2022

FOGHORN August 2022

Twobirds Flying Publications

SIG SAUER ECHO3 THERMAL REFLEX SIGHT

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SIG SAUER ECHO3 THERMAL other atmospheric variance that disrupts the
infrared emissions.
REFLEX SIGHT
Optimal thermal imaging conditions are clear
By: Sal Palma and cool environments where there is a wide
temperature gradient between the surroundings
and the desired observation object.

It’s also important to note that thermal imaging

does a fantastic job at detection, but unlike night
vision optics, thermal is poor at recognition, so
the hog you spotted in total darkness moving
through the brush could be Wilbur farmer John’s
pet hog.

In tactical application, you can mitigate the risk

of accidentally engaging a friendly target by
using IR beacons operating in the appropriate
spectral range.

There’s a great deal of misinformation

surrounding thermal imaging technology. First
and foremost, let me say that thermal imaging
cameras, or sights, don’t see through walls.
These optical devices measure infrared
emissions in the 7-to-14-micron (a unit of length
equal to one millionth of a meter) wavelength;
this region of the IR spectrum is referred to as
Long Wave Infrared (LWIR).

In thermal imaging an image is created when

heat radiates infrared energy which is detected
by microbolometer-based sensors and
presented to an LCD or LED display in the optic.
Thermal imaging cannot “see” through windows When there’s a good thermal gradient, the
or glass either; that only happens in movies, but image is clear and well defined as the picture
it's simply not reality. above clearly shows. The individual under
observation is about 80 yards away. The ECHO3’s
Another bit of misinformation is that thermal
AMOLED display image is excellent.
imaging is impervious to weather or
atmospherics, that too is not the case. Thermal
imaging performance is impacted by high
humidity, snow, over water observation or any

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The picture of
the boat at
anchor is a good
example of what
a thermal image
looks like under
conditions
where the
thermal gradient
is narrow. The subject is a 40-foot sloop, being
imaged over water, and in 92-degree weather
with bright sunlight.

It's important to understand thermal optics’

constraints to avoid disappointment, and to
leverage the technology to maximum benefit. At 180 yards a 10-degree field of view is
So, with that out of the way, let me tell you about approximately 95 feet, so to confirm the
SIG SAUER’s ECHO3 thermal reflex sight. ECHO3’s FOV simply measure the 40-foot sloop’s
image with a ruler then measure the picture
SIG SAUER Electro Optics Division consistently
edge to edge, which is slightly over twice the
produces outstanding optics, be they magnified,
sloop size; confirming a 10-degree FOV.
thermal or red dot; the ECHO3 is an example of
that talent.

SIG offers two models of the ECHO3, a 2-12x

digital magnification model with a 40mm
objective, and a 1-6x digital magnification
version with a 23mm objective. I’m probably at a
good point to briefly discuss objective lens
diameters in a thermal optic. A larger objective
diameter, all things being equal, increases the
detection range, but it has a narrower field of
view.

The 1-6x ECHO3 review sample with its 23mm

objective has a 10-degree field of view. We can
confirm that by a simple analysis.

The ECHO3 features 1-6X digital magnification,

but unlike what you see through an optical rifle
scope, digital magnification zooms the display,
and as you increase magnification, the image
becomes pixelated. The picture above was

Copyright 2022, Towbirds Flying Publications. All Rights Reserved.

captured at 3X magnification, the near range is internal memory, or power the sight from an
182 yards, and the group gathered on the right is external source like a pack. The latter being an
at about 220 yards. Under the environmental ideal configuration for extended operations like
conditions at the time, 3X magnification was surveillance.
about the maximum and still preserve a good
clear image. The image below is a side-by-side
comparison of 1X on the left and 3x right.

You can also notice less pixelation and that’s

because a broader thermal gradient.

The ECHO3 sight

ships with a quick
attach / detach
mount and has a
compact footprint
fitting nicely on
your Picatinny rail To power up the
without looking sight, you press in
like the Hubble on the joystick and
Telescope. Physical dimensions are nearly hold for 2 seconds;
identical to the ECHO 1 sight: an overall length of repeating the
4.2 inches, height of 3.3 inches, an overall width procedure powers
of 2.8 inches and a weight of 14.3 ounces. off the sight.
Pushing up on the
Uncooled thermal sights generally use one of joystick gets you
two microbolometer types, Vanadium Oxide into the magnification mode where you can
(VOx) or Amorphous Silicon (α-Si). The ECHO3 change magnification from 1X to 6X. Pushing
uses a 12 µm Vanadium Oxide (VOx) down on the joystick allows you to change the
microbolometer, operating in the 7–14-micron color palette, push left and you can adjust
range. display brightness and push right will take a
picture or video; saving it to the internal 14 GB
The ECHO3 is extremely simple to use, the user
of memory.
interface is a small joystick on the left; next to
the joystick is a USB port used to access the

Copyright 2022, Towbirds Flying Publications. All Rights Reserved.

One area that I’d like to see addressed in future I used posterboard and at its center cut a 2” x 2”
firmware updates, if the design allows, is the opening. I then picked up some Heat Therapy
inclusion of an internal memory format function Patches to act as the heat source and pasted the
to deal with the possibility of corrupt files. patch to the back of the target, so the heat
source was visible through the cutout as shown
SIG describes the ECHO3 as a reflex sight, I think below.
that’s derived from the fact that it is a direct view
optic that you can shoot with both eyes open, so
unlike other thermal sights, the shooter is not
looking through an ocular lens. Is that good or
bad?

I’m not sure that I can answer that question but

since the sight has no diopter adjustment, the
ECHO3 needs to be mounted well forward on
your rail so that your eye can focus on the
display. Eyeglass wearers may find it difficult to
use the sight, I wear progressive lenses and
ended up buying a pair of readers at my local
Walgreens, which worked out well.

The benefit of thermal imaging is that it can be

used in daylight or total darkness and the
When zeroing, your point of impact is not visible
ECHO3’s AMOLED display is adjustable for
with a thermal sight, so you’ll want to determine
brightness; however, I found it difficult to see the
the point of impact correction by measurement.
display in bright sunlight while wearing
The ECHO3 has 0.5 MOA wind and elevation
sunglasses. Taking my sunglasses off improved
adjustment increments and a total of 150 MOA
things but the display was still hard to see.
of wind and elevation adjustment.
Shooting a thermal
Zeroing the sight requires that you access the
sight requires some
configuration menu and scroll through a few
adaptation. For
dropdowns until you get to the Zeroing option.
starters, your target
You do that by pressing in on the joystick for
is an image derived
about a second.
from infrared
radiation, so
zeroing the sight
requires a heat
source, and the
paper target that
you’re accustomed to won’t do it, I ended up
constructing a thermal target.

Copyright 2022, Towbirds Flying Publications. All Rights Reserved.

After selecting the “ZERO” option, the sight The ECHO3 is configurable via an impressive
displays the zeroing screen and using the joystick assortment of options all of which are accessible
you move the reticle to the point of impact if it’s from the configuration menu.
visible. If it is not visible, you’ll want to measure
the needed correction and adjust the reticle 1. Levelplex Anti-Cant System.
position to match the correction requirement. 2. MOTAC (Motion Activated Display).
3. Enable Ballistic Data Exchange.
Moving the reticle down raises your point of 4. A choice of 11 color palettes.
impact and moving it up lowers your POI. Moving 5. A choice of 9 active reticles.
the reticle left moves your point of impact right 6. Capture for image and video
and moving the reticle right moves POI left. selection.

The ZEROING screen displays reticle movement You can also perform a factory reset from the
in MOA or MILS. The zeroing process is much configuration screen.
simpler to perform than it is to describe.
Levelplex, is an anti-cant system with scope cant
You can avoid sensitivity ranging from 3.0 degrees to 0.5
expending a ton degrees, or it can be disabled.
of ammunition
by bore sighting MOTAC (Motion Activated Display) Powers up
the ECHO3 when it Senses Motion.
before heading Enabling BDX allows active reticles that change
out to the with KILO Rangefinder Input providing the
range. I used appropriate holdover. With BDX enabled you can
the following customize fixed reticles that are programmable
procedure. using the BDX Mobile Application.
Fill a large coffee cup with water and microwave Palette option has 11 color palettes to help
for about 6 minutes. I then used a laser bore improve target resolution.
sighter to zero the ECHO3 at 15 yards.
Reticle option provides a choice of 9 reticles.
The ECHO3 is
powered by 2 My favorite is the capture feature, here you can
CR123A batteries configure the ECHO3 to capture single image or
that deliver an three image sequence, you can select video
advertised run capture instead of an image, and you can select
time of 6 hours; recoil capture rather than manual. Selecting
you can also use recoil capture allows the ECHO3 to capture an
an external power image or video when it senses weapon recoil.
pack for extended use, this is a very nice feature
THE ECHO3 is designed for hunters and tailored
and there are several power packs that can be
to predator and hog hunting. The ECHO3 is
charged in the field from solar panels.
simple to use, incorporates BDX technology, a

Copyright 2022, Towbirds Flying Publications. All Rights Reserved.

state-of-the-art sensor, lightweight and compact Manufacturer Specifications:
with a robust QD mount.
• Finish Matte Black
In closing thermal imaging technology is not for • Height 3.3 Inches
everyone and it’s still pricey but the ECHO3 is as • Length 4.3 Inches
good as you can get at its performance and price • Weight 14.3
point. SIG ‘s Electro Optics Division does it again! • Width 2.6 Inches
• Battery CR123
-SP
• Power Variability Variable
• Minimum Power 1
• Maximum Power 6
• Battery Type CR123A
• Battery Life 6 Hours
• Resolution 320x240
• Field of View 10 Degrees
• Country of Origin United States of
America

Copyright 2022, Towbirds Flying Publications. All Rights Reserved.