The PSO-1 scope: A few questions about its current state

[chambersenator 106]

NOTE: this question is specifically about the PSO-1. I'd like to avoid talking about the PSO-1-1, as mixing the two scopes will lead to unnecessary confusion.

I'm a big fan of the PSO-1 scope from years ago in ArmA 2, in both the DayZ mod and vanilla ArmA. My experiences with the PSO-1 in SA since it was added to the game have been a mix of good and bad. It's not been easy for me to do a lot of rigorous testing with it, given the amount of luck and effort needed to collect all the necessary gear to do a series of proper comparative tests in a variety of conditions (especially since I rarely have someone with me to act as a spotter). There's been a number of things written and videos made about the PSO-1 in SA, but a great deal of what I've found is either outdated or based on somewhat unverified information.

So I have a few questions I'd like to ask, and to avoid as much confusion as possible, I ask that those responding to try to separate and/or mark their comments into one or more parts:

• how the PSO-1 works in real life,
• how it works in SA right now, and/or
• how it should/may work in the future

Questions:

1. IRL, the PSO-1 is calibrated for the 7.62×54mmR round. In SA, if attached to an AKM, AK-101, or an AK-74, one would expect it to be less accurate the further away your target is, since the ballistic characteristics of those rounds are significantly different. In SA, does the PSO-1 account for these differences, and if so, how well does it compare to what one would expect IRL?
    
2. Now that FOV no longer is adjustable in the in-game settings, does the PSO-1 behave correctly at the default settings?
    
3. I prefer to use the chevrons for zeroing rather than adjusting it manually through the keyboard. Can all the chevrons be trusted in the current patch?
    
4. If I do all my zeroing inside the PSO-1, what should the manual zero be set at? I would assume it should be at 300m for the SVD, but would that still be correct if the scope is on an AKM, AK-74, or AK-101?
    
5. I would assume that there is a certain amount of accuracy penalty with a 'worn' scope compared to a 'pristine' one. Usually this is not much of an issue for me with other optics, but considering the long shots one can make with a SVD, even a small modifier would have a much more noticeable effect at longer ranges. Is there any known data on this?

One last request (thanks for reading this far, by the way). I'd like to keep this discussion focused on the mechanics and ballistics, and avoid getting into things like the merits and problems of long-range sniping as it relates to gameplay, hit detection, and desync. My primary concern is getting the bullet to go where I expect it to - what happens when it gets there is a whole different discussion.

[-Gews- 7443]

8 hours ago, chambersenator said:

IRL, the PSO-1 is calibrated for the 7.62×54mmR round. In SA, if attached to an AKM, AK-101, or an AK-74, one would expect it to be less accurate the further away your target is, since the ballistic characteristics of those rounds are significantly different. In SA, does the PSO-1 account for these differences, and if so, how well does it compare to what one would expect IRL?

The scope is not calibrated for a particular cartridge, the 'zeroing' system automatically calculates the required launch angle for the weapon and range in question. At long ranges the 'zeroing' system may become inaccurate, depending on the cartridge. In this case the slow 7.62x39 ceases to work after 600 m. It should work fine out to 800-1000 m for the faster 5.45x39, 5.56 NATO, and 7.62x54R. 

Here's an example of the nominal zeroing range versus the real ranges at which the bullet strikes the point of aim using 7.62x39:

(did not test at 900 or 1000 m)

8 hours ago, chambersenator said:

Now that FOV no longer is adjustable in the in-game settings, does the PSO-1 behave correctly at the default settings?

No. The in-game magnification is close to the nominal figure, at 4.14x, but the reticle is improperly scaled.

Here's a table for using the stadiametric rangefinder on a standing player character:

8 hours ago, chambersenator said:

I prefer to use the chevrons for zeroing rather than adjusting it manually through the keyboard. Can all the chevrons be trusted in the current patch?

In real life the three lower chevrons are intended to be used at the following ranges with the elevation turret set to 1000 m: 1100, 1200 and 1300 m. Those ranges are not relevant to DayZ combat so I doubt you are asking if the chevrons are correct at such distance.

The trajectory will (of course) change depending on the selected range setting, so the 3 lower chevrons can mark 120 possible ranges for the AKs and SVD. Are the ranges they provide useful? Not so much, in my opinion.

Here's a rough estimate with the 7.62x39 and a 100 m zero:

ZERO............100 
Chevron 1......390
Chevron 2......560
Chevron 3......670

Those are the lowest ranges the lower chevrons will provide with AKs or SVD. I don't like the jump from 100 to almost 400 m.

8 hours ago, chambersenator said:

If I do all my zeroing inside the PSO-1, what should the manual zero be set at? I would assume it should be at 300m for the SVD, but would that still be correct if the scope is on an AKM, AK-74, or AK-101?

Personally preference. I would run with it set to 200 m for the AKM, and at either 200 or 300 m for the AK-74, so-called 'AK-101' and the SVD, so as not to miss a headshot at the maximum ordinate.

8 hours ago, chambersenator said:

I would assume that there is a certain amount of accuracy penalty with a 'worn' scope compared to a 'pristine' one. Usually this is not much of an issue for me with other optics, but considering the long shots one can make with a SVD, even a small modifier would have a much more noticeable effect at longer ranges. Is there any known data on this?

As far as I know the accuracy modifier doesn't change depending on the attachment's condition.

[chambersenator 106]

Gews, your comment contains an incredible wealth of information. I truly appreciate the work you put into it. It puts my understanding of the peculiarities of the SA ballistic and optic system miles ahead of where it was before. There's a whole lot more ahead of me to learn, but it's a lot easier to move forward now that I have some empirical data to use as a reference rather than just my own tests and assumptions.

The point you made about the PSO-1's zoom being correct (or at least reasonably close to it), and it's the reticle that is not sized properly and exactly by how much is incredibly helpful. I had been looking at it as a combined zoom/reticle issue, and that assumption was screwing up my previous tests. I wasn't sure which factors were due to the optic issue, and which ones were due to the ballistic aspects, and if there were others I just might not be aware of.

I've always been a bit frustrated by how SA's ballistic/optic system as always felt just slightly off compared to A2's system, and it's compounded by not knowing exactly why that is so that I can adapt to the differences. I felt much more confident in A2 because it was so much easier to learn what was going on 'under the hood' given that there was considerable documentation and in most cases, one could expect the simulation to be close enough to real life that one could use the actual manufacturer's and military reference material and be reasonably confident that it would apply in A2. In SA, aside from it being in mid-development and there will be things that need some minor adjustments, there are additional factors that may be affecting things as well, but one is rarely 100% sure that they apply or not. I have little doubt that once modding is permitted, and a firing range mission/mod is available (with features like trajectory lines and color-coded velocity tracking, like the ones in ArmA), that I'll feel much more confident about what will happen when I pull the trigger. While there's often the danger of learning too much and end up "playing the code" instead of playing the game, when it comes to this particular aspect of DayZ, I feel that knowing information like this actually makes focusing on all the other aspects of the game significantly easier and enjoyable.

Edited February 13, 2017 by chambersenator