If for instance the IOR 9-39x56 were first focal plane. At 9x the crosshairs would be so small you could hardly see them and at 36x it would look like a telephone pole.
I don't know much about Nightforce, I'm sure they are a great scopes. I even checked in to stocking their product line, but I'll tell you. I called them and was treated so rudely that I will never consider working with people like that. Maybe it was just me.
I'm also interested in conducting some tests as you talked of. Let me know were to find the proper targets.
Suggest not reading between the lines. there aren't any hidden messages there, even if held up to a mirror.
Didn't mention any name brand, but if your really in the industry, then the what I call, "Marketing to sell" trends of making larger objectives, and larger tubes is nothing new, but that still doesn't change the laws of physics, chemistry, and affect the 'law of diminishing returns.
Facts, are just simply facts, cold, unemotional, unpolitical, and yes sometimes unpopular.
First focal plane reticules GROW as the power is increased.
That makes it easier to see BOTH,....the reticule, AND the target.
It's much harder,and expensive to make 1st Focal's for many reasons.
It is much, much, much more accurate to both Range, and use it as a Bullet Drop Compensator.
Second focal's SHRINK as power increases.
As power changes, second focals accuracy changes. Ergo the example of the IOR
It's easy to get confused by some of the marketing language out there.
As to the comment on Night Force, they set up a select supply channels years ago, and for the most part they are 'locked up'.
They have nothing to prove anymore, as they have won more and more LR, and ULR shooting records than any other company. They have become the one company the others are now chasing, or trying to copy.
Just check out the 50 BMG shooters, ULR varmiters, Air gun records, etc., against open weight classes.
Better yet, take one out during the day, AND night. You'll be amazed as I was years ago.
Night Force are set at the 1st Focal Plane, either 15X, or 22X.
You CAN easily use any other power, but the factoring changes, is still as accurate, but like any other scope maker will require some calculations.
22X is used on all 22X, 32X, or 42X because many long range shooter find it the easiest to use.
All ranging optics must use a preset power to range, and some can also be used as a BDC.
It isn't possible to range at one power, the use the BDC at another for accuracy.
The Mil Dot in a 5.5-22X56 at 22X give you exactly the dimensional-calibrations of MOA.
Plus once you've ranged the target, you have exactly the BDC set at MOA also. No fooling around with dials, etc.
Let me give another example using Brents R2.
Set at 22X, the distance between the vertical hash marks is exactly 2 MOA @ 100 yds.
Sat a deer was ranged covering 3 marks. Since the average deer is 18" from bottom chest to top of the back., we can now easily figure the range.
3 (marks) X 2 MOA = 6 MOA.
Divide the target size (18) by 6 = 300 yds.
To factor any other power ranges simply divide or multiply.
I'm quite familiar with many reticule systems, but personally find the RR, and R2 to be the best. No other system is that easy, and accurate.
With all due respect, what you are saying is most confusing. You first say that the first focal plane NF reticle will grow with a power change, then you also say the the calibration will change with a power setting change???
My NF reticle does NOT change size with any power change, period. The only thing that changes is the target size. Every place I've read about 1st and 2nd focal planes, this is defined as a reticle in the 2nd focal plane. You are the very first on here to state the exact opposite. Do you have some reference to point to that can clear this up?
In the first focal plane the reticle subtends the same proportion of the target no matter the power. In a 2nd focal plane, the reticle will subtend proportionately less of the target as you increase the scope magnification.