How Much Exposure Error Can Be Made With The Fuji X-T2 And The Olympus E-M1 Mark II And Still Have A Usable Image? Part III of III; Wrapup And Summary

Chincoteague Island Derelict (click to enlarge)
X-T2, 50-140mm f/2.8 lens @ 74.4mm; 1/640th sec. @ f/8; ISO 200
Converted to black and white in NIK Silver Efex Pro 2.0

In my last two posts, I conducted some tests to I could find out for myself (and I gladly share with all of you) how much latitude for exposure error my two current principal digital cameras' sensors have in creating images.  I made a series of exposures with each camera up to 4 stops overexposed and 6 stops underexposed.  You can read the posts here for the Fuji X-T2 and XXXX for the Olympus E-M1 Mark II if you want to see examples and my full narrative.  In this post, I want to review what I found.

Observations

A) I was a bit surprised to find that the Olympus M4/3 camera's sensor out performed the Fuji's APS-C sized sensor when it comes to exposure latitude.  This is not a comment on the subjective, such as the "look" of any particular image, color, sharpness, detail or otherwise, just that the E-M1 Mark II has greater latitude in bringing images back from the precipice than does the Fuji.

Fuji's 24mp sensor is larger and the size of the individual pixels is 3.9 microns while Olympus' 20mp M4/3 sensor has pixels which measure 3.3 microns.  Fuji's sensor is 368 mm² while Olympus produces sensors which are 243 mm².  That is a difference of 66% in Fui's favor.  Additionally, Fuji has an advantage of 18.1% in pixel size.   Fuji's advantages should result in better light gathering abilities, noise and overall image quality.  But maybe an 18% difference in pixel size and a 66% difference in sensor sizes are statistically insignificant. I just don't know.  In all respects it seems the Fuji should perform better. You would think?

I found the Fuji X-Trans III Pro sensor has a (subjective to my judgment) latitude of 2 1/3 stops overexposure and 4 1/3 stops underexposure.  That isn't shabby by any measure.

I found the Olympus TruPic VIII sensor has (again in my subjective judgment) a latitude of 3 1/3 stops overexpsoure and 4 2/3 stops underexposure.  That is simply amazing to me.

I found that I could pull out the same quality of image on the Olympus even with a 1 1/3 stops more overall exposure error than the Fuji.

This leads me to conclude the new Olympus sensor and processor has a significantly higher dynamic range—1.33 stops more—than the Fuji X-Trans III sensor..  Again, I"m a bit surprised by this.  Also, don't forget, image quality is a very subjective thing and even though the Olympus pulls more out of any particular file when the exposure is way off, I still like the Fuji colors and "look" better at this point.

B) The tonal transitions in both cameras were excellent.  I didn't see a difference between the two even though the Fuji is 14-bit and the Olympus is 12-bit.

C) I'm surprised that the 12-bit Olympus sensor outperformed the 14-bit Fuji sensor.  I was always taught, and it is backed by science, that 14-bit files is better than 12-bit files, but the differences seem to be unobservable in a practical sense, unless you are going to the extremes in enlargement, color correction, etc.  Just as with full frame sensors versus APS-C or M4/3, when conditions are reasonable, you really don't see a difference in image quality.  Only when you go to the extremes is when you find the full frame giving you better image quality at higher ISOs, lower light, higher contrast situations, etc.

D) As one would expect, digital imaging sensors are getting better and better, despite smaller sensors with more pixels.  In my judgment, either the APS-C or the M4/3 can fully meet almost all photographers' needs almost all of the time.  Your judgment may vary considerably according to your point of view.  In direct competitive comparisons, APS-C and M4/3 cameras and lenses are smaller, lighter, less expensive and still maintain extremely high image quality.  No surprise here for me.

The difference comes into play when one needs huge image displays, photographs under extremely low light, needs only the fastest focusing cameras or some very specialized lenses that are not available for either APS-C or M4/3.

E) The dynamic range of these two sensors is really close to the sensors on my previously owned Nikon D800E and D810.  The two Nikons will still outperform these, but not by much.

F) There really is little need to make multiple exposures and then combine them into what we call a high dynamic range (HDR) image.  I don't think HDRs can be totally eliminated as I think there are subtleties that combining more than one image can bring out that you might not be able to adequately accomplish manipulating a single image. That being said, as critical as I have been about Fuji's restriction to only 3 exposures when auto bracketing, now that they gave us the ability to auto bracket with 2 stops in between each exposure, I think that is sufficient, given what you can pull out of overexposed and underexposed image files.

I'm sure other things will come to me that I found interesting about these tests.  I'll report them in another post when they do.

I hope you enjoyed all of this.  Spring is just about upon us and I will be spending my time outdoors photographing instead of indoors testing and writing so much.
 
Thanks for looking. Enjoy! 

 Dennis A. Mook 

All content on this blog is © 2013-2017 Dennis A. Mook. All Rights Reserved. Feel free to point to this blog from your website with full attribution. Permission may be granted for commercial use. Please contact Mr. Mook to discuss permission to reproduce the blog posts and/or images.