A new follow focus system that may change the way you work

Hi all,

We are working on a new Kickstarter project that may change the way you pull focus with your Blackmagic Camera.

We are designing a new follow focus system that directly talks to the camera and the lens. It allows you to pull focus with a AF photo lens with the same level of precision as a Hollywood camera setup with a cinema lens.

Here is a link to a preliminary showcase video of our first prototype:

We would like to know how much interest there is for such a product, and how much do you want this system to work for your camera of choice. Specifically, are you willing to purchase this product if it supports a Blackmagic Camera for direct internal focus pulling?

Please tell me your specific model of Blackmagic Camera, and your go-to AF photo lenses.

thanks a lot,

Jack Lam
MOVCAM

It allows you to pull focus with a AF photo lens with the same level of precision as a Hollywood camera setup with a cinema lens.

It’s not for me. With that out of the way, I do have two questions.
1] Is there an option to make zoom lenses behave parfocal?
2] A photolens is just that. The internal motors are made to move the lens groups every now and then. When used for focus pulling how will this influence the motors live span? Is this ever tested over a longer period of time? I wondered the same when BM came out with their focus and zoom demands, but they never posted on the forum.

Success with the project.

I mean, I don't use Still Lenses on my Blackmagic Cameras anymore. I'm all in on PL with Cinema Lenses. What I would like is a Wireless Lens Control System that allows you to map a lens and save lens profiles. At the same time I'd love for it to communicate with the Blackmagic Camera, and potentially store those Lens Profiles in Camera Metadata. Then it would be great if those Lens Profiles were recognized in DaVinci Resolve, and allowed for lens corrections in Resolve based on that Lens Profile. But for production when you put that lens on the camera and load that lens profile the lens motor system provides the properly mapped focus and iris info on the hand unit system.

Teradek and Arri do lens profiles for their units that can be saved and used again in the future. But no camera communication except for the Arri with the Arri cameras. Arri does have some camera communication with their Hi-5 for some other higher end cameras, but still, would love for Blackmagic to be more open to this.

I love it, for BM Ursa's and Canon EF lenses. I'm interested. You could *really* have something desirable if you put or integrate those controls into a side panel of a battery powered wireless MOVCAM monitor, where you could operate the camera from something resembling a tablet.

I like it for the Blackmagic URSA Mini Pro G2 with EF lens mount and the Blackmagic Pocket 64 with EF mount too. Much of it depends on the price point and workability of the follow focus. As to lenses, if we are talking about photo lenses, I will say the Sigma ART 18-35mm f/1.8, and the Canon L series lenses on the EF mount.

Sounds interesting. The option to connect P6KPro with Ronin RS2 and pull focus with internal lens motor by using index finger on the gimbal dial has been pretty intuitive. I've used it a lot with P6KPro + Sigma 18-35, especially now while filming a trailrunning doc and other sports. I can see a market for this. I am guessing Sigma 18-35 is quite popular among P6K users.

Thank you for your questions.
1) Very good question. Panasonic LUMIX S zoom lenses have an internal data table that automatically compensates for any focus shift. So they behave like parfocal zooms via electronic compensation. I don't think Blackmagic cameras + EF lenses have such compensation built in their design.

2) Good thoughts on motor lifespan. We haven't don't scientific tests on this issue. But I have personally used this prototype with a S1H to shoot a short film, and it has performed well. We did have a few software bugs at that time, which were fixed ever since. We never had problem with the AF focus motors themselves.

thanks again for your questions.

It allows you to pull focus with a AF photo lens with the same level of precision as a Hollywood camera setup with a cinema lens.

It’s not for me. With that out of the way, I do have two questions.
1] Is there an option to make zoom lenses behave parfocal?
2] A photolens is just that. The internal motors are made to move the lens groups every now and then. When used for focus pulling how will this influence the motors live span? Is this ever tested over a longer period of time? I wondered the same when BM came out with their focus and zoom demands, but they never posted on the forum.

Success with the project.

What you described about lens metadata sounds like a very nice product idea. At the same time, I'd imagine it will take a very committed collaboration with BMD and lots of engineering efforts to make this into reality.

In the meantime, if we do end up adding support for BMD cameras, our product will still be a great option for users of cinema lenses because it comes with a powerful & responsive lens motor. Plus it will probably supports remote control of many camera settings.

We are paying close attention to the demand of BMD camera users. I certainty hope good things will happen in the future.

Jack

I mean, I don't use Still Lenses on my Blackmagic Cameras anymore. I'm all in on PL with Cinema Lenses. What I would like is a Wireless Lens Control System that allows you to map a lens and save lens profiles. At the same time I'd love for it to communicate with the Blackmagic Camera, and potentially store those Lens Profiles in Camera Metadata. Then it would be great if those Lens Profiles were recognized in DaVinci Resolve, and allowed for lens corrections in Resolve based on that Lens Profile. But for production when you put that lens on the camera and load that lens profile the lens motor system provides the properly mapped focus and iris info on the hand unit system.

Teradek and Arri do lens profiles for their units that can be saved and used again in the future. But no camera communication except for the Arri with the Arri cameras. Arri does have some camera communication with their Hi-5 for some other higher end cameras, but still, would love for Blackmagic to be more open to this.

regarding

"1) Very good question. Panasonic LUMIX S zoom lenses have an internal data table that automatically compensates for any focus shift. So they behave like parfocal zooms via electronic compensation. I don't think Blackmagic cameras + EF lenses have such compensation built in their design."

EF lenses provide zoom position on Pocket 6k at least that I tested. also the lens I tested provided also the updated focus distance when zooming. It would be just making code that corrects focus, I wonder why they have not made that in camera as an option to activate.

viewtopic.php?f=2&t=171985

Can this be combined with a lidar autofocus system or am I getting technologies crossed?

I want it for my p4k.

Ricardo Marty

For me this is too much like the nano. I got rid of it because I don't have the time or patience to fiddle around with LCD screens on set. I upgraded to a manual ff with physical AB knobs and I love it. I don't have to remember settings. I don't have to calibrate or worry about batteries or read a manual or stumble through menu structures. Set focus, move knob, done. Back to making the movie.

This may be different for DPs using focus pullers but the negatives remain. Make a wireless wheel with physical knobs and no screen and I'll buy it. Maybe. This wouldn't help with vintage lenses or as someone pointed out, (which I've never had the fortune of using) cine lenses. Plus the receiver taking up that much space is a hard sell for a small rig like you get with the bmpcc.

Not meaning to be a negative nilly. It's best to go into these things with an understanding of the challenges you'll face.

For me this is too much like the nano. I got rid of it because I don't have the time or patience to fiddle around with LCD screens on set. I upgraded to a manual ff with physical AB knobs and I love it. I don't have to remember settings. I don't have to calibrate or worry about batteries or read a manual or stumble through menu structures. Set focus, move knob, done. Back to making the movie.

I second this. If you’re on set, the manual FF are much easier and faster to get things going and pull focus.

Make a wireless wheel with physical knobs and no screen and I'll buy it.

Add the AB knobs or be blue to remotely set it and you’re golden, and of course price it affordably. Maybe, I’ll buy it too.

These have been out since the days of the 5DII, well over a decade. The general concensus is that certain lenses will work better than others, the limiting factor being the granularity and precision of the lens’ motors. Google USB follow focus and at least a dozen different models will show up. The OKII was the first, the Aputure looks to be the most featured. If they were any good I imagine people would be using them, there’s likely a reason they’re not.

Good Luck

Yes, it depends much of the lens. Some inexpensive EF SMT have good and silent focus, almost all L lenses have good focus, but not so silent. Newer lenses have smooth iris, the iris is still with steps but moves smoothly in between.

I think they are good for many uses, and BMD now finally have the EF lens control on good level. The lens also returns the focus distance and zoom, but not very accurately. The control is kind of absolute, but easy to throw that off by manually focusing, so yes there is limitations. Also the BMD USB PTP control, the basics are good, but much to improve, some clear bugs also.

The RF lenses would be much better suited for video tasks, but proprietary interface, EF was never designed for video, but on the later models, I think they have tried to improve that within the limitations of EF protocol.

The photography lenses in general are not that good for external servos. their focus and zoom do not work smoothly, usually hugely dampened for manual use and often terrible startup friction. The EF lenses also often have freely spinning focus ring and no way manually control iris.

I have lately been working with Sony ES8230 block camera. it has lens control to dream of, mechanically that is. it can do very slow speed and smooth zoom, is fully silent. but unfortunately limited somewhat by the VISCA control. We have build way around of that by combined speed and absolute zoom demonstrated on this video https://youtube.com/shorts/hw-derIYeHc?feature=share

For BMD pocket cameras the MOVCAM focus tool, considering the options, looks pretty good for many tasks.

Can this be combined with a lidar autofocus system or am I getting technologies crossed?

I guess that that is a no and a yes?

Thank you Kim for telling me about this. When we later study the possibility of supporting BMC cameras, I will make sure our engineers look into this.

thanks

Jack

regarding

"1) Very good question. Panasonic LUMIX S zoom lenses have an internal data table that automatically compensates for any focus shift. So they behave like parfocal zooms via electronic compensation. I don't think Blackmagic cameras + EF lenses have such compensation built in their design."

EF lenses provide zoom position on Pocket 6k at least that I tested. also the lens I tested provided also the updated focus distance when zooming. It would be just making code that corrects focus, I wonder why they have not made that in camera as an option to activate.

viewtopic.php?f=2&t=171985

That sounds like a great product idea. Unfortunately, we don't have plan to add lidar autofocus to our product.
The goal of our project is to bring professional-level wireless manual focus control to mirrorless cameras cinematographers in a form factor that makes sense for small cameras.

Can this be combined with a lidar autofocus system or am I getting technologies crossed?

You are welcome, I do hope when the interface gets more used BMD would put some efforts improving it...

But also, we do already have fully working BMD USB_PTP, SDI, BT, SBUS and B4 interfaces using microcontroller, so maybe worth looking into combining the efforts.

Ps. this was many years ago, experimenting electrical Parfocal using Micro camera under SBUS control. The camera did not report back the zoom at that time, the zoom position we got from servo that was controlling it

Thank you Kim for telling me about this. When we later study the possibility of supporting BMC cameras, I will make sure our engineers look into this.

thanks

Jack

regarding

"1) Very good question. Panasonic LUMIX S zoom lenses have an internal data table that automatically compensates for any focus shift. So they behave like parfocal zooms via electronic compensation. I don't think Blackmagic cameras + EF lenses have such compensation built in their design."

EF lenses provide zoom position on Pocket 6k at least that I tested. also the lens I tested provided also the updated focus distance when zooming. It would be just making code that corrects focus, I wonder why they have not made that in camera as an option to activate.

viewtopic.php?f=2&t=171985

That sounds like a great product idea. Unfortunately, we don't have plan to add lidar autofocus to our product.
The goal of our project is to bring professional-level wireless manual focus control to mirrorless cameras cinematographers in a form factor that makes sense for small cameras.

Can this be combined with a lidar autofocus system or am I getting technologies crossed?

Thank you for taking the time to answer.

I think it's a great idea!

It will depend on how smoothly it can operate with each lens. I think similar approaches have been made in the past and the lenses' motor smoothness was a limiting factor, but that might be different now with modern lenses.