing it for video recording. The software and readers will catch up in time, but it's something to we need to consider if looking at reviews. For real-time video recording on cameras like the GH5 the only rating we should now look for is the V rating, it's the whole reason it was brought in, because all other ratings show the burst or average speeds and guaranteed absolutely nothing for real-time video. Anyone investing in memory cards now for use with the GH5 and All-Intra based on some headline speed on the packaging where that card doesn't show the required V moniker , is going to be wasting their money. There is a reason why V60 and V90 cards are arriving now and being sold at a premium, they are different to normal cards. For example Sandisk can't take their current high speed cards and simply print V60 or V90 on there as it's more than just a printed a number and their current cards don't have the hardware/firmware to support the new standard. Regards Phil
  10. Hi All-Intra at 400Mbits/sec will need a card rated at V60 or better. Ignore all other marketing speeds or bench-marks of a card, they aren't relevant in this context. Unless the card says V60 or V90 it isn't going to work at 400Mbits/sec despite the advertised speeds. The V moniker means the card supports a new specially designed protocol for real-time video recording that allows these 'high' minimum guaranteed write speeds, the number after the V gives the minimum guaranteed write speed that the card will support when used with equipment that also uses the new protocol, which the GH5 does of course. Benchmarks on websites reviewing these cards may also cause confusion, as it is almost a given that benchmarks may show sustained write data-rates to below the V rating, but that will be because they are not bench-marking the card using the new real-time recording protocol and hardware. Regards Phil
  11. Hi With regard to V30, V60 and V90 cards, these specify a minimum write speed, regardless of the state of card (fragmentation, erased state etc) which is the important bit of course for real-time recording, so will be lower than the headline marketing speeds. Also it is important to note that to obtain these guaranteed minimum speeds these cards need to be written to using a different protocol, and the card itself needs to specifically support this protocol as well as the camera (of course the GH5 does). This means buying a card that doesn't show the V rating, because it appears fast enough based on it's other speed ratings or some website bench-marking, is not the best route to take and will likely see problems. Regards Phil
  12. Hi Same here, but there is a problem with maintaining quality with 60P. All-Intra is essentially compressing each frame as a JPEG. At 400Mbits/sec and 60 images a second to create Jpegs from, that is 400/60/8 = 830KB approx for each image. Take any image at 3840x2160 pixels and save it as a Jpeg compressed down to 830KB and quality is going to suffer, and that's ignoring the fact these would be 10bit images, which being squeezed into 830KB just isn't enough space to give a benefit, and would likely look worse than the standard IBP at a lower bit rate. When looking at 24fps each frame can be around 2MB in size, considerably better. So the higher the frame-rate, the more quality sees a drop in All-Intra unless the bit rate is raised. To get the same quality in 60fps All-Intra as seen in 24fps would need a bit rate of around 960Mbits/sec. 60fps compresses quite nicely and efficiently as IBP as it is a higher sample rate than 24fps, and IBP (if the processor can keep up) compresses better the more samples it has per second. So apart from easier editing, quality is going to better than trying to compress 60fps with only 400Mbits/sec available. Regards Phil
  13. Hi It is very likely the new ALL-I 400Mbits/sec recording speed will require V60 cards, and will refuse to work on any other card regardless of the claimed or achieved write speeds. V30/V60/V90 are new protocols/hardware changes, so it's not just a case of any fast enough card will trick the camera into thinking it supports a fast enough write speed, a V60 card reports to the recording device it's capabilities and handshakes, and the recording device then operates in different recording mode to guarantee write speeds. Basically many memory cards have played a marketing game with headline write and read speeds, and for real-time recording the highest speed isn't relevant, it's the minimum write speed that decides a good recording or failed one, regardless of when the card was formatted and if it has been previously used since. Memory cards that show V30/V60/V90 have guaranteed minimum write speeds, and this is achieved by new protocols and methods of writing to the card. These newer V60 cards aren't due to start arriving until the summer, which is probably why Panasonic have delayed launching ALL-I. So be careful about stocking up on memory cards until we know if cards that aren't V60 capable will be written to for ALL-I as a best effort type thing or will be blocked completely to save complaints when things go wrong. Regards Phil
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