Can somebody explain the resolution modes to me?

[mortslaw]

I'm confused on how the resolution modes are handled for Hikvision cameras. For example, with the new 4MP cameras, how is the image in 2MP mode handled vs 4MP?

I've seen some comments saying that a 3MP cam in 2MP mode will be the same clarity, but will have less vertical area and more horizontal area. Does this mean that in 2MP mode, it's just a different crop from the sensor?

 

[Michelin Man]

It's because of the aspect ratio of the images.

Depending on which 4MP cameras you are talking about because there's the Chinese 3.6MP cameras and the 'proper' 4MP cameras eg 2042WD. (although aspect ratio is the same-ish)

The 3MP cameras have a resolution of 2048x1536 (like a typical camera at 3MP) which has an aspect ratio of 4:3.
The 3.6MP cameras have a resolution of 2560x1440 which is 16:9.
The 4MP cameras have a resolution of 2688x1520 which is almost 16:9
In 2MP mode all cameras do 1080p (1920x1080) which is 16:9 like most cinema movies.

 

[zero-degrees]

@mortslaw If you are curious why people state that 2mp is clearer at night then 4mp please see the below link to understand how image sensors work. I am jumping to assumptions that this is where you are headed as this is where the majority of people go when "reading the forums and getting confused about 2mp/4mp cameras". If this is not what you are trying to understand my apologies, just trying to cut to the chase vs understanding exactly what is trying to be discussed about 10 postings.
http://www.cnet.com/news/htc-explains-why-4-megapixels-are-better-than-8/

 

[mortslaw]

Thanks guys. @zero-degrees Thanks for the link, I'm aware of that phenomenon because I encountered it when going from 12MP to 36MP in my last DSLR upgrade. I had seen some comments saying that 2MP(1080P) mode on a 3MP Hik would actually be a wider angle of view than when it is running in 3MP mode. I guess my question about 2MP mode on a 3MP sensor is whether they cropped the 1920x1080 from the sensor but didn't resample the pixels or are they resampling an image that is larger than 1080P on the sensor down to 1080P. I hope that makes sense. For example, the iPhone camera when switched to video mode just grabs the center of the sensor, 1920x1080 pixels, so your field of view is much narrower than it is in photo mode. It sounds like from what Michelin Man posted, that perhaps with 4MP cams, already being 16:9 ratio at 4MP mode, might just downsample to 2MP mode.

 

[Travieso]

good Information here guys I was curious on this as well also @Michelin Man So a 3MP cameras aspect ratio of 4:3 Whats its best view able 4:3? Cause Right now I have them at 16:9

 

[djangel]

good Information here guys I was curious on this as well also @Michelin Man So a 3MP cameras aspect ratio of 4:3 Whats its best view able 4:3? Cause Right now I have them at 16:9

Definitely use 4:3 for 3mp resolution. 1mp (720) or 2mp (1080) are best viewed at 16:9