Prism Scope VS Red Dot Sight – Main Differences

In this Q/A information guide, let's compare prism scope VS red dot sight

• How different are they?
• Does it matter that much to shooters?
• How to decide which one to get for your specific applications beyond the obvious

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Prism Sight VS Red Dot Main Differences

The biggest difference between a red dot sight and a prismatic sight is the method of producing the reticle inside the optic.

A red dot sight projects the reticle from the LED emitter onto the lens of the optic, then reflects back to the shooter's eye for a point of aim.

A prism sight is similar in size to a red dot optic, but the etched reticle on the glass instead of reflection. A Prism scope is very much a 1X fixed magnification hybrid scope with great light transmission between a magnified optic design and a red dot, and also smaller than an LPVO.

But what else is there beyond their obvious until someone points them out?

Please take a look at the bullet points below and ones highlighted in red.

Red Dot Sights

Pros

• Professional duty use
• Lower cost option
• Very simple system
• True 1X for fast target transition close up sight picture
• Can have different dot sizes and color
• Flexible mounting positions
• Compatible with magnifiers
• Use as offset or backup aiming point
• Unlimited eye relief & unconstrained eye box for improvised shooting positions
• Cheek position doesn't matter as long as the shooter can get behind the optic
• Night vision capability
• Use various aftermarket mounts

Cons:

• Parallax increases at certain distances (Often unnoticeable to the naked eye)
• Red dot sight reticle clarity varies for shooters with different levels of astigmatism
• Reticle disappear when the battery dies
• No bullet drop compensator reticle

Prism Scopes

Pros:

• Prism scope has glass etched reticle that is always on without a battery
• Diopter adjustment for better reticle clarity for shooters with astigmatism
• Better first round impact using detailed etched reticle holds (Red dot doesn't have that)
• Prism scope's eye box constraint inadvertently forces the shooter's eye to center the optic to reduce parallax for long range shooting
• Prsim scope is popular for limited division competition shooting
• Most prism scopes feature illuminated reticle

Cons:

• Prism scopes have Limited eye relief & eye box for CQB style shooting
• Can't use as an offset optic easily
• Can't combine with magnifier due to two independent focal points
• It's not a true 1X like a red dot
• Less mounting system or risers available

How To Decide Which One To Use?

Red dot sights are popular and the most common.

They're durable, simple and effective for fast target acquisition for shooting anything within 100 yards.

If you are using a optic for professional duty use, a red dot sight is the way to go.

1X prismatic sights are generally good for limited competition shooting. Better reticle clarity for shooters with astigmatism and able to reach targets as far as 700 yards on 1X with a much more detailed reticle with holds.

Prism scope and Red dot sights common FAQ

Why Can't A Magnifier Work With A Prismatic Sight?

Fact - Prism scope CAN work with a magnifier only if the diopter adjustments on BOTH optics are properly set.

However, the reason why people say they don't work together is that if you remove the magnifier, then the prism scope's diopter is no longer properly set to the naked eye.

Does A Red Dot Sight With A Magnifier Reduce Parallax At Longer Ranges?

A magnifier scope has limited eye box so it forces the shooter's eye to center the optic with a red dot sight mounted in front.

So yes it can reduce parallax at longer ranges.