Fuji 100-400 vs. 40-150 with TC vs. others

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mbike999 Regular Member • Posts: 191
Fuji 100-400 vs. 40-150 with TC vs. others

Upfront disclaimer: this a highly non-scientific test, and I'm not trying to discredit or promote any particular brand just describe some of my findings to hopefully help others in their long telephoto decision tree. My gear of late is 100% Fuji but I also have the opportunity to compare to my fiancee's Nikon gear.

I set out to compare the resolving power/sharpness between the Fuji XT2 with a rented 100-400 and the 50-140 with and without teleconverter, and also compare these to the Nikon D7500, 300 F4 PF combination. To do this, I used Norman Koren's 2002 test chart. I wanted to decide if having both the 50-140 and 100-400 together was justified given the cost, if I should instead wait for a new long prime lens from Fuji, or consider Nikon or Canon for long glass and certain AF benefits. My general purpose is for birding and other types of wildlife photography. I won't go into a lot of detail about how to utilize the resolution charts (this can all be found on Norman Koren's website) but the general idea is it provides a scale made up of lines which can be used to determine relative resolving power measured by discerning differences between individual lines on a scale. I also did some basic field tests of the lenses.

Some would rightfully argue this is a pretty unfair comparison given I'm comparing a superzoom to a prime, and an arguably amazing AF system of the D7500 (engine borrowed from D500) to the exceptionally good one in the X-T2, and other pros/cons afforded by an EVF versus OVF for this type of work. In addition, there are many aspects of the lenses that I didn't compare in this test.

For the resolution test, the cameras were all set to base ISO, on a tripod, with image stabilization OFF. Each lens was set wide open (which is what my use case would be most of the time). The tripod was kept in the same position the hole time, the only variable changed was the lens and camera. Each final photo was cropped to about the same field of view. Everything was shot in raw and then converted to jpeg without sharpening or other edits.

300f4 Nikon

100-400 Fuji

40-150 Fuji


My findings were as follows, in order of the observed LP/MM (point at which point individual lines begin not being discernible at set distances from the chart) is below. Note these measurement values are arbitrary and based on my use of them don't relate to more scientific tests of MFT, relative sharpness etc.

1. D7500 LP/MM: 175. The D500 with 300 F4 PF combo provide by far the cleanest and highest resolution image, which I found outstanding even with the 20 megapixel sensor (vs 24.3 megapixel fuji).

2. 100-400 LP/MM: 125. The 100-400 showed significantly less resolving power even with its 400mm advantage in this test.

3. 50-140 with 1.4 TC: 115. This was an impressive result given the 200mm disadvantage of the lens/teleconverter combination There

4. 50-140: 95. This result helped show that the 1.4 TC does in fact perform well and resolve more detail.

Overall I was disappointed that the 100-400 sample I had on XT-2 seemed to have much less resolving power in this test, even though it has over 100mm reach advantage over the 300 F4 PF combination. In the field, I also found there was simply no comparison with regards to focus speed, accuracy, and hit rate of the Nikon setup over the Fuji. I also found the 100-400 rather unwieldy in use compared to the feathery light D7500 300/F4 combo.

To thwart potential flame war, I will conclude by saying that I have access to and love both systems and the unique benefits each provide. There may be sample variation at play here which also factored into the results and so I'm interested what other people are seeing. And, I did not test the lenses stopped down based on my use cases which could affect performance.

I also know people are getting excellent results with this 100-400 lens so I wouldn't discourage trying for yourself and drawing your own conclusions, maybe with better controlled test methods!

I sum, find the 40-150 an awesome performer but the 100-400 not suiting my needs to the point where I could justify both. I am looking forward to Fuji's 2018 release of a telephoto prime to help compete better in this area. I also have a 2X TC on order for the 40-150 and look forward to testing that.

Thanks for sharing your thoughts and experiences.

Fujifilm X-T2 Nikon D500 Nikon D7500
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