Blackmagic Forum

I own a BMPCC4K and mainly shoot 4K BRAW.
As far as I know I use the full MFT sensor of the BMPCC4K in 4K BRAW, right?
(Does HD BRAW use only part of the 4K sensor?)

With a BMPCC6K I could only shoot 6K BRAW, which is too much for my PC to handle.

But I want to shoot Super35 to get the cinematic look/FOV.

Does it make sense to prefer a speedbooster on the 4K to get S35 FOV over buying a 6K?

If so, is the Viltrox reliable for EF-lenses with AF, lens stabilisation, electronic iris control or must it be the 5x more expensive Metabones adapter?

Is the Metabones really 5x better than the Viltrox?

Can I professionally work with the Viltrox?

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.

The crop factor with the Metabones SoeedBooster for BMPCC4K Ultra 0.71x is 1.349x so that’s actually a little wider than traditional Super35. In comparison the crop factor on the BMPCC6K is 1.56x half way between Canon APS-C and Nikon DX film gates.

My advice would be to not use a speed booster. I found that even the most expensive 0.64x Metabones degraded image quality too much. It's not just about sharpness, it also increases distortion and introduces some ugly flares. You could use wider faster glass to get exactly the same look. The Sigma 18-35 (non speed booster) is a very nice range for a standard zoom on the P4K. Or you could use the 6K.

Take a look...


M43 vs Full Frame (Same Focal Length Characteristics)
https://r.tapatalk.com/shareLink/topic? ... source=app

@plzbrt

plzbrt wrote: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

Where do I get firmware 2.3?
It is not on their website. Can you upload it?

One Amazon VILTROX EF-M2 II reviewer (tested on BMPCC4K) says: "The focus changes when zooming, the adapter gives the whole a blurred vintage look and it wobbles on the camera."

Viltrox says their adapter doesn´t work with the BMPCC4K.

But you can confirm that you have no problem at all (besides IS that is fixed with FW 2.3)?

daktulus wrote:@plzbrt

plzbrt wrote: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

Where do I get firmware 2.3?
It is not on their website. Can you upload it?

One Amazon VILTROX EF-M2 II reviewer (tested on BMPCC4K) says: "The focus changes when zooming, the adapter gives the whole a blurred vintage look and it wobbles on the camera."

Viltrox says their adapter doesn´t work with the BMPCC4K.

But you can confirm that you have no problem at all (besides IS that is fixed with FW 2.3)?

Here's the link to 2.3:
http://www.viltrox.com//en/uploads/20180409/1523262824121293.zip

Yes, there's a bit of play on the camera side with the Viltrox, but it's exactly the same with the Metabones I tried on my camera. You have to screw either of them to the cage, I use this little bracket on my Tilta cage: https://tilta.com/shop/lens-adapter-support-bracket/

The backfocus of the adapter can be adjusted by moving the glass element inside, it rotates on a thread, same as with the Metabones. If you have any parfocal EF lenses then you need to adjust that for the parfocal zoom to sit right.

Just to confirm what @plzbrt wrote.
With v.2.3 works even ibis on Canon 24-105mm mk2, also autoWB button reacts as well. Autofocus no.
I had 3 Metabones speedboosters earlier in past, so I can't provide direct and actual comparison, just impression. Besides risk with QC, Viltrox EF-M2 II is as capable as metabones up to f2.8 on lenses. Its focal reduction is around x0.685
So, as far as results go with nice example of newest Viltrox adapter, I think there's no reason to spend money for Metabones. But it seems obvious from reports that QC is not nearly as good as Metabones - I don't know if in that regard it is maybe better with mk2 version.
Also I can't say anything about durability after extensive usage - time will say.

Can I use EF-S lenses or only EF with the Viltrox?

Has anyone tested if the new Viltrox firmware 3.3 and 3.4 work for AF and iris control on Canon EF-S lenses?

I have some Canon lenses that have no IS, AF would be more important.

AF doesn't work.
I have a very good experience with Viltrox EF M2 II with the quality, as @plzbrt mention and very good explained.

If you want AF with Canon EF lenses to work consistently, you need the EF mount camera, like the Pocket 6K.
Cheers