Member Discussion

Its 10 O'cLock, Do You Know Where Your Cut Filter Is?

Its easy to notice when your IR cut filter is stuck open during the day.  The purplish tinting in the image is easily identified.  From a recent discussion. (Left panels are stuck).

But what about if your cut filter is stuck closed at night?  

How would you know?  Especially, if you weren't using IR lightning and even more especially if the filter had never opened from the day you bought it.

I could imagine just thinking this camera sucks in low-light and writing it off as such.  It might not even suck that much depending on the ambient light around.

If they can get stuck open then they can get stuck closed, I would think.

Thoughts?


Some cameras may have the current 'mode' identified in the web interface (assuming IP camera).  It will say 'Day' or 'Night' or 'Open' or 'Closed' to indicate if it's in day or night mode.
Unfortunately you can't rely on it 100% as the selection may change to the correct value since the proper command was sent for the day/night switch.  But if the filter is physically stuck and will not move even if the camera 'thinks' it did.

A more full proof method, if you have a camera with a removable lens you can unscrew the lens and look at the imager itself.  If the glass is clear, with no tinting, then the filter is away from the sensor and the camera is in night mode.  If the glass has a tint to it (Blue, Green, Red, etc) then it is in day mode.  You can do this at night with a flashlight to know for sure which mode the camera is in. 

Note, you should be careful with the lens removed so that debris doesn't get onto the sensor.

Also, use 'just enough' light to make out the tint of the glass.  Too much light may make the filter switch giving you incorrect results, i.e. you may force the camera into day mode unintentionally.  Usually, though faint, the filter makes a clicking sound when it moves.  You may hear it click, but this also doesn't necessarily mean the filter is switching correctly.  If something is physically blocking the filter then everything else will work but the filter will never actually move.

Is this a field fixable issue?  I've had numerous Arecont pano's suffer from this one one or more of the imagers.  Even had their tech support (excuse me a moment.... BAWAWAWAWA)   suggest I "rap" the camera with the handle of my screw driver to possibly shake it out of it's stuck position.  

I had no luck with that. 

Unfortunately, not really. A slight impact might knock it free but it'll probably happen again anyway. In one camera we tested, it corrected itself with a power cycle, but another just stayed stuck for good. 

So the filters wouldn't move out of the path at night?

What did the image look like compared to when it worked correctly?

Backing up to answer the original question, if you're not using IR at night the difference between performance with the cut filter on and off is not going to be the difference between a camera sucking and not sucking.

It's more like it sucks at 7.5 level when it should only suck a 7 on the suck scale (to put it in technical terms). Ambient IR generally is not enough to affect performance in a drastic fashion. 

Thanks!  

What about with IR then?  The filter still lets IR thru to a degree, even in the day time.  Do you think it would be obvious?