Scruit 0 Posted March 13, 2007 Camera is supercircuits pc-23c - 1/3" Monochrome High Performance CCD - 250,920 Pixels - 480 Lines Resolution - 0.04 lux Minimum Illumination - 1/60 - 1/100,000 Automatic Shutter - C/CS Mount Lens Compatible (lenses sold seperately) - 12 or 24 Volts DC/AC Power (power supplies sold seperately) - 2.3" x 2" x 3.77" - Weighs 192g - 5 Year Warranty Lens is Fujinon H6x12.5R 12.5-75mm Lens has a 52nn screw-in 850nm IR cut filter. Next to the camera is a Panvigor "120 feet" IR illuminator aimed at the focus point. The focus point is about 90' from the camera. During the day the image is very good and I can read the license plate easily. At night the IR illimnator kicks on and the plates reflect well and are readable. The problem I'm having is at twilight - where there's enough ambient light to stop the illuminator turning on, but not enough for a good image using the manual iris set to a compromise setting. I've attached a picture of the license plate camera at night. Question 1: Before I go out and try to price up a 75mm lens with auto-iris (camera supports auto-iris) is it worth turning on the backlight compensation? Would it help at all? Question 2: I set the iris/focus at night, not twilight. Is there any chance that setting the focus/iris at twilight would help? (where the light is lowest, considering the illuminator isn't on yet) I've tried covering the illuminator's light sensor with tape to have it run 24x7, but the sensor is behind thick glass and the light from the IR leds themselves will light up the tape and make the light sensor think there's light all the time. Result is the illuminator is half on all the time, not 100% Question 3: Would all my problems be solved by an auto-iris lens? What could I expect to pay for a usable 75mm auto-iris lens? BTW, the characters that are visble are 7 and 8 Share this post Link to post Share on other sites
cctv_down_under 0 Posted March 14, 2007 What shutter speed is th camera set to and what gain level? Share this post Link to post Share on other sites
Scruit 0 Posted March 14, 2007 What shutter speed is th camera set to and what gain level? Shutter speed is automatic - not sure I can change it. I haven't touched the gain. On the back of the camera there is a switch for Normal/BLC mode and there's a 'screw' for "Level" (is this the gain?) I was hoping the IR filter would block out more of the headlights - and it does block out enough that the license plate is visible during the day, and at night (with illuminator) regardless of headlights/highbeams. The problem is just that during the twilight period of about 30 minutes the illuminator is turning on after the the point at which there is enough ambient light for the camera to read the plate. If I adjust the gain upward then maybe the camera will be able to 'see' until the illuminator turns on. I wish the illuminator had a setting to adjust it's light sensitivity. I'm just about ready to take it apart and cover the light sensor with a piece of electrical tape. Share this post Link to post Share on other sites
SBTVideoman 0 Posted March 15, 2007 Hmmm...the answer may be that you have the wrong camera for this application. It may be worth trying a "wide dynamic" capable Day/Night model, such as one of the following: Bosch Dinion LTC0495 Bosch Dinion LTC0620 (1/2"version, expensive but nice) Siemens CCWC1335 Siemens CCBS1225 - 1/2" model with peak white inversion, which will automatically black out the bright vehicle headlights. Being a 1/2" camera it offers high performance..but expensive option. (BTW I do not work for Bosch, but they make nice cameras) Other manufacturers also have cameras with "peak inversion" - I seem to recall Ness has a "Smart eclipser camera", I think it's a 1/3" model but not sure if it's a day/night unit that will work with IR floods. Share this post Link to post Share on other sites
rory 0 Posted March 15, 2007 What shutter speed is th camera set to and what gain level? Shutter speed is automatic - not sure I can change it. I haven't touched the gain. On the back of the camera there is a switch for Normal/BLC mode and there's a 'screw' for "Level" (is this the gain?) I was hoping the IR filter would block out more of the headlights - and it does block out enough that the license plate is visible during the day, and at night (with illuminator) regardless of headlights/highbeams. The problem is just that during the twilight period of about 30 minutes the illuminator is turning on after the the point at which there is enough ambient light for the camera to read the plate. If I adjust the gain upward then maybe the camera will be able to 'see' until the illuminator turns on. I wish the illuminator had a setting to adjust it's light sensitivity. I'm just about ready to take it apart and cover the light sensor with a piece of electrical tape. Get an ND filter instead, a dark one (get several for testing). Also a camera with a Dynamic range would help as well. Example would be a Panasonic Wide Dynamic Day/Night. GE has a new model also, the GEC-HDR1-DN. Others already mentioned the Bosch as well. As for Infrared, if you can, get rid of that cheap one and get your hands on an Extreme CCTV UF100. The UF100 doesnt have a level adjustment so to speak, but when you order it you would order the right filter and lens (UF100 lens), and you can also tap the PSU to drop it down some if needed (20%+-). Speak to a pro that knows the UF100 for more info there. Also, post a day image, as its hard to tell, but it looks like it may just be a little out of focus as well. Was it focused under Infrared, Low Light, or full Light? Your best bet would be to set the iris in the daytime, and the focus under full infrared at night (without any filters on) - in this case - I would imagine. Looks like you need just a tad more IR also .. too much though and you wont see the plate at all, just one big white rectangle.. Share this post Link to post Share on other sites
Scruit 0 Posted March 15, 2007 Also, post a day image, as its hard to tell, but it looks like it may just be a little out of focus as well. Was it focused under Infrared, Low Light, or full Light? Your best bet would be to set the iris in the daytime, and the focus under full infrared at night (without any filters on) - in this case - I would imagine. Looks like you need just a tad more IR also .. too much though and you wont see the plate at all, just one big white rectangle.. The iris and focus were set at night with the illuminator and filter on. When I get home from work tonight I'll post full day and full night pictures. Changing the BLC made no difference to the headlight glare. Fortunately at night the illuminator is bright enough that the plate is still clear even with the headlight glare. Will post pics tonight. Share this post Link to post Share on other sites
cctv_down_under 0 Posted March 15, 2007 Might be better to go with a cam that has limited vertical smearing! The other option is inversion, tis makes the headlights black and means that the white part of the plate is balck as well, you can make out plates quite nicely this way. Share this post Link to post Share on other sites
Scruit 0 Posted March 15, 2007 At night: (trying to upload pic - get error message Could not access ftp directory: 'attachments/thumbs'. Please check your FTP Settings.) http://i103.photobucket.com/albums/m159/Scruit/night.jpg Share this post Link to post Share on other sites
Scruit 0 Posted March 15, 2007 Problem 'solved'. I opened up the illuminator and put a piece of electrical tape on the light sensor. It now runs 100% all the time. The plate lights up just like at night. Now I need to see if the plate is bleached out during the day... shouldn't be, as the ambient sunlight is brighter than my $70 illuminator. Here's a before/after. The before is the illuminator withthe light sensor uncovered. The after inset is the light sensor covered. http://i103.photobucket.com/albums/m159/Scruit/twilight_beforeafter.jpg Share this post Link to post Share on other sites
