AC130: Video footage of the Auto Focus in action

On both my 130's the feet display was totally random most of the time!! I was one time about 15' away ffrom people on the dance floor and the display was literally running back and forth between 3' and infinity!!! Infinity at 15'???? I don't think the display is very reliable at all. I still think it would we worth your while to send your camera back to Panasonic under warranty ....you could quite easily have a faulty lens or servo and they will (to save time) simply replace the whole lens and bits and pieces rather than do time consuming tests!!

Chris
 
The readout is quite reasonably accurate. But consider that you're dealing with a very wide angle lens and a very small chip, so it's entirely possible that if you were outdoors, broad daylight, wide angle, f/5.6 or so, then yes, proper focus might have been achievable at either 3' or infinity, because the DOF is so incredibly deep.

But ELN's results sound just plain wrong. If anyone else can confirm kwkeirstead's results and not ELN's, then yeah, it may be an issue with his particular camera.
 
Hi Barry

In my case it was mid evening inside a venue and the iris was open with a bit of gain and a video light on the camera so DOF should have been minimal. I found that outside in bright light, yes the readings were pretty accurate too. However ELN's camera definately looks like it has an issue and he could quite easily have a manuafacturing defect which can happen in any industry..If it was me I would certainly zap it back for a factory checkup ... Services centres are pretty fast too but maybe he has a daily use (like me) for the camera so it's a huge inconvenience to have to find a loan while your camera is away!! I have been really lucky and over the last 20 years have never had to effect a warranty repair ...that must say something for Panasonic Quality Control ??? ELN just has an unlucky break. Pity they don't have loan cameras if yours goes in for repair!

Chris
 
ELN614 said:
VERY INTERESTING yours works and mine doesn't
Click to expand...

Hi ELN614,
I will do this test in the next day or so for you, but bear in mind my 160A has already been acknowledged as having a problem (although different), which is now awaiting replacement parts from Japan to correct the issue.

I'm with Chris on this, produce your evidence/ data and then submit to Panasonic for analysis. This is what I did. They will either say it is a characteristic of the 130 (scary if they said that!) or they will want to fix it under warranty. Panasonic are a global company with a well respected reputation for quality and it sure looks like your camera is not performing to spec.

In the meantime, C,mon other 130/160 owners, help a fellow owner with some market research, feedback is what makes this forum so dynamic.

Cheers!
Rod
 
OK, same test, repeated with two different houses, from the same vantage point as in the previous test, about the same distance from house to camera for both SITE ONE: consistently goes to infinity when I zoom out. SITE TWO: Goes to multiple readings at zoom in (sometimes 3 feet, sometimes 10). This causes me to suspect the camera may have obtained a good focus but the distance meter is failing at times to display a proper reading. And maybe the "hunting" we see is just the distance meter running back and forth, with no signal actually going to the servo once the camera has found a focus. The conclusion here is we may not be tracking focus lock-in at all. The definitive test is to look at a recorded video with a stopwatch and measure the time it takes to get to focus.
 
I just did this test handheld real quick-like yesterday afternoon, by shooting a house across the street. My cam is an unmodified AC160.

Zoomed all the way in, everything is great. Zoom out to full wide, and it said something like 4'. Did it again, and it said 6.8'. But everything was very sharp and in focus despite whatever the distance readout was.

I have noticed that in use the distance readout may sometimes vary wildly, yet the cam is still focusing just fine. That distance readout just isn't reliable, but to me it's a non-issue. The cam is focusing just fine, despite what the readout says. Odd.

Tomorrow I will repeat the same test with the HMC150, just for fun, and see if it does the same thing.
 
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Hi ELN614,
well how strange! (but remember my camera is waiting service parts) :

Test and results: Full zoom on logpile across the paddock at the back of my house- just grass between me and the target. indicated 28 metres
pulled back to full wide angle and indicated 1 metre! But shots looked in focus. I will carry out a further trial in a more scientific way and record the results for closer examination.

This is a similar scenario to your barn shot, with clear ground between you and the camera, so no chance of spurious results ( as you originally stated "what is only 1 metre away if this camera is focussing in a centre weighted manner??).

It probably doesn't help, but I have always noticed the focus scale leaping around wildly. It certainly doesn't conform to Barry's statement of it being reasonably accurate in my case- but as I said, my camera has a known problem anyway, so I,m not sure whether you should put my results into your feedback.

However, is it possible that the reading is not actually the terminal focal distance but the hyperfocal distance?? That would make sense as , at max wide and average aperture on such relatively small chips the DOF would be pretty much from the end of the camera to the end of the galaxy!
 
Rod Pike said:
However, is it possible that the reading is not actually the terminal focal distance but the hyperfocal distance?? That would make sense as , at max wide and average aperture on such relatively small chips the DOF would be pretty much from the end of the camera to the end of the galaxy!
Click to expand...

That's almost certainly the case. Remember, the camera has no distance reference data to work with except the video signal. As long as the image is sharp (according to the focus algorithm) then the actual distance setting on the focus mechanism could be anywhere.
 
Hi Rod

My HMC's don't have distance readout as such..just a scale from 00 to 99 and it all appears to be pretty normal on the display .... Ay weddings I'm usually around 15 to 20 metres from the bride and groom and my display will indicate that as between 75 and 85 on the scale ....that seems about right to me ..Anything over that distance would be infinity anyway!! Before the bride arrives my camera is still in auto and the AF displays the reading pretty well statically ..maybe drops down or up a few..when it's completely stable I will then switch to manual focus and use my focus magnification to ensure it looks sharp. In a dance floor situation where we have gyrating bodies the AF display does move around a bit but certainly within distance parameters ..like between 55 and 65 but never crazy readings...the 130 would spin the display wildly and run from 3' to infinity and back again multiple times.

OK a quick suggestion? change the LCD display back to default and see if the numbers regain their sanity ....ie: the woodpile might be shown as 80 in zoom but it should still be close to that is wide ....It might just me the actual distance display????

I did your test on the HMC82 using the letterbox over the road and it displayed 92 every time at full zoom (12X) at full wide it drops to 70 BUT the camera of course has a lot more to focus on...the garden, the pavement and the road too ....however the displayed reading are logical and it never went to 20 or lower indicating the object was a few feet away ...Interesting to see what your default readings tell you

Chris
 
The results are really dependant on the weighted focus zone which Panasonic has never published to my knowledge. That's why I mentioned completely clear ground between the target and the camera. This is very important to avoid spurious local proximity focussing.

I doubt whether the focussing zone is full screen average, I believe it was mentioned elsewhere that it is centre weighted. If this is the case then focus should remain held on the centre subject. Mine seemed to , regardless of the readings, however ELN's was wildly out of focus on this test. Cutting to the chase : It is time to send it back to Panasonic for professional analysis I reckon.
 
Sorry I was on vacation soaking up the sun in the Caribbean. Forgetting I even owned a Panasonic camera.
So it looks like I am not the only one getting squirrely readings.
In the viewfinder, it too appears to be in focus but can you really trust a small screen? I wouldn't want to. we all know things look better on a smaller screen. put your footage on a 50" screen and you might be shocked to find your footage not in focus. No one can afford to do that.

The basis of hyper focus is setting the camera in the middle of the area... if the 130/160 sets it at 4 feet or less (on AF) I highly doubt that is a hyper focus.

And yes I use the camera on a day-to-day basis and can't afford to go without it. I will talk with my distributor about a loaner if it gets to that.

I would to hear more people's results. (meaning more than the 3 or 4 so far)
 
Hi all,
My panasonic 160a is back! with a new lens and servos assembly. Firstly, thanks to Pro video here in New Zealand for turning this round so quickly- They had to wait for parts from Japan which arrived last wednesday. I despatched the camera to them on thursday and received it back today! (Thursday) now that is service!

SO the results: No more random focus locks, it is very consistent and repeatable on full zoom, auto focus- targets 7m and 1.9m- not one indecisive moment.(and I guess that is a severe range to put such a long lens through)

The average refocus time can still be slow at up to 3-4 secs (digital stopwatch) if the contrast is low. But we know this is a contrast focussing system so that is acceptable. For high contrast subjects it is consistently at around 1-2 secs. That is very acceptable for the odd occasion when I use auto focus. SO there it is , data wins!
 
Thanks Barry. Yes I am a very happy chappy! I am now digging in to your book with renewed enthusiasm for the Panny.

As I have mentioned before I have no brand loyalty whatsoever, I just want the best I can afford and I want it to do what is says it can do.

I chose the Panasonic after donkeys years with Sony because this camera appeared to be unbeatable value for money. Now it works as it should I believe that is still the case.

I think the lesson is, when evaluating performance issues, create objective data and consider, but do not be deterred by subjective opinion. It would have been all too easy to accept that "it is what it is get over it".

There has been a vast amount of discussion, opinion, technical support and input from other members and we have all learned something I am sure.(I certainly have) That is what makes this forum dynamic. Long may it continue!
cheers!
Rod
 
thanks Mike, it has been a good thread and much learning along the way, with the unravelling of theories, not so solid opinions, and very solid technical input along the way (such as yours)!

I am surprised that ELN614, as the founder of this thread, didn't get more contributions to his request for user testing data though, with nearly 12000 views of this thread and 32 pages of debate! We should all help others where we can shouldn't we.

Right, I am off to shoot the cat (with the camera of course- she is my petulant test target for today!)

Cheers!
Rod
 
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