While DOF is an issue on the 4KT, I’ve not seen that at all on 4MP 5442s with the 1/1.8 sensor and I’ve installed a lot of them.
Good info from an extremely knowledgeable source - thanks
@bigredfish. Some random thoughts below.
Depth of field doesn’t immediately change from clear to blurry - there's a "circle of confusion" and it depends on how visually discriminating you are. So I'm wondering if since you have
"not seen at all" on the 5442's with 1/1.8" sensor and F/1.8 lens, how noticeably different (using same focal length/distance) would that reduction in DOF be with a 1/1.2" sensor and using SAME F/1.8 aperture? And then how much does it change as you open it all the way up to F/1.0 ... which also demands more from the lens.
In the "regular" camera world, you can open up that aperture and with a big telephoto lens, the drop in DOF is very obvious and often desirable to isolate the subject. But not near as much with wide-angle, especially if you aren't trying to nail focus on something really close up. Sure, if you want those wildflowers as a foreground element, you have to close the lens back up (or focus stack) ... but then defraction comes into play ... really soon on high-mega-pixel cameras.
So I played around with some DOF Calculators -
here's a pretty nifty one that also does a visual simulation.
For my specific application, the field of view is about a focal length of 28mm (35mm equivalent) and my area of interest is from 5-30 meters. So I set the focus point at 8 meters and I got the following numbers for the depth of field.
Even a 1" sensor (1/1.2" wasn't an option, but obviously would have more DOF) works (barely) for my parameters - obviously if you add telephoto and/or increase the near distance requirement (or are more visually discriminating), your mileage may vary. I also include the DOF distances when you set the focus at the HyperFocal (HF) distance. Note all distances are in Meters.
For a 1/1.8" sensor with 5.8mm lens focused at 8 meters
F/1.8 has DOF of 2.23-Infinity with HF@ 3.10 so focus from 1.55+
F/1.0 has DOF of 4.39-Infinity with HF@3.29 so focus from 2.07+
For a 1/1" sensor with 10.2mm lens focused at 8 meters
F/1.8 has DOF of 3.22-Infinity with HF@5.39 so focus from 2.7+
F/1.4 has a DOF of 3.72-Infinity with HF@6.93 so focus from 3.47+
F/1.2 has a DOF of 4.02-Infinity with HF@8.08 so focus from 4.04+
F/1.0 has DOF of 4.39-45.34 with HF@9.70 so focus from 4.85+
BTW, just to show how much difference zoom makes, if I set that 1" sensor to 18.3mm (which is a 35mm equivelent of 50mm), the DOF (at a focus point of 8m) is now only 6.37-10.75 meters.
So for my application of 28mm (35mm equivelent) field of view and area of interest from 5-30 meters, even with a 1" sensor and an F1/.0 lens, I could set the focus point at 9.7 meters and have "reasonable" sharp focus from 4.85 meters to Infinite. I could get a little "closer" by setting the focus at 7 meters so my DOF would be from 4-25 meters. Regardless, I would probably grumble about the sharpness at the near and far points! ;-)
So while it seems that the not-too-challenging situation of 28mm FOV with focus from 5-30 meters is doable with a 1/1.2" sensor and F/1.0 lens, it does approach the the optical limits.
Disclaimer: This is all theoretical based on laws of optics and assumptions above. Does not account for cumulative errors due to lens/sensor/image processing, etc. Plus I do NOT have hands-on experiences with the latest generation of 1/1.2" sensor and F/1.0 cameras.