AC130: Video footage of the Auto Focus in action

The chip and optic explanations that Barry and Jan gave make sense. But that a side this has more to do with level of expectations and working features for dollars paid. With a much less expensive DVC30 which was a Proline camera you got excellent auto focus. In my mind paying double or triple that much for an HD cam with an auto focus feature you should be getting as good or better performance. If it is not as good then advertise it as a manual focus camera and potential buyers will have a better idea of what they are getting. Or at least explain in the promotion literature that "one-push auto focus" is the only auto focus feature and the camera cannot do continuous auto focus or tracking auto focus which many found out the hard way.
 
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Hi Mark

My issues were definately increased with higher zooms so I'm assuming that if one used something like an HPX500 with even bigger chips, manual focus would be the order of the day ?? I must admit that AF was usable at full wide as the depth of field was fairly big so even inaccurate focus still gives you a sharp image. I see that you have an HPX170 ??? Does that cam have the same AF problems that the 130/160 exhibit or do you simply use it in manual. I wonder if this is something that all 1/3rd chip or bigger cameras have at higher zooms ? I have only had one instance on the HMC80's where it lost focus in auto (I forgot to switch the 2nd cam to manual) but it was at 12X zoom and it was a theatre performance in a very dark theatre and I had to zoom out but zooming back in the AF nailed it perfectly before I switched to manual. The 130/160 is very useable even in manual focus but for run 'n gun stuff where you need to grab the camera and shoot (plus look after another camera) auto is a lot more comforting..I actually found the limited iris range in autoiris with no shutter switching was more of an issue as you can quite easily just zone focus and 99 times out of 100 you would be accurate! It seems like AF is a common issue with the HPX250 according to the thread on the HPX forum so it must be common to all bigger chip cameras.

Chris
 
Barry_Green said:
I don't know of any other cameras with native HD chips and a 22x lens. I do believe that Jan posted that they did some tests against a Canon or Sony or something that had about an 18x or 20x lens, and that they found issues of comparable severity with those cameras, but I wasn't involved with that and didn't see that so I don't know what the particulars are.
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I recall one person here last November who was shopping for a camcorder, and was evaluating both the AC-160 and the Canon XF300. He ended up buying the Canon, despite its heavier weight and greater cost. The main reason he stated that he went with the Canon was because he felt it had better autofocus. He posted this video to make his argument:


 
Hi Lance

Significantly greater cost actually ..XF305's down our way are a tad over $7K whilst the 160A (that's with the mod already done) is just over $4K and the AC130 even cheaper. That's a huge amount extra to pay for better autofocus..the 130/160 is still awesome value for money in comparison

Chris
 
ChrisHarding said:
Hi Mark

I see that you have an HPX170 ??? Does that cam have the same AF problems that the 130/160 exhibit or do you simply use it in manual. I wonder if this is something that all 1/3rd chip or bigger cameras have at higher zooms ?

Chris
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Chris, I shoot with the HPX170 in manual focus about 90% of the time but do use auto focus for sporting events. It seems to do ok in higher contrast settings vs. low light overcast conditions. It meets my level of expectations.
 
ChrisHarding said:
Hi Lance

Significantly greater cost actually ..XF305's down our way are a tad over $7K whilst the 160A (that's with the mod already done) is just over $4K and the AC130 even cheaper. That's a huge amount extra to pay for better autofocus..the 130/160 is still awesome value for money in comparison

Chris
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Well, Barry was speculating about how well the performance stacked up to similar Sony and Canon camcorders, and I recalled this fellow who ended up getting a XF300. They are on sale right now for $6,000 at B&H, so I wonder if Canon is closing it out and will be replacing that camcorder soon? But the price is still significantly higher, and the XF300 is so very heavy, that I, for one, would not want to use it handheld.

I don't remember anyone doing an autofocus comparison with any Sony camcorders.
 
I can speak from first hand experience. The very few times I used auto-focus with my XF-300, I NEVER had an issue where a STATIC shot went out of focus for NO reason like my Panny 130. So why the change to Panasonic? The Canon XF-300 is plauged with interline twitter/shimmering, especially fine details. On the other hand, the Panasonic produced an excellent picture albeit "out of focus" auto-focus. Folks, I guess there is NO perfect camera. At least the Panny can be manually focused whereas the Canon's interline twitter would always appear when making a Blu-ray disc....and....NO....it is not the Blu-ray bit rate and compression used....the Panny produces excellent Blu-rays.
 
I was able today on an AG-AC160A to replicate the horse/pole scenario where it takes a long time for AF to "discover" the pole. If you get all of the pole in the viewfinder the AF settles down quickly.

Now, here are results for a PUSH AUTO test (my first test of this feature).

See the video in two parts with a couple of seconds of black screen in between (let it run!).

Part 1 shows the easily reproducible settling in behavior going from, in this case, a gazebo 90 feet away to a tree that is 10 feet away.

It seems to take longer to get to focus on the distant object than to get focus on the near object. (I did the test twice)

After the black screen, we see the effects of PUSH AUTO. Here, after repeating the AF near/far test a 3rd time, I started to use PUSH AUTO.

RESULTS:
It is faster focusing on the near object.

BUT, what is curious (and deserving of further testing) is that you get a "bounce" on the far object under Push Auto.

You can see clearly you can either get 2 bounces (it goes to infinity then backs up and bounces again before finally going to focus) OR you get only 1 bounce.

Personally, I find the 'bounce' distracting. I would need to edit that out.

Could it be that my camera is defective?.

I need someone to try to replicate my test.


In my opinion, one would not normally expect to see a focusing difference between near/far and far/near shifts.
 
That was me who bought the Canon and posted the video of the autofocus. The #1 reason we picked the canon over the panny was the 50mbps codec. I made this video once I saw that others were having issues... wanted to check it out for myself. Yes the canon is still heavier and more money (we got the 300 not the 305) but it has been a great investment as we have ended up doing a TON of green screen - and some of the projects had a 50mbps camera requirement which would have meant adding an external recorder to the panny. The lens is not quite as long, but more than long enough.

I have not seen the shimmering issue Lou mentioned. Hope I don't start seeing it now!
 
kwkeirstead said:
BUT, what is curious (and deserving of further testing) is that you get a "bounce" on the far object under Push Auto.

You can see clearly you can either get 2 bounces (it goes to infinity then backs up and bounces again before finally going to focus) OR you get only 1 bounce.

Personally, I find the 'bounce' distracting. I would need to edit that out.
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Ouch!! Those "bounces" at the 1:02 and 1:20 marks are indeed downright ugly. That does not impress me at all.

Thanks for posting this example.
 
Hey Walter

Just for fun I did a quick test using my HMC82 between objects as close as 10' and right up to more than 100' away using 50% zoom and 100% zoom (6X and 12X) and the camera nails it pretty well in full auto (sorry about the wobbles and pans ..I was too lazy to grab a tripod but seriously your 160A should snap that shed into focus instantly ....What zoom were you using there BTW???? Apology for the quality too..for time sake I rendered from 1920x1080 straight down to MP4 at only 640x360 !!


http://youtu.be/P5UcIQwxEww

I would like to see the same sort of test done with an HMC 150 to see if in fact it's the bigger chips causing the problem!!

Chris


Chris
 
Thanks kwkeirstead --- that also shows how horrid the auto focus is.... now is the trick and get a consumer level camcorder with auto focus with equal megapixel resolution and 22x optical zoom (or more) and see how it can handles the same test.
 
As Alice would say "Curiouser and curiouser"

One day later, testing at the same site, full zoom, f4.8

  • AF - fast for focus lock-in time on both near/far objects (a bit faster for near objects)
  • Push Auto - faster focus lock-in on both near/far objects
  • a bit of a “bounce”


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AutofocusTest AC160AAF20120919.mp4

Upload complete! Your video will be live at: http://youtu.be/PK5dNK0HUsg



AutofocusTest AC160APushAuto20120919.mp4

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Upload complete! Your video will be live at: http://youtu.be/3r7Sy6KxeqQ

I suppose I should do this again at say 10 X Zoom. No point complaining about a 22 X camera when its the only one on the market in its class.

Just because the camera is capable of doing 22 X does not mean we have to go full zoom.

Now, if AF is "fast" maybe we should reserve Push Auto for setup at the start of a clip.

After all, we go to great lengths to use remotes to avoid touching the camera and unless/until there is a remote that handles the Push Auto button, people are not likely to want to use it during recordings, with or without the innovative "Push Auto Extender" custom add-on.
 
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Hey. Im a New ac130a user (about 1 week) and have noticed the focus trouble also. I've tried several settings and the only one that really has an impact on autofocus that I can tell is using 60i. 24p hunts all over the place. What frame rates are you using?
 
Hi folks,

Here is a video that should give you helpful ideas on how to utilize the Auto Focus on this camera.
http://www.youtube.com/watch?v=I0to4OqIrBg&list=UUAtY7XCdtu016Uhyc4ngCSw&index=5&feature=plcp

Please know that the weight of the glass, the length of the lens, the pixel density all work in critical cooperation. I think that if you use the Area focus, you will find the AF to be far more useable. However, because the clues for focus are coming from 2 million pixels, small changes in the field of view will impact its ability to lock in and settle. I would tend to use the Push to Auto, while having the AF switched to off.

I hope this helps,

Jan
 
Jan,

I'm not a pro like most on here. I'm an up and coming event videographer. I will say that I purchased this cam because of the reviews and largely because of recomendations made by Chris and others on messege boards. I simply live too far away to test cams. It was pretty disheartening to then read he had abondoned the cam for something else. I simply don't have the flexibility to do that or the resources to go to another cam 3K was about twice what I wanted to spend in the first place... Ugh. I will say that after reading of the focus issues I had already adopted a strategy of using manual focus when stationary and autofocus when moving. I really haven't noticed the focus problem at all using that technique. When moving I have had very good success with the autofocus then again though my videos have been at weddings an quincearnera's. I have a quincearnera this weekend and will be filming the dance. I'm a little concerned with the autofocus as there will be more focus points and movement we film with two additinal cams GH2 and a stationary B cam so I have backup. But I really do want to make certain that I don't miss something important because of the focus problem. You pro's could you give me some advice on how I could minimize the issue.


My thoughts were to use manual focus and get the distance locked in.. then maintain that distance throughout the dance. Anyone else have ideas or suggestions.

Thanks in advance.

Darryl White
 
I do lots of music theater productions.

My strategy would be not to try anything fancy for an event two days in the future.

Consider this but wait for others to either disagree or reinforce. I would prefer to be shot down rather than give you bad advice.

I always use Area Focus.

I rarely use AF but have spent a lot of time testing AF on the 160A and a bit of time on Push Auto. I never use Auto Iris. I used to use a 100 foot surveyor's tape but now have a Bosch laser distance measurement tool.

Tripod, no OIS.

Get the ND Filter set properly.

Do your white balance.

Get as much depth of field as you can and know how many rows of dancers you will have.

Look at waveform.


Turn off AF, turn off Auto Iris, do not engage EVF DTL, turn on Focus Assist red highlighting and put the EVF to black and white.

If there are four rows of dancers, set the focus on the second row - I think the distance that will be in focus is shorter in front than it is behind your red highlighting.

Good luck !
 
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Jan_Crittenden said:
Hi folks,

Here is a video that should give you helpful ideas on how to utilize the Auto Focus on this camera.
http://www.youtube.com/watch?v=I0to4OqIrBg&list=UUAtY7XCdtu016Uhyc4ngCSw&index=5&feature=plcp

Please know that the weight of the glass, the length of the lens, the pixel density all work in critical cooperation. I think that if you use the Area focus, you will find the AF to be far more useable. However, because the clues for focus are coming from 2 million pixels, small changes in the field of view will impact its ability to lock in and settle. I would tend to use the Push to Auto, while having the AF switched to off.

I hope this helps,

Jan
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Thanks for the video link Jan, but I have to say this is not much help for a true autofocus situation. The video basically gave 3 out of 4 examples of saying "use manual focus instead..." I use the big cams and am a manual kind of user, but I often look to the 'little cams' to be put in situations where I really need auto to be auto. For example, putting the camera on a jib and only having hands free to operate the zoom & iris via lanc. From all of the forum chatter along with Panasonic's stance on "pros use manual..." I do not have the confidence to move from an HMC-150 to an AC-160. It just seems like this is a non-working feature.

Can you flat out say that the autofocus on the AC-160 is as good as the HMC-150 inside the same 12x zoom range? Your confirmation will go a long way to help me purchase this camera.

Thank you.
 
Bassman2003 said:
Can you flat out say that the autofocus on the AC-160 is as good as the HMC-150 inside the same 12x zoom range? Your confirmation will go a long way to help me purchase this camera.
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Hi,
The HMC150 has a 13X lens, that lens weighs in at half the weight of that of the 22X lenses that are on the AC cameras. Bigger things move more slowly. Add to that equation, the resolution of the HMC at 620,000 pixels, comes out at pixel shift similar to a 1,000,000 pixel imager. The AC130/160 has a 2,000,000 pixel imager. This is a higher resolution picture and and this means the camera sees a lot more detail. Certain laws of physics cannot be denied. Something that weighs twice as much cannot move as quickly. When the image offers more info upon which to focus, it will take more time. On that jib arm, if you are not manning that jib arm with a remote for focus and iris, stop/start record remote, then I would recommend the HMC150. If you are going to man it, then either camera will work.

I hope this helps,

Jan
 
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