I recently got an iMac 27 and it’s a beauty. I have used the Photo Booth and captured both photos and video. Given I shoot most of my video in Full HD format, I am used to a very high quality video. So, looking at the video captured by iSight, it felt not as good. That’s when I wanted to find out the technical details of iSight and I couldn’t find much on Apple’s website. So, I looked at the photo and video files to gather the information and here is what I found.
Photo:
It’s a jpeg image and the file size is 106 KB (Of course, size varies based on the details in the image).
Dimensions: 640×480
Color space: RGB
Color profile: iMac
Alpha channel: No
Video:
It’s a mov file and the file size is 3.1 MB for a 1 minute 2 seconds video.
Dimensions: 640×480
Codecs: AAC, H.264
Color profile: HD (1-1-1)
Audio channels: 2
Total bit rate: 334
I wanted a further break up on the bit rate and more details. So, using ffmpeg, I found
Audio: aac, 44100 Hz, bitrate: 400 kb/s
Video: h264, yuv420p, 640×480, PAR 1:1 DAR 4:3, 20 tbr, 600 tbn, 1200 tbc
Obviously, this is no where close to my camcorder’s full HD video which has
Audio: ac3, 48000 Hz, stereo, s16, 256 kb/s
Video: h264, yuv420p, 1920×1080 [PAR 1:1 DAR 16:9], 59.94 tbr, 90k tbn, 59.94 tbc
So, that’s a huge difference in video quality. Of course, I am not expecting iSight to provide me Full HD support, just wanted to know what it’s capabilities are. It definitely seems to be good enough for video chatting. I liked the fact that it can show even far off objects very clearly, though there is no way to zoom. There are some softwares that provide zooming capability, but that’s only digital zoom.
poeticcode 
You can actually record in 1280 x 1024 at a much higher bitrate (it’s a 1.3 MP camera, resolution you can’t change). That means that it’s a resolution between 720p and 1080p. You should not record in Photo Booth, but in Quicktime (you can record in iMovie high quality too) you get much higher quality IF you set it to the right settings. Go to Quicktime –> Preferences –> Recording –> Set quality H264 Best and the other setting to: Native
the last thing will make a huge difference and you have to click IN QUICKTIME at Make new Movie recording (under File) to start recording in HD, pretty nice.
Phil