Panasonic G7 Camera focus problem with example

I recently posted a problem I had with my Panasonic G7 camera going out of focus when video recording a subject.

This time I'm including an example that I've posted to YouTube

https://youtu.be/PAakOpQ6G_I

Can someone see why the camera has gone out of focus?

Brian

Yeah, that's just how continuous AF in video worked up until very recently. Or rather, didn't work, heh.

Not much you can do about it really. It's fundamentally broken in camera.

Latest flagship firmwares have finally made them usable for those needing video AF. But that only applies to G9, GH5 and GH5s unfortunately.

For all previous models, including your G7, you're better off using manual focus when shooting video I'm afraid.

You can still half press the shutter to focus while recording, so it's not that bad.

Stejo wrote:

Yeah, that's just how continuous AF in video worked up until very recently. Or rather, didn't work, heh.

Not much you can do about it really. It's fundamentally broken in camera.

Latest flagship firmwares have finally made them usable for those needing video AF. But that only applies to G9, GH5 and GH5s unfortunately.

For all previous models, including your G7, you're better off using manual focus when shooting video I'm afraid.

You can still half press the shutter to focus while recording, so it's not that bad.

Well I might have to improve my manual focus skills or change the way I video record things. Like you say at least the half press on the shutter works. Still I'm surprised that more G7 camera owners have not said much about this problem unless they mainly use the camera for still photo photography.

The worst part is in not knowing when the refocusing will occur but it does seem to happen when zooming at times.

Brian

Brisn5757 wrote:

Stejo wrote:

Yeah, that's just how continuous AF in video worked up until very recently. Or rather, didn't work, heh.

Not much you can do about it really. It's fundamentally broken in camera.

Latest flagship firmwares have finally made them usable for those needing video AF. But that only applies to G9, GH5 and GH5s unfortunately.

For all previous models, including your G7, you're better off using manual focus when shooting video I'm afraid.

You can still half press the shutter to focus while recording, so it's not that bad.

Well I might have to improve my manual focus skills or change the way I video record things. Like you say at least the half press on the shutter works. Still I'm surprised that more G7 camera owners have not said much about this problem unless they mainly use the camera for still photo photography.

The worst part is in not knowing when the refocusing will occur but it does seem to happen when zooming at times.

It's been a well known fact for a while that panasonic's video AF is unusable, so I guess most people don't expect it to work hence no complains about it.

Anyway, if you must use it, your best bet is 1 area AF, default size box. If your subject is well defined and you keep it inside the box, it kinda works usually.

Noted the hunting at the end of the clip. A second or so when you zoomed and found focus again? It is not very bad hunting TBH. Not ideal but that could be better than some others already. Get a newer and uppercase model could expect improvement.

alcelc wrote:

Noted the hunting at the end of the clip. A second or so when you zoomed and found focus again? It is not very bad hunting TBH. Not ideal but that could be better than some others already. Get a newer and uppercase model could expect improvement.

I almost got the Panasonic GX85 but it has a similar method of focusing. I choose the G7 camera has I was going overseas and needed a light smaller camera than my Canon 70D camera.

I did n;t have too many problems in the camera wanting to refocus when I was taking some video shots overseas but the parade seemed to being out the worst in this camera. It may have been due to the low lighting conditions as it was a dull overcast day and this camera uses contract to focus correctly.

I have other video clips taken of the parade where I alter the zoom slightly and there is no refocusing when I have stopped zooming so there doesn't seem to be a pattern after looking at my video clips of the parade. I do notice that at times the camera is refocusing during the zooming and when the zooming stops it does not try to refocus which I don't mind.

If I kept recording the little girl in the parade then aa second ot two it would have correctly focused again. There are a few cases where it has failed to refocus after going out of focus which is the worst thing the camera can do. I start to panic as I could be missing a good video shot.

Brian

Brisn5757 wrote:

I recently posted a problem I had with my Panasonic G7 camera going out of focus when video recording a subject.

This time I'm including an example that I've posted to YouTube

https://youtu.be/PAakOpQ6G_I

Can someone see why the camera has gone out of focus?

Brian

When looking at this video clip frame by frame I noticed that I had zoomed out a bit at the start of this video clip and it did not effect the focus.

For some unknown reason the focus seems to move to a focus that would be used when video recording something close to the camera rather than put the subject slightly out of focus. I'm wondering if the camera sends a constant signal to the lens to keep the camera correctly focused and if it lost this signal then the lens with go to closeup focus. There is also a delay when the camera has lost focus as most of the time the focus is very fast. I'm wondering why it takes so long before it attempts to refocus.

Zooming out slightly should not change the contrast in the center of the screen that is needed for accurate focusing. I can understand if the girl moved forwards and the camera then focused on the background but this is not the case as there is no attempt to focus on the background. I see no reason why the camera should go completely out of focus and not slightly out of focus.

Brian

... When looking at this video clip frame by frame I noticed that I had zoomed out a bit at the start of this video clip and it did not effect the focus.

I suppose it would be bet on our luck ? Yes, usually our cameras behalf better at the beginning.

For some unknown reason the focus seems to move to a focus that would be used when video recording something close to the camera rather than put the subject slightly out of focus. I'm wondering if the camera sends a constant signal to the lens to keep the camera correctly focused and if it lost this signal then the lens with go to closeup focus. There is also a delay when the camera has lost focus as most of the time the focus is very fast. I'm wondering why it takes so long before it attempts to refocus.

Zooming out slightly should not change the contrast in the center of the screen that is needed for accurate focusing. I can understand if the girl moved forwards and the camera then focused on the background but this is not the case as there is no attempt to focus on the background. I see no reason why the camera should go completely out of focus and not slightly out of focus.

Brian

It has been well discussed over internet and I suppose you can find a lot of reports on this. A recent test I watched : https://www.youtube.com/watch?v=NvkrWGjWY9k comparing various latest Pany models (can skip to 2:01).

I have no doubt that you must be well aware how CDAF work. CDAF in principal has to look for a focus on the entire sensor surface, so reduce the number of its focus point (sector) and restrict the area (size of the focus box) to look for a focus can shorten the time, i.e. reduce AF hunting.

When doing AF tracking (continuous AF in video), basically it uses all of the usable sensor area searching for a possible focus point. It starts to show its disadvantage vs PDAF which has only to watch on certain focus points and so in theory shorter time be needed. Because of the fixed line up of the PDAF points, it also allows the camera to predict the direction of movement easier. CDAF of, e.g. my GX85, has to first look at the 49 areas, and from the likely area find the highest contrast point and focus on it... Can imagine how inefficient it is (relative to PDAF).

Back to G7, the camera under Continuous AF will keep on searching for the sharpest focus. If the object movement is small (it might hunt even on still object, just smaller chance only), we can usually have a more stable focused result. When we zoom in or out, the camera will check for the focus again and hunting will appear. DFD theoretically can reduce the period of hunting. AF hunting generally cannot be avoided, just a matter of how fast it will return sharp again.

I think improved AF algorithm (GH5, G9 etc?), more powerful processing power, or use On Sensor PDAF (as Sony, Canon, Fuji and EM1-II) in future might keep AF hunting minimal.

alcelc wrote:

... When looking at this video clip frame by frame I noticed that I had zoomed out a bit at the start of this video clip and it did not effect the focus.

I suppose it would be bet on our luck ? Yes, usually our cameras behalf better at the beginning.

For some unknown reason the focus seems to move to a focus that would be used when video recording something close to the camera rather than put the subject slightly out of focus. I'm wondering if the camera sends a constant signal to the lens to keep the camera correctly focused and if it lost this signal then the lens with go to closeup focus. There is also a delay when the camera has lost focus as most of the time the focus is very fast. I'm wondering why it takes so long before it attempts to refocus.

Zooming out slightly should not change the contrast in the center of the screen that is needed for accurate focusing. I can understand if the girl moved forwards and the camera then focused on the background but this is not the case as there is no attempt to focus on the background. I see no reason why the camera should go completely out of focus and not slightly out of focus.

Brian

It has been well discussed over internet and I suppose you can find a lot of reports on this. A recent test I watched : https://www.youtube.com/watch?v=NvkrWGjWY9k comparing various latest Pany models (can skip to 2:01).

I have no doubt that you must be well aware how CDAF work. CDAF in principal has to look for a focus on the entire sensor surface, so reduce the number of its focus point (sector) and restrict the area (size of the focus box) to look for a focus can shorten the time, i.e. reduce AF hunting.

When doing AF tracking (continuous AF in video), basically it uses all of the usable sensor area searching for a possible focus point. It starts to show its disadvantage vs PDAF which has only to watch on certain focus points and so in theory shorter time be needed. Because of the fixed line up of the PDAF points, it also allows the camera to predict the direction of movement easier. CDAF of, e.g. my GX85, has to first look at the 49 areas, and from the likely area find the highest contrast point and focus on it... Can imagine how inefficient it is (relative to PDAF).

Back to G7, the camera under Continuous AF will keep on searching for the sharpest focus. If the object movement is small (it might hunt even on still object, just smaller chance only), we can usually have a more stable focused result. When we zoom in or out, the camera will check for the focus again and hunting will appear. DFD theoretically can reduce the period of hunting. AF hunting generally cannot be avoided, just a matter of how fast it will return sharp again.

I think improved AF algorithm (GH5, G9 etc?), more powerful processing power, or use On Sensor PDAF (as Sony, Canon, Fuji and EM1-II) in future might keep AF hunting minimal.

Thanks alcelc for the info ans video link.

In your reply you said "When we zoom in or out, the camera will check for the focus again and hunting will appear" This does not always happen. I posted a second short video to YouTube you can find it at this address. The video shows zooming and no refocusing.

https://youtu.be/ObFDFeReuPw

As you can see from the video when zooming it does not always adjust the focus after the zooming has stopped. This makes me wonder why sometimes that focus is checked and not at other times.

I have the camera set to focus on what ever is in the middle of the frame spot but maybe with continuous AF this gets overridden and the camera uses a different focus method.

You wrote about DFD, what is that?

Some say professionals never zoom but if your panning someone walking along the road, coming towards you then need to pan to prevent the person from being too big to fit into the frame.

Brian

Brisn5757 wrote:

alcelc wrote:

... When looking at this video clip frame by frame I noticed that I had zoomed out a bit at the start of this video clip and it did not effect the focus.

I suppose it would be bet on our luck ? Yes, usually our cameras behalf better at the beginning.

For some unknown reason the focus seems to move to a focus that would be used when video recording something close to the camera rather than put the subject slightly out of focus. I'm wondering if the camera sends a constant signal to the lens to keep the camera correctly focused and if it lost this signal then the lens with go to closeup focus. There is also a delay when the camera has lost focus as most of the time the focus is very fast. I'm wondering why it takes so long before it attempts to refocus.

Zooming out slightly should not change the contrast in the center of the screen that is needed for accurate focusing. I can understand if the girl moved forwards and the camera then focused on the background but this is not the case as there is no attempt to focus on the background. I see no reason why the camera should go completely out of focus and not slightly out of focus.

Brian

It has been well discussed over internet and I suppose you can find a lot of reports on this. A recent test I watched : https://www.youtube.com/watch?v=NvkrWGjWY9k comparing various latest Pany models (can skip to 2:01).

I have no doubt that you must be well aware how CDAF work. CDAF in principal has to look for a focus on the entire sensor surface, so reduce the number of its focus point (sector) and restrict the area (size of the focus box) to look for a focus can shorten the time, i.e. reduce AF hunting.

When doing AF tracking (continuous AF in video), basically it uses all of the usable sensor area searching for a possible focus point. It starts to show its disadvantage vs PDAF which has only to watch on certain focus points and so in theory shorter time be needed. Because of the fixed line up of the PDAF points, it also allows the camera to predict the direction of movement easier. CDAF of, e.g. my GX85, has to first look at the 49 areas, and from the likely area find the highest contrast point and focus on it... Can imagine how inefficient it is (relative to PDAF).

Back to G7, the camera under Continuous AF will keep on searching for the sharpest focus. If the object movement is small (it might hunt even on still object, just smaller chance only), we can usually have a more stable focused result. When we zoom in or out, the camera will check for the focus again and hunting will appear. DFD theoretically can reduce the period of hunting. AF hunting generally cannot be avoided, just a matter of how fast it will return sharp again.

I think improved AF algorithm (GH5, G9 etc?), more powerful processing power, or use On Sensor PDAF (as Sony, Canon, Fuji and EM1-II) in future might keep AF hunting minimal.

Thanks alcelc for the info ans video link.

In your reply you said "When we zoom in or out, the camera will check for the focus again and hunting will appear" This does not always happen. I posted a second short video to YouTube you can find it at this address. The video shows zooming and no refocusing.

https://youtu.be/ObFDFeReuPw

As you can see from the video when zooming it does not always adjust the focus after the zooming has stopped. This makes me wonder why sometimes that focus is checked and not at other times.

That is why I say, at the present moment we still are on certain degree to bet on how genius our AF will be. And members here suggest to have continuous AF off for more sure result from manual control is under a good reason.

I have the camera set to focus on what ever is in the middle of the frame spot but maybe with continuous AF this gets overridden and the camera uses a different focus method.

You wrote about DFD, what is that?

It is the Depth From Defocus, a software approach created by Panasonic permitting it to resist using on sensor PDAF hybrid sensor other brands of mirrorless use to improve AF tracking ability.

It uses the out of focus data of compatible lenses ( so Panasonic lens only) to cut down the journey of gradual in/out trial method on focusing used by CDAF. As a result it can bring the focus to the focus point much faster and so a faster AF. Add up faster AF every point will in theory speed up AF tracking.

IMHO it works but still have rooms to improve before 100% comparable to PDAF.

https://www.imaging-resource.com/PRODS/panasonic-gh4/panasonic-gh4TECH.HTM

Some say professionals never zoom but if your panning someone walking along the road, coming towards you then need to pan to prevent the person from being too big to fit into the frame.

Brian

For serious film production, they use slider to maintain the shooting distance...

Lately read reports that the Dual Pixal AF (sort of OSPDAF hybrid sensor used by Canon) or the latest Sony A series FF can do video CAF smoothly.

Might be the time for Pany to use OSPDAF as the industry heads on, and like stabilisation that it ended up using DUAL IS, to create a OSPDAF + DFD as a permanent solution.

alcelc wrote:

Brisn5757 wrote:

alcelc wrote:

... When looking at this video clip frame by frame I noticed that I had zoomed out a bit at the start of this video clip and it did not effect the focus.

I suppose it would be bet on our luck ? Yes, usually our cameras behalf better at the beginning.

For some unknown reason the focus seems to move to a focus that would be used when video recording something close to the camera rather than put the subject slightly out of focus. I'm wondering if the camera sends a constant signal to the lens to keep the camera correctly focused and if it lost this signal then the lens with go to closeup focus. There is also a delay when the camera has lost focus as most of the time the focus is very fast. I'm wondering why it takes so long before it attempts to refocus.

Zooming out slightly should not change the contrast in the center of the screen that is needed for accurate focusing. I can understand if the girl moved forwards and the camera then focused on the background but this is not the case as there is no attempt to focus on the background. I see no reason why the camera should go completely out of focus and not slightly out of focus.

Brian

It has been well discussed over internet and I suppose you can find a lot of reports on this. A recent test I watched : https://www.youtube.com/watch?v=NvkrWGjWY9k comparing various latest Pany models (can skip to 2:01).

I have no doubt that you must be well aware how CDAF work. CDAF in principal has to look for a focus on the entire sensor surface, so reduce the number of its focus point (sector) and restrict the area (size of the focus box) to look for a focus can shorten the time, i.e. reduce AF hunting.

When doing AF tracking (continuous AF in video), basically it uses all of the usable sensor area searching for a possible focus point. It starts to show its disadvantage vs PDAF which has only to watch on certain focus points and so in theory shorter time be needed. Because of the fixed line up of the PDAF points, it also allows the camera to predict the direction of movement easier. CDAF of, e.g. my GX85, has to first look at the 49 areas, and from the likely area find the highest contrast point and focus on it... Can imagine how inefficient it is (relative to PDAF).

Back to G7, the camera under Continuous AF will keep on searching for the sharpest focus. If the object movement is small (it might hunt even on still object, just smaller chance only), we can usually have a more stable focused result. When we zoom in or out, the camera will check for the focus again and hunting will appear. DFD theoretically can reduce the period of hunting. AF hunting generally cannot be avoided, just a matter of how fast it will return sharp again.

I think improved AF algorithm (GH5, G9 etc?), more powerful processing power, or use On Sensor PDAF (as Sony, Canon, Fuji and EM1-II) in future might keep AF hunting minimal.

Thanks alcelc for the info ans video link.

In your reply you said "When we zoom in or out, the camera will check for the focus again and hunting will appear" This does not always happen. I posted a second short video to YouTube you can find it at this address. The video shows zooming and no refocusing.

https://youtu.be/ObFDFeReuPw

As you can see from the video when zooming it does not always adjust the focus after the zooming has stopped. This makes me wonder why sometimes that focus is checked and not at other times.

That is why I say, at the present moment we still are on certain degree to bet on how genius our AF will be. And members here suggest to have continuous AF off for more sure result from manual control is under a good reason.

I have the camera set to focus on what ever is in the middle of the frame spot but maybe with continuous AF this gets overridden and the camera uses a different focus method.

You wrote about DFD, what is that?

It is the Depth From Defocus, a software approach created by Panasonic permitting it to resist using on sensor PDAF hybrid sensor other brands of mirrorless use to improve AF tracking ability.

It uses the out of focus data of compatible lenses ( so Panasonic lens only) to cut down the journey of gradual in/out trial method on focusing used by CDAF. As a result it can bring the focus to the focus point much faster and so a faster AF. Add up faster AF every point will in theory speed up AF tracking.

IMHO it works but still have rooms to improve before 100% comparable to PDAF.

https://www.imaging-resource.com/PRODS/panasonic-gh4/panasonic-gh4TECH.HTM

Some say professionals never zoom but if your panning someone walking along the road, coming towards you then need to pan to prevent the person from being too big to fit into the frame.

Brian

For serious film production, they use slider to maintain the shooting distance...

Lately read reports that the Dual Pixal AF (sort of OSPDAF hybrid sensor used by Canon) or the latest Sony A series FF can do video CAF smoothly.

Might be the time for Pany to use OSPDAF as the industry heads on, and like stabilisation that it ended up using DUAL IS, to create a OSPDAF + DFD as a permanent solution.

Hi Albert.

I own the Canon 70D which has the Dual Pixal AF built into it. I have used this for the annual parade  without any focusing problems, a good system. I wanted to try out the G7 for the parade this year as it has a number of video options such as mp4 50fps and is lighter and smaller than the Canon camera.

If I could setup the Panasonic G7 camera so that it would stay at a certain focus until I half press the shutter button to refocus then this would be a big help. There is an AF + MF option in the custom settings which I have set to off and was wonder if this would help?

My main concern when the camera is set to Manual focusing is that there may  be a lack of depth-of-field which means only some of my video shots will be in focus and it would be difficult to quickly manually focus...A skill I need to learn for this camera.

Brian

Brisn5757 wrote:

alcelc wrote:

Hi Albert.

I own the Canon 70D which has the Dual Pixal AF built into it. I have used this for the annual parade without any focusing problems, a good system. I wanted to try out the G7 for the parade this year as it has a number of video options such as mp4 50fps and is lighter and smaller than the Canon camera.

If I could setup the Panasonic G7 camera so that it would stay at a certain focus until I half press the shutter button to refocus then this would be a big help. There is an AF + MF option in the custom settings which I have set to off and was wonder if this would help?

My main concern when the camera is set to Manual focusing is that there may be a lack of depth-of-field which means only some of my video shots will be in focus and it would be difficult to quickly manually focus...A skill I need to learn for this camera.

Brian

I think Pannumon had explained how to do it at your another thread few days ago : https://www.dpreview.com/forums/post/62012608

I had taken similar advices from other members and am developing the skill. When doing 1080 is perfectly fine on GX85 (I don't zoom a lot and pan slowly), I had quite bad hunting problem on 4K.

alcelc wrote:

Brisn5757 wrote:

alcelc wrote:

Hi Albert.

I own the Canon 70D which has the Dual Pixal AF built into it. I have used this for the annual parade without any focusing problems, a good system. I wanted to try out the G7 for the parade this year as it has a number of video options such as mp4 50fps and is lighter and smaller than the Canon camera.

If I could setup the Panasonic G7 camera so that it would stay at a certain focus until I half press the shutter button to refocus then this would be a big help. There is an AF + MF option in the custom settings which I have set to off and was wonder if this would help?

My main concern when the camera is set to Manual focusing is that there may be a lack of depth-of-field which means only some of my video shots will be in focus and it would be difficult to quickly manually focus...A skill I need to learn for this camera.

Brian

I think Pannumon had explained how to do it at your another thread few days ago : https://www.dpreview.com/forums/post/62012608

I had taken similar advices from other members and am developing the skill. When doing 1080 is perfectly fine on GX85 (I don't zoom a lot and pan slowly), I had quite bad hunting problem on 4K.

Hi alcelc.

There has been a lot said about this problem that I forgot about a solution that someone offered me. Thanks for the link.

Brian