I am not into lens/sensor scores or MTF chart readings etc ... I have nothing against it, in fact I envy those who can understand all the math/science (that goes into the lens/senor scores/charts) and make their purchase decisions based on it ... but I generally do not have patience/skill to go into scores and charts ... I buy lenses based on the reviews from a few sources that I trust (including several members in CR) ... sometimes, I buy camera gear based on how comfortable I am with it ... but generally, I feel that most modern camera gear is more capable then my skills as a photographer.
WHAT I WANT TO LEARN & UNDERSTAND:
I would like to learn & understand how someone gives a score to a particular lens or sensor. In this case I chose DxO because, over the past few years, I've read several discussions about DxO (prior to that I was not even aware such a company exists) and it got me interested in wanting to learn a bit more. Generally discussions related to DxO seem to invite war, blood bath and then end up with personal insults (I am also equally to blame for some of those discussions). So, I'd like to request your assistance to help me (and anyone else who is interested) understand DxO scores in "layman's" terms ... but please, I beg you not to turn this into DxO worshiping / hating contest. Also, please refrain from using this topic to poke fun or insult or score a point over fellow member ... we come here because of our passion for photography, so we are basically like minded citizens ... so please help me (and others) learn.
NOW THE QUESTION:
I was looking at some lens comparison scores over at DxO today (a screen shot of which I've posted below). According to this a $3000 dollar lens seems to have better sharpness than a $12000 lens. I do understand that a lens is not just about sharpness but also about various factors such as how well it auto focuses ... but for now I just want to understand only the sharpness part of the scores. From my understanding, the scores suggest that the Sigma 120-300 f/2.8 is sharper than the EF 200-400 L IS (without using 1.4 TC), when both have them are tested at f/4 ... is that correct?
... also, is there an explanation to DxO scores? as in how they have arrived at that score?
... and if there is no explanation (for how they allotted those scores), how does one know if they are accurate?
Appreciate if you can assist in helping me understand in simple terms without jargon ... and once again, no blood bath please.
Thanks in advance