Thoughts On the Fujifilm 50-140mm f/2.8 And 100-400mm F/4.5-5.6 Lenses As Well As the Fujifilm Matched 1.4X Tele-Converter

Fujifilm X-T1, with 50-140 f/2.8 lens @140mm; 1/4000th sec. @ f/2.8; ISO 400 (click to enlarge

I'll make this short and sweet to save you time.  If you want to read a bit more, you can.

1)  The XF 50-140mm f/2.8 R LM OIS WR Fujifilm lens is spectacular!

2)  The XF 100-400mm f/4.5-5.6 R LM OIS WR Fujifilm lens is Excellent with a capital E!

3)  The XF 1.4X TC WR Fujifilm matched tele-converter doesn't degrade the image quality in any substantial way in either lens.

4)  Don't hesitate to buy any of the three of these excellent tools.  

5)  End of story!  Wow!

I don't use test charts.  I normally go out and use gear and look at my photographs.  If the gear meets or exceeds my expectations and I like the images I make with it, I'll keep it.  If not, I send it back or sell it.  Much of the minutia that is reported about lenses in "lab analysis" type reviews you can't see in real life anyway.  It is like looking at the recently published images from the Nikon D5 at an ISO over 3 million!  Means nothing to 99.9% of us.

I'll give you my opinion, but you decide what my opinion is worth.  Maybe something, maybe nothing.  I've been passionately photographing for 46 years and easily bought over 100 lenses—maybe 150.  I've kind of seen it all—film, digital and several formats, etc.

100% crop from center of image above (click to enlarge)

Since I sold my Olympus M4/3 gear, I took the opportunity to expand my Fujifilm lens collection with some of the money I received.  While on sale last month, I purchased both the the XF Fujifilm 50-140 f/2.8 R LM OIS WR and XF 100-400mm F/4.5-5.6 R LM OIS WR lenses as well as the matched XF 1.4X TC WR tele-converter.  I hadn't had much time to use them, but I have recently had a chance to get out and use the three pieces of gear and here is my initial assessment.  The key word here is "initial."  I'll continue to use them and if my opinion changes, I'll let you know.

XF 50-140mm f/2.8 R LM OIS WR

The 50-140mm Fuji lens is spectacular!  I don't ever remember using that word when describing a lens' performance.  Even wide open at f/2.8 it is one of the sharpest, if not the sharpest, lenses I have ever owned.  Excellent stopped down all the way to f/11 and, if you look really closely at 100%, you can see just a tiny bit of diffraction limiting at f/16 but otherwise excellent even at f/16!  With the Fuji 1.4X matched tele-converter? Excellent as well!  I don't see any appreciable image degradation even at 100% on my 24" calibrated monitor.  There may be some if you run MTF charts, etc., but to my eye, I just don't see any degradation that one would notice.  And even then you really have to look for anything in the most minute details.  Stop down one stop and I couldn't tell the difference in image quality with it on or off any where in my images.  This is the best tele-converter I've ever used and I've own several Nikons.  

100% crop from extreme left side of frame of image above; wide open at f/2.8 (click to enlarge)
Sharp in the middle is kind of a no brainer.  Sharp at the extreme edges says something.

The focus was dead on with my X-T1 in every exposure.  The OIS is also spectacular.  The best I've ever used, including my Olympus E-M1's IBIS.  The lens feels good in one's hands and has a very high quality of manufacture. The tripod foot is sturdy and of a very good size so the lens locks down well.  Handheld (at reasonable shutter speeds) or on a tripod, I found my images to be technically excellent. 

100% crop from extreme right side of frame of image above; wide open at f/2.8 (click to enlarge)

A comment on focus.  It is fast and sure.  I used this lens to track a passenger train moving diagonally to me at 79 mph.  Every exposure was in sharp focus.  Another plus.

Verdict:  This lens is probably one of the best lenses I've ever owned, if not the best, when it comes to sharpness and resolution.  I won't be selling it.

XF 100-400mm f/4.5-5.6 R LM OIS WR

100-400mm lens WITH the 1.4X tele-converter (click to enlarge)
Focal length is 560 as marked on the lens, 840mm in 35mm equivalent; 1/1000th sec. @ f/8 (wide open)

The 100-400mm Fuji lens is Excellent with a capital E!  This copy of the lens is completely different in image quality than the first one I purchased a month ago.  In the first sample, I got very few sharp images.  I think there must have been a loose element or something as, even on a tripod, most images were not sharp.  I'll chalk that up to sample variation, which occurs in all products or maybe even some heavy jostling during shipping.

I would say this lens is a "tick" down from the 50-140mm lens, but you have to have a critical, practiced eye to see the difference.  Even wide open at 400mm and f/5.6 it is excellent.  I would not hesitate to use this lens at any focal length wide open.  Image quality is excellent all the way to f/11 with just a tad of diffraction limiting showing up at f/11 and a bit more at f/16.   And these test are looking at RAW files.  With the JPEGs, the lens optimization feature fixes that sufficiently.  Once you get to f/22 and f/32, you can see image degradation, but I would never use those two apertures, so that is irrelevant to me.  

100% crop of the above image (click to enlarge)
Remember, this is the equivalent of 840mm and wide open!  I have no complaints.

With the matched 1.4X tele-converter I see the same as I did with the 50-140.  Excellent even wide open, which is now f/8 at 400mm with the loss of 1 f/stop.  Focusing was dead on and I didn't see an appreciable difference in sharpness handheld or on a tripod, if my shutter speeds were reasonable.  Reasonable at 100mm is different from reasonable at 400mm!  The OIS is excellent but the 50-140mm lens' OIS is more effective by a stop or so than the 100-400.  But the OIS is no slouch.  It works well if you are one to handhold your lenses.  When on a tripod, my recommendation is to turn off OIS on both lenses.  

The lens feels good in one's hands and has a very high quality of manufacture as well. I do have one major criticism.  The tripod foot is much too small for a lens with this long effective focal length.  I suggest you buy at least a 4" well made plate to anchor to the foot (so it becomes one, so to speak) so the lens locks down well.  I don't understand why Fujifilm put such an inadequate tripod foot on this lens.  I hope they, or a third party, make a more substantial one in the future. 

Verdict:  Excellent lens at all focal lengths and all but the smallest apertures, without or with the 1.4X tele-converter.  I won't be giving this lens up any time soon. 

CAUTION:  My words pertain to my copies of each of these pieces of gear.  Product variation is real. Read some of the articles written by Roger Cicala at LensRentals.com. They see hundreds of copies of the same lens and image quality is all over the place.  You will see how much variation there is.  In fact, the first copy of the 100-400mm lens I purchased was a real disappointment. Your mileage may vary with your lenses.

Thanks for looking. Enjoy! 

Dennis A. Mook 

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