Ciao vga256,
thanks for the feedback!
I'm constantly shooting 1832 x 1024, 14-bit lossless, with FPS override @24 fps (resulting in 23.971 or 23.984 fps, heaven knows why).
For most scenes, this results in continuous shooting for me. In very extreme circumstances, where I have a very very wide dynamic range, I have to turn SD overclock on via the sd_uhs module. With SD overclock activated, in my personal (and limited) experience I have seldom encountered full buffer and abrupt stop in the recording. But still, of course, it may happen, depending on the scene.
Another consideration: I love the Sigma 18-35, although I use it more for stills. For video, after some time (and money) spent trying other (not-too-expensive) glass, I must admit that I find the good old 18-135 IS STM kit lens nearly unbeatable. Its focus accuracy and speed is unbelievable when coupled with the 70's dual pixel AF, its motor is the most silent I've experienced, and it has IS, which is a game changer for video. With it, I shoot constantly at f/5.6, which (apart from providing a nice intermediate focus depth for most circumstances) I find to be the strong spot for this lens (also as confirmed by dxomark tests, see here:
https://www.dxomark.com/Lenses/Canon/Canon-EF-S-18-135mm-F35-56-IS-STM-mounted-on-Canon-EOS-70D---Measurements__895, particularly for sharpness), with a 3-stop (ND8) ND filter that allows me to have a proper ETTR setting with a ~180° rolling shutter (1/50s shutter speed) in most situations (I may need to stop it down to f/8 with very bright subjects in direct sunlight). I find that its structural lack of sharpness is negligible when shooting video @ 1832 x 1024, while of course other weaknesses, such as chroma aberration, vignetting etc can be corrected during post-prod if you shoot Raw. Would love to hear any comments on this.
Happy (Raw) shooting!
Sergio
Ps: I also tried resolutions higher than 1832 x 1024 via the 5X zoom trick, but I really find it hard to consider this option as anything other than a technological capability demo. I used it to shoot some portraits of very distant neighbors chilling out on their home balcony during peak COVID stay-at-home lockdown past spring, and the 5X zoom was exactly what I needed. But apart from that specific situation, I wish somebody explained me how to use this feature in real life.
