Range, Stadimeter and MaGui woes

[Von Due]

Here are 3 pics showing a target, the attack periscope at x12 and the stadimeter active. Periscope about flush with the surface, a little above.

The target is a tramp steamer, vanilla issue.

Mast is stated to be 22.9 meters, ingame notepad shows 22 meters.

Range is about 690 meters to the aft mast, measured on the map with gods eye enabled.

I adjust the stadimeter (top horizontal line) so it gives me the range closest to 690 meters. I then do NOT move the stadimeter, but adjust the tilt of the periscope for the 3 pictures.

On the topmost image, I line the horizontal center line up with the waterline of the ship.

In the middle picture, I line up the top of the mast with the stadimeter line. The horizontal center line is no longer at the waterline.

In the bottom picture, I align the stadimeter with the bottom of the "knob" at the top of the mast. The horizontal line is no longer aligned with the waterline.




Can someone tell me what is going on before I flip my old tired lid?

[bstanko6]

The water line, the target ship, and your U-Boat are all moving. You said the periscope is just above the water, so that delineation is greater. Try raising the scope higher.

[Von Due]

I wish raising the periscope would help but here are some in game finds:

The tramp steamer will consistently give me too great range when I measure it using the periscope. The UZO appears to give better results. How much of an error you might ask?

With the periscope raised full, I can expect errors beyond 1.5km when the target is more than 1 km away. That is a massive error.

Lowering it to water level seems to give less error but it's still great. With the periscope near the surface, I can expect an error of 1.5 km or more if the target is more than 2-3 km away. Still a massive error but far better than with the periscope raised full.

Even with the target as close as 850 meters, I still get an error of several hundred meters, if I align the horizontal line with the waterline and the stadimeter with the top of the mast. When the target is about 700 meters, the error is a couple of hundred meters.

In the vast majority of cases, the stadimeter/grades show a too great distance. Only in real bad weather where the target bounces up and down may I, or may not, get a closer than actual range.

This problem is particular (AFAIK) to the tramp steamer and the merchant fleet mod. Other ships like the large merchants give very good results using the periscope.

[bstanko6]

I see what your are saying.

I personally never use a stadimeter. I used the wheel. Even so, unless I am timing shots amongst a convoy, range was never important.

If you are adamant about using the stadimeter, then you may be using a mod that is interfering with the visuals of your stadt. You may have to make adjustments.

[Von Due]

Some other finds where I compared the periscope notepad with the stadimeter, for each pixel row (!!!) from and including the horizontal line (pixel row #0) to the 2nd mark at the 33rd pixel row. Resolution is 1360x768.

First column is the pixel row, 0 being the horizontal center line. # means a grade/line on that row.
2nd column is the (rounded off) degree at x1.5 as reported on the notepad.
3rd column is for x6 and
4th for x12.

pixel x1.5 x6 x12 note
33# 2.0 0.5 0.2 2nd deg. mark for x1.5
32 1.9 0.4 0.2
31 1.9 0.4 0.2
30 1.8 0.4 0.2
29 1.7 0.4 0.2
28 1.7 0.4 0.2
27 1.6 0.4 0.2 for 27 and 26, compare 14 and 13
26 1.6 0.4 0.2
25 1.5 0.3 0.1
24 1.4 0.3 0.1
23 1.4 0.3 0.1
22 1.3 0.3 0.1
21 1.3 0.3 0.1
20 1.2 0.3 0.1
19 1.1 0.2 0.1
18 1.1 0.2 0.1
17# 1.0 0.2 0.1 1st deg. mark
16 0.9 0.2 0.1
15 0.9 0.2 0.1
14 0.8 0.2 0.1 for 14 and 13, compare 27 and 26
13 0.8 0.2 0.1
12 0.7 0.1 0.0
11 0.6 0.1 0.0
10 0.6 0.1 0.0
09 0.5 0.1 0.0
08 0.4 0.1 0.0
07 0.4 0.1 0.0
06 0.3 0.0 -0.0 Negative zero!
05 0.3 0.0 -0.0
04 0.2 0.0 -0.0
03 0.1 -0.0 -0.0
02 0.1 -0.0 -0.0
01 0.0 -0.0 -0.0
00# -0.0 -0.0 -0.0

Note the negative zeros. Also note the different number of pixels between the horizontal line and the first mark, compared with the number of pixels between the 1st and 2nd mark.

Also worth noting is a consistent rounding down to nearest tenth.

Another matter is, at Wilhelmshaven I read the distance to one of the type 34s there pretty accurately at 2750m (error less than 50 meters). The moored tramp steamer on the other hand gave me too great range compared to measured range. I am wondering if the visual height of the mast is not the listed value but much nearer 22 meters than 3. The mast height is just a table value and I am not at all sure if the table is auto generated from the graphics but filled in manually, with whatever arithmetic errors that could sneak in.