Ignore the film footage, those were overlays added on post-production to the film. When you looked through teh scope the reticles were noting like what you see in Youtube or Das Boot.

I was wondering if you'd chime in. :) Hope all is well.

Yes John all is OK thanks God :Kaleun_Cheers:

I check daily here but I don't usually have much time to read or reply.

:up:

Hitman is the reason I ventured down the path of wanting to learn more - his research back 10 years ago or so was what got me initially curious. Thanks Hitman!

Sorry, I am not sure I understand what you are saying

The optical magnification in telescopes is increasing the apparent angular size of an object by a certain factor, compared to what would be seen by the naked eye.
The decrease in field of view, looking through the same eyepiece, is a direct consequence of that, right?

So, it seems that zoom and field of view are proportionally linked to each other by definition.
If not, than the magnification power number is just meaningless.

That one looks really amazing... :Kaleun_Salute:

A highly detailed and accurate, historically and physically, submarine simulation, representing the actual particulars of the boat, as they functioned in real life?
Yes, please!

Visualize the lead angle? How was it different from setting the lead angle on top of the bearing ring on the scope tube? The one visible in the "bubble" when looking through the scope?

Or was it automated, with TDC-like functionality?

So, the stadimeter prisms were only visible through one eyepiece, but not through the other, is that right?

Why not just align the ghost image, or move it all the way out of sight, when not being used?

In the scope photo on the first page, the ring sits on the bottom ocular, whereas on the photo above, it sits on the top. Otherwise they seem to be pretty much identical. Is there any significance to that, in terms of functionality?

@derstosstrupp and Nikdunaev:

You are both talking about this image?
http://www.tvre.org/images/02_fot_07.jpg

Yes, exactly

That whole unit rotated, so you could simply rotate the ocular with the RAOBF down.

As to the eyepiece with the lead angle inside of it, I don’t know much more than that unfortunately. I only have documentation of StaSr but not the older scopes.

Rotated, as in, could be assembled either way, or rotatable by the actual user in operation?

Rotated in operation. I think that’s what that little tab handle is at the bottom left. In the picture with RAOBF at the bottom

Right... I see the little tab now. Did not notice it before.

Why would you want that though?
Is it something to do with preferring to look with your left or right eye?

Hi Hitman!
We were referencing your mods, so, perhaps, you are the person who can clarify this a bit more! :Kaleun_Salute:

It is quite obvious that films can, and often do, get these kinds of things very wrong.
Still, I believe the photo on the first page to be genuine. Is it not an actual shot from the time?

Anyway, even if this particular picture is not real, it does show the seemingly ubiquitous centiradian reticle.
Seriously, all the film people use it, there must be some source where they got it, right? :yeah:

Further, I trust that this exact reticle is replicated in your mods. A similar one in mods for Silent Hunter V.

So, can you say, whether there is a specific periscope, or some other optical instrument, that this centiradian scale is based on?

In Sh3 it works like you say, there is a direct and inverse relationship between zoom and field of view. However, it is not like that in real life, it depends on the construction of the optical device.


In this particular case, the zoom ratio was 4 ( 1.5 to 6 ) but the field of view ratio was 4.22 ( 38 to 9 ). Since the graticle is just a 2d overlay it can't be accurate for both.


To give more examples, the field of view for the 7x50 binoculars was 7.1 but some 10x80 binoculars had a field of view of 7.25 even though they had 10x zoom. The field of view was different even between different models of the 10x80 binoculars.


What I did for DGUI was to use a 36 degree field of view for the low power, this way the periscopes can be calibrated at both magnifications. This is not historically accurate but I think it is more useful.


Regards

This makes sense. To be sure I rechecked the C/2 manual I have and it indeed only recommends using the graticle at 1.5x.

:salute: Many times, adding the "historical" figures into a game for most anything causes more problems than it solves.

Hi, sorry to dig up the past but I'm doing some research about periscope fidelity in games.

If the magnification ratio is exactly 4 indeed, I think it's actually possible to get a graticle calibrated for both zoom levels. The field of view wouldn't interfere with the graticle use (it would just mask some ticks that are on the border).

The ratio between fields of view can be different from the ratio between magnification factors. It just means the vignette effect will be different.

Here is an illustration of what I think the observer would see:
https://i.postimg.cc/Sx05jJy2/Vignette.png
Notice that the image disc diameter is smaller at 6x.

What do you guys think?

EDIT:
What you say is that you used the 6x 2D layout for the 1.5x mode? That would mean the in-game vignette is exaggerated for the 1.5x mode. Did I get this right?

Here are my findings so far:

https://i.postimg.cc/SsWvpHZP/Table.png

Interesting info. to be sure. But I'm not sure a "wrong" this or that is strictly correct.
Real world vs. computer screen, etc.
I'm more of a fan of does something work in the game to simulate it's subject vs. strictly historical specs, etc.
To often, plugging in historical performance specs of equipment, weapons, etc. (which many times are inaccurate anyway, being based on lab specs vs. real world use) causes more problems than it solves in a computer simulation of such. Many times, putting in historical specs for x, breaks function y of some other system, weapon, etc. in a game that was designed to work with the original specs of x.
What is more important is how does it perform in the sim, especially in the "big picture" of the entire sim.
I.e., iirc, GWX's attack scope had a mag of 10x. Historically correct ? No. But a good idea for the limited view of a computer game ? I think so.
Another example is the "pinpoint accuracy" of depth charges originally found in SH3. Historically correct ? No. But it helps make up for the dumb as bricks AI escorts and poor damage modeling. I like it myself, even with the sensor/damage model work since done to the original game, and it's actually not difficult to escape from anyway.