The Nikon F System: A Brief Overview

The Nikon F System: A Brief Overview

The Nikon F system set the gold standard for SLR design when it was introduced in 1958. It has been used, with only slight alteration, in cameras for eight decades, and has quite the impressive list of accomplishments, accessories, and lenses. Because of this, though, the F system may seem overwhelming to newcomers. 

That’s why we’re here to give you a brief overview of the system, as well as some recommendations on where to start. Here’s the video version of this article, but keep scrolling to find the text version.

History & Overview

Nikon’s F mount was introduced in 1958 alongside the original F 35mm camera. It has three bayonet lugs with a throat of 44mm and a 46.5mm flange distance.

More importantly, the Nikon F system is special because it has remained largely the same from its inception until today, only adding certain features, such as autofocus and internal aperture control, as time went on in order to modernize alongside their competition. 

Not having to switch to a different mount in order to use autofocus (like Canon's EF mount, Nikon’s biggest competition at the time) was a huge advantage for Nikon, and allowed them to retain many customers who had invested in the system and didn’t like having to buy a new suite of lenses just to have autofocus. They also probably stole a few frustrated Canon customers who felt like their FD collections were suddenly obsolete!


Over the years, the Nikon F mount has accrued modern features that make some lenses incompatible with some bodies. While all F lenses will fit on all bodies, you may lose features such as autofocus and internal aperture control control depending on what lens you mount. Let’s briefly examine the major types of Nikon lens.


Original lenses for F, with two-pronged “bunny ear” system for metering. Most are single-coated and will only have full compatibility with the oldest Nikon bodies without some modification. 


The first major improvement to the Nikon F system was adding the AI system, otherwise known as automatic indexing. You can spot an AI lens by the post directly underneath the aperture numbers, which indicates the maximum and current aperture to the body.

Older lenses had to be “indexed” to meter properly. This means the photographer needed to rotate the lens to its widest aperture when mounting.

Most Ai lenses will also have the bunny ear prongs, allowing them even greater compatibility. Many Pre-Ai lenses have also had the AI post added to them, as Nikon offered this as a service for photographers looking to upgrade to a newer body without having to buy all new lenses.


The next improvement involved auto-exposure and general automation of the camera. Ai-S lenses are able to communicate more information to the body and also standardized the aperture stop-down mechanism, allowing for more consistent exposure with a wider variety of lenses.

The extra communication allows for advanced auto-exposure modes, like the shutter priority mode of the Nikon FA or full program modes of later bodies like the F-501.

Body-Drive Autofocus (AF & AF-D)

The autofocus revolution forced all manufacturers to re-assess their lens mounts, and Nikon was no different. Fortunately, they were able to fit autofocus into their bodies in a simple way, by having a mechanical key in the body that fit into each lens. This key rotates to focus the lens when the shutter is half-pressed.

These lenses have aperture rings and can be mounted to any camera with an Ai tab.

Electronic Autofocus (AF-G, AF-S, & AF-P)

The most modern incarnation of the Nikon F system removes the physical focusing key and transmits all data electronically. These lenses, beginning with the G series in 2000, also do not have an aperture ring, which means mounting them on older bodies will result in compatibility issues. Notably, you won’t have control of the aperture and will be forced to shoot at the lens’ widest setting.

Notes about Lenses

Because Nikon has produced so many lenses, some can be found for low prices. Series E lenses, for example, are consumer-grade lenses that use simpler optical formulas and cheaper construction. These lenses offer a good manual experience at a low price.

Early autofocus lenses are another good example. They have slower autofocus and compatibility issues that make them less attractive to modern digital shooters. Because of this, their prices are generally low. They can be used on older bodies, though, as long as they have aperture rings. Basically, you can get a new or almost-new lens for the same price as an older version.

All of this is not even beginning to touch on the large amount of third party lens options for Nikon. The F mount has been one of the most popular mounts since it was introduced, and has lenses of every focal length from an incredible variety of manufacturers. Companies like Zeiss, Vivitar, Voigtländer, and Tokina have produced quality optics for Nikon for decades.


Throughout its history, the Nikon F system has included hundreds of models, from consumer-grade to very niche professional markets. Depending on what you are looking for, there are plenty of great options to suit all budgets and shooting styles.

Manual Focus

Going back as far as possible, the Nikkormat series was the consumer-grade alternative to the professional F body. These bodies are a great place to get into the F system because their price has not gone up considerably in the past few years. 

While the Nikkormats require lenses with bunny ear prongs for metering, that isn’t much of a limitation because most Nikon lenses had them until they introduced autofocus. These cameras are mechanically-controlled, only requiring a battery for the internal light meter. The Nikkormat EL in particular is a great value for money, even adding aperture-priority auto-exposure.

To go a bit pricier, cameras like the Nikon FA may be appealing to those looking for more advanced features. The FA is a bit of an uncommon body, but it added matrix evaluative metering and advanced electronics to a pro-sumer body. This camera is a bit less known than others due to poor sales, and can be purchased for quite low prices, all things considered.


Nikon F autofocus bodies are generally a great value. While some may shy away from “plastic fantastics” like the F-501 (N2020) or the later F65, these cameras offer far more features than older, metal bodies with lower weight and cheaper prices. 

The F501 in particular is an interesting camera. It has a physical shutter speed dial and handles a bit like an older, manual SLR, but in a plasticky body with advanced program modes and autofocus. Taking price into account, this is, perhaps, the best of both worlds.

Notes on Bodies

The top of the line, at least in terms of prestige, would be an original F or any member of the F series, from the F to the F6. These cameras represent the bleeding edge of technology for each era, and Nikon’s absolute best at the time. 

Prices may be a bit higher, but there is an element of pride and prestige in owning an F that collectors and photographers worldwide will recognize. Despite production being halted in October 2020, 2004’s F6 can still be found brand new today.


To Nikon

The Nikon F system is incredibly popular for its compatibility between models. Only Pentax can claim the same level of dedication, but Nikon’s superior sales and abundance of products gives them the edge.

Nikon F lenses will fit on Nikon F bodies, with only very few exceptions. If the lens requires an in-body focus motor, you will lose autofocus. The same goes for lenses without aperture rings. The actual bayonets and mounts, though, have remained the same since 1958. 

To Other Systems

Nikon F is surprisingly adaptable for an SLR system. F lenses can be mounted on many other systems, including Canon EF and mirrorless. Older Nikon lenses, especially Ai series, are popular for adapting and for videography. This is because the focus rings are normally quite smooth and don’t move as the lens focuses in and out. You can also de-click the aperture for smoother performance.


The Nikon F system is a system for the people. Its long active life means that there are lenses to cover almost every need, from ultrawide to super telephoto. Normally, in fact, there will be three or four versions of any particular focal length.

Getting into Nikon may seem intimidating, but the truth is that there are no bad options from Nippon Kogaku. They have produced top-notch cameras for decades, and their products can be trusted to perform.

So don’t despair at all the options, just take the time to assess your own needs as a photographer. When you’ve decided what matters most, chances are there will be a Nikon that’s perfect for you.


This article was originally published on 12.10.2020.

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