Fujifilm XF 100-400mm f/4.5-5.6 R LM OIS WR Fujinon X-Mount Lens, Black {77} with Tripod Mount

Fujifilm's 100-400mm telephoto zoom built for X-mount shooters working outdoors.

On an APS-C Fujifilm body, this lens covers a 35mm equivalent of 152-609mm, which puts serious reach in a relatively manageable package at 3.03 lbs. The optical construction runs 21 elements across 14 groups, with five ED elements and one Super ED element working together to keep chromatic aberration in check at the long end where telephoto lenses typically struggle most. A 77mm filter thread keeps things accessible for polarizers and ND glass.

The 5.0-stop OIS system is the reason handheld shooting at 400mm stays viable, and the twin linear motors keep autofocus fast enough for birds in flight or athletes mid-stride. Weather sealing rated for operation down to 14°F, combined with a fluorine coating on the front element, means this lens doesn't need to stay in the bag when conditions turn. For shooters who want even more range, it accepts both the XF 1.4x TC WR (effective 140-560mm) and the XF 2x TC WR (effective 200-800mm) teleconverters, making a 609mm maximum grow considerably when the situation demands it.

For X-mount users who need a workhorse telephoto that performs across a wide range of outdoor conditions, this lens covers ground that typically requires multiple primes or a much heavier setup.

Who It's For

Wildlife photographers get the most direct benefit: the 152-609mm equivalent reach plus 5.0-stop OIS means sharp handheld frames of distant or moving subjects, and the weather sealing holds up in rain, dust, and cold. Sports shooters working sidelines or tracks will find the linear motor AF keeps pace with fast subjects. Bird photographers can push further with the XF 2x TC WR teleconverter, reaching an effective 800mm on an APS-C body. Travel photographers covering safaris or natural parks get a single lens that handles both mid-range and long compression shots without swapping glass.

Key Features

• 100-400mm zoom with 152-609mm 35mm equivalent on APS-C
• f/4.5-5.6 aperture range, f/22 minimum
• 21 elements in 14 groups with five ED and one Super ED
• 5.0-stop optical image stabilization for handheld telephoto work
• Twin linear motors for fast autofocus on moving subjects
• Weather-sealed to 14°F with fluorine-coated front element
• Compatible with XF 1.4x and 2x teleconverters
• 77mm filter thread, 3.03 lbs weight

FAQ

What's the 35mm equivalent focal length on an X-mount body?

152-609mm on APS-C Fujifilm bodies. That's a 4x zoom range in a single lens, which eliminates the need to swap between a 150mm and 600mm prime for most outdoor work.

Does this lens work with teleconverters?

Yes. The XF 1.4x TC WR extends it to 140-560mm equivalent, and the XF 2x TC WR pushes it to 200-800mm equivalent. Both teleconverters maintain autofocus performance.

How much does the OIS system help at 400mm?

The 5.0-stop stabilization system makes handheld shooting at 400mm practical without a tripod. For fast-moving subjects like birds or sports, that margin matters.

What's the minimum focus distance?

Fujifilm specifies 1.3m (4.3 feet) at the long end, which is typical for telephoto zooms but worth checking against your shooting distance.

Is this lens sealed for bad weather?

Rated for operation down to 14°F with water and dust sealing at 12 points. The fluorine-coated front element sheds water and dirt, so it stays functional in rain or snow without special protection.

How fast is the autofocus?

Twin linear motors drive focus fast enough for subjects in motion. Combined with the OIS system, handheld tracking of birds in flight or athletes mid-stride is achievable.

What filter size does it use?

77mm. That's the standard size, so polarizers and ND glass are affordable and widely available.