I am struggling hard trying to make the Focus Pro (FP) work with photo lens (no hard end stops).

Lens:
Tamron 24-70 2.8
Camera:
BMPCC 6K
Focus Pro
all in one set

A decent workhorse photo zoom lens (no hard end stops).
I was completely unable to make it work.
Setting motor endpoints manually didn't help a tiniest bit, this function simply doesn't do the job.
This manual endpoint thing isn't there just holding place for some future firmware updates, or is it?
Is there any way to make FP work NOW?

(I also tried on a few other no hard stop lenses, no joy)


Please help.

Hi, Mark. Let me forward this to our relevant team for further checking. I'll keep you posted.

DJI Gamora Posted at 5-3 07:43
Hi, Mark. Let me forward this to our relevant team for further checking. I'll keep you posted.

Thanks Gamora.

I have a bunch of photo lenses that I would like to keep using. So I very much hope DJI makes it really possible to manually apply end limits.

In the meantime I bought a DZO Pictor 20-55 (had to shoot, and couldn't wait). Here is one more thing I hope your firmware engineers would consider:
- Even at the LOW torque setting the motor is excessively strong. When testing the end limits it literally slams the lens quite violently, so that I can't help wondering how long would the lens last with such treatment
Would be good to see more flexible torque settings at the low end.

Mark Jackal Posted at 5-3 19:23
Thanks Gamora.

I have a bunch of photo lenses that I would like to keep using. So I very much hope DJI makes it really possible to manually apply end limits.

Hi, Mark. Thank you for patiently waiting. We now received feedback from our relevant team, please refer to the information below:
DJI FOCUS PRO does not support this type of lens without mechanical limits.

The automatic lens is not supported mainly for the following three reasons:
1. The automatic lens has no mechanical limit so the position for manually stopping the lens focus ring cannot be controlled accurately. As such, when the accuracy cannot be guaranteed, the focus effect will be poor.
2. Because the focus ring on the automatic lens has no mechanical limit, any point on the focus ring can correspond to the same focus distance. Even if the position for manually stopping the lens focus ring is ideal, the position for manually stopping the lens focus ring and the actual focus position may not correspond after the lens completes auto focus. This will require the customer to stop the lens focus ring manually again and perform a calibration.

3. The focus ring of an automatic lens is typically non-linear, which means that different rotation speeds or intensities will result in different focus distances. As a result, changes in motor speed can lead to a failure in achieving accurate focus.

Considering the above three reasons, the overall experience and use effect are not ideal, so we do not recommend the customer use automatic lenses.

DJI Gamora Posted at 5-5 22:18
Hi, Mark. Thank you for patiently waiting. We now received feedback from our relevant team, please refer to the information below:
DJI FOCUS PRO does not support this type of lens without mechanical limits.

Good day, and thank you for trying to help!

There are a few things however that I guess your colleagues preferred to elegantly avoid elaborating.
Let's see them point by point.

1. The automatic lens has no mechanical limit so the position for manually stopping the lens focus ring cannot be controlled accurately.
- Then, what was altogether the point of having a "set manual endpoints" option? Wasn't it there to enable the user to do exactly what the name suggested, i.e., compensating for lack of mechanical limits by entering software-based limits?
What is it precisely that the "set manual endpoints" option exists for, if not for this?

2. Because the focus ring on the automatic lens has no mechanical limit, any point on the focus ring can correspond to the same focus distance. Even if the position for manually stopping the lens focus ring is ideal, the position for manually stopping the lens focus ring and the actual focus position may not correspond after the lens completes auto focus. This will require the customer to stop the lens focus ring manually again and perform a calibration.
- I tried many times (as some of Youtube reviewers did) to grab the focus ring by my hand during calibration, but this would be the least accurate way of all ways, it doesn't really work.

3. The focus ring of an automatic lens is typically non-linear, which means that different rotation speeds or intensities will result in different focus distances. As a result, changes in motor speed can lead to a failure in achieving accurate focus.
- This might be a valid point.
However, I have been toying with my new DZO Pictor 20-55 for a few days, and let me report some feedback!
Although this lens is in the Focus Pro lens library, I have a feeling that the lens profile still needs perfecting.
My lens is perfectly shimmed, and adjusted for parfocality. Generally speaking, FP manages focusing quite well.
Except, at distances between 0.6 and ~2 m (I still have to correct the focus with the grip wheel turning it to the "closer" side).
Similarly, although much less pronounced, it happens at the long end of the focus range (need to turn the grip wheel a bit to the "farther" side).
Perhaps this lens's profile might be reviewed and brushed up in the coming FW updates.

Thank you once again for your involvement, and I hope you find some time soon to shed more light on the "set manual endpoints" mystery.

Mark Jackal Posted at 5-5 22:56
Good day, and thank you for trying to help!

There are a few things however that I guess your colleagues preferred to elegantly avoid elaborating.

Let me forward your feedback to our relevant team, Mark.

Mark Jackal Posted at 5-5 22:56
Good day, and thank you for trying to help!

There are a few things however that I guess your colleagues preferred to elegantly avoid elaborating.

Thank you for patiently waiting. Here's an update from the relevant team:
1. The purpose of manually setting the “focus motor” limit is to control the focus within the desired range with no need to intentionally control the rotation stroke when the front dial is turned to minimize the loss of focus due to misoperation.
2. Regarding the “DZO Pictor 20-55”, please take a video to demonstrate the focusing effect if convenient.

DJI Gamora Posted at 5-7 07:26
Thank you for patiently waiting. Here's an update from the relevant team:
1. The purpose of manually setting the “focus motor” limit is to control the focus within the desired range with no need to intentionally control the rotation stroke when the front dial is turned to minimize the loss of focus due to misoperation.
2. Regarding the “DZO Pictor 20-55”, please take a video to demonstrate the focusing effect if convenient.

Thanks!
1. - Kinda mixed feelings. Still hope it can be addressed in upcoming new FW versions to make it somehow work for photo lenses...
2. - Will do, but it might take a few days as I'm currently head over heels in routine shooting. But I will definitely do it.

Mark Jackal Posted at 5-7 20:20
Thanks!
1. - Kinda mixed feelings. Still hope it can be addressed in upcoming new FW versions to make it somehow work for photo lenses...
2. - Will do, but it might take a few days as I'm currently head over heels in routine shooting. But I will definitely do it.

Hi, Mark. We'll take the first one as your suggestion and we'll wait for the video. Have a nice day!

DJI Gamora Posted at 5-9 04:30
Hi, Mark. We'll take the first one as your suggestion and we'll wait for the video. Have a nice day!

OK here goes the story. No video because the story turned out quite simple at the end.

One important thing to mention: I'm a long term expat stationed in Guangzhou, China.

This time I had a week long shooting in Shenzhen, and was able to clear one day to spend at DZO trying to make the lens work with my DJI system (I'd go right to DJI but I wanted to make sure it wasn't the lens to blame first).

PROBLEM in short:
- DZO Pictor 20-55.
- DJI FP has a dedicated preset for this lens which I thought would make things smooth and easy.
- It didn't. A perfectly shimmed lens simply couldn't hold the focus.
- When calibrating the lens, it was impossible to enter a right correction value to compensate for the distance between the lidar and the focus plane.
- Correction values were different at infinity and close end.
- Choosing a value in between these two took me nowhere.
- When focusing manually, the distance to the object shown in the bottom left corner of the grip screen was almost always different from the distance markings on the lens barrel (say, the lidar showed 1.6 m, but the focus ring marking showed 1.7-something).

DZO after sales support:
- The lens itself was in normal working order.
- The support lady told me, I quote, that "Our technician informed me that DJI is not fully compatible with our Pictor Zoom lenses".
- Which I, after all years spent in this country, took with a tablespoon rather than a grain of salt. (but I think you DJI guys need to know what your partners say).

SOLUTION:
- As I still had a few days of intensive shooting, I needed a working system, and I thought I had paid enough to have such...
- So I quit trying to make the DJI FP preset work,
- And calibrated this lens as a generic lens like if it wasn't even on the preset list. (the long way, just following the DJI manual: 1 m, then 4 m, all that).
- And voila. Everything worked like a charm.
- Even the distance readings are matching now.

My CONCLUSION:
- I'm no optical engineer, but I guess that if the lens works perfectly in full manual mode (although with distance readings well off), and it works perfectly when calibrated as a generic lens, then it is not the lens to blame.
- DJI were in a hurry to market the FP, and loaded it with a heap of presets some of which were not exactly ready to be released.
- Thanks DJI for a good product that (no sarcasm) helped me a lot on set, and a huge booooooooo to DJI for releasing undercooked presets.

WHAT NOW?
- Nothing as far as I am concerned, I am happy with the lens and the Focus Pro, although it took me forever to find a simple way to fix it.
- DJI may invite me for a coffee and ice cream next time I'm shooting in Shenzhen (14-26 June), and apologize for wasting my time.

CASE CLOSED. (coffee at DJI would be a great coda though)

Mark Jackal Posted at 5-20 05:26
OK here goes the story. No video because the story turned out quite simple at the end.

One important thing to mention: I'm a long term expat stationed in Guangzhou, China.

Thank you for the reply. Mark. currently, we have no resolution can provide but we will check the lens profile in the list. Regarding this issue: "set manual endpoints" to use a photo lens, but that's the sense that we recommend. This is not suitable for all photo lenses. But that's a solution. This lens can try to adjust The flange distance after using the Ronin APP for calibration.
Additionally, we will give feedback to R&D to test, but before that, please adjust The flange distance. Also, the Focus Motor Torque can be adjusted in the Focus Pro Grip screen.

DJI Gamora Posted at 5-23 06:26
Thank you for the reply. Mark. currently, we have no resolution can provide but we will check the lens profile in the list. Regarding this issue: "set manual endpoints" to use a photo lens, but that's the sense that we recommend. This is not suitable for all photo lenses. But that's a solution. This lens can try to adjust The flange distance after using the Ronin APP for calibration.
Additionally, we will give feedback to R&D to test, but before that, please adjust The flange distance. Also, the Focus Motor Torque can be adjusted in the Focus Pro Grip screen.

Good evening, and thanks.
We have mixed up a few separate things here, let me sort it out.
-
1 - Photo lenses.
I understand there is no, and there is not going to be a solution, at least in foreseeable future. Fair enough, although in full honesty you had to instruct your Youtube shills to avoid using "for all lenses, all cameras and all gimbals" formula.
(manual endpoints don't help at all when it comes to the photo lenses, anyway)

2 - DZO lens.
Here we are talking about flange distance, but it is clearly not the case. My lens, like I mentioned, couldn't be adjusted in this way, because it needed different FD correction values depending on focusing distance.
For the benefit of the community I am ready to sacrifice some of my time and gas, and meet DJI technicians in Guangzhou or Shenzhen, to show them how it happened on my setup.
If they are not interested, OK, my personal problem is already solved anyway.

Quitting the preset and calibrating it like a regular lens worked from the very first attempt.
Hence, it is just the lame preset
Hope, DJI returns to it at some point of time.

3. Motor torque.
I know how to adjust the torque. What I meant was that even at the lowest setting the motor is excessively strong for some lenses, and it'd be nicer if the torque could be adjusted with more flexibility... like, in steps of 10%.

Anyway, Gamora, thank you for your time, my system works now, and I have no more questions at this stage.
Let's consider this case closed - with the exception of the lens preset that of course needs to be addressed, but it is another story

Mark Jackal Posted at 5-23 07:09
Good evening, and thanks.
We have mixed up a few separate things here, let me sort it out.
-

Thank you for clarifications and update, Mark. For the lens prest, we'll take it as a suggestion and forward it to our relevant team. Thank you for your continued support.

DJI Gamora Posted at 5-24 07:46
Thank you for clarifications and update, Mark. For the lens prest, we'll take it as a suggestion and forward it to our relevant team. Thank you for your continued support.

i got some problem too so a calibrate lens focus distance is required 1m and 4m. So some lens has minimum focus at 1.5m or 1.2m how to fix a calibration 1m to 1.5m ?  or use another Length for cal ?

ironvern Posted at 6-4 02:33
i got some problem too so a calibrate lens focus distance is required 1m and 4m. So some lens has minimum focus at 1.5m or 1.2m how to fix a calibration 1m to 1.5m ?  or use another Length for cal ?

Hello.DJI Focus Pro LiDAR 1 meter calibration distance range is 0.5m~1.5m, you can operate it.

You can refer to the user manual.
https://dl.djicdn.com/downloads/ ... ser_Manual_enII.pdf

I’m very confused by the focus pro, I’ve tested it with the Tokina 11-20 and Tokina 16-28 (both stills lenses with hard stops) and it was working great.

I tried it with the Sigma 18-35 stills lens and added my own hard stops on the focus gear and it works about 50-60 percent of the time. Mostly in the 10’ - 3’ range it will work. The strange thing is if I do a fast push in camera move, it may track focus perfectly, but doing a pull out the same speed it will miss focus. I can usually get either pushing or pulling to be in focus, but no way of knowing which will work.

I tested the rokinon cine lenses (24 & 50mm) and had really poor results with those as well. My results were nearly the exact same as they were with the 18-35 and the 50mm was much worse, not really even usable at all.

I tested an old 50mm Olympus OM1 film camera stills lens that has hard stops and that was working nearly perfect.

I don’t understand why I’m getting such varied results. Why can’t the rokinons work?