2012 imac Image Retention not screen capture-able

[WrrN]

Maybe this is normal and I simply don't understand what IR really is, but I had a 2012 iMac delivered November and just today (May 2013) showed first sign of image retention. So I did a screen grab and the resulting image shows nothing unusual.
Would I have to take a photo of the screen to see it captured electronically?
Does this mean that pixels are not affected, but possibly some image memory being reflected onto the outer panel? (this doesn't even seem plausible)
I'm confused and also wondering if I should call Apple about this. The image was strong enough to see clearly without question.

 

[shoulin333]

When you do a screen grab your are saving what the video card is outputting, not what is displayed on the screen. This is to be expected.

 

[WrrN]

When you do a screen grab your are saving what the video card is outputting, not what is displayed on the screen. This is to be expected.

Thanks for elucidating me. That makes sense.

So, I've seen so much talk about this issue and my take is that this is "acceptable" by Apple's standards. Is there any benefit to me calling Apple Care about this issue? It sure seems like a 2500 dollar machine should be better than this.

 

[Ice-Cube]

If proven, Apple will just replace your Mac with a new one, which has a equal chance of getting IR.