JVC 170 Contrast Flicker Problem
 

I have no problem in the daylight but in low light I seem to notice a flicker problem with the highlights. I can turn down the overall exposure but then the talent is too dark.

I also have been having problems with the auto focus. When I leave the camera locked down I noticed it was not holding it's focus. When I zoomed into the talent the auto focus did not hold. Perhaps these problems are related.

I have made a demo video of the problem, password "vtlp".

JVC support has been working with me but so far they are a little clueless as to what is going on. I was asked if this happening to all three cameras I own and yes it is. Therefore it's not a camera malfunction problem.

Any help would be appreciated.

Re: JVC 170 Contrast Flicker Problem
 

One thing is certain, the autofocus looks like next to useless on this camera, that close up from the books at 01:00 looks more like a aliasing problem to me but that flicker problem is something I have never seen before, since you are able to duplicate that on all 3 camera's and when even JVC is clueless about it then this looks like a serious bug. If I would own these camera's I'd send them back in and ask for a refund if they where not able to fix it.

Re: JVC 170 Contrast Flicker Problem
 

I found this in the manual, I wonder if this would help my problem?

According to the JVC 170 Manual

White Clip
For setting the point to apply white clip for input video signals with a high luminance level.

It is always set at 108%. You have to change the Wide dynamic Range (WDR) in order for this value to be changed to 103% or 100%

Re: JVC 170 Contrast Flicker Problem
 

I found that WDR (Wide Dynamic Range) setting help with the flicker. I also tried clipping the whites setting but this had no effect. Here is a video showing the results using the heavy setting for WDR.

Password "vtlp"

I am not sure in event live filming I can set whether to have WDR on or not. Why doesn't this camera just do the exposure dynamics automatically?

Re: JVC 170 Contrast Flicker Problem
 

Interesting problem you have. I think that while this might be a design issue I advise that you check a few things first. Most of the issues you point out are really aliasing problems with high detail parts of the image. See if the detail adjustments for this camera can be lowered a bit. That might help. Also were these videos shot in progressive or interlaced? Interlaced video, even in HD, can cause the issues you are experiencing. Third, auto focus can really mess you up, especially on wide shots in darker spaces where the camera has no idea what you really want in focus.

Re: JVC 170 Contrast Flicker Problem
 

Thanks for taking an interest in my problem, you are right reducing the detail does solve the flicker but it leaves the talent as a blur. I did some test but it's raining and I don't have as bright as dynamics as I had before so I will rerun the test at another day. I think adjust Wide Dynamic Range setting did even more good for the contrast dynamics.

I am using progressive 30p

Yes the auto focus is going haywire. I shot talent on a stage with LED lights on them and the camera could not even hold focus on the foreground. Maybe facial recognition would have been better but I think the auto focus should work better by itself.

One thing I have not heard from support and I know this needs to be done is to update the firmware. However I feel the camera should come from the factory up to spec. These cameras were on back order so maybe the firmware was not working properly.

Re: JVC 170 Contrast Flicker Problem
 

Having to activate wide DR to somewhat solve the flicker problem is not a normal behavior of a good functioning camera, the problem you have shown is something I have not seen in any camera I ever owned the past 10 years, have you tried to reset the camera so all settings are at default?

Re: JVC 170 Contrast Flicker Problem
 

Yes, support had me reset the camera by holding a number of buttons.

Press and hold #1
Press #2,#3,#4
Then press #5,#4
Then release #1

Nothing changed, I expect I will see better results when I update the firmware.

Re: JVC 170 Contrast Flicker Problem
 

I have a new test video. This is happening on all three cameras whether on manual or auto focus. I can darken the exposure and it helps but not does not get rid of the flicker with the bright whites of sunlight coming in.

So do you think I should send the cameras back to the manufacture?

Password "vtlp"