What Is A Normal Shutter Speed For Identification At An Entrance

Good description.

First question - do you require color? If not, have you used IR?

Secondly, how good in low light are the cameras you have tried?

There are a number of ways to improve low light performance - as you mention iris and shutter speed. The other 'big' one is the low light sensitivity of the camera, some cameras are just a lot better than other ones (e.g., Ranking IP Camera Low Light Performance). To that end, any 'general' answer needs to directly address the low light performance of varying models.

Third, can you share an example face shot? For example, you mention "very little contrast in the faces" but I am not sure how much / bad that is, as people's judgment on this can vary. This (and the models) would help us get a better sense of what optimizations are available.

I require color.

The camera is supposed to deal fairly well with low light, as I am told by the data sheet and the supplier. I have another camera, that is performing better, in mind, but I have to justify the extra cost. And that is sort of why I am asking a general question about the shutter speed. I am pretty sure what is wrong in the scene, and how to fix it. It is whether or not it is normal to set maximum shutter speed to be 100+ to capture faces, which is my question.

I can't send any images because of boring legal reasons.

By "very little contrast" I mean that there is not enough difference in color between the pixels in the face, for the h264 encoder to understand that there is detail there. Other features, like writing on clothing, is sharp and clear on the person.

But I don't want to focus on the optimizing stuff. I really just want to know if it is normal with short shutter speeds, because I suspect this is one of the questions that will pop up in the discussion about the cameras. Questions like "Do you really ned the short shutter speed? We usually use 1/30 in other places, and have gotten only positive reports about how pretty the pictures are." If 1/30 is really the standard for identification purposes, then what I perceive as motion blur may have some other cause, or may simply be a figment of my imagination.

Couple questions:

If the shutter speed is set to 1/50 and someone is walking slowly without bobbing and weaving, does the head shot contain what you would consider adequate amount of detail/contrast, without blurring?

If it doesn't, what ss is necessary (assuming a slow moving image)?

As John says it matters how fast the subject is moving to determine blurring. In the end though, what matters is how fast the subject is moving thru the frame/FOV.

A level, straight-on shot at a subject moving directly toward the camera is going to have less blur than one where the subject is moving at an angle toward the camera.

Is the distance to target always the same (approx.)?

Are people coming at different angles thru the pinch point?

Can you reduce the angle of the shot by moving the camera back and using a longer focal length?

Wow, it's like I could have written this myself!

One of our customers is a higher-end restaurant chain, who also like to keep the lighting dim at night. Since every site has its own design "oddities", the lighting for the ID shot at some is also particularly tricky, between backlighting, small overhead pin lights, etc.

In the past we've generally used Panasonic SuperDynamic cameras for this purpose (CW or CP484 with SDIII, later CW504 with SD5), but there are instances where even these couldn't really get a good image... and as in your case, management is adamant that the lighting will not be changed to improve facial shots.

Their current spec is Axis P3384 cameras for all public areas, as the Lightfinder feature works very well with the overall dim lighting. There are a couple of instances where we use the WDR function instead, but for the most part the better exposure is more important than "pretty" balanced images.*

For ID shots, I find what usually works better than WDR, is to set them to Lightfinder, enable BLC, then create custom exposure zones using mid-grey-level objects that are under approximately the same lighting as faces will be once inside - door mullions work surprising well for this, or sometimes a bench or planter just inside the door.

I'd have to check, but I'm pretty sure I'm using a 1/60 minimum shutter speed on these - still get a little blur if someone is walking briskly, but since people usually come in the door and stop to look around and/or wait for a hostess, that's not a major problem most of the time. Most sites have a hostess stand right there, and we'll try to aim cameras so it's in or near the edge of the frame, so we get faces as people are talking to the hostess.

*What would really be ideal in this situation is if the camera could automatically switch between LF and WDR modes based on lighting level, while not changing day/night (or IR Cut) mode as we too want them to always be in color... but currently the only way to do this is to have it switch WDR modes based on using the day/night mode switch as a trigger. The problem I found with that is, when it switches to night mode (ICR out), then toggles LF on... the exposure suddenly increases enough that the camera soon goes back to day (ICR in), which triggers a toggle to WDR... which makes the image dark enough to trigger ICR out... and these cameras also have no adjustment for that trigger level (or didn't at the time), so the only way to counter the hysteresis was to fiddle endlessly with exposure settings. So I just set them all to LF and left it at that.

If someone stops or slows down I get a clear picture at longer shutter speeds. And if they walk towards the camera, and the face somehow stay pretty still in the camera, I get a clear image. So I am pretty sure it is motion blur.

How do I "set the p3354 to lightfinder"? I have two, and can't find any setting for it. All I do is set the exposure zones and fiddle with the gain. I have tried the p3354 in the positions of the Avigilon cameras, and fell I get better images. So I guess that is where I'll end up.

I feel i have gotten a fair bit of answers to my question. Thanks all for playing:)