Built-in iSight vs External iSight

Question

Hello.
I have a late 2008 MacBook Pro with the built-in iSight camera. But also recently found an external iSight camera at an auction website that I might want to buy. How do the quality of the cameras compare?
Also with two cameras attached, am I able to switch between the two while using quick capture in iMovie 09 without stopping the recording?

Answer 1

eightsecond wrote:
... recently found an external iSight camera at an auction website that I might want to buy.
I suggest that you *test any external iSight before you buy*, even if you get a warranty or performance guarantee from a retailer that you know and trust.
Some users who have recently bought used external iSights have posted about their difficulty in the iSight Forum. Here is one example if you do not want to search for yourself:
  http://discussions.apple.com/thread.jspa?messageID=9015271
External iSight is a great camera, but they are getting old as electronics go, and you have no idea how the one you buy now has been used or treated by its previous owner(s).
I suggest that you buy locally and test any external iSight you are considering on your Mac before you pay for it. That way you know whether it will work, and a local seller may be able to answer questions, if any, about connecting and using iSight before you buy. If you need help with how to make sure an external iSight works, see "How to test your iSight to ensure it is functional."
Even if the external iSight you are considering is advertised as NIB (new, in box) or NOS (new, old-stock), it may not be covered by Apple Warranty. If the seller is not providing you service guarantees or warranty, you may be want to check Apple's iSight Service: Frequently Asked Questions, especially if you cannot test the iSight before you buy to be sure it is working.
Moreover, if you buy an external iSight now, verify whether all connectors, cables, and iSight mounts that you need are included. If some items you need are missing but you still want to buy the iSight, this info may be of interest. (Note that Apple no longer offers the "iSight Accessory Kit, Part Number: M9314G/B" that is mentioned there.)
If you or your Apple Service Technician need but cannot locate something from the discontinued Kit or something from the list in the iSight Service: Frequently Asked Questions page, http://www.synaptech.com can help obtain parts that are still available.
If you consider buying an external iSight sight-unseen from eBay or other internet seller, I strongly suggest that you (try to) get a written guarantee that you can have the iSight examined by your Apple Authorized Service Provider and can have a refund or exchange if the iSight doesn't pass his condition verification.
If you are willing to consider alternatives to a used external iSight, you may find this user tip of interest: http://discussions.apple.com/thread.jspa?threadID=2018211
How do the quality of the cameras compare?
Quality is subjective. You should judge it for yourself by testing.
Here is one comparison example I did some time back. The one on the left is with a built-in iSight, but the current iSights may perform differently.
As is normal for different digital cameras, images comparing two cameras are very different. Which you like better will likely depend on personal taste and may vary with subject matter and lighting conditions. To remove as many variables as possible, I made the following comparison image showing the same subject in the same location during the same video chat using the two different cameras (internal vs external iSight) on same iNtel iMac Core Duo. You can see some of the differences in color balance, sharpening, and contrast settings used by the two cameras. Click the image below if you want a larger picture:
One other possible difference is resolution. All external iSights are 640x480 (Ø.3MP) cameras. I think that all the 2008 MBPs are 1,280x1,024 resolution (1.3MP). To be certain, you can test your MBP's iSight's resolution with QuickTime Pro if you have it. If you don't have QT Pro, use the test explained in this page.
However, depending on which software you use, this resolution difference may not have any practical importance for you. Not all apps can use the higher resolution of the 1.3MP built-in iSights, so there's no need to trade Macs or cameras purely on account of which built-in iSight you have (unless you have a definite need increased resolution.)
Testing is the only real way to determine how images from a particular iSight will look on a particular display when driven by a particular software application. With those tests, each individual can decide whether the image quality is sufficient for his particular need. If higher quality is needed, a good camcorder or digital still camera will give better results than any webcam.
Also with two cameras attached, am I able to switch between the two while using quick capture in iMovie 09 without stopping the recording?
Probably not.
Capturing, converting, processing, and writing video to disk imposes a significant load on your Mac. The exact extent of this load may vary depending on a wide variety of factors including which app(s) you use, the configuration (example: how much RAM is available) of your Mac, which apps are running, how much disk space is available, and possibly even the lighting and complexity of the subject of your recording.
Moreover, although iMovie '09 (iMovie v8.x) can continue to record while a different app is active, not all apps can. For instance, Photo Booth immediately stops recording unless its recording is the currently active window.
Even if you have two apps that each can record in background, trying to process two video streams simultaneously may be beyond your Mac's capability. The only way to know for certain is to test.
EZ Jim
G5 DP 1.8GHz w/Mac OS X (10.5.7) PowerBook 1.67GHz (10.4.11)   iBookSE 366MHz (10.3.9)  External iSight