Which Rifle Scope Objective Lens Diameter Should You Use(And How to Find the Best Lens Diameter)

It could be a non-erasable heartwarming shooting experience if you are a thousand shots strong today. Whether a novice shooter or a pro hunter tactical expert, it goes without saying a rifle scope upgrade doesn’t cut without the specifics.

rifle scope objective lens diameter

To narrow down the technical jargon and features of your scope functionality requires overstepping the misconceptions. This is particularly inescapable when it comes to your scope objective lens diameter. What you choose matters for precision.

What rifle scope objective lens diameter should you choose? Does it always mean a larger lens translates to high field visibility? Not so quickly with an affirmative.

This piece will help clear up your thoughts and assist you to understand the appropriate objective lens diameter to single out for your weapon. Let us have a look at the definitive aspects.

The basics

  • Usually, your objective lens would be located right in front of your riflescope but quite a distance in from your eyes. This is to bring closer your target as the diameter of the objective lens regulates the illumination.
  • A large objective lens diameter means more light into your riflescope backed up by a superior field of view. This is to enjoy a brighter view but that doesn’t imply a larger scope objective lens diameter doesn’t come with setbacks.
  • If you think of a 50mm by 40mm mounting, you might have to struggle with a 30 yard away shot, if you are timely with big scope adjustment. For shooting newbies, this might be even trickier.
  • Scopes are effortlessly identified with specific numbering. A 3-9×40 scope specification implies you have 3-9x magnification and 40mm objective lens diameter.

The decisive points

Application matters

What most riflemen don’t know is that the lens diameter significantly affects your shooting big time. With a large objective lens diameter, you might get away with the extra light in your scope especially in dimmer surroundings.

This might be a size for dawn and dusk shooting adventures for clear visibility through a wider field of view isn’t easily achievable.

The position of the objective lens

A large size of the objective lens assumes a higher position on your scope than would a small objective lens. This is because you have to leave space between the objective lens bell and the top side of your barrel.  A slightly higher mounting of the scope usually helps clear the barrel.

Certainly, you will raise the cheek of the buttstock comb in order to realign your eye with your rifle exit pupil. It helps to avoid the parallax error associated with poor eye-to-scope alignment and reduced eye relief.

Besides, you have to enclose your large objective lens in the confines of a large objective lens bell. Consequently, it leaves you with the burden of having to test diverse rings. You will also have to grapple with reduced precision for close range shots.

Fine-Tuning for a higher magnification, a large objective lens will provide a clearer view. However, if your scope is higher than your rifle it might be difficult to take a shot. But then again, at close range, a large objective lens is a great option to take shots.

Seeking a higher power and portability?

For consistent power regardless of the adjustment level, you need to choose a larger objective lens diameter. The aim is to achieve a high scope power for low light shooting escapades. A 40mm diameter and above is a good selection to back your precision in this case.

Keep in mind, large objective lens diameters come with the added weight specifically during the long hours of outdoors shooting.  Also, your scope objective lens diameter and magnification also affect your light transmission depending type of exit pupil.

Wrap up

Some would rather opt for a small objective lens instead of sacrificing optical quality since this is important for scope clarity. But this is usually detrimental to shooting in a darker environmental especially when you want a quick target.

I take it with a grain of salt, shooting with objective lens diameters of the 50mm, 56mm, or even 75mm. As much as you might work just as fine, the associated cons can be disturbing, if not absurd.

A 40mm is the common standard pick, which is just perfectly in between the higher and lower side. It is a remarkable choice for those who own scopes with low magnification.

I hope it’s now stress-free to pinpoint your ideal objective lens diameter for your flawless shooting tactical expertise. Is it?

Sources: I am a big fan of Wikipedia Scope Section

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