Sightmark Photon RT 4.5-9x42S Digital Night Vision Rifle Scope Review

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Sightmark Photon RT Digital NV Rifle Scope
Image Credit - Sightmark

Generation: Digital
Magnification:  4.5-9x
Objective Diameter: 42 mm
Resolution:  640 x 480
Field of View:  22.5 ft/100 yards
Eye Relief:  70 mm
Water-resistant:  Yes
Length/Weight:  16.57 x 3.93 x 3.62 in/30.7 oz (without batteries)
Illuminated Reticle:  Yes
Power Supply:  4x AA
Battery Life:  3.5 hours (with IR)
IR Illuminator:  Yes/Built-in

Best Uses: NV Hunting, Total Darkness Hunting, Day Hunting, Target Shooting, Crossbow Hunting, Tactical Use

Sightmark Photon RT 4.5-9X42S Digital NV Rifle Scope

If you're open-minded about exploring the recently new technology of digital NV devices, the Sightmark Photon RT is an eye-catcher.  It hit the shelves for 2018 with a bang, and it has better upgrades than what the discontinued XT Series could ever offer.  It might be sad news that the ever-popular XT Series is no longer available, but let's check out if the RT rifle scope has what it takes to pull a grieving fan out of their depression!

If you are interested in the Photon you will love the Sightmark Wraith 4K 3-20x50 digital riflescope, it under a thousand dollars and is sure to impress

The digital NV rifle scope has an improved CMOS sensor with camera resolution of 768x576 pixels on an LCD 640x480 display.  Already, resolution improvement of 40% is what you can expect with the new RT series.  This is also made possible with the 940 nm built-in IR illuminator that can extend your NV sight picture out to 150-200 yards!

Sightmark Digital NV rifle scope and accessories
Image Credit - Sightmark

If you want to improve the detection range for your nighttime hunt, you're in luck.  Simply add your own long-range IR illuminator by mounting it to the Weaver rail on the side of the scope.  You can even deactivate the built-in IR and depend solely on the separate IR of your choice.

As a digital scope, you can use the Photon during both day and night conditions.  It comes pre-loaded with six reticles including two for crossbow hunters.  To suit your preferences for any time of the day or night, you can toggle between red, white, green, and now also black reticle colors.

With a built-in USB port, included USB cable, WiFi connectivity, and a built-in video and sound recorder, you can connect to your smartphone and play back the critical moments of your successful hunt with a memory capacity of up to 5 hours.

With a "One-Shot Zeroing Feature," you can get this scope sighted-in at the range faster than ever before.  Don't forget the 4.5-9x magnification is going to give you sight far beyond what you should naturally see in the dark.  After all, it's the point, right?


  • Price
  • High magnification
  • 6 illuminated reticles
  • On/off IR function
  • 40% improved resolution


  • Short battery life

Sightmark Photon RT 4.5-9X42S Q&A:

What is the Difference between Traditional Night Vision and Digital Night Vision?

In this case, the Photon digital NV scope uses a complementary metal-oxide-semiconductor (CMOS) to convert light that comes in through the objective lens into an electronic signal to be projected onto a micro display.  Digital NV also requires some form of artificial light at night to produce bright images, hence why an IR is always required for use.

Traditional NV uses an image intensifier tube (IIT) to convert ambient light into electrons to be multiplied in the thousands.  They're then projected onto a phosphor screen exiting as photons once again to produce a bright image to the viewer with or without the use of an IR.

They're two completely different forms of night vision devices.  Digital can also offer more electronic features, are comparable in quality to a Gen 2 device, and are typically cheaper.

What is the Difference between the XT and the RT Series?

The RT series offers 40% improved camera resolution, adds a black reticle to the mix, has an 850 or 940 nm IR available, and adds zoom magnification.  However, the XT series did have the upper hand when it came to better battery life span and an overall lighter weight.  But, for the upgrades, the compromises had to come from somewhere.

What is the Difference between the 42 and the 42S RT Models?

The only difference in the 42 and 42S models is the IR illuminator.  The 42 is a non-S model with a 940 nm IR illuminator that has a potential max detection range of 150-200 yards.  The 42 S model has an 850 nm IR with a potential max detection range of 220-300 yards.

Which is better: 850 nm or 940 nm IR Illuminators?

To keep the answer brief, the 850 nm IR provides longer detection ranges with better clarity for most NV devices.  The 940 nm IR has a shorter detection range.  While all IR light above 720 nm is invisible to the human eye, the source of the invisible IR beam may project a barely visible red glow the shorter the wavelength that can potentially be visible to prey that spot you.

The 940 nm may be desired for extreme covertness, but it does take extremely sensitive camera technology to maintain image quality.  Without this sensitive, high-tech gear, motion blurriness and focusing shifts may be expected.  It might be worth it to opt for an 850 nm IR to have the longer detection range and better picture quality thanks to the more compatible tech of the mass majority of cameras available on NV devices.

Can the IR Illuminator be Removed on the Sightmark Photon RT Scope?

No, it can't be removed.  However, it does have a brightness, spot to flood, and on/off feature to customize it for your needs as appropriate.

What is the Sightmark One Shot Zero Function?

On a daytime rifle scope, you would use the windage and elevation dials to make the adjustments necessary to get on the point of aim of your first bullet strike to re-center for the bull's eye (see our "How to Sight-In Your Rifle Scope" instructions here).

On the Photon RT, you make the same adjustments electronically with the controller on the screen to match the "x" on the display with the point of impact of your first shot.  The reticle adjustments will automatically be saved, and you can now aim for the bull's-eye expecting a dead-on shot.

Noteworthy Features:

  • High magnification of 4.5-9x for up-close details in the dark
  • One Shot Zero Function for easy sighting-in
  • Choice of 850 or 940 nm IR Illuminator with S or Non-S models
  • 40% resolution improvement over XT Series
  • Digital NV scope with built-in video/sound recording

Our Verdict on the Photon 4.5-9x42S Digital NV Rifle Scope

To light your trail through the dark, the Sightmark Photon 4.5-9x42 Digital Night Vision Rifle Scope is your affordable option.  It's brand new to 2018, and it has a lot of improvements to offer the tech-savvy nighttime shooter. It even made our line-up of the best night vision scopes for AR-15's.

Sightmark RT 4.5-9x Digital NV Scope mounted on gun
Image Credit - Sightmark

Digital NV scopes aren't for everyone, but if you're quick about finding your way around menus and control buttons, this might be the economical NV scope for you.

If you consider yourself both an expert shooter and a tech-savvy user, the ATN X-Sight II 5-20x85 Digital Night Vision Rifle Scope might be right up your alley.  It's equipped with every feature you could expect when you combine a NV rifle scope, laser rangefinder, compass, gyroscope, and more.  You might just meet your match when it comes to managing several features in what is ultimately a rifle scope at heart!

Sightmark didn't just throw out the XT Series.   They improved it and made the changes necessary to make it an even better NV scope - the RT Series.  With innovative changes like this, you can count on Sightmark's proven, across-the-board quality to deliver high performance when you need it - tonight!

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