Honestly, and I mean no disrespect, I love how we just share unqualified opinions these days.
I mean we got people that don't no dick about what's being discussed just pipin up because they have an internet connection..... and I hear ya. What were we gonna do if you'd just thought "I don't know anything about this.....I should just not talk.".....well, we'll never know.
What he's describing is a sort of poor mans white balance you could use in a store or at a range or really anywhere you have a nice uniformly white surface to look at.
Is literally the same way that high end cameras are calibrated before use. You know....those things that are designed to transmit light as efficiently And color as accurately as possible in order to better recreate an image.
Had never thought of this OP, thanks for sharing. Great trick we can use basically anywhere in order to compare and contrast anything we get our paws on.
Appreciated.
Jeez, not sure what you're upset about. I was not being rude to the OP Alamo. I was just telling him that this "method" he was talking about sounded like nonsense and that the guy that showed it to him isn't making sense.
Ok let's begin with white balance and the human ability to see it. Unless you are trained at understanding the relationship between colors, and how our mind perceives color and the constant shift to 5500k, it is literally impossible to see if the color balance is on. (I spent a couple of years as a color dark room printer, the old school kind that uses YGCBMR color filters to adjust color. I literally made my living on color balance) So looking through something and comparing the color of something white between two scopes only tells you how much more one scope skews towards a part of the YGCBMR spectrum as opposed to the other scope. At least that's what I can think of, unless i'm missing something, which is entirely possible given the multitude of variables here and the fact that i didn't listen to their actual conversation. And the only way to do this is in a controlled environment.
So putting a scope 2' away from white paper, is only going to tell what I just described. It won't give us any real understanding of color fidelity, resolution, contrast, flare control... and sure as heck wont tell us if the scope can track worth a damn. So no, this "method" will tell us pretty much nothing useful about a scope.
As for high end cameras being calibrated with white before use, not sure where you saw someone do this, but they are a hack. No one that knows anything about photography would purposely use a white surface to calibrate off of unless they had absolutely no choice and were going to manually adjust from there. There are too many reasons to list, but the first is that, white is not always white, second, that white, depending on the surrounding environment, may be too bright for your digital sensor to handle. As it's clipping, you're getting invalid information and an incorrect white balance. What professionals calibrate to are 18% Gray cards or a McBeth(not sure if they still call it this) color chart.
And as for "those things that are designed to transmit light...", yep have some experience with them given that I used to, as part of my job, test lenses for a living. I probably should have qualified myself better for the OP but it seemed like too much to type so let me do it now. I have a degree in commercial photography (although it was a long time ago). I spent 10+ years in advertising and film production, and 5 years as a high end retoucher and finisher. I'm certainly no scout sniper or professional firearms guy, but I do know optics (from a user standpoint, not engineer) as I literally built a life using them and comparing them.
In my spare time, I purchase rifle scopes and compare them side by side because it's a fun hobby.
So... back to what i originally said...
With regards to the "engineer's method", no disrespect but sounds like nonsense.
