The Fujinon XF 100-400mm f/4.5-5.6 R LM OIS WR lens is a serious telephoto zoom! If you’re looking for a long telephoto lens for your Fujifilm X camera, your options are very limited, and this one might be your best bet; however, it’s bulky, heavy and, with an MSRP of $1,900, very expensive. Is the Fujinon 100-400mm lens worth the cost?

Fujinon is Fujifilm’s brand name for their lenses. The XF in the name means that this is a premium lens (in other words, not budget) for X-mount cameras. The lens has a focal length of 100mm to 400mm, which is equivalent to 150mm to 600mm in full-frame terms. The R indicates that it has an aperture ring on the lens, which it does, but unfortunately it’s unmarked, which seems like a strange choice. LM stands for Linear Motor, which is the auto-focus system that’s inside the lens. OIS means that it has built-in optical image stabilization. The WR stands for Weather Resistant, which is useful if you are attaching it to a weather resistant camera. While the full name of this lens seems excessively long, it does give us a good overview of what we’re looking at.

When my Fujinon 100-400mm lens arrived in the mail, I was shocked at the size and weight of it. I had read all about how big and heavy it was, but it still took me by surprise. The lens weighs more than three pounds, and is just over eight inches long when retracted at 100mm and is nearly 11 inches when extended to 400mm, not including the lens hood, which adds another three inches. It’s massive! You need to know that it’s very big and heavy, probably more than you are expecting.

The lens seems to be made with plenty of plastic. Not quite as much as Fujifilm’s budget lenses, but more than I would have thought for an XF lens, and I wonder how it would survive a fall. Hopefully I will never have to find out, but I do know that if it does fall it will fall hard! Beyond that, it seems well-built and well designed. There are three switches on the side: OIS on-and-off, Auto-Aperture on-and-off, and a close-focus inhibitor. The aperture ring works well, but is disappointingly unmarked. The focus ring is nice and smooth for manual focusing. The zoom ring twists the lens in and out for zooming. This lens accepts 77mm filters.

The Fujinon 100-400mm lens is very sharp at 100mm and mediocrely sharp at 400mm. This is a zoom lens and has sharpness similar to other Fujinon zooms, so don’t expect prime lens sharpness. Comparing my Fujinon 90mm f/2 to this lens at 100mm, the 90mm produces crisper results. This shouldn’t surprise anyone because primes usually produce better results than zooms, and the Fujinon 90mm f/2 is one of the very best Fujifilm primes. Even so, sharpness on the 100-400mm lens is pretty darn good for a zoom, at least at 100mm. I found sharpness to be excellent at apertures f/11 and larger from 100mm to about 250mm. From roughly 250mm to 350mm sharpness is still excellent, but not quite as good, and it seems to be best between f/5.6 and f/8. Sharpness gets noticeably worse when the focal length is longer than 350mm, becoming the least crisp at 400mm, including some obvious corner softness when wide open. At 400mm I think the sharpness is comparable to the Fujinon 50-230mm budget zoom, and f/8 seems to be the optimal aperture. I would avoid apertures smaller than f/16 at all focal lengths, as diffraction is noticeable.

I didn’t notice any chromatic aberrations, although the camera might be automatically removing it. I found no distortion, so expect straight lines to be straight. From 100mm to about 300mm there’s little-to-no vignetting, but vignetting becomes noticeable when wide-open and approaching the long end of the lens. At 400mm, even when stopped down, the vignetting doesn’t completely go away. The maximum aperture is f/4.5 at 100mm, f/5 at 200mm, f/5.2 at 300mm, and f/5.6 at 400mm, which is sufficient. I would prefer a larger maximum aperture, but that would only make the lens bulkier, heavier and more expensive than it already is. The minimum aperture at all focal lengths is f/22. Bokeh, which is the quality of the out-of-focus area in an image, is pretty good. The minimum focus distance is almost six feet, which means that you won’t be photographing anything from close up, but achieving a shallow depth-of-field isn’t particularly difficult thanks to the long focal lengths. Fujifilm claims that the image stabilization is good for five stops, but I really don’t think so. It’s definitely helpful, especially at the longer end, but I wouldn’t count on it working any miracles. I found it best to turn the image stabilization off when using a tripod.

Auto-focus is extraordinarily quick and quiet considering how many heavy moving parts are inside the lens. It’s not the fastest Fujinon lens, but it’s still fast. The inhibitor switch is helpful if you’re not close focusing. Manual focusing is great when using a tripod, but I found it a tad awkward to do hand-held just because of the size and weight of the lens.

The Fujinon 100-400mm is a difficult lens to use, especially at the longer end. When the lens is attached to your camera, you want to make sure that you hold the lens (not just the camera). You’ll find yourself wanting to use a tripod, or at least a monopod, and you’ll need to mount the lens (not the camera) to it. When not using a tripod, you’ll need to use good techniques to keep it steady, similar to shooting a rifle. Fast shutter speeds will be your friend. I seemed to get better results at the longer end when using the electronic shutter instead of the mechanical. Atmospheric distortion is magnified when zooming in on far away objects. With a good tripod and techniques this lens can be used in low-light situations, but I found that it likes a lot of light and does well in daylight. I got better results when I took my time and was very deliberate and precise. While the lens is particularly challenging, it can also be especially rewarding.

Perhaps the best way to think about the Fujinon 100-400mm is that it’s a fantastic 100-350mm lens, especially from 100mm to about 250mm, which is where it produces the best results. The last 50mm is a bonus—sufficiently good, but disappointing when you consider how much it costs. In other words, 400mm is available when you need it, but consider avoiding it when you can. If you think about the lens in that way you will likely be happy with it, but if you are counting on the long end for top-notch image quality, you’ll be let down. Whether you’re happy or not, the fact is that your options are limited. Fujifilm’s longest prime lens is the 200mm f/2, which retails for more than three times as much as the 100-400mm. The next closest prime is the 90mm f/2, which isn’t especially long. The 50-140mm f/2.8, which isn’t much cheaper than this one, but is optically superior, might not be telephoto enough, depending on your needs. Lastly, there’s the 50-230mm budget zoom, which is nearly five times cheaper, but optically inferior, and also might not be long enough. Those who are deciding between the 100-400mm and the 50-140mm will have to determine if 140mm is telephoto enough for their photography. If so, I’d recommend the shorter lens. If you are deciding between the 100-400mm and the 50-230mm, if you plan to use the lens only occasionally, it might be difficult to justify spending nearly two thousand dollars, so you should probably go with the cheap one; if you’ll be using it often or need the longer reach, the 100-400mm is better, but you’ll have to put up with the heft. For those who need a long telephoto option, you might just have to get this big lens, because there really are no good alternatives. Thankfully, the Fujinon 100-400mm is a pretty good telephoto zoom lens that can produce stunning pictures.

Edit: I overlooked the Fujinon 55-200mm as an alternative. It’s better than the 50-230mm, and much less expensive than the 100-400mm, although with a maximum focal length that’s half as long. If you can’t afford the 100-400mm or need something that’s smaller and lighter, this is one that you should consider.

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Example photographs, captured using the Fujinon 100-400mm lens on a Fujifilm X-T30:

See also: Fujifilm Gear