Est. 2020

Fujifilm 100-400 f/4.5-5.6 R LM OIS WR Lens Review

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Quick Facts about the Fujifilm XF 100-400 F4.5-5.6 R LM OIS WR Lens 

  • Weight: 3.03 lbs/1375 Grams
  • Weather Sealed: Yes
  • Filter Size: 77mm
  • Angle of View: 16.2 to 4.1 Degrees 
  • Focusing Distance: 5.74’/1.75m
  • Max Aperture: F4.5-F5.6
  • Minimum Aperture: F22
  • Image Stabilization: Yes
  • Mount System: Fuji X
  • Price: $1,899.95
  • Zoom: Extension 
  • Accepts Teleconverters*

Table of Contents

Who is the Fujifilm 100-400 F4.5-5.6 for?

Although it may not seem like it initially, the Fujifilm 100-400 is a very popular telephoto focal length on full-frame cameras. 


With a full-frame equivalent of about 150-600mm, this reach covers sport, wildlife, bird, and landscape photography. (Of course, there are different types of photography like possibly portraiture, etc.)

However, these extreme telephoto lenses are often reserved for pro photographers due to their cost. 

For example, with a MSRP of $1,900, this lens is quite big for Fujifilm cameras AND costs more than a new camera body. 

So, let’s figure out if the Fujifilm XF 100-400 F4.5-F5.6 is worth it.

Of course, there are other types of photography that you can use this lens for. 

However, with a cost of $1,900, it definitely deters most hobby photographers. 

Which Fujifilm Camera Bodies Work Best for This Lens?

I believe that the Fujifilm XF line is one of the best camera systems for camera enthusiasts and travelers. However, there is one commonality between most Fujifilm camera lines, the lack of a significant grip. 


With this lens weighing 3 pounds (1375 grams), there are only two types of cameras that I can recommend to use. The first is the X-TX (X-T5, X-T4) and the second is the X-HX (H-H2s, etc.). 


That isn’t that you cannot use the 100-400 or that 150-600 with the X-S10 or X-T40. However, they will be horribly unbalanced.

What other lenses cover the 100-400 (APS-C)/ 152-609 (FF) equivalent? 


There are a couple great lenses within the XF telephoto system that cover this focal length. 

Zoom Lenses


Given there are numerous options within this focal length, here is a quick run-down for each of these lenses. 

55-200: The budget kit lens that can be purchased for only $400 used. 

70-300: One of the newest entries among the telephoto zooms, it’s great but difficult to find. 

50-230: An XC lens that struggles in low-light and lacks weather sealing. The XC deters most photographers. 

150-600: An amazing lens that loses one stop of light compared to this 100-400. However, it gains 200mm on the longer end. 


Prime Lenses

  • Fujifilm XF 200mm F2

Nicknamed amongst Fujifilm users as “The Great White Sharp,” the Fujifilm XF 200mm F2 is an entirely different class amongst XF lenses. (Especially with a MSRP of $6,000) However, at this moment, it is Fuji’s only prime telephoto lens with a focal length above 90mm.

Dials, Switches, Knobs, Tripod foot, and More

Fujifilm 100-400 vs 55-200
Fujifilm 100-400 vs 55-200

There are a couple of less-advertised features on this lens that drastically impact the user experience. 

First, we have a removable tripod foot. (Please be careful when twisting the knob on the left. Make sure you have a firm grasp on either the camera or the lens.)

Second, we have three switches located on the bottom of the lens near the lens mount, OIS-ON/OFF, a focus-limiter, and the auto-aperture switch.

Here are a few quick recommended settings for these buttons/switches. 

    • Keep ON. You will need Image Stabilization with this extreme telephoto length. 


  •  Focus Limiter
    • I recommend keeping this switch on “Full.” This is in the event something is closer than the 5 meter limit on the other side of the switch. (5 meters = 16 feet)


  • Auto-Aperture
    • Keep the auto-feature on the auto-aperture switch OFF. Then, use the camera body or lens aperture ring to control the aperture. 


Speaking of the aperture ring, it’s important to note that this 100-400 does NOT have a marked aperture ring. (Much to the dismay of Fujifilm users everywhere…)

However, there are numerous buttons that are customizable on X-Mount cameras that can change the aperture. OR to view the aperture, just look at the LCD Screen or in the EVF. #It’s not that big of a deal 

Note: The 150-600 does not have a marked aperture ring either. 

Build Quality Review

In regards to build quality, I am going to be quite critical of this lens. 

The 100-400 has a very poor design feel, and not up to the red-badge standard. 

If anything, it feels that the lens is built entirely out of plastic. And for $1,900 that is not something that should happen. I would go as far as saying, the build quality of the 100-400 and the 55-200 are very similar, and the 55-200 is over $1,000 cheaper. 

I might be complaining too much. This lens weighs about 3 pounds (1375 grams), and when fully extended, it is 10.55 inches (268 millimeters.) It does feel manageable with the X-T4. 

Although the 70-300 and 150-600 are not red-badges, these plastic lenses feel more expensive. 

I have no problem with the weather resistance (13 weather seals in 12 different locations), but for $1,899 I would hope so. 

When I think of the build quality-price ratio of this lens, I am reminded that I could purchase the Sigma 150-600 two times(!) for a full-frame camera mount at this price point. (It’s frequently on sale…)

What is the 100-400 FOV?

To give an example of what the 100-400 FOV looks like, here are a few photos that compare the 50mm focal length to the 100-400mm’s length. 

(50mm is the approximate equivalent of the human eye.)

How to get sharp images with this lens

Now, the massive reach of this lens is very apparent from these photos.

After all, the angle of view changes from about 16.2 to 4.1 Degrees.  

However, with that 400mm (FF 609mm), we run into another problem called sharp images. 

Whenever you are beginning photography, you will be taught about the aperture triangle: Aperture, ISO, and Shutter Speed. 

However, as the focal length continues, so does another variable, having to increase your shutter speed. (Shake is magnified) 

Now, I am not explaining this well. However, the general rule is, “Your shutter speed should be double your focal length.” 

Even though this camera does have optical image stabilization (more on that below), just be careful and try to follow that shutter speed rule. 

With a telephoto zoom lens this big, I just try to avoid dropping my shutter speed below 1/500s.

Fujifilm 100-400 Sharpness Test

Reviewing these photos, you can see a major decline in image sharpness and quality at 400mm. 

And back when I had this lens, I performed a major disservice to you, the reader. I didn’t exactly figure out where the decline in image quality started. 

I’m sorry. 

If I had to guess, the fall-off started somewhere between 300-350mm, yet became very apparent around 370 millimeters. 

I don’t know how often image sharpness at 400mm is going to be important (especially in the corners.)

Examining my personal styles of photography, I never take brick wall photos at 400mm. 

However, what is important is foliage reproduction. (My personal bane.)

Fujifilm 100-400 270.6mm @F5.6
Fujifilm 100-400 270.6mm @F5.6

This lens performs best between 200-300mm along with the middle of the aperture range (F6.4-F8) like any lens. 

However, compared to newer lenses, the image quality was just not there (again.)

Bokeh Performance 

Now, the transitions were very pleasant from both foreground to subject and subject to background. 

At 400mm with an aperture of F5.6, you will be able to get some subject isolation as seen above. 

However, you will not get the creamiest bokeh from this lens. (You can use this lens for portraiture, but it’s not necessarily designed for that)

You will also need to be careful with distortion with a camera lens this long. (Distortion goes both ways…)

So, think of this camera as better for the reach than the bokeh and you will be happy.

Bokeh Balls

When reviewing the bokeh balls of this lens, my first impressions on the back of the LCD screen were mostly positive @F4.5

I didn’t see any cat’s eye or onion ring effects. 

However, when examining these pictures in post-production past F4.5, I noticed something… the bokeh balls aren’t round. 

And they NEVER round out. 

Sure, some of that could be due to the complex optical design of the lens (The Fujifilm 100-400 has 21(!) lens elements in 14(!) groups.)

However, the hexagonal shape bokeh bothered me. Even at F8, when every other Fujifilm telephoto zoom lens’s bokeh balls round out, the 100-400 never does. 

I guess what I am trying to say is…. Don’t zoom in to examine the bokeh balls.

Autofocus Performance 

  • Any Eye
  • Tracking Sensitivity +2
  • Autofocus Speed +3

The video above doesn’t tell the entire story of the 100-400’s autofocus. 

It does lose me for quite a while, especially in the second-part where the trees are in the top-left of the frame. However, let’s cover some good things about this lens’s autofocus real quick. 

#1 No Clicking 

Some of the first Fujifilm lenses have a noticeable clicking sound when the autofocus is attempting to keep up with a face moving across the entire frame. 

Thankfully, this lens does not. 

#2 It worked well when I was in the center of the frame

Yes, I double-checked my settings to see if wide, continuous tracking was on. 

It just lost me in the trees. 

#3 It’s fast

Whenever I jumped into the center of the video, it picked me up quickly. 

But let’s talk about the X-T4’s autofocus because that is where this becomes a difficult conversation

How to Set-Up an X-T4’s Autofocus

When testing this lens, I was reminded of the X-T4’s severe autofocus limitations. 

So, here are just a few tips for X-T4 users. 

  • Use a relatively simple scene with a lot of contrast between the subject and background. 
  • Don’t have distracting things like branches waving in the wind behind you. 
  • As we covered in the 10-24mm review, if you need to, use a focus limiter. 

I think videography is wayyy different from photography. And if you can master the quirks of the camera, you still will be able to get quality video from this system. 


  • F18 @ 100mm

According to the Fujifilm website, the 100-400 is rated for up to 5 stops of Image Stabilization with the OIS enabled. Although this might be a slight exaggeration, you will be able to achieve some hand-held shots with this lens if you choose. 

If you are using the long-end again, it might be helpful to find something to balance the lens on AND keep the OIS switch on. 

Like mentioned above, I always attempted to keep my shutter speed at 1/500s or higher for this lens. I will just raise my ISO and underexpose my image. 

Macro Performance and Focusing Distance 

The focusing distance is 5.74 feet/1.75 meters. 

The maximum magnification ratio is .19x, 

And although the magnification ratio is a “meh” on a scale from bad to good, I am very much concerned with the almost 6 foot (1.8 meter) focusing distance. 

Look, I don’t expect a minimum focusing distance that excels with a lens like this. However, the new 70-300 has a focusing distance of 2.7 feet/.83 meters. 

And let me tell a story why this 5.74 feet focusing distance is causing such a fuss for me. 

I was sitting down at the water, just watching birds fly from tree to tree and enjoying the hot, summer day. When, all of a sudden, this bird flew down and landed right next to me. “Great,” I thought. But when I pulled the lens out, I couldn’t focus on the bird because it was too close. (As seen in the photo below)

I attempted to move, but I scared the bird. It flew away. I was disappointed. 

That story happened two to three times before I just gave up. 

However, I just think it’s important to note birds have a very erratic flight path. They could land really close, which is awesome. Or be very far away, which sucks. 

You’ve been warned.


Don’t count on this lens for sunstars. Sure, we can get some starting around F18. But… yeah. No. I take back what I said. Not a good sunstar option.

Fujifilm 100-400 Sample Images

Alright, here are a few sample images from the 100-400 before we begin the rest of the pros and cons of this lens. 

Pros of the Fujifilm 100-400

  • Good Focal Length

The 100-400 (FF 150-600) is a versatile focal length used by many travel photographers who need a super telephoto zoom. 

  • Fast (BUT inaccurate) autofocus 

As you saw in the video above, the autofocus latches onto my face quickly. However, the X-T4 loses me in the trees and whenever I was in the outer-third of the frame. 

  • Locking Zoom

It’s a nice feature that I am a huge fan of. 

Cons of the Fujifilm 100-400

  • That minimum focusing distance

Not a good look if you have such a great opportunity for a photo but cannot take it because the bird is too close. 

  • Price-Build Quality Ratio

Feels way cheaper than the $1900 price tag. Not a good look by Fujifilm 

  • Bokeh Balls

They just never rounded out. It was disappointing. 

My Final Notes

For a long time, XF photographer’s only super telephoto option was this lens or reach into non-native glass. However, since 2020, there are better lenses out there for a cheaper price. I don’t recommend this lens. 

My Rating

Price: 2/5
It’s too expensive, hands down. The 150-600 is built out of plastic as well, and feels more deserving of the red badge name. 

Reliability: 3.5/5

It’s mostly reliable as long as you don’t need to take photos of brick walls at 400mm AND birds don’t fly within 6 feet (1.8 meters) of you. 

Functionality: 3.5/5

Yeah, it wins back some points here. The 100-400 is a good focal length. 

Style: 4/5

-1 point for always showing fingerprints. 

Total: 13/20 or 65%.

My Final Ratings