Dealing with bright and dark areas (at the same time)

[chewingyu 0]

I have this 'dilemma'. I need to install cameras at truckdocks to look at activities within the truckdock container. So, the camera has be located from inside the warehouse looking at the truck dock opening.

 

Here's the problem. The reflected sunlight from the road is causing the auto-iris to close up, thus rendering the images a too dark to see what is inside the truck.

 

Anyone who has had a similar problem and successfully tackled it?

[CCTV_Suppliers 0]

The only solution available that worked for us is Panasonic WV-CP484 with a good lens... and for the price, you get the best performer for your application.

 

I am sure similar results could be achieved using higher end cameras and with more cost, but this model above gives you balanced performance and it works!

[griffonsystems 0]

yeah you need a camera that has wide dynamic range - panasonic is one of the best at it.. i have also used ganz wdr cameras for this with good results

[chewingyu 0]

I am told that Fujinon lenses would be able to help. Anyone with any experience with this lens make?

[cctv_down_under 0]

The lens can help in some respect...but the main issue is the WDR...Wide Dynaic Range...if you dont havea camera that supports this, then adjust your Gain Back ....dont use AGC, turn off BLC and increase yopur DC Level

[CameraGimp 0]

I don't see why a fujinon lens would help unless it is a video iris lens. The problem is the camera/lens is the lack of dynamic range of the camera and the way it is reacting to the highlights and so causing your lowlights to be under exposed.

 

You can either try a wide dynamic camera such as the Panasonic suggested or one using the Pixim chipset or you can try and make the camera ignore the highlights. The second option will result in the highlights clipping but you will get better definition in the low lights.

 

Features such as BLC and Pk/Av adjustment on a video iris lens could help.

If you have advanced BLC you might be able to tell the camera to 'ignore' the bright areas. This would need a static scene, ie not on a PTZ and the truck always park in the same place.

If you have a video iris lens you could set the pk/av pot to Av. This will weight the exposure towards the average light level and allow the peaks to over expose.

Don't forget neither method will increase dynamic range, they just shift the exposure so you will lose the highlights but gain in the lowlights. It will always be a trade off, if you can't accept this you need to trade up to a more expensive camera.

[cctv_down_under 0]

Actually your right the lens wont help a lot....but response time and quality of ground glass can help withbright scenes, not a lot I admit, in fact in some ways it enhances it as there are less abhorations and therefore more light concentrated on the sensor...but haviung many elements in the lens can help to balance the light more evenly

[chewingyu 0]

Thanks for the info, ppl. So, what do I do?

Get wide dynamic range with video iris lenses?

Will it cost a bomb?

[cctv_down_under 0]

You either need to balance the lighting or go for a Wide Dynamic Camera that supports masking (painting an area to affect).. or quite simply you could put up posts or bollards making the vehicles reverse into a very small space, then zoom in from the ware house so that the bright area is not seen...quite often we try to work around the environment rather that change it.

 

If you could zoom in to a point where you no longer have the effect of the bright daylight and could control the area that the truck could stop within, then you might stand a chance.

 

The best three wide dynamic cmaeras that I have seen thus far are.

 

Panasonic - SDIII

Bosch - LTC0495

Ganz - Wide Dynamic Camera

[chewingyu 0]

Thanks. Will have to look into how I can apply your suggestions. : D