AC130: Video footage of the Auto Focus in action

Negligence is the answer - I was late, arrived 10 mins into the game and did not check things properly. I noticed it after about 5 minutes and shifted to 1080/60p.

I did a recording of another entire game the following day at 1080/60p and will be posting segments. Much better !

This is a lot more difficult than recording stage performances.

I suggested they slow down when they are about to score a goal to give me time to zoom in. And, that they avoid crowding in front of the net (hard to give a view of the goaler).

They laughed and replied they are old timers and if they were to slow down any more they would not be skating.
 
Jan, but what has changed? the camera is pointing at something in auto and attempting to focus on what it thinks we want- how does pressing the button make that clearer to the camera? It does work but I still don't understand what extra information is being fed to the focussing system by the button, that couldn't be built in to the focussing mechanism automatically.
Rod
 
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This brings us back to the original question: Do the new assist functions improve the actual auto-focus itself or are they just aids when the focus starts blurring?

BTW: The more I use the camera the more I think it takes excellent video.






Rod Pike said:
Jan, but what has changed? the camera is pointing at something in auto and
to focus on what it thinks we want- how does pressing the button make that clearer to the camera? It does work but I still don't understand what extra information is being fed to the focussing system by the button, that couldn't be built in to the focussing mechanism automatically.
Rod
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kwkeirstead said:
At the link you will see a 10 minute segment of a hockey game recorded on AG-AC160A with AF set to ON. The recoding was done at 720/24p. Other segments done at 1080/60p can be posted if there is an interest.

http://youtu.be/OVzaOJsr0Ag
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I don't see that video being any benefit in evaluating this issue. The camera is kept wide angle the whole time. And with the fast movement of the hockey players recorded at 24p, they are pretty much a blur.
 
Jan_Crittenden said:
When you define exactly what you are asking the camera to focus on, it will take that simple command and execute. It isn't a contradiction at all. If you don't it will adjust AF on what it thinks you want.

Best,

Jan
Click to expand...

Jan, but what has changed to give the camera new understanding when you press the button?? Let's say the camera is locked off and pointing at something in auto and attempting to focus on what it "thinks" we want- ( and failing- I can duplicate this on my 160a) How does pressing the button make that focussing info/ requirement any clearer to the camera?

It does work but I still don't understand what extra information is being fed to the focussing system by the button, that couldn't be built in to the focussing mechanism automatically. I am really taking to this camera but I want to understand, as an engineer, what the turbo focus button acts on to immediately snap focus. It has been given, nor is receiving any extra information from the lens. Understanding the mechanics will make us all better understand this camera.
Rod​
 
kwkeirstead said:
Here is another hockey game done the next day at 1080/60p.

Any improvement?
Click to expand...

It just makes me miss hockey even more; damn strike. I wasn't trying to critique your earlier video by any means. I was just wondering if the hockey footage was going into some documentary, short story etc.. as to if that's why you chose the 24p.
 
All OK, the 24p was an error, that's it.

I think I realized it part of the way through and then switched to 1080/60p. The next-day recording was entirely done at 1080/60p.

I like critiques - it's really the only way to improve.
 
First, let me go "on the record" and state that this is an excellent camera! The different scene files work well. The form factor and balance are excellent. Lastly the 22X lens is awesome as is the DOF.

However, in regards to your question, I have my own personal reservations.

If we are paying $400 plus dollars for an UPGRADE and it only ASSISTS the auto-focus via two added functions, then the answer is a BIG NO -IMHO.

My particular thought is as follows:

While 'shooting' a scene in Auto-Focus mode, if ONE observes the camera GOING OUT OF FOCUS, it's too late no matter how fast it takes a finger to reach and push the new TURBO button. Your scene will still be out of focus for that time and RECORDED as same-especially GLIDECAM users who assign auto-focus on the GLIDECAM etc. The added auto assists should have been included in the original production for those users that must use auto-focus.

With the aforementioned in mind, this camera should be used in MANUAL "everything" as it is a professional-style camera. I will agree that EXPANDED focus would help those who use Manual focus, depending on ones vision.

Just my thoughts...your milage may vary :-)



Prism Video said:
Do you think the focus upgrade is worth the money?
Click to expand...
 
Rod Pike said:
Jan, but what has changed to give the camera new understanding when you press the button?? Let's say the camera is locked off and pointing at something in auto and attempting to focus on what it "thinks" we want- ( and failing- I can duplicate this on my 160a) How does pressing the button make that focussing info/ requirement any clearer to the camera?

It does work but I still don't understand what extra information is being fed to the focussing system by the button, that couldn't be built in to the focussing mechanism automatically. I am really taking to this camera but I want to understand, as an engineer, what the turbo focus button acts on to immediately snap focus. It has been given, nor is receiving any extra information from the lens. Understanding the mechanics will make us all better understand this camera.
Rod​
Click to expand...

An answer to this question from Panasonic or Jan would help in your decision.
 
Hi Rod

The way I see it works is much the way as a still camera...you give the lens a scene and push focus and it focusses on the scene ...swing the camera left to a closer object and it will be out of focus cos you only asked it to focus on the previous scene ... a virtual still picture with no information change. When subjects are moving all over the place especially with a small dof then I would assume you would have to hit the button for each shot?? My Panasonic GH1 seems to work exactly the same in video mode!! If I set the scene and push the shutter half way down it snaps into focus but if I move away to the left or right I lose it...with CF on the GH1 it does a fairly good job but seems to have the same issues as the 160....I just use it for stills now.

That is my understanding anyway with the 160 and logically that's how it must work..I cannot see how, in full manual, it can lock onto a scene with the button and then change focus if you move the camera...every new scenario must require a button push!!

I don't think Jan is ignoring you..she can only give you a definitive answer when she gets one from the tech experts at the factory.

Chris
 
Hi Chris,
Yes that makes sense in manual mode and I,m sure Jan and Panny will come back when she has an answer, as this original focus issue has been rumbling on for a while.

But the issues raised on this thread related to auto focus. Jan said that because of the weight of the lens and the number of pixels being analysed contributed to the slower action. Others have made the point along with me , that if that is the case then how is it that the push button can instantly snap in when the auto focus doesn't?

The bit I don't undersatnd is that the turbo button also works in auto mode and when a focus lock up occurs, a press of the button snaps it into focus immediately. And yet the camera has received no additional info from the lens- it is as if the turbo button clears a memory block, just like an escape button on a computer.


However I really like this little camera and I guess I, like everyone else, will work around its quirks. But here's a thought: I paid hard earned money for this and I wonder how Panasonic would feel if only 95% of it was cashable! hehe- I will now lighten up and have a glass of wine!
Cheers!
 
Hey Rod

That sounds like a good idea. If you have the AC160 is auto you will notice that the zoom numbers run around a lot...I used to put mine in feet and when I was say 10' away from people on a dance floor it noticed that the zoom used to run wildly from 3' right up to infinity...to me that was crazy and my brain here figured that maybe every frame of the video was being "analyzed" for focus ? I would think that with push focus, the camera acts like a still camera and just takes one single frame and bases the focus on that! That would be the same again as a still camera and fairly easy to do an accurate focus. It was the continuous running that really bothered me and it even happened if I switched to auto on a fairly static scene..like a bride and groom getting married where not much movement takes place and in theory focus shouldn't change at all on a static wedding scene where there is virtually no distance change between the subjects and certainly no change in camera to subject distance!! My HMC82's only display focal length from 00 - 99 but on a static wedding scene the AF is pretty stable so I let it find an focus and then switch to manual so maybe the 160 tries to analyze just too many frames per second???
In push to focus on the 160 I see no issue at all with static scenes..it will do an awesome job but for someone like me who films the bride walking down the aisle, a push focus will only last until the DOF limit is reached, then you have to focus again and follow focus manually.

On my HMC82's I did a test at full zoom (12X) and swung quickly between objects between 10', 30' and 100' away and then back again and it nailed it every time yet on my 130's even zoomed in a wee bit if you panned over to a different subject at a new distance, it would take a while to lock in which as you can appreciate, at a wedding doesn't look good as things happen fast. I can only deduce that this a a trait that bigger chip cameras have?? The new little AC-90 actually resolves a 2K image and then processes it back to HD which is impressive yet it's AF is deadly fast...then again...smaller chips!!!

The important fact to realise here is that Panasonic never said that the upgrade would rectify the slow AF..the upgrade (or the 160A cameras ) simply were given a turbo focus button and focus assist..From all the literature I read nothing was ever promised about making the autofocus better/faster!!! All in all the cameras are very usable..I shot 80 hours of weddings on mine and my only major gripe (which made me get rid of them) was the autoiris that didn't change shutter speed as well so the camera needed constant attention and ND changes which ain't easy when you are solo and shooting with two of them!!

Hope you have chilled out totally and are busy now cracking open the second bottle!!

Chris
 
wasa mara Chrish? you're my best mate you are- must keep things in focush musn't we?

Seriously, yes it is a great camera I just wish it did what it said it would on the box! Following movement and action is not what this camera is good at- very disappointing. It's all very well for other pros to mention planning shots etc but in an unpredictable and unknown situation ( ie run,n,gun) pulling manual focus is not only a pain in the butt, it is virtually impossible with fast moving sports.
But I guess we are stuck with it and in my corporate and training work it is not a major problem. However, my plans to buy a second backup for 2 camera stuff (was going to be a 130) is shelved for the moment and I am now not going to sell my second Sony and will use this. It means a bit of colour grading in post but at least that is predictable.

Now wheres the next bottle!

Cheers!
Rod
 
Hi Rod

I just wanted to say that the focus issue actually goes away after your third bottle so keep at it and there will be no more focus issues..everything will just be nicely blurred!!

However I do agree with you! If you walk into a car dealership and buy a new car with AT and it doesn't shift correctly..I think you would be pretty upset if the dealer said ..rather just use manual shift the auto doesn't work as it should!! That was my major beef!! Then again from a business POV if you, the manufacturer have already shipped 10,000 units out to dealers, recalling every one because the AF does work correctly will be a trifle costly to your business so let's face it, it won't happen and the turbo button was introduced purely to try and keep clients happy. The sad bottom line is that AF doesn't work correctly and I doubt whether you will be able to get any sort of factory mod to fix it either. That is purely my opinion and one of the reasons why I dumped (and lost hard earned money) on my two cameras but I really couldn't see any point in fighting something I wasn't happy with....I really can't see any problem unless you are planning to shoot run 'n gun ... in manual it is quite usable but from a business ethics point of view I still think that the camera should be recalled and made to work as other Panasonics work or remove the AF on new units and keep them manual!!

Enjoy your last bottle ..must be getting late in New Zealand now!

Chris
 
We all have heard how a chip with more pixels is making it slow to get a focus. Panasonic has decided how much of the chip area to sample in order to determine focus. if it is anything like the box that will show up on the screen (that can move around) plus add in the physical size of the chip... I am scratching my head on how focus is an issue.
I was going to have you look at the very first clip of my video I originally posted. BUT YIKES the video has been 'deleted by user' WTF... I didn't delete it. Looks like I need to upload it again.
 
The more I test my AG-AC160 the less issues I have with AF.

But, I mostly do stage events and only twice now have I recorded fast action (hockey game). Check out the recording I did at 1080/60p where the camera is mostly open, with no resulting focus issues, but there are a few quick zooms where you might be able to tell me if it looks blurry or not.

I have a suspicion that some of the 'hunting' that the camera appears to be doing never results in a change in focus - it may be it is scanning and decides to make no changes. If this is true, then we should just ignore the "hunting".

The other thing I found is do not use Push Auto with AF on. It seems to be the origin of the 'double bounce" that I noticed. Here, the explanation might be you press Push Auto, it does its thing and then AF takes over backs up and tries twice to get an AF focus which it already had. The behavior seems analagous to the way the focus bar works where the best technique seems to be that you approach, go past, then back up and approach again.

Anyway, I discovered that chewing gum plus a felt chair leg protector seems to allow testing of a built-up Push Auto button. Push Auto for me is not an easy operation with the recessed button that ships with the camera. The good news is the problem is easily fixable.
 
Chris,yes even the room wouldn't focus after a while! and yes of course Panasonic will go into denial I'm sure. Remember windows 95 and BSOD's? what a load of rubbish, but we all paid for the windows 98 which fixed some of the problems. then came vista- dropped like a hot potato because of the problems- but we all paid for win 2000- now we are at win 7 and ,as a product it is pretty good, but how many times did we reload operating systems and modify programmes to get round someone elses problem which we were led to believe by forums, was the way we were doing things??

ELN614, the problem you originally showed on your deleted clip is the same issue I randomly have with my 160A which makes follow focus in auto quite difficult and this is the disappointing thing for me. Also the frozen focus is the very heart of my issue. I think a response from Panasonic on your sample would be very welcome.


Karl, we shouldn't have to adapt our style and avoid hunting of a less than satisfactory focussing system- see ELN614 video again.. The reason I occasionally press the turbo button in auto is because the camera focus has frozen and that clears it. I guess my point is that on a camera that cost me over $7000 nz, I would expect auto focus to work every time in well lit contrasty scenes. It is a fabulous little camera in all other respects and if the auto focus issue wasn't there it would certainly be the best and most powerful and versatile camera on the market- a class leader in alll other respects.

And yes, the button , with the camera on a tripod is very difficult to reach - I did mention elsewhere that if it was assignable to a user button it would be a great improvement. So chewing gum and chair leg protectors fix it - maybe If we use a piece of string for measuring focus distance we would have the perfect chewing gum and string fix! ANy chance Panasonic technical development will offer us a job??? hehe!!
Rod
 
Hi Rod

Was the deleted clip the one with the pole and the horses in a paddock??? That one was an example of the AF playing up but then again that situation might not arise at all in your work...I sorted out the camera shifting focus during a static scene by simply switching to manual but I did have a couple of shoots (cutaways in a Church) where the AF decided to focus on the people behind and not my subjects which was annoying!! If you are doing repeatable subjects then you can always do a reshhot of a clip but you can't stop a wedding ceremony cos the cam went out of focus. Now the AC-90 is supposed to be every sharper than the 160 in good light due to the backlit chips and autofocus is very fast so I can only assume that it's something to do with the 1/3rd chips..the smaller 1/4.7 chips in the AC-90 actually resolve close to 2.3m pixels which is huge...the camera actually creates not a 1080 image but a 4K one!! It then downsizes to 1080...quite amazing for small chips. I saw a few posts about inaccuracies in the 23X lens of the 160 so I wonder if that causes the AF issue.
Sadly you have the camera so I guess you just have to work around issues.... I'm getting an AC-90 when they come out so that might be a nice 2nd cam for you....I can report of it's performance once I put it thru the mill..at less than half the price of the 160 and really pristine HDMI 4:2:2 output ... I think it just might be worth a look.

OK, it's Sunday in our part of the world so relax and watch the Bathhurst V8 racing!!

Chris
 
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