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Posts posted by alexO

  1. Does a7c still have 1.2X crop in 4K mode at 30fps compared to a7iii?  Can't find it anywhere in the specs, not sure if they managed to do full sensor or just decided not to mention it.

  2. Too bad 1.2x crop in 30fps. Most likely meaning that readout could not keep up in 30fps, as a result expecting high rolling shutter on the level of 35ms(similar to a6300/a6500). 

    Quote from  dpreview: "24p 4K video is taken from a 6K region of the sensor, while 30p shooting comes from a roughly 5K region with a 1.2x crop".

  3. I was watching closeout sale of NX500(500$ US) and thinking if I should pick one up. Used were selling slightly north of 400. Now after sale is gone and NX500 sold out(aside from sellers who still sells it for 800 original retail price) used prices jumped to about 500 and I won't be surprised if they would go even slightly higher. I am sure eventually they would go down, but it probably not gonna happen until late this year if not later.

  4. Actually never mind, RS is the parameter of the single frame, so there should be no correction for fps. So 25p RS should be identical to 24p, while 30p should be 1.225^2=1.5 times smaller(26ms). This makes sense, it should be kept under 1000ms/fps, otherwise the next frame starts before the current one finished processing. So for 30p RS should be under 33ms, while 24p under 42ms.

  5. majoraxis, Andrew confirmed few pages earlier that there is no crop in 25p, therefore RS should be slightly worse. If we assume it scales linear with number of pixels needs to be read it should be worse by 1/24=4.2%. If we take baseline to be 39ms this would give 40.6ms.

    In case of 30p from sample videos I estimated relative crop to be 1.225, correcting by higher frame rate gives (30/24)/1.225^2=0.83 factor. With the same 39ms baseline it would give 32.5ms.


  6. I was joking, I agree, in perfect world we should be able to control any post processing which is automatically done by the camera. "It's not a bug it's a feature" is usually referred to an excuse made by software developers when they try to convince the user that a flaw in their program is actually what it's supposed to be doing.

  7. Looks like 4K 30p crop is more severe than HD 120p - Jordan(camerastore) says it's around 2 relative to FF, which looks about correct from their review above around 14:10 mark. He also says it's about 1 stop worse.

  8. KrisAK, I don't think HD straight out of camera qualifies as full readout, which assumes reading full 6K sensor(cutting only top and bottom section to get down to a proper aspect ratio) and then do a proper scaling to 2K/1080p. If it was the case, there should be no difference in sharpness between HD out of the camera and downscale to HD from 4K footage, also rolling shutter should be as bad as 4K(it takes roughly 30ms to read the whole sensor).

    I am not an expert and have limited experience with low level of hardware(I am an ex physicist), but if I have to guess there is some low level logic on a CMOS sensor level which combines all those pixel together to produces HD footage. So scaling is not done by the CPU, but by the sensor itself. Initially we had line skipping, then pixel binning, and now I think it might be a bit more sophisticated, but still not a proper downscale you could archive by computers in whatever editing software you use. So despite all pixels been used I don't think it qualifies as full readout(no one calls binning the full readout, this is just extension of it).

    Feel free to correct me if someone knows more technical background on sensors. This is just my guess.

  9. When people talk about raw video I don't think they imply it at full native resolution of 28Mp, this would be insane. Look at 5Dm3 raw video for example, each frame is at HD resolution with 14bit of color information. So it's not true raw per say, but a downscaled raw instead. If we had video files with 14bit that would be perfect. No need for any kind of s-log tricks, which improve dynamic range but introduces banding and other issues after grading.

  10. Nicolas, I've downloaded original 100Mbit versions from vimeo, not whatever they reencode for general viewing. Those are original files which come from the camera. Gordon makes them available for download if you are registered vimeo user.

  11. Is it just me or 1080p looks rather soft? I am comparing it with down scaled 4K version on HD monitor. I think Samsung is doing a much better job producing 1080p with minimal rolling shutter and fairly decent sharpness(surely it's not as sharp as 4K version, but difference is not as dramatic).





  12. 1.68X is relative to APS-C. So relative to FF it's gonna be 2.58X for cinema 4K. So working 4K area is gonna be smaller than GH4's 4K(which I think is 2.3X). Without speedbooster(not available for NX system) or fast short focal length native lenses I could see how it could be problematic. 

  13. DRIM Vs and crop is actually official info from Samsung NX500 product page, not just speculations. It even specifies 1.68 crop (relative to 1.54 APS-C) for cinema 4K and 1.77 for UHD 4K. http://www.samsung.com/sec/consumer/store-only/store-camera/product/EV-NX500ZAMIKR

    On US webpage it says DRIM Vs and only says about reduced field of view for 4K.


    Small raw buffer(for those who are interested in still photos) have been confirmed as well via Korean manual.

  14. really? You was nice to me despite insulting my wife under wrong assumptions? I just want a simple thing - normal field view, and not getting into the face as you wrote(you are the one proposing to get extra super wide lens, not me). I want to change lens when I need to change field view, not to keep it the same by going from still to video. I never even owned Panasonic camera and don't religiously worship any camera makers. I see no point to continue that descussion and therefore I am taking off. 

  15. ​You're right, sorry.

    Alex, do notice though that Ebrahim said exactly the same thing as you without:

    1) Spreading the fallacy that amateurs are less skilled than professionals.

    2) Describing a camera that he hasn't tried to use yet as "unusable".

    3) Dismissing the opinion of the many who could work around the crop factor with ease just because he can't or doesn't want to.

    ​The only thing I described as unusable was 4K, which is probably the main feature of this camera. 12-24mm is barely a solution in this case. At least in case of Panasonic you could have a speedbooster/lens turbo, which are not avaiable for NX system. All in, I think it was a bad decision by Samsung to provide 4K area which is smaller than 1" sensor.

  16. SleepyWill, which part of not wanting to swap the lens you are incapable of comprehending? I don't need 12-24mm lens, which is large, incredibly slow, and fairly expensive. If I have to buy it just to get 4K it would make more sense just to buy NX1 instead. I use prime 30mm on APS-C most of the time and need the same field of view for still and video. While I agree that pre-order on new products generally don't make sense, in this case we know what NX500 was suppose to be - NX1 minus weather sealing, EFV, 120 slow-mo, DR log profile, and having smaller buffer and slower burst rate. Samsung even initially advertised it having the same DRIMe V processing engine, but now changed it to DRIMe Vs. They clearly dropped a ball here, probably couldn't deliver what promised and changed it in the last moment. Classic bait and switch. Not sure where all that blind fanboyism is coming. Sounds like you are paid by Samsung to do a typical  damage control here. 

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