cglaeser

The real problem is that few manufacturers include the shutter speed when citing a minimum lux value, and many of the new IP cameras support a shutter speed as low as 1 or 2 seconds. For example, I have an Axis 223M megapixel day/night camera. The data sheet lists a low light value of 0.2 lux. However, my testing indicates that this 0.2 lux requires a 2 second shutter speed, which is useless for anything but stationary objects. My front driveway is illuminated with a 5 lux street light, and even that is too low for the 223M using a 1/30 shutter speed. So, to answer your question, when you compare lux values, you must also compare shutter speed. Since most manufacturers fail to include the shutter speed, it's difficult to do a meaningful comparison. Best, Christopher

It must be moved to a better web hosting service. The 1&1 hosting service puts too many websites on each server. While the traffic to the CCTV forum is relatively low, it must compete with all the other websites that share the same server. Best, Christopher

Couple of quick points: - There are some very low lux cameras, but they are relatively expensive (may cost $8,000 or more). - Manufacturers typically do not mention the shutter speed with thier low-light lux rating. To achieve those low lux numbers, they may use a 2 second shutter speed, which is useless if you want to record movement. For example, 0.1 lux at 1/60 is considerably better than 0.01 lux at 2 seconds. Best, Christopher

Would be an extremely compelling demo if there was a way to precisely control night lighting at various lux levels (e.g. 1.0, 0.5, 0.1, 0.05, and 0.01 lux). Best, Christopher

Check out the Axis 233D. It includes 35x zoom PTZ with autotracking. http://www.axis.com/products/cam_233d/index.htm Best, Christopher

Performance remains poor. I've read this book before. I know how it ends. Performance will improve when this forum is hosted with a top-rated hosting service. You can talk and talk to the current hosting service, but in the end, it won't help. I know it's not easy picking up sticks and moving to another service. Been there, done that. However, after the move, you'll say wow, why did I wait so long. Check out some of the Top 10 Web Hosting rating services and read the reviews. Best, Christopher

Brownout? Thermal? Do you have a good power supply?

What is the size of the parking lot? Is there light at night? Best, Christopher

Unfortunately, there's not much we can do about it except do as you have done and continue to report the problem to the forum moderators. As was stated above, this problem is not caused by issues on our computers. The problem is at the server. The most likely cause it too many virtual hosts being hosted on one physical server. Someone needs to contact tech support at 1&1 and request improved bandwidth. Best, Christopher

Thanks. Did you find any specs that specify the shutter speed of the 0.01 lux? I located various specs on the net, but no shutter speed. Best, Christopher

Are there any IP cameras with a lux rating as low as 0.01 or even 0.0005 rating? Best, Christopher

Thanks, the Axis 223M has those settings as well. Here's the problem. When manufacturers publish low light specifications, they typically do not include the shutter speed required to achieve that lux value. For example, the Axis 223M specifications are 0.2 lux, BUT .... at what shutter speed? Well, my testing indicates 0.2 lux requires a shutter speed of 2 seconds. Sure wish I had known that before I purchased the camera. 2 seconds may be fine for viewing parked cars, but is pretty much useless for person identification. So, that's why I asked about the Arecont low light lux value and shutter speed. Is that 0.01 lux at 1/60, or is it 2 seconds? That's a *huge* difference in performance, and that's why 0.01 lux does not mean much without specifying the shutter speed. Best, Christopher

This forum is much too small for that to cause performance problems. Best, Christopher

Right, I added megapixel to the thread. I found a product spec on the net that indicated 0.01 lux, but the specs did not mention the shutter speed. Based on my experience with the 223M, I know how that game can be played (i.e. extremely long exposure time to achieve low lux value). Do you know the shutter speed of that 0.01 lux figure? Best, Christopher

It's probably the web server. Most hosting companies use virtual servers, where many web sites are hosted on one physical server. To save money, some hosting companies cram far too many web sites onto one server, and performance drops to practically unusable. I had this problem with AIT, and it just kept getting worse, so I reviewed a web hosting rating service and selected Hostmonster.com. So far, performance has been exceptional. Best, Christopher

The problem with the Axis data sheets is they don't specify the shutter speed used to measure the reported low light rating. Any exposure longer than about 1/25 is not really usable for a security camera, but Axis typically use exposure times much longer than that. I have the Axis 223M, which has a low lux rating of 0.2 lux in the data sheet. What they fail to mention is the lux rating is for exposure times of between 1 and 2 seconds, which is completely unusable for person identification. I have measured the low light capabilities of this camera, and a shutter speed of 1/25 is no where near 0.2 lux. So, when I see an Axis low light rating of 0.008 lux for the 223D without an associated shutter speed, it make me wonder. FWIW, Mobotix does include shutter speed with low light ratings, so their numbers are useful. Are there any low light fixed megapixel IP cameras available? Is there anything comparable to or better than the Mobotix M12 SEC Day-Night? Best, Christopher

This must be them ... http://www.axis.com/promotion/new_generation/products.htm Best, Christopher

To which camera are you referring? Best, Christopher

Slick. I especially like the form factor. Best, Christopher

Can you provide any details? Best, Christopher

Does anyone have experience with both the Axis 223M and Mobotix 12M or is there a review on the net that compares both? In particular, how do they compare wrt low light at night? The specs of each camera list the minimum lux level, but the 223M specifications do not mention the shutter speed used to determine that lux level, so it's difficult to compare based on specifications. Best, Christopher

I use a Minolta IV, but pretty much any photo light meter will do. You can find conversion tables on the net that will convert ISO/shutter/f-stop to EV to lux. Best, Christopher

Here's an image taken with the Axis 223M at dusk. http://tinyurl.com/bfy4u7 I waited as long as possible to take the dimmest light that might be usable for identification purposes. The light meter indicates ISO 400, 1/4 second, f/1.4.7 (this meter can measure fractional f stops). That corresponds to about 7 lux. The Axis is set to 1/50 shutter speed and 36 gain. IMO, 1/50 is the slowest shutter speed possible to keep motion blur under control. Setting the exposure time to anything longer (e.g. 1/25) causes too much motion blur to really be useful. I think this image is barely usable at 7 lux. At 1 or 2 lux, the image is too dark with too much noise. The Axis brochures indicates a minimum illumination of 0.2 lux, which is considerably less than 7 lux. Why the huge difference? Because they are using an exposure time on the order of 2 seconds. Here's an example of me walking very slowly when the exposure time is set to 1 second. http://tinyurl.com/b43297 Is that me, or is that the dog standing on hind legs? More important, is this really a day/night camera? Best, Christopher

Excellent! Thanks for posting this. Do you by chance have access to a photography light meter? I know the Mobotix is reporting reflected lux values, but it would be great if we could independently measure the ambient lux value. Best, Christopher

Right, we agree, the banding is not due to high gain. That's why I provided a different explanation than your original answer. Take another close look at the sunlight photo of the car. Look at the high contrast diagonal parts of the car wind shield and front bumper. See those horizontal bands near the high contrast transitions? Those bands do not appear in the SEC model, and yet, here they are in the IT model, which uses the same sensor. I'm suggesting those bands were introduced by the firmware when the megapixel image was reduced to a VGA image, and at night, those bands are amplified by the high gain. I asked Mobotix tech support and they confirmed it. Best, Christopher