AC130: Autoexposure issues yesterday while shooting a parade outdoors with my new AC130

L

LanceOregon

Well-known member
We had a Veterans Day Parade here yesterday. The sky was overcast and covered with clouds.

The good news: I had no issues with Autofocus outdoors that I could detect. In fact, I was quite impressed by the sharpness of the video. Automatic White Balance also continued to work well too.

Since I'm struggling a bit in getting up to speed on this camcorder, I decide to shoot the parade in Auto mode. Shutter was set to 1/60th, and I recorded in 1080/30p. However, in testing before the parade started, I notice that my iris was changing often, and then giving me a noticeably different looking exposure.

I thought about going into manual mode, but then that threw off the white balance, and I had not played yet with setting it manually. So rather than fiddle with this just as the parade was getting ready to start, I just went ahead and shot in Auto mode.

I was getting a message to use 1/4 ND, and then set my ND to that. However, the iris setting was showing up rather small, and I did not want to use too small of one, so that sharpness would not be affected. So I then switched to 1/16 ND just before the parade started.

However, if anything, it seemed that I started to get more frequent noticeable changes in exposure. If you look at the first third of this video, you should see the exposure changing numerous times. This often happened when making significant changes in the zoom magnification.

I received a few messages to go back to 1/4 ND, but they quickly went away, and I never changed the setting from 1/16. The sound recorded very well. I'm most happy with my audio-technica shotgun microphone that I bought.

But I'm quite concerned about how autoexposure behaved in this shoot. What do you think? I don't yet have a Vimeo account, but I suppose that I should get one. I did upload the complete original MTS file from the camcorder to YouTube. No post processing of any kind was done.

Should I be seriously worried? Could I have done something wrong in setting up my camcorder? I would appreciate anyone's thoughts about this issue.

Here is the video

 
Hi, is there a way to give us a shorter sample of your problem. Something less then a minute? Thanks
 
yes, a shorter example would be great... but if you're talking about exposure changing, in auto, when you go from a wide shot that is mostly daytime sky to closer shots that are mostly tarmac... that' doesn't seem like a problem...?


Also, don't forget that the aperture can't be as wide on the long end of the zoom as it can at the short end... so you will have some interaction between zoom and exposure if the iris goes wider than f3 or so... so backing off the ND might give you more consistent exposure across the zoom range.
 
There's a section between 3.40 and 4.04 where things go up and down a bit, but it looks like the glare off the silver car bonnet is closing the iris a bit.

Remember, even if you switched to Manual iris after you were set up, the light will still move on you if there is the slightest change in cloud cover.

Later on in your clip, 10.00 - 10.40, the iris is again closing when you zoom in towards the white banners, again to be expected.

At 13.24 again you zoom in on a dark section of Army truck and the iris opens as it should, then you zoom out as the track goes past and you hit lots of sky so the iris closes on you.

Next time let it start in auto if you like, but the switch to manual if you have those problems with white banners, glaring bonnets or sky will solve most of your problems.

Earlier this year I did a fast moving Australian Rules football match under fast moving heavy clouds that were breaking up, it really looked like a nightmare, but it looked no worse when I left it on auto and concentrated on panning 180 degrees on the back of a ute I was sharing with building supplies and a wheelbarrow!
On auto it was moving 5 stops each time the sun came out!! No wonder I couldn't keep up with the football while trying to change the iris! Sometimes you can't win!

Cheers,

Vaughan
 
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I am coming to the conclusion that these cameras are set up to sensitive. The auto focus changes just as rapidly as the Iris. When someone is shooting in manual mode, there is a reason.

If you have the camera changing and jumping around quickly, it make the footage look like garbage. I could auto focus, change the settings to manual iris, but that is not the point.

I have shot on other cameras that have done a wonderful job at making the footage look decent to good on a all manual setup. What is the point of having this if you can't use it without you looking like you don't know what you are doing. I can see the camera changing settings from going like say outdoors to indoors or visa versa. But, even if I slightly point my camera down from like say someones body to feet, you can see the jump in exposure.

This should be a gradual or unnoticeable event. Or at least a setting in the camera to change the sensitivity to your needs?

Having some doubts about my AC160 for my type of shooting on it
 
Vaughan Wood said:
Next time let it start in auto if you like, but the switch to manual if you have those problems with white banners, glaring bonnets or sky will solve most of your problems.
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Thanks for your input Vaughn. I think you are spot on here. I am going to need to switch to manual in situations like this.


Dstar said:
I am coming to the conclusion that these cameras are set up to sensitive. The auto focus changes just as rapidly as the Iris. When someone is shooting in manual mode, there is a reason.

If you have the camera changing and jumping around quickly, it make the footage look like garbage. I could auto focus, change the settings to manual iris, but that is not the point.

I have shot on other cameras that have done a wonderful job at making the footage look decent to good on a all manual setup. What is the point of having this if you can't use it without you looking like you don't know what you are doing. I can see the camera changing settings from going like say outdoors to indoors or visa versa. But, even if I slightly point my camera down from like say someones body to feet, you can see the jump in exposure.

This should be a gradual or unnoticeable event.
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Dstar: This has been my concern too. I thought that the change would be more gradual and not so abrupt.

Although I have yet to notice any problems with autofocus being too sensitive. But I have not been shooting people indoors at close distance, as you have. I will be recording a number of people indoors this Saturday at our local police headquarters. That should give me a good test if the AC130 will be a good run and gun camera or not.

If this is simply an issue of over-sensitivity as you suggest, could not Panasonic perhaps address this in a firmware update?
 
You guys are like the first pioneers. So we await your results on this. Let us know how the indoor shoot goes at your police headquarters.
 
Please take the few minutes that it will take to become familiar with the Function Button and its ability to control where the camera looks to control iris and focus. This is a powerful tool and not to use it is like saying you don't want to use that 5th gear on your Ferrari.

Now it will not resolve issues created by zooming in, it is a 22X lens and the max iris opening is different at the zoomed in part vs, the widest range. It will though help your camera look to the area which is most important to make auto adjustments.

Best regards,

Jan
 
Have you guys tried the manual focus assist function? Would probably help when focusing, it's a sort of hybrid auto/manual focus, and would prevent the "hunting" problem on focusing, even though it's not TRUE auto focus when you have that feature turned on.
 
Deer Film said:
You guys are like the first pioneers. So we await your results on this. Let us know how the indoor shoot goes at your police headquarters.
Click to expand...

I think that I will try using Face Detection at that event on Saturday, and see how that works.

Here is a photo of our police chief, and the department's mascot:

McGruff_Jerry.jpg
 
I do want to make it clear that while others have noticed issues with Autofocus, I have not experienced any problems with it in the shooting that I have done so far.
 
I used some Auto modes while shooting yesterday and I just used manual Iris to avoid the the change in exposure. Kind of learned so far, without going completely through the menu, that I don't what to use Auto Iris. It has to much of a change in exposure that it is completely noticeable. The same with the Auto White balance. It seems, unless Panasonic changes with firmware update to allow a more gradual change in these settings, that you have to stick with manual setting to avoid changes in exposure, white balance, and focus, that will be completely noticeable in your footage.

I noticed while shooting a night football game, that you can see changes in the color temp when zooming in and out. Zooming closer to the players on the field, the color temp seems to change to more of daylight settings (or look). When I zoom back out, it seems to look more normal to the proper white balance? Way to sensitive!

It is like Panasonic had this technology that can allow the camera to recognize and change setting very quickly and they wanted to show it off. If you are following someone from indoors to outside, the camera can change quick enough to capture this shot. But, it is overkill on just normal shooting. You don't what all of these changes going on so quickly when you are just doing normal shooting. Exposure changing from just panning around, white balance changing when zooming in and out on a subject, and auto focus flying around. Try correcting all those in post! Editors get ready!
 
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Since I haven't gotten on my soap box in the HMC150 forum about this for a while, I'll do it here :happy:

Learn to use all manual everything.

Not trying to sound flippant or anything, but it's ultimately a really bad idea to trust a computer algorithm to make artistic choices for you. You are putting yourself at the mercy of a computer chip to decide what should and shouldn't be in focus, or what the proper iris level should be, or what the proper lighting is. Not to say those features don't have their place, but relying on those features when you don't have to is opening yourself up to this sort of problem.

Learn to make those decisions for yourself on the fly. I'm not saying it's easy, it often isn't. But when you learn to do your own focus/iris/WB instead of just leaving it in auto, you'll find that you'll simply become a better shooter, and begin thinking about how to do things you never really thought about.

To borrow Jan's Ferrari analogy... it's like buying a Ferrari with an automatic transmission. Kinda defeats the purpose :)

(And for the record, I never really learned to drive a stick)
 
Mike, I totally understand. When shooting most of my stuff I do that. But when shooting some sports from up high or on a pole, manual comes in handy. Using the FX1, I have not had one issue with this in all manual setup. That is a 6 or 7 year old camera. Got my new one and wow, this camera is over changing everything. I just thought that it would be some what usable with newer technology.
 
Here is my point!

I know you should not completely trust manual settings for most stuff. But, what if you are shooting some productions or live events and have your camera on a crane. I am not talking about something that would be televised or a major dvd. You should be able to trust some manual setting without having footage look completely out of wack. I could see if no camera before had allowed you to do this, it would not be an issue.

You place a HMC150 on a crane and shoot a school production with manual setting, no problems. I would be afraid to do that right now with my AC160.

All I think is that the newer cameras should do it just a little better, not worse. Have you ever tried manually changing iris, focus, zooming, on a crane, while taping a live event. Fun.....I just want something usable with this newer camera in regards to manual settings. Am I asking too much?
 
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A crane with I'm assuming no remote focus/iris control is one thing. I'm just saying in general.

It's my soapbox, d*mm*t, stop trying to knock me off of it! :)
 
Re: Iris... Isn't this camera along with all the cheaper camcorders that don't use ENG lens have ELECTRONIC shutters??? I think that is why exposures jump.

I too found the constant need to adjust the ND filter and the lack of good f stop range annoying on this camera. I think I was at f9.6 and it was asking me to add some more ND. ??? In manual mode it goes to f11 and my old DVC30 goes to f16.
When I did add the ND it was giving me something like f3.6. WTF that kills my depth of field. I think Panasonic tried too hard to manage exposure. Sad because a good ENG lens typically only a few simple filter settings. (shade, full sun or partial sun) This thing has 4 ND settings which need constant adjustment in full sun.
Before I get the "Ferrari lecture" I'd like to say I shoot a moving object outside and I do a lot of zooming in and out so manual is not an option. I have shot using my DP800 (twice the cost of this alleged "Ferrari"), D410a (also twice the cost of this alleged "Ferrari"), DVC30 (a Honda of cameras) and have never had an issue with being in auto exposure. This camera was constantly wanting me to change filter settings.:shocked: Unable to manage the exposure within one filter (and with no noticeable change in sun light.) Worst of all-- I don't have the luxury to stop following my object, I am taping, and change filter settings.
I'd use my JVC HM700 but it sucks juice so fast I'd have to invest in a million dollars worth of batteries to get through the day.
Also on the exposure thing. I notice on my HMC80 that the exposure 'jumps' or 'pops' instead of transitioning.

One other note to respond to the OP notation of sharpness. I believe this camera has a sharpen image algorithm just like the digital still cameras. So don't give the lens the credit.

They can call this camera a Ferrari when:
1) The Iris ring has f stop number and the ring doesn't spin round and round.
2) the focus ring has meter/feet numbers and doesn't spin round and round like a merry-go-round.
3) I can manually dial in my own color balance temperature, with 100 degree increments. Pointing the camera at a white object may get you 95% there but my a manual dial would get me the other 5%. As we all know a white painted object has it's own degrees of color which could throw off your balance and if the surface has a type of shine or gloss to it-- it too can throw off the temperature setting.

Kudos to making a camera without predetermined color balance setting like 'sun', florescent, incandescent, etc... I don't think I ever used that setting unless the camera was giving me an incorrect color balance, due to too many light sources. (typically they were churches and I don't do weddings any more) This is where a color balance wheel would be AWESOME. It could be similar to the "SHTR" (shutter) wheel on the 130/160. Hint hint Panasonic engineers.
 
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