Author Options:

Photo Blocker Circuit Answered

Alright everyone I have been shopping around looking at devices like the photo blocker db-1. One thing I have found is they are expensive. So i was wondering if anyone knows how to build a circuit that can sense a camera flash and then trigger a flash bulb to activate.


are you talking about one of those red light camera blockers? like this


if so, you have a couple of problems. #1, they're probably illegal in some jurisdictions....#2, they're not as effective as the manufacturers will claim. people tend to think red light cameras are just static still image cameras...and...they do have that functionality (the shot with the flash is definitely taking a still picture)....but they're also video cameras. if an event is triggered (i.e. a red light violation) the still photo is saved, but so is a certain period of video footage. if the still image doesn't give a good plate reading, then the people that operate the camera will just rewind or fast forward the video footage till they get a good enough plate read. so that millisecond that your flash is going off to obscure the plate will not be guaranteed to actually help you out

Many places also have speed cameras now but the same still applies. Your flash isn't going to be quick enough to interfere with the camera taking the picture. But it will be enough that the police and prosecutor can see what you where trying to do and add charges accordingly.

Yes that's what I'm talking about. They are not illegal in my area and I'm more concerned about these photo radar vans that are being set up in my area. I got a ticket from one for going 2 mph over the speed limit. I fought it and got it dropped in court but it is a huge pain in the ass. I've seen reviews of the photo blocker db-1 and it actually works really well.

Check Ebay for a remote slave trigger, they are around 5 bucks and available for many different systems.

Connects to the flash and activates it when a light burst is sensored, so it works as long as the main flah can reach the sensor.

Or search this site for slave flash if you want to make your own.