Webcams

[esocolofsky]

looks like the C920 uses H264 while the C910 does not.  apart from that, there are a host of features that are different on the two specs pages (C920 vs. C910), but i'm not sure if it's just that logitech decided to list them separately to make them look like different products or if they really *are* that different.

i'm spec'ing cameras for museum installations rather for web use; my main concerns are image quality/resolution (seems equal), mac support (only the 910 mentions this), and if possible, the ability to control / disable auto exposure (i believe this is what the 910 is referring to as "RightLight").

thanks!

[pilut · Accepted solution]

The C920 does video processing in the webcam as opposed to the C910 using the computer's CPU for the task.  The result is much lower CPU use with the 920.

The 920 is capable of 1080p, vs. 720p for the 910.  However, while I saw 1080p a few times in Skype when I first got the 920, I'm not getting 1080p recently.

If you install the Logitech software, the webcam controll does allow selecting "Right LIght" on or off with either model.

I haven't seen a 920 driver availble for Mac.  My experinece with the 910 and 920 is in Windows 7.

[esocolofsky]

ah, the onboard compression makes a huge difference.  sounds like the 920 is a clear winner for better framerates at HD resolutions.  (that would explain why some vendors don't even carry the 910 anymore, only the 920.)

other forums have mentioned that the 920 and 910 both work on OSX, but the logitech software does not.  so, i'll have to work around that hurdle.

thanks!

[pilut]

Ok.  I'm pretty much a Windows type of guy but my wife just got a MacBook Pro.  If I'm ever bored enough I may try the 920 with the MacBook.  Or not. 

[Andrey123456]

Sensor size is main difference 5 megapixels c910 vs 3 megapixels  c920. I guess c920 has same kind of sensor, just cut to match aspect ratio 16:9 This may be the reason for two step only zoom and impossibility to grab 4:3 video

http://logitech-en-amr.custhelp.com/app/answers/detail/a_id/17516/related/1

http://logitech-en-amr.custhelp.com/app/answers/detail/a_id/28927

I bought c910 and I am satisfied with the product.  Sensor and image processing software are good for this price.

In most light conditions 720p resolution is a reasonable limit for this sensor working in 2x2 software binning mode it allows to get good quality video. 1080p mode gives you more pixels, but does not give more image details even in still image capture. May be in some special cases with strong and equally spread photostudio light it is possible to see more details @1080p? but i did not notice it with regular room light.

C910 gives stable, good picture working in 4x4 binning mode 640x480. In any regular room light conditon, also using table lamp. C920 does not have this mode according technical spec. 1080p picture in low light  looks like "1080 lines of noise"

Conclusion: if sensor is not able to give good image quality at max resolution in most light conditions (who has photostudio light at home?) why to pay more for c920? Waste money for H264encoder royalty and compromise on real image quality - sensor size? Open source VP8 gives very good results. There are differences between VP8  and H264, but they are insignificant for this kind of sensor.

The only thing that I don't like in C910 is short USB cable.  My old quickcam4000 was connected to desktop without extender.

Suggestion to software team: in C910 driver camera properties add checkbox that will force camera to give fixed 640x480 resolution - 4x4 binning in order not to let application software change it. It improves a lot image quality in all conditions.

binning - when group of pixels e.g. 2x2 or 4x4 are combined some way, software or hardware, to create one pixel. Some sensors support this mode on CMOS level and it is like increasing pixel size.

reduces noise and icreases sensitivity

[AGM]

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esocolofsky wrote:

ah, the onboard compression makes a huge difference.  sounds like the 920 is a clear winner for better framerates at HD resolutions.  (that would explain why some vendors don't even carry the 910 anymore, only the 920.)

other forums have mentioned that the 920 and 910 both work on OSX, but the logitech software does not.  so, i'll have to work around that hurdle.

thanks!

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The onboard compression can only be used properly (no additional CPU usage) when you use the Logitech software. 3rd party software cant use or even see the H264 stream without using additional CPU power.

Also without the Logitech software the microphones only deliver 32 KHz, though that might be the case with the C910 too, but I never checked it myself.

Some people like the video quality of the C910 more, others like it better on the C920.

I personally like the C920's more, since it looks more natural and not digitally sharpened, like the C910's does. The C920 also has a much better automatic white balance and better autofocus.

Both can deliver quite high framerates, the only difference is that the C910 cant do that with the Logitech drivers installed and even if you use generic UVC drivers, it will produce small artifacts at the edge of the screen from time to time. Not bad ones at all, but some people might not like that.

[JackDeth]

I use the C910 with Ubuntu Linux and it works perfectly! Excellent picture and sound quality in a variety of lighting conditions. Prob'ly the best web cam I've owned so far.