John Sheehy

Lives in NY, USA
Works as a Retired Communications Technician
Joined on Jul 9, 2003

John Sheehy's recent activity

  • Replied in Questionss
    I did.  I haven't looked closely at the RAW data yet.
  • Define "more". More absolute shot noise means higher SNR, yes, but more relative shot noise means a lower SNR. Absolute is the actual variation from the average in photons; relative is the ...
  • There aren't two groups. This is a multi-faceted area of opinion. These are the facts as I see them: FF shines when it gives you shallower DOF, or your subject is still enough to use Av mode at ...
  • The 7D2 and to a lesser extent, the M6, have ridiculous amounts of sharpening applied.
  • Replied in Questionss
    It helps to have a RAW file to diagnose the problem, and suggest a work-around. It is possible to create software tools that fix RAW files. A small .exe, for example, could be written to take an ...
  • Perhaps, but sometimes base ISO comes up a little short on headroom, in some cameras (but not the 6D2). It would be safer to say that 200 and 160 have the same DR, because 160 is just 200 with 1/3 ...
  • Replied in More
    That's not true at all. The 5Ds collects slightly more light with the same exposure (except down around f/1.4), and has less read noise at low ISOs and only a hair more, as measured, at high ISOs, ...
  • Replied in Wrong?
    The 6D2 looks more sharpened than the rest
  • This is a nice extension to image stabilization, in cameras that re-align the multiple images before merging them. Not the most elegant way of dealing with subject motion, though, as you say. One ...
  • Replied in Which?
    I have clearly made distinctions about when pixel size matters and when it doesn't, and how much it matters for what. This specific case, base-ISO DR, benefits from a higher pixel density, for a ...
  • Replied in Which?
    No. There is no reason why the 6D2's 26MP should be expected to perform better than the 5D4, except that it is newer. Pixel size is not a major factor, except that image-level base-ISO DR does ...
  • Noise has a negligible effect on DR at the highlight end, for the pixel sizes and noise quantities we are dealing with; the highlight end is virtually a hard clip for most intents and purposes. Wha ...
  • Replied in Which?
    I really can not read a whole lot into the fact of an ISO 4M video camera with 2MP sensor. I have shot pushed ISO 4 million on my original 6D, and with a bit of scrubbing, I can get a result that ...
  • In any Canon that mathematically scales the original RAW digitization for 1/3-stop ISOs, PDR is incorrect for the top figures in the sawtooth shapes. You see, Bill does not actually measure the ...
  • Your reply suggests that you did not understand what I wrote. My point was NOT subjectivity including approaches to managing risk, but the objective fact that final SNR has just as much to do with ...
  • There is no such thing as a global "ISO cutoff" in my world, not even counting the possibility that a photo-op might be rare (and noise is more permissible). The amount of intended final ...
  • A comparison like this is distorted in small ways on so many fronts. At least one camera is chosen to be shown at 100%, which is always visually more pleasing than upsampled versions from other ...
  • Perhaps that is true if you need to shoot ISO 600 exposure at the ISO 100 setting, but the 7D2 has better high-ISO performance than any other recent Canon APS-C camera, and it has less read noise ...
  • No, you don't, which you prove by providing the link further down this post, which is not normalized for true ISO exposure index, or he quantity of pixels per sensor, or per unit of sensor area. Th ...
  • Replied in Am I paranoia?
    Do you strike deep? Do you creep into people's lives? The 6D2 has shadow noise at ISO 100 that Canon has moved away from in all of its other recent sensors, including ones in very inexpensive ...
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