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    The largest online community devoted to anamorphic filmmaking.
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    • You're right and I'm wrong. I misread your post. Again, I'm not an engineer, just interested in how things work. I thought what you were implying is what I used to (incorrectly) think: a 4k sensor can only resolve 2k before it begins aliasing. Because Nyquist says you can resolve 50% of the frequency before aliasing. And... a lot of great 2k images come from 4k downconversion... so... it makes sense... The truth, however (I think) is that a 4k sensor can resolve all the way up to 4k without aliasing... because there are two pixels in every line pair and 2 * 1/2 = 1.  But... this is only so long as that 4k image represents, for instance, a 4k zone plate with resolution equivalent to fewer than 2048 sinusoidal gradients between black and white (line pairs, but in sinusoidal gradients rather than lines): But the zone plates in the links above are black and white like pairs. Hence infinite odd order harmonics (or actually I think square waves would be right, not sawtooth waves, which would mean every harmonic is represented? I don't know the equation for a square wave): So yes, the F65 looks just great, but those resolution charts will theoretically cause problems for any sensor so long as the resolution isn't being reduced by the airy disc and/or lens flaws. Because black and white zone plates like the one above are of theoretically infinite resolution so you need a high pass filter elsewhere in the acquisition chain or anything will alias. Anyhow, I just think it's interesting that non-sinusoidal resolution charts represent, in theory, infinite resolution at any given frequency because of the higher order harmonics and that anti-aliasing filters are, ultimately, fairly arbitrary in strength, and tuned more to taste than to any given algorithm or equation, and only one small part of a big mtf chain. Nature abhors a straight line let alone a straight line with infinite harmonics so in most real world use the aliasing problems seen above will not present themselves (though fabrics and some manmade materials and SUPER high contrast edges will remain problematic and I see a lot of aliasing in fabrics with the Alexa and C300, the cameras I work with most, as well as weird artifacts around specular highlights). In conclusion, you're right and I am definitely wrong as regards my first post; I misread what you wrote. And if I'm also wrong about any of what I've written in this one I'm curious to learn where I have it wrong because ultimately my goal is to learn, and in doing so avoid misinforming others.  This also explains why the F3 and Alexa share a similar sensor resolution less than twice the (linear) resolution of their capture format. Bayer sensors seem to be about 70% efficient in terms of linear resolution and 2880 is slightly greater than 1920/0.7. Canon's choice to oversample by a factor of 2 with the C300 was just due to their lack of a processor at that time that could debayer efficiently enough I think, nothing to do with Nyquist. 
    • * Bitrate of at least 240 Mbps (at 23.98/24 fps) recording So after the '400Mbps' firmware update, 4K 10-bit log GH5 should be good to go!
    • I haven't use the A6500, however if the Pocket's HD looks like it has more real resolution vs. the A6500 that means that the Pocket is storing more real detail in the output file. E.g. the A6500 is doing a form of binning etc. that results in loss of detail (information) and thus lower resolution is captured. As you've seen with the C300 I, a 4K sensor with a decent oversample to 1080p results in excellent resolution 1080p. The C300 I is a special case- it averages two sets of greens to get 1080p, and takes R & B as is, thus no deBayering takes place, and the results speak for themselves. So 'Ks' on the sensor side and how those K's are processed into the desired output do indeed make a huge difference. Best results for 1080p on the A7S II and GH4 was to shoot 4K and downsample in post (probably the A6500, too example here*, what artifacts are you seeing- is in-camera sharpening turned off?). Hasn't it been clear for years that some cameras provide much more detailed 1080p (and now 4K) than others? The standard way to test real resolution to validate (or invalidate) camera manufacturer resolution claims is to shoot boring (and controversial, lol) test charts! Like Geoff Boyle does here: https://vimeo.com/geoffboyle * this 4K video looks much better- very detailed! He's using a tripod so that helps with compression artifacts. That's one way to work around low bitrates- keep motion to a minimum. Another way is to record externally at a higher bit rate.
    • Pocket HD is noticeably better than A6500 HD, and I'd like to know why. Sure, low data rates, the way it is downsampled in-camera. Indeed the A6500 UHD 100mbps provides better HD, but on closer look there are still artifacts. I have footage from a borrowed C300 to compare, and the 1080p is pristine in comparison. I also have 4k from a borrowed BMPC and UHD from my buddy's FS7, and that's a whole different league. No wonder, you say? Yeah, but doesn't this confirm the statement that "Ks" don't tell you anything?
    • Cool video. You are a natural talent with a great eye. Man, I wish you would make a feature narrative. That cool house of yours would be an awesome location for a dark, Swedish thriller. Yeah, I pretty much talked myself out of the A7ii earlier today... of course I may have talked myself into waiting a couple months and buying a GH5... Ugh... Haha, I'll probably just use only my 5D3... but I do want a camera with IBIS. But like I said to Jase, once I start investing over a thousand into the e-m5mk2, I may as well throw in the extra for the extra features of the GH5. It never ends.  Have you ever used the SLR Magic 17mm? As of now it seems like I can't go wrong with either the Olly or the SLR Magic.