daktulus wrote:
Is the Metabones really 5x better than the Viltrox?
Can I professionally work with the Viltrox?
I've been working with a 4k and the Viltrox EF-M2 as a shoestring budget b-cam since the beginning of the year and I'm quite happy with it, a couple of things though:
-you get the extra one-ish stop of transmission just as with the Metabones, but at the cost of wide open sharpness, there's a bunch of comparison videos on youtube already that show this and my experience is the same, it's quite a bit softer wide open than the Metabones, not unusable but just not really good. So if you're into super wide open or very low light then the Metabones will perform better.
-the Viltrox is a bit wider, giving you a field of view comparable to the 4.6k sensor which is more at a 1.4ish crop rather than the 1.5 or 1.6 of the Pocket 6k, so you get the same very slight vignetting as on the 4.6k Ursas with some APS-C lenses. The Metabones 0.71 seems to be closer to the expected 1.5x
-I have not had any problems with iris control not working on the Viltrox on any lens I tried, but image stabilization is a mess right now, it just doesn't work with the current Pocket 4k firmwares that turn off the IS while not recording, you have to downgrade the firmware on the Viltrox to version 2.3 to enable the old "dumb" always on IS. None of the newer firmwares work right now, I hope they eventually release one that fixes this and reacts properly to the "new" IS behaviour. All while the Metabones seems to just work.
Other than that it's been really reliable so far, the construction is solid and if you clamp it down to the camera cage (it has the same attachment point at the bottom as the Metabones) then it's solid and tight with almost no play on the lens side on everything I used so far.
daktulus wrote:(Does HD BRAW use only part of the 4K sensor?)
yes, the sensor crops in to window for the HD readout, that's just how raw works - not counting the new 12k in-sensor scaling shenanigans.
So if you're shooting HD braw on the 4k you're not getting full sensor readout, a speedbooster doesn't change this.