IR blur on Axis P1344?

[mike_va 0]

I did a quick read of the manual and as best I can tell, there is only one focus setting (not two for visible and IR). Unless you can find an acceptable sweet spot, I guess your best option is to use the best IR corrected lens you can find. FWIW, I have an Axis megapixel camera and it's always been a reliable performer, but I've never considered Axis to be a strong competitor at night. FWIW.

 

Christopher, thanks for the response, I even broke down and read the manual.

 

I've eliminated IR, I have the same problem using a flood light outside (PAR incandescent) and I've eliminated the window. So I'm just manually switching it back and forth using the IR filter select of the camera.

 

I'm almost starting to wonder if there is a camera defect? You can hear a whirring when it switches, perhaps the are adjusting the backfocus and this was not calibrated right? Or took a hit in shipping or? Axis has not responded to the support request yet but it is the weekend.

 

Thanks again, Mike

 

P.S. Some of the Axis don't look that good spec wise at night, I have an older 2120 and it sees nothing (as one might expect from the lux rating). On the other hand I have a CNB BBM24F and a VCM24F and they are better at night than the P1344. I can use the P3344 on the front of the house, but can't use a shutter speed higher than 1/30s at night.

[cglaeser 0]

Both are out of focus though. The BW seems to be somewhat focused on a couple objects but everything else is out of whack.

 

Can you see the focus plane in that last B&W? I'm not certain, but it may be extremely narrow. Is one of the fences near the focus plane?

 

Best,

Christopher

[cglaeser 0]

I checked again, and yes, I think the focus plane is very close to that tiny pot near the top of the stairs. The focus appears to fall off both in front of and behind that pot. Keep in mind that the DOF is divided about 1/3 in front and 2/3 in back of the focus plane.

 

Best,

Christopher

[mike_va 0]

Both are out of focus though. The BW seems to be somewhat focused on a couple objects but everything else is out of whack.

 

Maybe a depth of field issue? This is what I'm used to seeing with a camera with the aperture open, is this similar for the iris (which is open at night)? Please let me know if I'm not looking this the right way.

 

Also it is windy (and cold) here perhaps a smidgen of blur? I think I'm at the limit of what I can think of to try.

 

Thanks for the help, Mike

[mike_va 0]

I checked again, and yes, I think the focus plane is very close to that tiny pot near the top of the stairs. The focus appears to fall off both in front of and behind that pot. Keep in mind that the DOF is divided about 1/3 in front and 2/3 in back of the focus plane.

 

Shouldn't the color have roughly the same focus?

[mike_va 0]

Tried it on a different scene. The focus settings are different depending on whether the filter is enabled or not.

[cglaeser 0]

Shouldn't the color have roughly the same focus?

 

No, not unless the lens is IR corrected. In a cheap lens, even red, green, and blue within the visible spectrum will focus differently.

 

Best,

Christopher

[mike_va 0]

Shouldn't the color have roughly the same focus?

 

No, not unless the lens is IR corrected. In a cheap lens, even red, green, and blue within the visible spectrum will focus differently.

 

I guess that makes sense. I had started this experiment with a P3344, which does not have this effect. I assumed that the P1344 would be similar performance but in a box camera. I'm using the lens that came with the P1344 (Megapixel Tamron).

 

I guess that is a possibility although disappointing if true. I'll ask Axis when the get back to me.

 

I just tried the same experiment on the P3344, it auto-focuses on almost the exact same spot with the filter in and out. For the adjustment I used the advanced tab and the same focus box for each case.

[cglaeser 0]

I had started this experiment with a P3344, which does not have this effect. I assumed that the P1344 would be similar performance but in a box camera.

 

Do the 3344 and 1344 use different lenses?

 

Best,

Christopher

[mike_va 0]

Do the 3344 and 1344 use different lenses?

 

Nope, the 1344 is CS type. The 3344 is built into the camera (dome).

 

They spec out the same though so I assumed (again) same electronics different packaging.

[cglaeser 0]

Nope, the 1344 is CS type. The 3344 is built into the camera (dome).

 

I'm guessing one is IR corrected and the other is not.

 

Best,

Christopher

 

Edit: I was just reading the specs on an IQEye 755. There are several lens options, including wide varifocal, telephoto varifocal, and wide varifocal IR corrected.

[mike_va 0]

I'm guessing one is IR corrected and the other is not.

 

Edit: I was just reading the specs on an IQEye 755. There are several lens options, including wide varifocal, telephoto varifocal, and wide varifocal IR corrected.

 

Maybe so, they've opened my ticket so we'll see what they say. BTW, I have a second (new) P1344 that I was trying not to open. It does the same thing.

[mike_va 0]

I'm guessing one is IR corrected and the other is not.

 

Axis has responded that this is an IR corrected lens. I've sent my server report as they requested so we'll see what they can figure out.

[mike_va 0]

I'm guessing one is IR corrected and the other is not.

 

This was a very good guess. As it turns out, these were some of the first models and they were NOT IR corrected.

 

Now have some Computar megapixel lenses that Axis sent, these do not have the problem. Attached are the focus positions with the IR filter on and off, nearly identical.

 

Thanks to everyone for the help!

[cglaeser 0]

As it turns out, these were some of the first models and they were NOT IR corrected.

 

Yep, I thought that might be the case. Thanks for the follow up.

 

Best,

Christopher