tron said:
This was very informative. Maybe this information was available elsewhere but I just noticed (apart from the fact I had already read that fps is not increased in crop mode...) So this is crippled intentionally for landscape and studio users and many 7DII users report AF problems. So it seems that there are no camera solutions when we are FL limited at least for birds... I am sticking with my 5D3s for now...
No, it is not "crippled" intentionally to fit a profile - instead they defined the camera's niche by catering to its strengths. The software is limiting the ISO sensor output - And I'd make an educated guess that's primarily because of the image processing size. The camera can't apply as much NR and in-camera correction at the max output and still maintain a "Canon acceptable" frame rate for the buffer size - considering its not using C-Fast or UHS-III (as far as I can tell). There are only so many mbps you can push through the pipe at UHS-I class 3 (30mbps to be precise) where as a UHS III class 1 can achieve 220mpbs. C-Fast is as fast as many SATA SSD disks (up to 6gbps with current tech), because that's what it is only with a more rugged interface connector. But its rare, and C-Fast has the commensurate price to show it. By not using either of those formats, they limit themselves in A) data transfer rate from device to card and B) the amount of time for in-camera processing before it
must pump the bits to the storage device to clear space for the next frame.
The sensor is nearly the same pixel density as the 7DmII, but covers almost 62% more surface area. Without dumping a much more powerful processor (or a pair of them) into the frame, they were never going to be able to hit the same processing performance - especially at very high ISO - as the 7DmII. The algorithms eat a *lot* of processing, and increasing the processing area (surface area pixel count) is squared in terms of processing costs. So its not 2*T, its T^2... and a bit, and that assumes no increase in pixel color depth.
So rather than let very noisy images get out in the wild straight from the camera, (or have substantially longer times for writeback, and commensurately larger files) they chose to cap ISO at 12800, although going over 6400 is probably not wise. They actually do the same with all their cameras given the technology of when they're made. With current technology, you're not going to get very many more MP than what the 5Ds/5Ds R/7DmII have because of the limitations in physics. Some things *can* be done... but they're esoteric in nature and deal with complex computational algorithms or interesting adjustments to chip manufacture such as Back-Side Illumination. You either interpolate a proper image using calculation, or you increase photoreceptor size/efficiency. The physics (and physicists) are
not going to budge, unless someone develops warp drive. And even then... probably not in our lifetimes.
The 7DmII issues are likely limited to a few bad bodies that made it past QC, a few users who haven't compensated for the higher pixel density, and a few users who didn't bother to calibrate their lenses. Remember, "a few" when you're talking about several thousand produced bodies can easily number a few dozen per thousand. And even a few of them, posting on every site they can, can make a camera seem like a real problem.
Does the 7DmII body have an inherent design issue? No. I had a "problem" 7DmII body, AF/Soft focus across the board. I noticed the issue right away and after some consternation exchanged it within two weeks. The second body has been perfect and is beyond my expectations for an APS-C sensor.
By the way, the 5DmIII sensor is one of the best sensors produced by Canon. Other than some features, you are certainly not sacrificing anything to stick with it. If you get a 5Ds/5Ds R (or a 7DmII), you're going to be disappointed at 100 percent crops cause there
will be noticeably more noise on the 5Ds at anything over ISO 400 - and over ISO 1600 on the 7DmII - depending on the camera settings and in-camera NR. The 5DmIII's pixel density is far less than most APS-C cameras, and is certainly less than a 5Ds/5Ds R/7DmII. That means the 5DmIII will have less noise, all things being equal - and if noise is your image quality determiner, the 5DmIII will win
every single time. That part is physics at play. Outside of construction and build quality, everything else falls to the user and their experience with the tools at hand.
Just my opinion. Your mileage may vary.
.
