Unfortunately our gunsights don't work properly in the first place so you can't actually do that accurately
I know but with no Icons it gets you in the ballpark and that's all you need you cant rely 100% but in the ball park will get you on target and more kills.
I know if an AC is wing tip to wing tip in my sight he is 200-250 out if his ac is half that he is approximately 600 and so on it gives me what I need to move in for the kill.
I'm sure lots have seen this but its always nice to have as a review again it gets you in the ball park the rest is up to your skill set. Its not an exact science but it works for me.
This was written by Andy Bush in his Sim HQ article
Using the Gunsight To Determine RangeRegardless of the design of the sight that you like to use, it has lines or curves that you can use to estimate range. In its most simple form, this consists of flying behind a target and comparing the size of the target to markings on the sight. These markings represent how large a target of a known size will appear at various ranges. Can we do this with our simulation gunsights? In most cases where the sim has range cues, the answer is yes. Here's how.
In AH, we can go to the offline area and fly behind one of the drones at our desired convergence range. Film this using the recorder function (Alt+R). Then play back the film and stop the film when at your convergence range. Observe the relationship of the wingspan of the drone to your sight. We will compare the size of the sight features to the target wingspan.
You have two ways to do this. One way is to use the standard forward view (F1) and then use the zoom (Z ) feature to expand the view. Note the relative size of your sight feature to the drone wingspan. Here is what the default gunsight looks like:
With the default sight, you can see that the P-51 drone wingspan appears to be about half again as wide as the gap between the horizontal bars of the sight when we are at the 300 yard point. The wingspan of the P-51 is representative of a typical WW2 fighter wingspan. If you use this relative target size as an example of what a 300 yard range looks like when compared to the default sight, you won’t be far off regardless of whatever type of target you have. And, no matter what sim you fly, this technique remains valid...as long as you can determine range by some means, you can use the sight as a range indicator.
A second method is a bit more complicated...but easier to use. The idea is to customize the sight such that markings on the sight match the target size at your convergence range. The design of the markings should be chosen to make this size matching as easy as possible. The actual procedures for this technique will be discussed at the end of this article. Here is a typical example:
In either case, you have a sight that tells you what the target should look like at your convergence range. This type of ranging is known as stadiametric ranging, and while the procedure is a bit more complicated in real life, this technique works well in Aces High.
Good! Now we have found a way to solve the first problem of range. Now we move on to the second problem...how do we get our gun into the target’s plane of motion?
here the link
http://www.simhq.com/_air/air_031a.htmlNOW this again is to get you in the ball park it works just fine It helps me toss taters too... lets not break out the graphs. Good Movie of range and Sight Here take a peek