Large Sensor Comparo

[pozzello]

Various 1/1.8" (and now 1/1.2") sensor'd cams on a test board on the front of the house:

album here: Large Sensor Comparo

On the board, clockwise from top left:

• Dahua HDW5442TM-AS (4mp) with stock 3.6mm lens (exp 1/60)
• Lorex E861ab (aka DH-HFW1831e) w/ 6mm f/1.0 lens conversion (exp 1/60)
• Lorex E891ab w/ 6mm f/1.6 lens conversion (exp 1/30)
• LongSe 8MP 3.6-11m VF (exp AUTO)
• Hik 2087G2-LU bullet (exp 1/120)
• Dahua HDW5442TM_AS (4mp) with 6mm f/1.0 lens conversion (exp 1/60)

On the house above and to the right is the
- Dahua HFW1831E which will most likely be replaced with the Hik 2087G2 for overview duties once i'm done goofing around here... (exp 1/30)

Also in the album are shots from a few others with slightly different views:

• Hik 2347 (4MP ColorVu w/ white LED's and stock 6mm lens) (exp 1/120)
• Lorex LNB8005C w/ stock 4mm lens & Dahua FW (the only one here with smaller 1/2.5" sensor, for comparison) (exp AUTO)
• (another) Lorex E891ab w/ 6mm f/1.6 lens conversion (exp AUTO)

All are running 10FPS into my BI server.

 

[pozzello]

this spot intentionally left blank, for now.

 

[alastairstevenson]

Dahua HDW5442TM_AS (4mp) with 6mm f/1.0 lens conversion

Presumably not due to the limited depth of field - but the left side of the image seems to be out of focus.
What do you think?

 

[pozzello]

er, yes, most likely a focus issue on that one I set it on my bench and focused at about 12ft indoors, so probably not quite right for the deeper view required here...
It is interesting to note the extra brightness the f/1.0 lens brings in, vs the stock f/1.6, even with the narrower FoV.
(talking about the comparing the two DH-5442's that is...)

 

[alastairstevenson]

On the topic of focus - to what extent have you seen any problems with lenses that are not well IR-corrected, ie when the scene is viewed only with IR illumination, the focal point changes enough to be noticed?

 

[pozzello]

Well, this set of cams are intentionally set to full time color, so IR hasn't been an issue. I have several old Hik 2032 bullets converted to 25mm for LPR duty at 60-70ft. these obviously use IR at night, but I also focused them at night with a plate on a stand out in the street... Daytime focus seems OK on those, so the lenses must have been good ones for that (ie, IR-corrected)...