Anykeeper lenses on Dahua IPC-HFW2100

Hi,

When I ordered my IPC-HFW2100 cameras, I was a bit unsure which lenses I should order, so I ordered cameras both with 3.6 mm and with 6 mm (from factory).

I also ordered some cheap 3rd-party lenses from Anykeeper just in case. I am generally happy with the cameras as-is, but one of the 3.6mm cameras was a bit blurry in the left edge of the image, so I decided that I'd test one of the 3.6 mm Anykeeper lenses that I had bought.

I opened up the camera, and compared the lenses. They were of identical length, but the front glass looks different, and the markings are a bit different too. Here's a comparison:

I mounted the Anykeeper-lens, and to my surprise it was quite a bit wider than the factory lens, even though they are both marked 3.6 mm. Anyway, I was happy with that, because I actually needed a slightly wider view anyway. The image quality is comparable, but I do think that the Anykeeper lens perhaps exhibits a bit more chromatic aberrations (pinkish shadows in highlights). Overall sharpness I'd say is pretty much the same, but I got rid of the left-side blurriness that I had with the factory lens.

IR-cut filter works the same as with the factory lens, so I'll keep the Anykeeper lens on this camera.

I am in no way affiliated with Anykeeper, I just thought it would be nice to inform the forum about it. The item I bought was the lens they call 3 megapixel.

I ordered a few myself since M12 is out of stock. I will reply once I get them inhand and test them.

Interesting. It's possible the Anykeeper lenses from that batch are mis-marked, but specs on inexpensive Chinese gear are always a roll of the dice.

So, the question would be what the FOV appears to be for this lens. The specs say 85 degrees, which is typical for a 3.6mm 1/3" lens.

If you went to this page and plugged in the numbers (say, width of view at 10' out), it would come back with an estimate of the focal length.

http://www.pelco.com/sites/global/en/sales-and-support/downloads-and-tools/tools/lens-calc.page

Kind of a pain for a $5 lens, I know, but I like to figure out discrepancies like this.

The field of view is quite wider than I had expected. Here is a before and after from 10 feet.

I'd expect less distortion on a 3.6mm lens. That's quite the fancy boobytrap in front of the door though. Nobody sneaking in through that one without making some noise...

I'd love to see an image comparison between the dahua 3.6 lens and the anykeeper 3.6 lens.

So, what is the FOV from a 2mp with a 3.6 on the 15th floor? LOL.

or a 1.3mp with a 3.6 a few feet away about 15 feet high?