Hi, same issue discussed here:
http://feedback.arma3.com/view.php?id=3119

Nice. ;)

It happens.

Pre condition seems to be that you have been swimming.
If you run towards ladder, use the ladder without going down into the water, and climb up again (with the ackward animation), it has no effect on the scopes.
The point of how to get into water, from the beach or jumping from the pier seems to have no effect.

Its centered around the ladder climbing upward animation.

If you swim across the pier to the beach part, with the roll up animation grabbing your weapon, your optics mode work again.

Loadout tested with:
Automatic machinegunner

Steps to reproduce more or less the same.
In my case tested with the stratis airfield piers.

Instead of the optics you will get the normal zoom effect.

I totally agree.

Imagine some sort of infiltration / hostage rescue mission.
You wouldnt want to flatten the place with artillery or an airstrike.
But using sniper support, of course.

A quick google search lead to this example:
http://morovision.com/night_vision_monoculars/MV_14.htm

I think the mountable NV monocle is the fanciest solution for night operations of snipers. You can keep the existing optics (for both forces), which means if the sniper is needed to close in, in can unmount the monocle and use it on his headgear while at the same time beeing able to use the tactical sights on his rifle.
One more multi purpose item.
The problem is, that it will need an additional picatinny slot, or is added to the scope slot.
The biggest challenge might be applying the NV rendering filters/shaders to only one side of the screen when used on headgear(scaling the mask of the current nv goggles), while rendering the rest normally. (from dusk till dawn ;) )

EDIT: (With the current optics available, beeing small in size, using NV goggles with them in RL would be possible.
With perhaps bigger scopes being added in the future, it wont.)
D'oh, or rather not, didnt think of the IR sensor location.

If the split rendering turns out to be a problem, it may be the best option to model one new scope and use it as a template for NV and thermal sights.
Which might have been the plan all along, as it is an alpha and the major content is yet to be added.

So voting up for dedicated NV/thermal scopes and or the NV monocle.

I would rather not add a new feedback report.
This will just add duplicates and further work for the mods.

As per moderator statement, every vote, even those of ppl clearly not understanding the meaning behind a bug tracker and downvoting everything at first glance, is counted and thus helping this report staying alive.

I would monitor it and in case it gets merged or closed eventually approach the mods. :)

This is a dynamic lightning bug.
It occurs on Dusk-Night and Night-Dawn changes. The video by Derbysieger shows it pretty well for the Night-Dawn change.

Main problem:
-ambient lights, such as the moon and star lights get triggered on/off by the same time the streetlights are.
-streetlights intensity fading is bugged. Streetlights in RL are triggered on/off with fading within minutes (not within half an hour) and then shine with the highest intensity.
-near instant change between lights (day) and lights (night) preset, after long fading period

Result: during the cycle, you get a more or less half an hour of darkness.
Check Moon cycle dates and Sunsets times for different dates.

Steps to reproduce:
-start up editor and place the player in town /airfield base etc.
-set date to 6.july 2035 (default date) and time to 20:55
-Preview and set time acceleration and watch the cycle and the lights
-between 21:19 and 21:22 the lights behaviour changes drastically, everything is turned on to max
-try again with a new moon date like the 11.3.2013, see how the ambient light of stars gets switched on
-add vehicles and see how their lights get affected as well in their intensity. see the screenshots below.

Screenshots:
Change in Town
http://i.cubeupload.com/tXoIDA.jpg
http://i.cubeupload.com/AaGGv6.jpg
http://i.cubeupload.com/Ghp4YH.jpg
Moon change:
http://i.cubeupload.com/h2dsmm.jpg
http://i.cubeupload.com/nB5FAx.jpg
http://i.cubeupload.com/WaWxkq.jpg

Also, dont downvote feedback posts you cant be absolutely sure its not a bug.
If its hard to reproduce at first, doesnt mean that it doesnt happen.
Its either a bug or due to placeholders, as this is still an alpha. You'd better let the developers decide.

Please confirm if your were able to reproduce the effect.

This is also an issue if you use a built in Z-Axis of a Joystick for collective control.
You can easily spot the difference by the climbing-speed instrument.
It feels like only the the range +50% to -50% is used.

Joystickmodel: Saitek Cyborg V1

Same Problem but it differs.

My specs:

Intel I7 3770K @3,8Ghz
Asus Z77 WS
16Gig RAM
2x HD6950 2Gig Club3d in CF

Graphic settings used:
All ultra and very high; FXAA Ultra; Atoc: All
Viewing distance 12000
Object 12000
Shadow 200

Helicopter showcase starting point: (lot of objects, viewing distance,PIP etc.)
GPU Usage: 27% / 27%
FPS: 12-14
CPU: 30/32/30/32 %Load (so one thing i can tell is, it uses each core to the same percentage, measured by CoreTemp)

Scuba showcase: (fewer very detailed objects)
GPU 67%-70% for both in cf!
CPU 53% (reporter is right, cpu usage never above 53-54%)
FPS 27-30

Infantry showcase: (low viewing distance, npc models, shadows)
GPU 67-70% cf
CPU 53%
FPS 27-30

Vehicle showcase:
GPU 40-60% cf
CPU 53%
FPS 19-25

So its not a basic Crossfire problem, at least at my end.
It can use up to 70% for rendering and get higher fps, but only if certain things are missing in the view. Basicly lot of objects like buildings and vehicles (especially helis) and rocks/nature objects.

Then i tried the default settings for ultra/ very high / standard but used the standard settings of viewing distance: 1600 objects: 1300 and shadow 100
So that more or less the object count is the same for each setting.

Standard:
GPU 30% cf
CPU 30%
FPS 36-41

Very High:
GPU 40-44% cf
CPU 32%
FPS 30

Ultra:
GPU 40-50% cf
CPU 35%
FPS 27-30

So what it basicly does is, it can scale the GPU Power, if its calculations based on postprocessing rendering, AA, PIP, shaders etc. and deliver more or less the same FPS while having increased image quality.

What the engine seems to drastically fail at, is scaling the used GPU Power to render geometry. Imagine if you can only utilize 30% of the gpus power to render geometry, but increase the object (and polygon) count with each higher quality setting, the fps will naturally go down.

The engine has to make more calls for rendering polygons, and therefore the problem may lie within the thread coding and the cpu usage (bottleneck?).

I hope this helps in any way.

Edit: Funny thing is by using binoculars or the scope on rifles (even on near objects etc.)
you dont only get 60fps on all ultra and highest viewing range settings
it also utilizes up to 92% on both graphic cards!
Somehow if less is needed to be rendered, the gpu load rises and so does your fps.
Changing the resolution or something doesnt have any effect on overall performance, so its not based on less pixels beeing rendered by the smaller viewing field of a scope.

Could someone please mod binoculars, actually showing everything? change some mask layers or something.