imac frustration - calibration

[Sarah_]

Hello Damien,

I am trying to calibrate my 27" apple iMac screen using a Spyder 4 Express.
It looks relatively simple until asked for 
1. Gamut  (Normal or Wide)
2. Backlight (Fluorescent CCFL  or  White LED  or  Red LED)

There is no information on this in the Product Information Guide, the Quick Start Guide or Manual.
I have read your tutorial, and understand the importance of obtaining the correct answers to these questions.
A young lady at the Carindale store advised she thinks it is a "Normal Gamut" with "RGB LED IPS Backlight", her voice sounded quite unsure as she advised it wouldn't be important anyway unless I was a photographer. I thanked her for her help. After spending the morning repeating my questions to eight people on the apple support line, I find myself here.
(Thanks for being here!)

I know this isn't an Apple forum, but hoping you might be able to point me in the right direction for answers.

Sarah 

[Damien Symonds]

I'm barely more confident than your young lady at the store, and in truth, it might take you a few goes to get this right.

I'm fairly confident that she's right about the gamut - Normal.

I'm pretty sure somebody mentioned recently that their iMac was RGB LED, so yes, give that a go first.