fredmiranda.com
Login

Comparing 42MP vs 61MP: Real-World Resolution and Contrast

  
 
p.1 #1Comparing 42MP vs 61MP: Real-World Resolution and Contrast
I've just received the Sony A7R IV with its 61MP sensor, and while the ergonomic and software upgrades are impressive, I'm particularly interested in the extra detail provided by the 20% increase in linear resolution over the A7R III's 42MP sensor when using my best lenses at different apertures.

As expected, the resolution and contrast boost are most noticeable in the center of the image. Although the A7R IV's resolution advantage can still be seen off-center with our top lenses, the improvements are minimal.

For this comparison, I'll be using my best lenses, including the Voigtlander 65mm f/2 APO-Lanthar, Sony FE 135mm f/1.8 GM, Sony FE 50mm f/1.4 ZA, and several others. All of these lenses are optimal and perfectly centered.

This should give an idea of what to expect when upgrading from the A7R III to the A7R IV for landscape photography.

P.S. I used Lightroom's beta profile for this comparison, but note that colors may appear off with this profile. Distortion, chromatic aberration, and vignetting were not corrected, so please disregard color rendering in this analysis.


Voigtlander 65mm f/2 APO-Lanthar: A7R3 vs A7R4




thumbnail showing 1:1 areas at infinity distance







Center at f/2: Even wide open, I can see more fine detail on the A7R4 crop







Mid-zone at f/2: Wide open, the A7R4's resolution advantage is not very noticeable at mid-zone is not noticeable even with this superb prime lens







Extreme edge at f/2: Same as mid-zone

Sep 16, 2019 at 06:12 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
Details
p.1 #2Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Voigtlander 65/2 at f/4

F/4 is this lens' optimal aperture and it shows on the crops.





Center at f/4: I see a noticeable resolution improvement at center at optimal aperture







Mid-zone at f/4: Smaller fine detail improvement compared to center, but still there







Extreme corner at f/4: Similar to mid-zone

Sep 16, 2019 at 06:15 PM
vdo1
Offline
Details
p.1 #3Comparing 42MP vs 61MP: Real-World Resolution and Contrast
How about Sony’s own Imaging Edge or whatever it is called these days, I guess it would be supporting the camera?
Sep 16, 2019 at 06:17 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
Details
p.1 #4Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Voigtlander 65/2 at f/8














Sep 16, 2019 at 06:17 PM
1bwana1
Offline
Details
p.1 #5Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Yep, Ray Charles could see the difference side by side. The a7RIV is better.

Not sure how much I would notice viewed at different times, different viewing conditions, and if images were of different subjects.
Sep 16, 2019 at 06:32 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
Details
p.1 #6Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Let's compare it now by interpolating the A7R3 to match the A7R4 file size (60MP) at f/4 (optimal resolution for this lens)







Center at f/4: A7R3 interpolated to match the A7R4 file size







Mid-zone at f/4: A7R3 interpolated to match the A7R4 file size







Extreme corner at f/4: A7R3 interpolated to match the A7R4 file size (Ignore color rendering. beta profile)

Sep 16, 2019 at 06:36 PM
RoamingScott
Offline
[X]
Details
p.1 #7Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Looks like a nice boost in sharpness once downsampled!!
Sep 16, 2019 at 06:42 PM
GMPhotography
Offline
Details
p.1 #8Comparing 42MP vs 61MP: Real-World Resolution and Contrast
I'm noticing some good increases through all the images posted. I may repeat a BB with this body . Need to find which one CV 21 or CV 75
Sep 16, 2019 at 06:50 PM
GMPhotography
Offline
Details
p.1 #9Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Not to get OT but my Rokinon 85 is on fire with this body
Sep 16, 2019 at 06:51 PM
photomadnz
Offline
Details
p.1 #10Comparing 42MP vs 61MP: Real-World Resolution and Contrast
It can certainly be incredibly good under ideal conditions. Working in a high end pro lab though I have printed extremely large (60 x 40 inch+) tests and the results were so close it was hard for people to pick. Sometimes it takes a reality check to recall why you loved that 42 meg sensor in the first place. With the best glass and ideal post processing that is.

The downsides I found were a greater proportion of handheld loses due to the denser sensor which therefore required a higher shutter speed/iso which lost some dynamic range and increased noise. Also diffraction is way more noticeable.

For me currently I would take the @40-45 meg with the build quality and the slightly better focus of the R4. It is the sweet spot for me and I lose nothing in real world. Lets see how close to that the A9II gets.

For those getting the R4 though Im sure you will love it regardless. Its what you do with it at the end of the day after all..


Edited on Sep 16, 2019 at 06:55 PM · View previous versions
Sep 16, 2019 at 06:54 PM
 


Search in Used Dept. 

saxguy
Offline
Details
p.1 #11Comparing 42MP vs 61MP: Real-World Resolution and Contrast
GMPhotography wrote:
I'm noticing some good increases through all the images posted. I may repeat a BB with this body . Need to find which one CV 21 or CV 75


Which CV21 - 1.4 or 3.5?

Sep 16, 2019 at 06:55 PM
GMPhotography
Offline
Details
p.1 #12Comparing 42MP vs 61MP: Real-World Resolution and Contrast
The 1.4 . Got to see if I saved the test on my computer
Sep 16, 2019 at 06:56 PM
snapsy
Offline
Details
p.1 #13Comparing 42MP vs 61MP: Real-World Resolution and Contrast
RoamingScott wrote:
Looks like a nice boost in sharpness once downsampled!!


I don't believe any of the samples Fred has posted so far in the thread have been downsampled. The first sets are at native resolution and the last is with the A7rIII upsampled to the A7rIV resolution.
Sep 16, 2019 at 07:06 PM
snapsy
Offline
Details
p.1 #14Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Fred, can you post a center crop comparison with both cameras upsampled to 120MP? That way both images will undergo resampling, which should provide a more equitable comparison methodology.
Sep 16, 2019 at 07:07 PM
snapsy
Offline
Details
p.1 #15Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Also, any chance you took some pixel-shift shots as well
Sep 16, 2019 at 07:16 PM
ftllens
Offline
Details
p.1 #16Comparing 42MP vs 61MP: Real-World Resolution and Contrast
I do see finer details for sure, but a lot less than I expected. What's more impressive is the CV 65's resolving power!
Sep 16, 2019 at 07:18 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
Details
p.1 #17Comparing 42MP vs 61MP: Real-World Resolution and Contrast
snapsy wrote:
Fred, can you post a center crop comparison with both cameras upsampled to 120MP? That way both images will undergo resampling, which should provide a more equitable comparison methodology.


Both images interpolated to 121MP using PS bicubic:

Center area at f/4 for both:




Sep 16, 2019 at 07:21 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
Details
p.1 #18Comparing 42MP vs 61MP: Real-World Resolution and Contrast
ftllens wrote:
I do see finer details for sure, but a lot less than I expected. What's more impressive is the CV 65's resolving power!


It should be 20% more detail for the center area using perfect technique and a high resolution lens. Off-axis, expect a much smaller improvement.

Any lens asymmetry (decentering, skew) will be more noticeable with the higher MP body.
Diffraction will rob some of that extra resolution (starting at f/5.6) so the A7R4's resolution advantage is more noticeable at optimum apertures. (focus stack may be needed to extract the extra fine detail)
All lenses will benefit from the extra resolution but only the best ones may see the ~ 20% resolution improvement at center.
Sep 16, 2019 at 07:30 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
Details
p.1 #19Comparing 42MP vs 61MP: Real-World Resolution and Contrast
I've noticed that the higher EVF's resolution makes it much easier to nail focus since it shows more fine detail.
Sep 16, 2019 at 07:36 PM
DavidBM
Offline
Details
p.1 #20Comparing 42MP vs 61MP: Real-World Resolution and Contrast
Big improvement on r4 both upsampled to 120.

Any chance of a test with the r4 downsampled to 42MP? We can hope for benefits then due to reduced false colour, moire and other artefacts.
Sep 16, 2019 at 07:39 PM


FM ForumsSony ForumJoin Upload & Sell
  
 

You are not logged inLog inRegister

Switch to mobile view