AC130: Video footage of the Auto Focus in action

Thanks for your reply Jan. It looks like the AC series might not be for me. I hope Panasonic can come to grips with the lens route they have chosen to follow as my usage of the XF300 with an 18x lens has shown excellent autofocus performance. Too bad Canon is not as generous with the rear LANC controls as Panasonic.
 
Hi Bassman, so the answer is NO- for all the reasons Jan states, this camera will not perform auto focus as consistently slickly as others- However, as a new convert from Sony after 20 years or so, I was also disappointed with this aspect: However, I have learned much about this camera and one of the understated beauties is that the function switch will convert your camera to spot metering/focussing mode. This would indicate a vastly smaller thinking area for the camera to assess contrast and then bring it into focus. ( Contrast is the key here too- I understand that the focussing mechanism looks for variations in gradation and contrast)

I have asked Barry to advise what area of the screen that the camera measures in normal auto mode but he said that Panny haven't made that info available. However I would bet that it is vastly bigger than the function area box. Unless you are shooting sweeping landscapes the chances are that there will be a fairly crucial and small point of interest. So this feature is very powerful. Jan, any thoughts on the measuring area in normal mode?
 
It's important for me, to keep this in perspective.

In my case, the AF issue has been very manageable. I follow a lot of the others' comments in that I turn off AF in the menu, use the Focus assist, and typically switch to manual once I have used the AF to help obtain a good, sharp image.
But really this is good advice for any cam used in shooting such events, NOT just the AC160. No AF system on any camera is fool-proof. If it's for a paying gig, these are wise steps to take with any cam. You cannot totally trust any camera's AF to be spot-on all the time.

I shoot mostly theater and concerts. I use a pair of HMC150's and the AC160 together.

Yes the HMC150 has the better more reliable auto focus, but that's where its advantages really end. The AF on the HMC150 is reliable probably 95% of the time. My Canon XHA1 is reliable probably 95% of the time as well.
On the AC160, it's reliable probably 90% of the time. The AC160 is in my judgement, a much better cam. Its exposure control in the low light of theater is a major improvement. I mean it's day and night. So much so that it gets really difficult to match them in post, even when they use matching presets, etc.

So yes, I have learned a few tricks that help me keep my cameras in sharp focus, and am appreciating the advantages the AC160 can bring to the table in lots of other areas. It really is a great camera.
 
It really and truely depends on your shooting scenario! Theatre and Concerts, shucks give me an AC-130 any time ...but where you are shooting solo with two of them and one camera nedds to look after itself then you do need a more "auto" camera....I still shoot wedding ceremonies and speeches in MF on my HMC's but then what happens at a photoshoot and it's on a steadycam??? There are times I need AF However what really killed me was the limited autoiris and I often have a camera at an outdoor wedding unattended and with the 130 if a cloud comes over, it expects an ND change which didn't work for me. If your only issue is focus then the 130 is quite manageable in manual and yes, it;'s a great camera but just didn't suit my auto needs when I needed them which the HMC does do!! Look at all the features and what you are going to shoot and then decide on which camera is the right tool for the job...none of the Panny range are "bad" some just are more suited to special tasks than others.

Chris
 
I will try to sum up my thoughts and be done with the chase. I do not think anybody is saying the AC-160/130 is not a great camera. What I see happing is internet forum pressure for Panasonic to improve the camera's auto focus performance through a firmware upgrade (or "a" model for that fact). As consumers and users of professional gear, we expect a constant in features as we go forward in time with improvements. If a previous camera has very useable feature we expect that feature to be at least as good on a later improved model. If not, then it seems that we are going backwards in a way.

Some the autofocus tests posted here are quite embarrasing for a modern professional camera. Very slow reaction time. At this point the technical "why" does not matter because I know I would not want to be caught in a paying situation having to deal with that performance. So one could say "just buy a different camera then..." Well true, but I like Panasonic cameras and want my colors to be in the same family with other Panasonic cameras.

Maybe the 22x lens was an overreach and the cameras should have had 18x? Is the 22x marketing gain worth the poor AF performance? It never works to redefine peoples' work methods just because a technical hurdle can not be overcome. The only way I would ever use auto anything on a professional camera is if works! If it does not work well enough to be used on a job it is a fail for this type of camera. Seeing the albeit smaller chipped HMC-90 with super IS and very quick auto focus just pours salt on the wound!

Sorry to be going on about an auto feature as I am a manual shooter. I am making the point that watering down time-improved features to include new items is never a positive in the end. We have learned to live with rolling shutter but focus is kind of off limits :)
 
I have to agree with you on the focus thing- I am still coming to terms with it even on my 160a. I guess it was my single biggest disappointment having switched from Sony. It is slow and sometimes struggles with finding a sweet spot, even using the function spot focussing facility. ( I tried that again yesterday and it is not as snappy as I thought , and sometimes just hangs on to the previous focus point, which I guess shouldn't happen as it defeats the object of the function. I carried out these tests as I incorrectly stated that I thought it would be more precise- well not on my camera anyway.

What I don't understand is that the "instant" snap focus button works a treat, so what signal or information does it send to the lens that isn't already there? Does it search for extreme contrast? (which must already be there surely?)

However, it is a powerful and comprehensive piece of equipment for shooting video. I do, in spite of its shortcomings, like it a lot. I will work around the things that don't suit me ( the fixed shutter speed being one- but as Barry points out, the shutter speed governs the flavour of the footage and only the shooter should control it.) Hey! heres another thing for the 160B- what about a switchable mode- fixed shutter and auto shutter??? That would solve the sunny/cloudy dilemma for out of doors users. ( Panny, don't clap just put the cheque in the post)

So in summary, and I think it has been said elsewhere, this is not an ideal run and gun tool. It defintely suits scenarios where one sets up and can plan a shoot. For this mode of shooting ( which is most of my work fortunately) I don't see any better value for money given the vast amount of manual control one has with the little Panny 130/160.
Cheers! Rod
 
kwkeirstead said:
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

pixel-vfl3z5WfW.gif

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.
Click to expand...



These videos are indeed better than your earlier example. Still, there is an annoying "bounce", which I still find to be distracting.

I simply cannot justify spending more money to have my 130 upgraded to the 130a, if this is what I will be getting.
 
Hi Lance

I also used to get that bounce ..it was almost like the old "jello wobble" on early CMOS cameras but I only noticed it on about 10X zoom or higher ...if I accidentally bumped the tripod the image would bounce with decreasing frequency until it settled down but if one did the same accidental tripod leg jolt with an HMC camera at the same zoom the image would of course shift, but never bounce!! Probably the big lens and the big chip contribute to the "bounce"??? I just had to be very careful at any zoom that the camera was 100% stable ... My remote is on the tripod handle so that didn't help me any!!! At a wedding I found it tough to have to swing the cam over to a reader at a lectern and zoom in before they started talking...the bounce doesn't seem to last very long though so it's just a matter of treating the camera a little more gently when zoomed.

Chris
 
kwkeirstead said:
I do lots of music theater productions.
My strategy would be not to try anything fancy for an event two days in the future.
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I think that would be prudent. I'm attending the practice tonight just so that I can work through it.

kwkeirstead said:
I do lots of music theater productions.

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 !
Click to expand...

Funny thing is I apply most of these principles already
Tripod is always the safest for me. I do not use auto Iris and do use the Focus assist EVF set to black. I'm more concerned with the father daughter dance. Should be fairly simple but I don't want to mess it up so I'm going safe and using a manual focus. I have done before and was pleased with the outcome. Think I will just stick with what worked for me in the past.

Thanks for the help.
 
Update on Push Auto

At Jan's suggestion I put AF to OFF and did a quick test of Push Auto.

Results: NO bounce of the type noticed when doing Push Auto in AF mode.

http://youtu.be/rRRuozGQ5IQ

I guess the point is you can get really good/fast results on Manual simply by pressing Push Auto,

I get the impression that when you try to use Push Auto on top of AF, the Push Auto does its thing and then AF adds its 2 cents worth.

There are enough controls on the camera to accommodate a mix of AF and Manual when you need to change from one to the other.

I have, subject to more testing, reached the conclusion that I will not mess with Push Auto when the camera is in AF mode.

And, I have no great urgency to use Push Auto at all until I have built up that button - its next to impossible to push the button when it is flush/recessed.

I would actually be happier with a way to do Push Auto via a Remote Device (no such remote exists so far as I know)- I don't like touching the camera when it is recording.

After 6 months of trial and error with my Manfrotto fluid head, I managed to get the right tension in both directions. Previously, starting friction always seemed to give a jerk.

I tried a motorized pan gadget - terrible - it would pan up to a pre-set point, then stop and give a jerk backwards.

Manual zooms are not easy for clumsy people like me - always seems jerky. So, i use the little grey Panasonic remote which works pretty well.

As for my remote focus/iris control, I find it overly sensitive - you are at 50 and want to go to 55, one mini-turn puts you at 60, then going backwards, you get to 52 - I cannot understand why it has to behave this way.


All in all, ZERO complaints with the 160A other than a request to Panasonic to build up the Push Auto button but no big deal, I can build it up myself easily.

Surely we can get to where you put your finger on spot focus and trace a directional arc to where you want focus/framing to be and a camera would pan/tilt along a smooth curve to where you you invite it to go.

Example: Lets go from a railway station, along the track at train level but then zoom up to a flashing signal at crossroads.

When pigs fly?
 
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kwkeirstead said:
...you can get really good/fast results on Manual simply by pressing Push Auto...
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Jan_Crittenden said:
... 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...
I hope this helps,

Jan
Click to expand...

Why do the two things seems to contradict itself. On one hand you press the Auto Focus button and you get "really fast focus" but if you're in Auto focus you get really slow focus because of the above statement by Jan. So which is it??? Too big of a lens, too many pixels in image, and the law of physics makes it impossible for move fast BUT you good accurate fast focus when you press the button?
 
kwkeirstead said:
Update on Push Auto

At Jan's suggestion I put AF to OFF and did a quick test of Push Auto.

Results: NO bounce of the type noticed when doing Push Auto in AF mode.

http://youtu.be/rRRuozGQ5IQ

I guess the point is you can get really good/fast results on Manual simply by pressing Push Auto,
Click to expand...


Ah, now that looks much, much better!! Thank you so much for following up on this further for everyone.

This could suit my style of shooting very well. As I pretty much use my AC130 in full manual while on a tripod. But sometimes pinning the focus down correctly manually can be a pain, and slow to get right. So performance like this could be a useful tool for me.

So maybe the upgrade would be worth it to me after all. Tell me, how useful have you found the magnified focus assist function? That would also potentially be helpful, I would think. Either looking through the eyepiece or the LCD, it can be quite challenging sometimes to confirm the focus.

I wish that there was someway that I could see how the screen actually looks when using that magnification feature. At age 60, my eyesight can use any assistance that it can get!
 
ELN614 said:
Why do the two things seems to contradict itself. On one hand you press the Auto Focus button and you get "really fast focus" but if you're in Auto focus you get really slow focus because of the above statement by Jan. So which is it??? Too big of a lens, too many pixels in image, and the law of physics makes it impossible for move fast BUT you good accurate fast focus when you press the button?
Click to expand...

No clue but let us all stay tuned for an explanation.
 
There is an old saying that probably applies here: " It is what it is. "

It's actually more positive to just accept a situation for what it is, rather than feeling sorry for yourself, or for the situation existing.

The saying "Is the glass half empty, or half full?" could also apply.

Does one judge a product, or even a person, based upon a single issue? Or aspect of an issue?
 
Oops, what is the "magnified focus assist function"? Is this the red Focus Assist button, the EVF DTL button or some other feature I have not yet discovered?
 
Magnified focus assist is not available on the AC130 or AC160, but it is available on the AC130A and AC160A. When you have an "A" model, you can assign the Focus Assist button to either display the red focus assist, or instead to display a magnified section of the screen so you can see pixel-for-pixel.
 
Hi Walter

Your cam has been upgraded so you will have it but you must select either focus assist or magnified...I never had it on the 130's but my HMC's have the magnify assist only..even with my lower res screen it's still pretty nice to use and pretty accurate...with you hi-res LCD or EVF you should get a very sharp magnified image which is easier to check focus with than the red outline when there are multiple objects in the scene but the red outline is very precise...for your work the mangified image will work very well indeed!!

Chris
 
ELN614 said:
Why do the two things seems to contradict itself. On one hand you press the Auto Focus button and you get "really fast focus" but if you're in Auto focus you get really slow focus because of the above statement by Jan. So which is it??? Too big of a lens, too many pixels in image, and the law of physics makes it impossible for move fast BUT you good accurate fast focus when you press the button?
Click to expand...

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
 
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