Aperture size

[gu3st]

Hi guys

I'm looking at getting some 5442 turret styles from Andy. I live in South Africa, so shipping is a mission and expensive, so it's difficult for me to get tester cameras to dial in the lens options.

So I'm looking at either 2.8mm or 3.6mm (generally close up in my backyard - 8-20feet distances, not too concerned with identify - more want it to just notify me if humans are detected).
I noticed that the fixed lenses have a slightly bigger aperture than the varifocals (looks like F1.6 vs F1.8 respectively). Does this make a practical difference in low light? If not, I would rather just get a couple of varifocals and dial them in. If it makes a meaningful difference, then I will have to do more research around whether the 2.8 or 3.6 would be better.

Thanks!

 

[Rob2020]

All the comments I have read on Ipcamtalk indicates the fixed lens 5442 has better night time performance than the same model with varifocal. The 2.8 would provide more overview while the 3.6 would have a slight edge in identifying. I generally would say buy the 3.6 but if you distances are correct (8 - 20 feet) you might want the 2.8.

 

[wittaj]

All things being equal, the fixed cam will provide a better image at night due to the smaller f-stop. With a varifocal, the fstop gets larger the more you zoom.

So it ends up being a compromise between the area you want to cover and IDENTIFY versus the available light.

If the fixed lens is slightly better at night but your target is 25 feet away, you are better off with the varifocal and higher fstop optically zoomed in to IDENTIFY at that distance.

For basic human detection to let you know someone is back there, I'd go with the 3.6 fixed lens.

 

[kobebeef]

If you want F1.0
Must buy IPC-HFW5449T-ASE-LED or IPC-HDW5449TM-SE-LED
The front end of the F1.0 lens will be slightly larger than the F1.6
Previously, I tried to replace the HFW5442T with F1.0
but I gave up, because the shading plastic sheet in front had to be enlarged in diameter to fit it.