yeah Ive got enough zoom to do just one lane of traffic heh.. its a 6-60mm and I'd guess I am about ~45-50mm right now, and its not full road width as it is.. ive moved it a bit to the right from that image as away traffic was leaving the frame and coming back.
What was the brand / source / price on that lens. It looks like very good quality so far.
the bullet you have is high on my list, but I think i am going to try something like this first:
http://www.amazon.com/Univivi-U06R-WideAngle-Lights-Illuminator/dp/B00M3O5ERK
just to see if I can do it a bit quicker and cheaper, for the price and power of your IR I am keen on trying the 940mm just so it remains discrete as it shines at cars.. I am pretty sure this lens will take it and I dont think i need that much power as I do the optics.. so win win?
Save your $30. That thing claims 130 feet and you are capturing at 200 feet, so you are beyond the claimed specifications of the illuminator already. Remember that the inverse square law says that every time you increase the distance by a factor of 1.4 you halve the illumination. The specifications on those cheaper illuminators are also notoriously optimistic. The two schools of though I have seen are halve the distance claimed, or convert the claimed distance in metres to feet and you are in the ballpark. I'm not using an expensive illuminator but the angle is only 30 degrees.
This is the type I am using. It claims 80m and I capture at 15-20m and 1/1000s shutter. At 50mm you could easily use a 15 degree illuminator so you aren't wasting any light.
Noise in the image appears to affect the ability of ANPR to recognise that a plate is there. I was using the test page of a local company providing ANPR solutions and it would happily and correctly read my day time captures, however it didn't even recognise that a plate was there in my night time captures, despite their being no difference in the human readability between the two. I'm using an old Dahua and the gain is all the way up so the image is incredibly grainy. You have a camera with better low light performance, plus you are running a slower shutter, so probably wont need so much gain, and it might not be an issue for you, but everything I have read, and my own testing seems to indicate that really clean images are important for night ANPR performance, and you should get as much illumination on the subject as you can to help achieve that.
the abf button on the back is auto back focus, open my tablet.. get the focus as good as I can then hit that button and it fine tunes it.. very sweet.
I've got my eye on the
Low Light 2mp version of the Dahua with that same feature as an upgrade to replace the old Dahua in my number plate capture setup. Can ABF be set to automatic so the camera adjusts for focus shift when moving from day to night, or when your depth of field changes due to iris settings, or is it strictly a push the button on the back function?
One last question. What hardware have you got crunching the numbers on the Open ALPRD? Is it CPU intensive, or could you run it as a background process on a server doing other tasks?