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Axis 1MP 3004V Higher PPF Than The Axis 2MP 3005V?

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Brian Selltiz
May 23, 2013
IPVMU Certified

This may be a simple question but...

Take these two cameras in a hallway scene, put a subject 40' away from the camera down the hallway

3004-V delivers 19 ppf (80 degree fov)

3005-V delivers 14 ppf (118 degree fov)

Since it is a hallway, and the extra field of view doesn't matter, the 3004 is the better choice and will deliver a better picture correct?

As to why, I am guess it comes down to the wider fov on the 3005 being a result of the bigger imager?

Thanks!

JH
John Honovich
May 23, 2013
IPVM

The M3004 has 1280 horizontal pixels while the M3005 has 1920 or 50% more. (M30 data sheet)

The M3004 has 80° HFoV while the M3005 has an 118° HFoV or 47.5% more.

They should be roughly equal in PPF then, no? Where did you get 19ppf and 14ppf?

Members reference: PPF guide

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Ethan Ace
May 23, 2013

I was just going to ask the same thing. Side note, you can also get a 6mm M12 lens for these cameras, if you want something narrower (i.e., use the higher resolution 2MP model but with the longer lens option for higher pixel density, longer coverage).

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Brian Selltiz
May 23, 2013
IPVMU Certified

I was using the Axis lens calculator.

I was not aware of the lens options on these models, thanks Ethan.

JH
John Honovich
May 23, 2013
IPVM

Brian, thanks, I replicated your numbers as such:

Interestingly, the calculator is presuming that the M3005 has twice the horizontal field of view as the M3004 (in the case above 133m vs 67mm). This is consistent and linear (at 10m distance, it's 17m for the M3004 vs 33m for the M3005). That said, I am not sure why this is the case. Let me ask Axis, maybe I am missing something here.

That said, Ethan's suggestion for longer lens option should work regardless.

JH
John Honovich
May 26, 2013
IPVM

Axis' feedback:

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Brian Selltiz
May 26, 2013
IPVMU Certified

But, in the end, the 1MP delivers more pixels on target, thereby 'better resolution', than the 2mp within the 1MP's FOV, it's just that the 2mp delivers a wider picture. Right?

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James Talmage
May 27, 2013
IPVMU Certified

Brian,

You are correct - it is more pixels on target.

A couple things: if you plan on ceiling mounting these and looking down a corridor, you need the 2MP, the 1MP doesn't have enough tilt to see that far down the hallway (unless you have very high ceilings - which will in turn hurt your PPF). It is a design flaw IMHO. (Note: they both have the same tilt, it's just that the 2MP's wider view compensates for the limited tilt).

The lens option Ethan recommends should work great - but it MAY ruin ceiling mounting for BOTH cameras. (I haven't tried the longer lens - but unless it somehow allows for greater tilt - your going to be in trouble).

Now, before you go and decide you are just going to wall mount it, understand you will need to mount to a wall at the end of the hallway (or a soffit that runs across the hall). This is again related to the limited motion of the camera gimbal. See my diagram below.

This set of issues drives me nuts! We do LOTS of long hallways that would be perfectly suited to these cameras if it weren't for these issues.

That said you CAN force the M3004 past the tilt stop point in a pinch. We did it on 2 cameras when we first discovered the issue. It makes a horrendous sound and likely voids your warranty. Also, it will likely not be possible to force it past the tilt stop point once you have installed the optional longer lens.

The Acti D61/D62 cameras should cost about the same or less than those being considered (with considerably larger sensors and better lenses to boot). Be warned; It seems Acti has some issues with their VBR codec (at least as it relates to Exacq integration). Also - I don't know if Acti can do corridor mode (is Axis the only mfg that does corridor mode? It is just a 90 or 270 degree rotation of the video). Loosing corridor mode would be a big bummer, as it eliminates a lot of wasted pixels on the wall, and (more importantly IMHO) a bunch of dead space below the camera.

I haven't used the Acti products yet, but we are seriously considering them.

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James Talmage
May 27, 2013
IPVMU Certified

To be exact you are going to lose 3.5 feet in height over 40 feet using the m3004 aimed as tight to the ceiling as possible.

On an 8 foot ceiling, this means you will be cutting off the heads of anyone over 4.5 feet tall at the far end of your 40 foot hall.

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Brian Selltiz
May 27, 2013
IPVMU Certified

Hi James,

Thanks for the info. Quick question, you ran into the tilt limitation even when in corridor format on the 1MP?

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James Talmage
May 27, 2013
IPVMU Certified

Yes.

From the spec sheet Tilt = +/- 45 degrees. This is measured off straight down, meaning you can only get within 45 degrees of the ceiling. In corridor mode your VHOV is 80 degrees. Half that is 40 degrees. 45-40 = 5 degree down tilt.

In non-corridor mode it is worse, as with the narrower lens.

Again - it is a real shame that a detail as minute as tilt angle so thoroughly complicates the application of an otherwise awesome camera (I really do like the new M30 series).

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Brian Selltiz
May 28, 2013
IPVMU Certified

James,

You likely saved me alot of headaches on this one (if we win it). Thank you very much for sharing your knowledge.

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James Talmage
May 29, 2013
IPVMU Certified

Brian,

Glad to be of service. Just pay it forward contributing where you can.

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