Blackmagic Forum

Hi,
I just had a thought... if BM would use their new autofocussing firmware to control a focus motor (maybe develop their own one, or partner with some brand...)...
The Camera AF could directly control the focus of the cinema lens then!

would be very nice, eh?


regrads
Mike

Michael, if you mean the PDAF sensor pixel-based firmware BMD is developing now, yes that’s a possibility. The LiDAR technology relies on radar-style distance measurement and might also be available if there’s no patent issues applying the technology to cameras. Were you suggesting BMD develop their own LiDAR code?

Hi Rick,

I was suggesting, that -- since the new pixel-based AF -- the camera already knows, what is sharp.
So it's easy to e.g. have their own focus motor powered & controlled via USB-C to keep the focus correct.

regards
Mike

I wonder why other camera makers haven’t done this. Perhaps there’s a technical reason it’s not feasible. Or maybe nobody’s thought of it yet.

Thanks, Michael. Yes that would be a great feature for me since my lenses are all manual.

Most photography/hybrid cameras uses PDAF to drive motors intrinsic to AF lenses.

Cine cameras typically use 3rd party LIDAR to drive external motors on manual lenses. DJI uses their own Focus Pro (an outdated version in fact) on the Ronin 4D to drive either AF lenses with internal motors or manual lenses with outboard motors.

It sure seems BMD could use the new PDAF system for AF L-mount lenses to control outboard motors. PDAF is generally superior to LIDAR too, except for very low light, plus one less thing to mount, no concerns about obstruction from say a matte box, or of course calibration based on mounting location.

Hopefully BMD is already planning to implement this, as a company making dedicated cine cameras. Obviously they need to perfect the PDAF system for AF lenses first, then adapt it to external motors with manual cine lenses. While film crews may always prefer manual focus, for single users AF is sure nice to have.

Uh no. Nothing is going to be more accurate than LIDAR. That is just silly. Just ask any Tesla owner with self driving....

ekultra wrote:Most photography/hybrid cameras uses PDAF to drive motors intrinsic to AF lenses.

Cine cameras typically use 3rd party LIDAR to drive external motors on manual lenses. DJI uses their own Focus Pro (an outdated version in fact) on the Ronin 4D to drive either AF lenses with internal motors or manual lenses with outboard motors.

Well no. Cine cameras on drama use focus pullers who may or may not use distance rangefinders. They typically give indications but are rarely used to drive focus.

This is because there’s an element of performance with focus pulling that relies on someone understanding the timing and choreography of when to direct the gaze of the audience to a different part of the frame.

I believe the main problem of LIDAR for advanced focus applications is that it’s only really good for distances closer to camera. You can’t really use it when something is say 50 meters away to discern what should be in focus when you also have stuff that’s 51 meters and 49 meters.

JB

Yeah it’s really for doc and one man band operations.

John Brawley wrote:… Cine cameras on drama use focus pullers who may or may not use distance rangefinders. They typically give indications but are rarely used to drive focus.

This is because there’s an element of performance with focus pulling that relies on someone understanding the timing and choreography of when to direct the gaze of the audience to a different part of the frame.

I believe the main problem of LIDAR for advanced focus applications is that it’s only really good for distances closer to camera...

JB

This middle paragraph above is essential in any recording and can be best performed by an experienced focus puller. An automated continuous focus doesn’t know your intentions for a shot, but it’s my understanding that the Preston Ranger II does allow you to make focus changes among different actors for instance in a two or three way conversation. DJI Focus Pro also has provision for back and forth focus on whomever is speaking next but I leave it to those with experience if they want to comment.

A traditional focus pull between two predetermined locations is very limited compared to what is made possible by having more options in a modern rangefinder. It’s just another tool that still benefits from being controlled by you.

I feel a LiDAR solution is best for me as a sole operator but the cost is a consideration. Someday I may be able to speak from a position of experience rather than theoretically.

I think having external motor capability for the BM autofocus would be awesome and make smaller rigs possible for run-and-gun one-man operation, especially for PL mount lenses. This would really help with my my latest experiments in minimalistic rigging for my Pyxis so I can use it more like I would my Sony camcorder. Having a native PL mount, not an adapter on an L mount, lets me put a cine parafocal zoom lens on the Pyxis without supports, but having a PL mount Pyxis means I will never be able to use the current BM auto-focus.

I have the DJI Lidar, and one of the best and most essential pro features of their autofocus that BM should include in this current implementation is overriding the autofocus manually on the fly. While I don't expect the BM existing camera hardware to have force feedback like the DJI, where you push against a phantom focus puller on the dial allowing you to override or slow down the autofocus and then let go when you want the autofocus to take over, if I had an L or EF mount Pyxis with an autofocus lens, even just using the dial on the left side in a manual override mode would be great. The way I would envision this, autofocus would work until you turn the dial, then manual would take over and you could quickly press the focus button just above the wheel to re-enable. The point is that I don't have to turn off autofocus, simply moving the dial allows manual to take over, and then I can turn it back on.

All of that being said, manual focus on digital cameras is so much easier than on film, where you really need a tape measure and actors who follow directions on where they are supposed to stand and walk.

Given I don’t expect to purchase a Pyxis 12K until 2026 and given that by then I expect BMD will have a firm of continuous auto focus tracking on the Pyxis 12K by then, it will be interesting to see how DJi Focus Pro may evolve by then as well. Sometimes there are benefits being late to the party.

I’ve worked with both focus pullers and the DJI Focus Pro and I prefer the former every time.
I’ve NEVER had autofocus until the DJI thing came out and the times I use it are when I’m doing a specific move. Otherwise I’m just pulling manually.

Oh yeah there’s no comparison. A human artist who understands what you’re trying to accomplish or a tool you have to program? Ha!

I would rather Blackmagic create their own DJI Focus Pro.

John Brawley wrote:

ekultra wrote:Most photography/hybrid cameras uses PDAF to drive motors intrinsic to AF lenses.

Cine cameras typically use 3rd party LIDAR to drive external motors on manual lenses. DJI uses their own Focus Pro (an outdated version in fact) on the Ronin 4D to drive either AF lenses with internal motors or manual lenses with outboard motors.

Well no. Cine cameras on drama use focus pullers who may or may not use distance rangefinders. They typically give indications but are rarely used to drive focus.

This is because there’s an element of performance with focus pulling that relies on someone understanding the timing and choreography of when to direct the gaze of the audience to a different part of the frame.

I believe the main problem of LIDAR for advanced focus applications is that it’s only really good for distances closer to camera. You can’t really use it when something is say 50 meters away to discern what should be in focus when you also have stuff that’s 51 meters and 49 meters.

JB

Very true. LIDAR range is low. I was thinking about simpler scenes with relatively close subjects. More complex scenes when there is intent to change focus to specific subjects to draw attention is a completely different scenario. I do not see focus pullers being replaced, even with AI.

Guys, that's not the topic
I agree on focus pullers are better, but LIDAR is there, and BM announced AF in their firmware.
For one-man shows, these are big helpers, let's say, better than nothing...

regards
Mike

Without having used DJI LiDAR Focus Pro, it seems to me to be a very good assistant for a sole operator where the camera operator indicates where, when, and who is the principal focus. A real focus puller knows this and also knows the how it’s applied (if a variable rate of the change of focus between various principal foci is appropriate) as the artist.

A sole operator likely can only set focus points but not control the variable rate of changes between points as the scientist who monitors more than participates. The tool makes it easier to get a good shot for a sole operator who might overshoot a change of focus and possibly could help a dedicated focus puller.

I think the radar AI aspect is very helpful when light is lower and when apertures are somewhat larger. So it’s a tool that helps achieve a cinematic result. I can see where the tool might not do the best job when apertures are very large unless it can be trained on eyes or something that remains in view. The focus puller is more flexible as they understand the shot.

Warning, tangent ahead!
I don’t know about you, but I’m growing weary of the term ‘artificial intelligence’ because it’s misleading. The tool certainly can be cognizant (recognize things) but it’s absurd to think it understands things. Intelligence implies understanding. Just because we qualify the tool’s skill by calling it ‘artificial,’ most people put too much trust in the ‘intelligence’ of the tool. ‘Artificial cognition’ just doesn’t have the same cachet.

Fun little factoid but the manufacturer of my high end servo subwoofers (Velodyne) was so successful with their lidar tech that they gave up on the subwoofer part of their business. Luckily after years of inactivity they finally sold it to a German company who would continue developing and servicing the subwoofers.