Wide or Narrow Mode for Optimum Day & Night Video Quality?

[russ331]

Video in Wide Mode is captured from the 2304 x 1296 CMOS pixel array & scaled down to fit the 1920 x 1080 frame size.

Video in Narrow Mode is captured from the central 1920 x 1080 CMOS pixel array. There is no scaling of the image.

From comments made elsewhere on this site recently, it's becoming apparent to me that scaling is undesirable, & contrary to optimum image quality.

This being so, I should be using my front facing Mobius B in Narrow Mode, the loss of peripheral FOV being a worthwhile trade off.

Am I wrong?

 

[Isoprop]

Video in Wide Mode is captured from the 2304 x 1296 CMOS pixel array & scaled down to fit the 1920 x 1080 frame size.

Video in Narrow Mode is captured from the central 1920 x 1080 CMOS pixel array. There is no scaling of the image.

From comments made elsewhere on this site recently, it's becoming apparent to me that scaling is undesirable, & contrary to optimum image quality.

This being so, I should be using my front facing Mobius B in Narrow Mode, the loss of peripheral FOV being a worthwhile trade off.

Am I wrong?

The Mobius does a pretty good job of pixel binning but you obviously won't get the same quality as when there's no scaling involved. All the same, I don't think you'll normally notice the difference unless you look hard. Like you say, it's a trade-off.

 

[daniel_bel]

The picture size is the same; 1920x1080 in your example.
The wide angle has more area in the same number of pixels, hence there is obviously less detail.
Consider the narrow mode as a slight zooming. You see it better, but there's less of it.

Not even considering resizing artefacts here.

When I want to see the landscape in my movie, I select wide of course. If you want to have precise evidence in front of you, you select narrow.
Enjoy one of the few choices you have in this life.

 

[russ331]

My rear Mobius B was already set to narrow mode. I've now also set the front cam to narrow mode.

I read somewhere that there's no scaling of the image with the Street Guardian range of cameras. Not sure about other brands.

 

[DarkStryder360]

Been using Narrow all this week for a change, and I have to say I am very unimpressed! For some reason quality did drop compared to scaled Wide

 

[electricbeach]

I know I bought the wide to improve the night quality, which it did over the narrow.

 

[Signhere]

I know I bought the wide to improve the night quality, which it did over the narrow.

The "wider" lens B and C do appear to give brighter images in low light conditions. The FOV "wide" (pixel binning) setting should give cleaner images in low light conditions.

See https://dashcamtalk.com/forum/threads/mobius-grainy-at-night.6686/page-5#post-116203 .

http://focusonphotography.blogspot.ca/2012/02/pixel-binning-is-here.html

 

[russ331]

A while ago I tried wide & narrow modes under firmware v1.20. I couldn't detect any obvious difference in video quality, however, in the absence of simultaneously shot video from 2 Mobius cams, it's just subjective opinion.

Recently, I've been trying the cult favourite v0.59. I like it in wide mode...



But in narrow mode it gives the appearance that the camera aim is way off. The firmware change log confirms there were issues with v0.59 in inverted narrow mode...



I've now updated to v2.33. Narrow mode looks good. Think I'll keep it this way for a while...

 

[richcam]

Wow, Signhere there is a hell of a difference in the quality of those two photos taken in low light conditions, which lens did you use, was it B or C, and I assume the Field of View 'Wide' was the better of the two in your particular case.

russ331, you have now complicated the whole issue because in 'narrow' mode the image quality is very good.

I've just updated the Mobius software to v2.37 and amongst the options is:
------------------------
VIDEO MODE 1
Movie Resolution=[0];0:1080p(Wide AOV),1:1080p(Narrow AOV),2:720p(Wide AOV),3:720p(Narrow AOV),4:WVGA (Wide AOV), 5:WVGA (Narrow AOV),
Movie Frame Rate=[4];1:60fps (only for wvga and 720p Narrow AOV),2:50fps (only for wvga and 720p Narrow AOV),3:30fps,4:25 fps,5:20 fps,6:15 fps,7:10 fps,8:5 fps,

Movie quality=[0];set movie quality,set movie data rate,0:Super,1:Standard,2:Low,
Movie high dynamic range=[0];set movie high dynamic range,0ff,1n,2:Enhanced Brightness,
Movie file format=[0];set movie file format,0:MOV,1:AVI,2:MP4,3:WAV (Sound Only)
------------------------
As you can see I have movie resolution set to 1080p 'wide' but now I'm wondering whether it should be set to 'narrow'. I have a lens 'A' fitted which I though would have a better chance of recording crisp footage of number-plates of oncoming vehicles which is something I feel is important in the event of a hit and run accident, so am wondering whether 'narrow' would be better?

Incidentally, is there any improvement to be made in image quality and the sharpness of number-plates of moving vehicles by reducing the frame rate from 30fps to 25fps or indeed 20fps.

Movie quality is set to 'Super', I assume this is bitrate, and bearing in mind I have a 128GB class 10 card fitted I'm not overly concerned about file sizes. All I'm after is high quality video footage.

Movie high dynamic range is set to OFF because from what I have read that it increases the risk of blurred number-plates on cars that are moving.

As for the file format, VLC can pretty much play any video format and I am familiar with .MOV and MP4 when viewing videos on the Mac, though not sure which is best to squeeze the best quality out of a video.

 

[russ331]

I have a lens 'A' fitted which I though would have a better chance of recording crisp footage of number-plates of oncoming vehicles which is something I feel is important in the event of a hit and run accident, so am wondering whether 'narrow' would be better?

The Horizontal Field Of View with Lens A is 85° in Wide Mode & 75° in Narrow Mode. Typical DashCams have a large FOV to capture peripheral evidence, so 75° FOV may be a step too far in the opposite direction. Your choice.

 

[richcam]

The Horizontal Field Of View with Lens A is 85° in Wide Mode & 75° in Narrow Mode. Typical DashCams have a large FOV to capture peripheral evidence, so 75° FOV may be a step too far in the opposite direction. Your choice.

Thanks for the info, I guess I will be carrying out further experimentation to see what works best, I must say the comparison photos posted above by Signhere did show quite a dramatic difference in the quality in low light conditions.

 

[Signhere]

Wow, Signhere there is a hell of a difference in the quality of those two photos taken in low light conditions, which lens did you use, was it B or C, and I assume the Field of View 'Wide' was the better of the two in your particular case.
...

Thanks for the info, I guess I will be carrying out further experimentation to see what works best, I must say the comparison photos posted above by Signhere did show quite a dramatic difference in the quality in low light conditions.

In low light conditions, pixel binning ( wide FOV) should give cleaner images.

The photos were used as an example from an article about pixel binning. My Mobius w/ lens B ( v0.53) does produce grainier images in low light conditions in "narrow" mode.