Green “Auto Focus target square” in DJI Go changes size and shape. Is that telling me something?

[Brett8883]

On the Inspire 1 in the DJI Go app the green “Auto Focus target square” changes shapes and sizes when using tap to focus depending on the object being focuses on and I wonder if this is telling me something such as a focus target has been recognized or the variance of the focus region maybe?

I ripped these screen shots from some guy’s video to show the different shapes and sizes of the “auto focus target square.”

Here is the “normal” auto focus target square which is fairly large and perfectly square. As a DJI Go 4 app user as well this is the green target focus square that is ubiquitous with the DJI apps


However, with the DJI Go app and the Inspire 1 sometimes I get this short but wide auto target square after taping on a subject.

Here’s another version that is wide and taller than the last one but not as tall as the fully square one.
I There is also get this very small AF target after a tapping to focus.

On a standard SLR camera I would take this to be the arrangement of the focus points used to calculate the focus region but I have found no documentation to suggest the Inspire 1 has scene intelligent focus points.

I tried searching the forum for this, maybe I just don’t know what to search but I can’t find anything on it. Hard to imagine this hasn’t come up before but does anybody have any ideas?

 

[Brett8883]

@Donnie Frank you seem to be the I1 guru. Any ideas?

 

[Ralph thompson]

I have seen the same but have assumed that this represents a group of pixels that are in focus. It may pick up a roughly elliptical or circular grouping but presents it as a rectangle or a square. Just a guess.

 

[Donnie Frank]

@Donnie Frank you seem to be the I1 guru. Any ideas?

I don't think this is exclusive to the Inspire 1 or even the Go App. I've seen the Go 4 App do the same thing. That said, I can only speculate that the square changes size and shape based on what it thinks the camera sensors lock onto as a "focusable field." But that's just an educated guess.

D

 

[Brett8883]

I don't think this is exclusive to the Inspire 1 or even the Go App. I've seen the Go 4 App do the same thing.

The reason I said that was on my Mavic Pro I’ve never seen it change shape or size no matter what I focus on. Maybe it does it with other aircraft though.

@Ralph thompson and @Donnie Frank thanks for your responses.

In this example
Do you think it is telling me that it is locked focus on just the guys neck and isn’t averaging the focus of the guy’s neck, the guys face, and the wall behind him? That would be good to know so if it doesn’t change size I would know I probably don’t have a good focus lock on my subject and can reTap to focus or manually focus.

I guess I thought it was just averaging the focus of anything in the large green square. If it is able to recognize different focus points and intelligently choose some over others that’s pretty cool!

 

[Donnie Frank]

The reason I said that was on my Mavic Pro I’ve never seen it change shape or size no matter what I focus on. Maybe it does it with other aircraft though.

You lost me. This is the Inspire 1 forum and you specifically stated that this was on your Inspire 1 (I assumed X5 camera since the X3 is a fixed-focus camera). I see no mention of a Mavic Pro. That said, the X5, Mavic Pro and P4P all use the same focus algorithm. I have seen the green box change size and shape for all 3 (can't swear to the X5, but I THINK it does the same thing). The problem is that we're comparing Go App apples to Go 4 App oranges. I BELIEVE both apps share the same focus GUI.

@Ralph thompson and @Donnie Frank thanks for your responses.

In this example View attachment 29558
Do you think it is telling me that it is locked focus on just the guys neck and isn’t averaging the focus of the guy’s neck, the guys face, and the wall behind him?

When it comes to auto focus, the green square seems to take on a "seek and destroy" algorithm, picking random objects for focus. So it's simply to just use one's finger on the screen to direct the green square to the area of focus. I'll reiterate that I'm no expert on DJI's proprietary focus algorithms (which are more than likely a heavily-guarded secret). These are my best guesses.

That would be good to know so if it doesn’t change size I would know I probably don’t have a good focus lock on my subject and can reTap to focus or manually focus.

On many occasions I have tapped the screen multiple times because I was dissatisfied with the focus or unconvinced that the focus was accurate. So that's what I would recommend. My focus choices depend on the gig. If I'm shooting the X5 for the film industry, I use manual focus with the Focus Assist (red lines). If I'm shooting real-estate, I just tap the screen. If I'm shooting mapping photos, I tap the screen until I see the digital zoom and a positive focus. So it just depends on the bird and the situation as to how I handle focus.

I guess I thought it was just averaging the focus of anything in the large green square.

Well...it's not like focus depth is 1" deep. The depth of field is pretty deep on these cameras. So focus is pretty forgiving. So whether the camera focuses on your neck or your nose isn't really going to matter.

If it is able to recognize different focus points and intelligently choose some over others that’s pretty cool!

Best that YOU choose where to focus by tapping the screen. Especially if your subject is only 10' away (which never happens in real aerial photography / cinematography) and your aperture is closed beyond f/8.

In other words, if you're flying a Mavic for real estate, just tap the screen. If you're shooting for film, use manual focus and Focus Assist.

D

 

[Brett8883]

You lost me. This is the Inspire 1 forum and you specifically stated that this was on your Inspire 1 (I assumed X5 camera since the X3 is a fixed-focus camera). I see no mention of a Mavic Pro. That said, the X5, Mavic Pro and P4P all use the same focus algorithm. I have seen the green box change size and shape for all 3 (can't swear to the X5, but I THINK it does the same thing). The problem is that we're comparing Go App apples to Go 4 App oranges. I BELIEVE both apps share the same focus GUI.

I was responding to you saying the green square changing shapes and sizes in DJI Go 4. I was saying that on my Mavic Pro, which uses DJI Go 4 I’ve never seen it changes sizes, like with the I1 which uses DJI Go, but maybe it does on other aircraft like the Phantom, that use DJI Go 4. I wouldn’t know I haven’t flown a Phantom.

Well...it's not like focus depth is 1" deep. The depth of field is pretty deep on these cameras. So focus is pretty forgiving. So whether the camera focuses on your neck or your nose isn't really going to matter

Nose and neck no but 6 feet distance at f/2.8 would only have a 2.5 foot depth of field. f/1.7 would be about 7”. So if it was averaging in any part of that wall behind him his face wouldn’t be in focus.

But overall, yea it seems to be exactly what it seems to be. If I’m shooting with autofocus and shallow depth of field I will hope to see the auto focus box change shape since that will mean that it recognized an object to focus on. Thanks.

 

[niki]

Why I'm getting notification about this thread? Last post is from Sep 2020.

On the topic, I've never seen the focus square to change shape. It's probably device related or the screen shots are from altered app.

 

[Brett8883]

Why I'm getting notification about this thread? Last post is from Sep 2020.

On the topic, I've never seen the focus square to change shape. It's probably device related or the screen shots are from altered app.

Idk I didn’t get any notifications till you just commented. This happened on my standard iOS version of DJI Go too. I don’t have an I1 anymore and it doesn’t seem to happen on the I2

 

[niki]

Idk I didn’t get any notifications till you just commented. This happened on my standard iOS version of DJI Go too. I don’t have an I1 anymore and it doesn’t seem to happen on the I2

Maybe it's iOS related as for the last 5 years I didn't saw such a thing on my android and CS.