I have found a very nice video tutorial and finally understood some new concepts I did not get before. Specially that what a 'full frame' sensor is and that a 1.6 sensor (crop depends on the sensor's size) is like the Canon 7D's. So, the crop factor on a full frame sensor (like the Canon 5D Mark II for example) equals to 1 and 1.6 for the 7D.
Check it out, it is called:
Lenses (focal length, crop factor, macro lenses)
http://www.youtube.com/watch?v=vV-s31II-OU
Also check out:
Composition - Photography with Imre
http://www.youtube.com/watch?v=vDbQLL_BcR4
Here's his channel:
http://www.youtube.com/user/binarygraphite
Another two from the same guy that are worth checking out are:
DSLR Tips: How to blur backgrounds on portraits
http://www.youtube.com/watch?v=aAxJRF73vwc
DSLR Tips: Using polarizing filters
http://www.youtube.com/watch?v=7Vvz_d6APXk
Here is his channel:
http://www.youtube.com/user/cameralabs
And... last but not least, two more tutorials on how to that properly Portraits:
How to Take Great Portrait Photos
http://www.youtube.com/watch?v=wyxQKNpk58U
The Portrait Photography Masterclass
http://www.youtube.com/watch?v=lkwH8NQLdv4
You guys have a wonderful weekend!!
Kind Regards ^_^