How to use periscope marks?

Q3ark · 01-11-08, 03:40 PM

Like the title says. What are the periscope marks for?

Just curious realy. What are you supposed to use them for?

Had a quick search around and couldn't find any tutorials for them.

ryanwigginton · 01-12-08, 02:03 AM

Good question. The marks look good. But I've not used them once for lack of knowledge.

Q3ark · 01-12-08, 08:16 AM

Went through the periscope section of fleet sub manual last night. My head hurts from all the new information, I can now disassemble and re assemble a type 91KA40T/1.414HA Periscope

( ok so i exaggerate

). Unfortunatley i am no closer to understanding how the periscope marks are used.

Rockin Robbins · 01-12-08, 08:36 AM

Those marks are meant to measure degrees. Unfortunately, we have the same overlay for high and low magnification views in both scopes and the marks were different for the attack scope and observation scope. Also, they are correctly scaled for only one magnification. So the questions are: which scope and magnification do they fit? And what is the scale of the markings?

I'm thinking that a little detective work with WernerSobe's Natural Sinking Mechanics test range and a hatload of trigonometry could answer these questions. I'm also thinking that knowing these answers would make the spread adjustment an aimed device instead of a by guess and by golly device.

I can't do it now, but I will get to it. I'm a sucker for technical aspects.

It's a moral defect.

gottagift · 01-12-08, 04:35 PM

I found this information on Page 68 of the SH4 Manual.

The meaning of the reticle marks is outlined in the table below:

Optic Used-------------(Zoom Level)----------Small Marks-------------Large Marks
Periscope------------(Low Magnification)-----------1°---------------------4°
Periscope------------(High Magnification)-------0.25°(0°15’)---------------1°
TBT-----------------------(7x)-----------------0.2° (0°12’)---------------1°

Hope this means more to you than it did to me

seaniam81 · 01-12-08, 04:39 PM

Ya it makes sence. The marks are to help aim your spread shots.

Gino · 01-12-08, 06:53 PM

These reticle scales are the basic means for determining target range. On COD's periscopes, on L.P. (low-power) each scale mark represents 1-degree of optical angle. On H.P. the longer marks are 1-degree apart and each shorter mark is 1/4-degree. Knowing that at 1000 yards range, a length of 52.5 feet subtends an angle of 1-degree provides you with a means for converting known lengths to range. It would be tough to do all but the simple calculations in your head, but the Range Omnimeter

is one example of a quick tool for determining range using these reticle marks. If the attack officer knows the masthead height of a target and sets this value on the Omnimeter, he can then observe the relative optical height of the mast in terms of scale divisions and then read off the range to the target directly from the Omnimeter.

For example, if I know that a ship's masthead height is 70 feet and it appears to take up three reticle marks on the vertical scale with the scope set on H.P. then I can immediately read from the Omnimeter that the target's range must be 1860 yards.

The horizontal reticle scale can be used in the same way using a target's known waterline length and estimated angle on the bow. Or the two ideas can be used together to first find the range, then observe the apparent waterline length, and then read the angle on the bow directly from the Omnimeter.

Other example:

I guess someone's gonna build this one next...
Need more info?

Likewise:

groetjes,

Q3ark · 01-13-08, 07:11 AM

Very interesting thanks for the info Gino. Wonder if this works correctly in game I think some testing is in order after work tonight.

Blue · 01-13-08, 06:47 PM

While reading, I just realized a new question.......

When using the Stadimeter is it nescassary to align the scope's horizontal center-line with the horizon or surf. line? I see that proper alignment is obviously required when calculating range manually. Does it matter with the Stadimeter?

Q3ark · 01-13-08, 06:58 PM

Quote:

Originally Posted by Blue

While reading, I just realized a new question.......

When using the Stadimeter is it nescassary to align the scope's horizontal center-line with the horizon or surf. line? I see that proper alignment is obviously required when calculating range manually. Does it matter with the Stadimeter?

No you don't have to line up the horizontal line with the waterline on the ship. It'll work just fine

01-11-08, 03:40 PM	#1
Q3ark Watch Officer Join Date: Apr 2007 Location: York, England Posts: 346 Downloads: 47 Uploads: 0	How to use periscope marks? Like the title says. What are the periscope marks for? Just curious realy. What are you supposed to use them for? Had a quick search around and couldn't find any tutorials for them. __________________ Johnny was a chemist's son, But Johnny is no more. What Johnny thought was H20 was H2SO4. Last edited by Q3ark; 01-11-08 at 03:59 PM.

01-12-08, 08:16 AM	#3
Q3ark Watch Officer Join Date: Apr 2007 Location: York, England Posts: 346 Downloads: 47 Uploads: 0	Went through the periscope section of fleet sub manual last night. My head hurts from all the new information, I can now disassemble and re assemble a type 91KA40T/1.414HA Periscope ( ok so i exaggerate ). Unfortunatley i am no closer to understanding how the periscope marks are used. __________________ Johnny was a chemist's son, But Johnny is no more. What Johnny thought was H20 was H2SO4.

01-12-08, 08:36 AM	#4
Rockin Robbins Navy Seal Join Date: Mar 2007 Location: DeLand, FL Posts: 8,900 Downloads: 135 Uploads: 52	Dredging my memory here Those marks are meant to measure degrees. Unfortunately, we have the same overlay for high and low magnification views in both scopes and the marks were different for the attack scope and observation scope. Also, they are correctly scaled for only one magnification. So the questions are: which scope and magnification do they fit? And what is the scale of the markings? I'm thinking that a little detective work with WernerSobe's Natural Sinking Mechanics test range and a hatload of trigonometry could answer these questions. I'm also thinking that knowing these answers would make the spread adjustment an aimed device instead of a by guess and by golly device. I can't do it now, but I will get to it. I'm a sucker for technical aspects. It's a moral defect. __________________ Sub Skipper's Bag of Tricks, Slightly Subnuclear Mk 14 & Cutie, Slightly Subnuclear Deck Gun, EZPlot 2.0, TMOPlot, TMOKeys, SH4CMS

01-12-08, 04:35 PM	#5
gottagift Bilge Rat Join Date: May 2007 Posts: 1 Downloads: 17 Uploads: 0	interpreting periscope marks I found this information on Page 68 of the SH4 Manual. The meaning of the reticle marks is outlined in the table below: Optic Used-------------(Zoom Level)----------Small Marks-------------Large Marks Periscope------------(Low Magnification)-----------1°---------------------4° Periscope------------(High Magnification)-------0.25°(0°15’)---------------1° TBT-----------------------(7x)-----------------0.2° (0°12’)---------------1° Hope this means more to you than it did to me

01-12-08, 04:39 PM	#6
seaniam81 Commodore Join Date: Dec 2003 Location: Ontario, Canada Posts: 624 Downloads: 87 Uploads: 0	Ya it makes sence. The marks are to help aim your spread shots. __________________ Ultima ratio regum. (The final argument of kings) - Inscription on french cannons, on order of Louis XIV

01-12-08, 02:03 AM	#2
ryanwigginton Weps Join Date: Apr 2007 Location: Nottinghamshire Posts: 368 Downloads: 68 Uploads: 0	Good question. The marks look good. But I've not used them once for lack of knowledge.

01-12-08, 06:53 PM	#7
Gino Pacific Sub Expert Join Date: Aug 2006 Location: Las Vegas, Nevada Posts: 148 Downloads: 56 Uploads: 0	These reticle scales are the basic means for determining target range. On COD's periscopes, on L.P. (low-power) each scale mark represents 1-degree of optical angle. On H.P. the longer marks are 1-degree apart and each shorter mark is 1/4-degree. Knowing that at 1000 yards range, a length of 52.5 feet subtends an angle of 1-degree provides you with a means for converting known lengths to range. It would be tough to do all but the simple calculations in your head, but the Range Omnimeter is one example of a quick tool for determining range using these reticle marks. If the attack officer knows the masthead height of a target and sets this value on the Omnimeter, he can then observe the relative optical height of the mast in terms of scale divisions and then read off the range to the target directly from the Omnimeter. For example, if I know that a ship's masthead height is 70 feet and it appears to take up three reticle marks on the vertical scale with the scope set on H.P. then I can immediately read from the Omnimeter that the target's range must be 1860 yards. The horizontal reticle scale can be used in the same way using a target's known waterline length and estimated angle on the bow. Or the two ideas can be used together to first find the range, then observe the apparent waterline length, and then read the angle on the bow directly from the Omnimeter. Other example: I guess someone's gonna build this one next... Need more info? Likewise: groetjes, __________________ Gino

01-13-08, 07:11 AM	#8
Q3ark Watch Officer Join Date: Apr 2007 Location: York, England Posts: 346 Downloads: 47 Uploads: 0	Very interesting thanks for the info Gino. Wonder if this works correctly in game I think some testing is in order after work tonight. __________________ Johnny was a chemist's son, But Johnny is no more. What Johnny thought was H20 was H2SO4.

01-13-08, 06:47 PM	#9
Blue Watch Join Date: Dec 2007 Location: New York Posts: 15 Downloads: 23 Uploads: 0	While reading, I just realized a new question....... When using the Stadimeter is it nescassary to align the scope's horizontal center-line with the horizon or surf. line? I see that proper alignment is obviously required when calculating range manually. Does it matter with the Stadimeter?