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Graeme Nattress

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  1. "potential pedophiles taking pictures of kids at a public event" - I mean, it's a few years since I was back in the UK, but do such events that photographers appear at feature naked children, or children involved in sex acts? If so, I'm utterly shocked. If not, your statement is ludicrous. Or is it just "potential paedophiles"? What about "actual paedophiles" or are you not as concerned about them? "The threat in approaching any potential criminal" - surely there is no more threat in approaching a potential criminal than approaching any randomly picked person. I can see that approaching an actual criminal could indeed produce a violent situation, but potential criminals are just probabilities, and when it comes to a street photographer, a probability as close to zero as that of any other random person in the street. "moronically believing their civil rights are at dire risk" - but as the video above shows their civil rights were trampled on, and not just in that case, but in many others. It's their civl right to peaceably go about their lawful and peaceful hobby of photography without being accosted by Police. "they dare hand over their name and address" - because they don't have to and their right to privacy is just that, a right in any civilized society.
  2. Your friend was doing what the police are meant to do - pursue criminals. Your friend was not harassing photographers pursuing their hobby. The police in the above video were wasting their time, and that of the photographers on meaningless and pointless effort. It seems pretty obvious that when they're harassing a photographer they're not exactly putting their lives on the line for public safety. They are not even doing their job which is to allow people to perform their safe and lawful hobbies in peace - to allow the people to get on with their lives free from criminal disruption.
  3. And even if they are, it matters not because they'll download a better quality image off flickr than they can take themselves. Again, I see no reason at all to stop photographers, although putting my cynical hat on, I'd say it's much safer and easier for the police to stop a photographer than to stop a terrorist, and that in doing so they're putting their own safety ahead of that of the society they're pledged to protect. And if there was evidence it would certainly be touted as rationale for these police when they're made to be accountable for their anti-photographer acts, and it would also mean that the Metropolitan police advice to their police that photography is not a crime would not have been given.
  4. And who's fault would it be then? I see no evidence that either criminals nor terrorists go around taking photos pretending to be tourists. None. And as for the difficulties the police have, perhaps it's because they're wasting their time pulling photographers up on nonsense charges rather than actually doing their jobs? Surely the job of the police in any reasonable society is to protect it so that hobbyists can go about their hobbies in peace without being locked up, or bullied into moving on?
  5. Dynamic Range is a measure of a camera system - how far it can see into the shadows and how far it can see into the highlights. Dynamic Range can be measured objectively, but even then there's a subjective component as each and every viewer will have their own noise tolerance threshold. This governs how much of the shadow part of the dynamic range they find actually usable. Latitude is related to Dynamic Range, but it is also scene dependent. Latitude is the degree to which you can over or under expose a scene and be able to bring it back to a usable exposure value after recording. It is dependent upon dynamic range, which is going to set the overall boundary of by how much you can over and under expose, but it's limited by the scene too, and how bright and dark the scene itself goes. Say a scene has a range of brightness of 5 stops (a typical Macbeth chart for instance), and let's use a camera that has a 12 stop dynamic range. If we place the scene in the middle of that camera's recordable range, we have 7 stops to play we can we could over or under expose by 3.5 stops and still recover the scene. But if the scene was a real world scene of actor against a sunlit window and the range of brightness of 15 stops, you don't have any latitude at all - no matter how you expose that scene you're going to loose shadow or highlight information. So yes, Latitude and Dynamic Range are related, but different. Often people who really should know better use the term Latitude when they mean Dynamic Range, and indeed that's quite common. Graeme
  6. That sounds like a most interesting shot - looking forwards to seeing what you've done.
  7. My argument from above is that all cameras regardless of manufacturer or sensor technology have a performance which is determined by actually measuring the camera system, rather than looking at an image container specification. I wholeheartedly agree that performing good measurements is the only real specification that matters, and yes, you should (and we do) look at resolution across colours. When we do so, we find our cameras actually perform very well indeed. Graeme
  8. We clearly stated what the the measured resolution would be of the camera system right from the start, and indeed, were actually a bit conservative on that figure as in practise we have achieved more. That is not dishonesty. We have always described the nature of the sensor and colour filter array pattern used, number of pixels, measured resolution of the camera system as a whole. Just as when you do a 4k scan on film, you don't actually see 4k measured resolution from 35mm film - it's somewhat less, and different in each of the RGB channels too, the 4k refers to the container rather than the actual measured resolution of the image content. Similar with video where even VHS had the same 576 or whatever lines as the broadcast TV used for picture information, but the horizontal measured resolution was somewhat less, or HDCAM where one of the compression steps was to reduce the 1920 to 1440, or DVCProHD where they did 1280 to 960. Even with cameras, the only way that can achieve a measured resolution equal in size to the container format is to allow for such excessive aliasing as to render such resolution advantage useless. So, the measured resolution in percentage terms compared to the container resolution for RED is similar (often better) than that of 1080p cameras. "And I don't prticularly rate F35 or Genesis, either." Ah, finally something we can agree on! I knew it would occur one day, but wasn't quite prepared for it to happen today. We probably agree on other things too... Graeme
  9. With any camera system (lens / filter / sensor / recording / image processing), and it doesn't matter who makes the camera, there is the size of the recorded image, and there is the amount of detail that can be measured through the system. With every camera, there's a a container specification, and a measured result. Graeme
  10. Sensor in RED One is active area of 4520x2540, or 11.4mp. In normal shooting, the area beyond 4096x2304 (or 4480x1920, or whichever shooting mode you're in) is used for look-around so that you can see what is coming into shot before it gets into shot. When we're talking sensor pixels like this, we're talking exactly the same as Canon and Nikon etc. are on their digital stills cameras in stills mode. Graeme
  11. I thought he was making a compelling argument that 11.57 was greater than 12, with his statement "beyond 12:1 by even the most generous calculations.". So here we have in the "students ask questions here" section of the forum, someone asking some pretty reasonable questions to help them understand more what's going on, and Phil comes in with his "point of order" which is incorrect, and demonstrably so using basic high school math. Phil also knows that so called "1080p" cameras don't actually measure 1080p resolution. They're called that because they live in a 1080p container, but we know that actually measuring resolution is the only way to know what the resolution of the system really is. When we measure the highest-end of HD cameras (Sony F35), we see resolution that doesn't reach quite out to 1920 horizontally, and fine detail corrupted by significant chroma aliasing and mis-alsignment of the RGB channels. We also see rather strong vertical luma aliasing that is strong enough to make it through to broadcast, rather than just appear on test charts. With video, digital or otherwise, there has always been a disparity between the resolution of the container and the measured resolution of the underlying image. That is why we told people initially that although a sensor might record 4k samples across it's width, the measured resolution would be around 75% of that. When we did our first actual measurements we found that number to be 78%, and now with advances in compression and processing techniques, we can see up to 85%. Similarly, charts show very low luma aliasing and chroma moire, because it's not worth having a high measured resolution if most of it is corrupted by aliasing. Graeme
  12. 4.5k wide mode is 4480x1920*12bits*24fps is approx 295MB, giving slightly lower compression ratios than the 4k 16:9 mode I used earlier. Phil - I see that people are posting here asking questions to help them understand things. Surely that's what this forum is about, not picking fights whenever anyone asks a question about RED, and then giving them wrong information. Graeme
  13. Point of math: 4096x2304x12bit*24fps = 324MB/s. RC28 ~28MB/s, which is 11.57:1, which is less than 12:1. RC36, about 36MB/s leads to 9:1, and RC42 leads to 7.7:1, approximately. There is full demosaicing in hardware, which you can tell by pressing the 1:1 LCD view switch, which passes through a crop of the full demosaiced image to the outputs. Graeme
  14. I said the reference was nebulous, not the image quality of film. "Film" is not one thing you can point at with a single look or character, hence it forms a nebulous reference - a reference cloud so to speak, rather than a single point. Graeme
  15. In motion picture imaging, film is a well known (if somewhat nebulous) reference point. Because we mention film as a reference point doesn't in any way constrain our thoughts on how things should work or look. Other than to say that, there's no real way to answer your question, other than that we don't feel that comparisons or references are constraints. Graeme
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