Camera "bloom"

[bcarusi 0]

Not sure I have the right technical word, but I'm having an issue with brightness balance.

Long story short, I found an excellent tutorial online that goes through a complete security / surveillance installation start to finish; it was pretty in-depth at 50 or so pages, but in any case, the installer put a system in a church and documented the whole thing.

 

I was inspired and ended up buying that system for my home and one more for my own church but... The camera in the worship center looks great at "normal lighting" but on a Sunday morning when all the stage lights are on it pretty much is one big white blob... I'm using one of the On-Q bullet cameras (excellent quality but does not handle the dynamic lighting in that room well).

How does one handle stage lighting? I'm guessing that my issue is that there is so much "darker area" around the edge it is just not adjusting properly - is there a better camera to recommend?

The DVR is an aposonic R22 if that makes any difference.

 

BC

[Soundy 1]

Do these cameras have auto-iris lenses? If the overall lighting of the scene varies a lot, that's the best way to deal with it - it allows the lens iris to close down automatically when the light is brighter.

 

If you have extreme contrast within a scene (especially with really harsh backlighting), you'll need something with a WDR function (Wide Dynamic Range)... or at the upper end, something like Panasonic's SuperDynamic models.

[bpzle 0]

WDR and I second the Panasonic recommendation for what you're trying to do... To date, I have not seen better.

[tomcctv 190]

Not sure I have the right technical word, but I'm having an issue with brightness balance.

Long story short, I found an excellent tutorial online that goes through a complete security / surveillance installation start to finish; it was pretty in-depth at 50 or so pages, but in any case, the installer put a system in a church and documented the whole thing.

 

I was inspired and ended up buying that system for my home and one more for my own church but... The camera in the worship center looks great at "normal lighting" but on a Sunday morning when all the stage lights are on it pretty much is one big white blob... I'm using one of the On-Q bullet cameras (excellent quality but does not handle the dynamic lighting in that room well).

How does one handle stage lighting? I'm guessing that my issue is that there is so much "darker area" around the edge it is just not adjusting properly - is there a better camera to recommend?

The DVR is an aposonic R22 if that makes any difference.

 

BC

 

 

 

Hi BC so you have had this problem for over a year why is it you could not get tech support to help you after all this time.

[Soundy 1]

Where does it say he's had this problem for a year?

 

What I can find for "On-Q", it looks like the make very mediocre consumer-grade cameras to complement a line of home-automation products... probably explains the poor performance over harsh lighting conditions.

[bcarusi 0]

The OnQ camera is actually pretty good - it has a balun built in to work over cat5 and in normal office conditions has good picture quality. It has been installed for about a month - problem is that I used it because that is the one the guy in the tutorial used - I know someone who works for OnQ (another division) and they slipped me one so I didn't feel comfortable calling their tech support in case my friend did not get it through normal channels.

I think I'll give that panasonic a try - it is most definitely very wide dynamic range. For the application, I've begun looking into PTZ options as well - difficult enviornment...

 

Thanks for all the tips.

 

The tutorial I used is on amperordirect under resources in the security section - pretty good but they left out the part about the camera having trouble in bright light.

 

Thanks again all.

 

C

[Soundy 1]

Note that the Panasonic SuperDynamic cameras are NOT cheap, and while they are excellent, you may not need the SD or even WDR. Its main purpose is when there's a very wide range of lighting within one scene - for example, a person in a doorway with bright sunlight outside, or other such severe backlighting situations.

 

If the people on the stage are front-lit, then WDR probably isn't what you need (nothing wrong with it, just don't want to see you toss money at a function that's not required)... if the issue is mainly that the camera can't handle the variations between lit and unlit scenes, or that there's just too much light, this is where auto-iris comes in.

 

It would be really helpful if you could post a couple of stills of the scene, both with and without the stage lights.

[bcarusi 0]

It would be really helpful if you could post a couple of stills of the scene, both with and without the stage lights.

 

Sorry it took so long, but here are a series of pics - In order they are no lights, house lights only (no stage), "Normal" stage lighting, and full on... With an empty stage it is kind of hard to tell, but when people are up there and you are at normal or full on you pretty much just see white blobs.

 

 

Zooming in would probably solve some of the lighting issues but the camera is fixed zoom -

 

BC

[Soundy 1]

Yup, dynamic range is exactly your problem: the camera derives its exposure from looking at the entire scene, but most of the scene is actually fairly dark (the backs of the pews). Put a lot of people in there, especially in their "Sunday best" dark suits, and the camera isn't able to compensate.

 

Zooming in would help... tilting the camera up a bit MIGHT help as well, although probably not enough. Something does does spot or even center-weighted metering would be even better, but those aren't common functions in analog CCTV cameras (some megapixel cameras, like IQEye, let you define exposure zones that would address the situation perfectly).

 

Looks like this camera has probably 3.6 or 4mm lens... something like the CNB VBM-24VFs (if you want a dome) would probably work well, as they're auto-iris, have a really good dynamic-range function (not fully "WDR", but still good), and include a 2.8-10.5mm varifocal lens so you can get in tighter on the stage. CNB has other models that are WDR as well, but I don't use them, so I don't have any model numbers right off the top of my head.

[bcarusi 0]

Just for fun, with the same scene issues in mind. Is there a relatively low cost PTZ camera that might work well? We use it sometimes to put a baptism up on screen and that way we could just use one camera. I can't seem to find anything in the $500 or less range - my expectations might be too high.

 

Thanks for the above advice - I understand some of the issues now.

 

BC

[Soundy 1]

Yeah, a "good" PTZ won't be cheap... and keep in mind, you'll still want one that has auto-iris and WDR, or you'll be right back to the same problem when you zoom out. Plus, you'll need some way to control it - if the DVR supports it, you might be able to use that, although it might not be too convenient. Otherwise, you'd need some sort of joystick controller... which of course, is an additional cost.

[survtech 0]

It looks like too much AGC. On a lark, if the camera has adjustable or defeatable AGC, turn it down/off. That may help when the lighting is high, but could cause a dim picture when the light is lower.