Starlight Mp limitations
- Thread starter trauts14
- Start date
fenderman
Staff member
- Mar 9, 2014
- 36,891
- 21,407
dahua as one 3mp bullet..hikvision has low light 3mp....the is little to no pixel density increase between 2mp and 3mp most goes to the extra vertical fov....
with a varifocal camera you can get more pixel density with a 2mp than you can with a fixed 4mp if the lens on the 4mp is too wide...with varifocal you dont waste extra pixel on areas you dont need to cover.
fenderman
Staff member
- Mar 9, 2014
- 36,891
- 21,407
the more pixels you have the worse the camera will perform in low light - assuming everything else equal...there are a bunch of threads discussing this...dont chase megapixels..
bug99
Pulling my weight
- Dec 27, 2016
- 398
- 154
The available light per unit time (ex 1/30 second) is divided between the pixels, as @fenderman is pointing out and is in many threads. I think the term "Starlight" is a marketing term from Dahua which they attach to some of the newer models that use Sony Starvis sensors and have achieved better than 0.01Lux sensitivity. Based on what i see on some of the threads here, although the sensitivity to light drops by 10x or so when comparing a 8MP Stravis to a 2MP, it is by no means unusable. I am quite interested in the fixed focus IPC-HFW4830E-S and the varifocal IPC-HDW5830R-Z for example. They seem to be a good compromise in low light and increased pixel zoom if H.265+ is used for storage. IPC-HFW8630E-Z is another interesting model that almost is Starlight level.
Isn't low light performance more a matter of sensor size? A 4MP sensor could have the same light gathering characteristics as a 2MP if its sensor was 2x (or some factor) larger to allow equivalent light gathering per pixel. Isn't that part of what makes the Starlight cameras that much better? The Starlight (2MP) sensor is larger than traditional 2MP camera sensors.
Mike A.
Known around here
- May 6, 2017
- 4,199
- 7,066
It's not larger. The main difference is that the structure of the individual pixel elements in the sensor are back-illuminated and reversed vs that of more typical front-illuminated sensors. That is, in a front-illuminated element, the light has to travel through the electronics to reach the photodiode. In the back-illuminated design, Sony flipped it to put the diode on top and the electronics under providing a more direct light path. See illustrations below.
Attachments
Last edited:
The Starvis sensors are better than the Exmor-r in terms of low light performance and clarity, is that correct?
alastairstevenson
Staff member
Mike A.
Known around here
- May 6, 2017
- 4,199
- 7,066
Starvis is an Exmor-R back-illuminated design with higher sensitivity and wider range into near-IR.
So I suppose the more accurate way to say it would be that Starvis are better Exmor-R sensors (vs better than) for low light applications. They're specific Exmor-R sensors (such as the IMX290/291 above) that they label with the "Starvis" branding. They are better low-light than various other Exmor-R sensors in that sense.