DXOs P-MPIX is NOT a Lens Sharpness Metric | FF in Crop is same as Crop Camera with same pixel pitch

Thank you to our sponsor https://www.lensprotogo.com for providing the D850, D500 and 24 1.4 Lens used in this test! This was not a paid promotion, they simply lent me the cameras and lens. If you need a fast rental, they are my go to!

For many years I have had questions about DXO Marks various camera tests and scores. The thing that bothered me the most was that they were publishing data and I was never really certain as to how they were coming up with some of their numbers, and I know many others feel the same way I do.

One of their most controversial metrics is the P-Megapixel or Perceptual Megapixel which for the life of me I always refer to incorrectly as the “perceived” megapixel score. It is a cool idea in that it is trying to give viewers an idea of the amount of resolution they would get in a final image when pairing a lens to different sensors. There are a huge number of problems with this idea, the biggest of which we still aren’t exactly sure as to what formulas they are using to come up with these numbers.

Heres the bigger problem, new camera owners, or those shopping for a new lens often use these scores to try to get an idea of how “sharp” a lens is. This is not what the P-Mpix score is, which is instead trying to to describe how many megapixels one would get when using the combination. I actually stumbled upon this accidentally when I was testing lens sharpness on a full frame D850 in crop mode compared with a D500. I chose those cameras because they have similar pixel pitch, a variable that impacts diffraction (and therefore image sharpness) and what I learned was, same lens, on similar sensor designs (including pixel pitch) equals similar sharpness.

While DXO doesn’t have D850 test scores that I could find, there were scores for the D810, a 36MP camera. The D810’s PMPIX Score was 23, compared to the D500s 13 (out of 21).

Crunching the Numbers we get:
23/36.3 = 63.3%

13/20.9 = 62.2%

So this leads me to believe they are taking their tests and applying a “lens penalty” to the overall resolution of the camera. This is whacky because it means if you start with a higher MP camera, the score will be higher, regardless of the actual lens and image performance.

Granted, the D810 is not the same as the D850 and there are likely some differences, but what we can gather from this, is that even when the crop areas are similar to the naked eye, their PMPix scores are vastly different.

This is why we cannot consider DXOs PMpix score as a lens sharpness metric, it should be viewed as a total image detail metric. Having it labeled as “sharpness” is very misleading to the general public, because without doing a similar test, there is no way to really know, and the perception is this PMPIX is a lens sharpness score. It isn’t.

I invite anyone interested to download my test images and compare them for yourself: https://www.dropbox.com/s/xs844ccv2wsisd2/Finals-D850-D500.zip?dl=0

There are a huge number of valuable and other interesting questions that can be asked about image sharpness, and Ill have at least 2 more videos on the topic coming soon!

Michael’s Intro Camera Tutorial Videos:

MAVEN Filters, Mini Microphone

Michael’s Maven Straps

Best Canon RF Lenses For Beginners Start of 2020 | Canon R RP

By request, I am answering the question of what are the best lens options for a new Canon R or RP owner. Taking into consideration that we can adapt existing EF lenses, that many Canon lens profiles are supported, and the R / RP are not great for sports shooting, here are my suggestions, as well as an overview of each of the existing RF mount lenses at the time of this recording. Also, please note Canon has about 10 more RF lenses coming very soon.

If you are struggling to learn your R or RP, check out my free tutorials on youtube!

If you want an advanced course on the RP, check out my Crash Course on my website!

Michael’s Intro Camera Tutorial Videos

MAVEN Filters, Mini Microphone

Michael’s Maven Straps

EF to RF Adapters
Canon Control Ring Mount Adapter EF-EOS R

Canon Mount Adapter EF-EOS R
EF Lenses

Canon EF 85mm f/1.8 USM Lens

Canon EF 50mm f/1.8 STM Lens

Canon EF 16-35mm f/2.8L III USM Lens

Canon EF 70-200mm f/2.8L IS III USM Lens

Canon EF 100-400mm f/4.5-5.6L IS II USM Lens

RF Lenses

Canon RF 24-105mm f/4L IS USM Lens

Canon RF 35mm f/1.8 IS Macro STM Lens

Canon RF 24-240mm f/4-6.3 IS USM Lens

Canon RF 28-70mm f/2L USM Lens

Canon RF 50mm f/1.2L USM Lens

Canon RF 85mm f/1.2L USM Lens

Canon RF 85mm f/1.2L USM DS Lens

Canon RF 15-35mm f/2.8L IS USM Lens

Canon RF 24-70mm f/2.8L IS USM Lens

Canon RF 70-200mm f/2.8L IS USM Lens

Uncut Gems

This is not a movie for kids or even teenagers. It vulgar and appalling in many ways, but the reason it is so good is because it is an unapologetic, truthful essay on human nature, desire and flaws. The title is not about precious gems, it is about the characters, each of which have at least one redeeming quality and one incredible weakness. It is highly symbolic and many will be able to relate to it. Very thought provoking. Its hard to recommend because of some of the scenes that are just shocking and inappropriate, but its portrayal of true human nature makes it very strong.

Why Canon will dominate 2020 | 7+ New Cameras & Many New Lenses Coming!

For many years Canon has been resting on the laurels of their Brand name and success. It has opened the door for Sony and other camera companies to step into the video markets. Canon finally responded with the EOS R in 2018, but its about to get absolutely bonkers for Canon. Here’s why! Enjoy!

My Training Videos & Gear

MAVEN Filters, Mini Microphone

Michael’s Maven Straps

The 1DXIII has already been listed on BHPhoto.com!

Rumors of Canon Gear Coming:

EOS Rs Rumored Details:

EOS RII in Testing

Rebel T8i Like Camera Registered

Canon Has 2 new M mount Cameras coming

Canon’s New Hybrid EF/RF Idea

6 New RF Lenses

4 Crazy Fast Canon RF Primes

3 RF Lenses, One EFS Coming

2 Canon RF Kit Lenses

#Canon2020 #CanonLenses2020 #CanonMirrorless2020

Before you buy that nice lens from Wal-Mart! Check for these 2 things!

We had a group member find a great deal on a Canon 24-70 2.8 LII lens on Walmart.com. Turns out, it was too good to be true! Here is what to look for and why a good deal might hurt you in the long run!


My 90D FB Group

Michael’s Canon 90D Crash Course

Michael’s Intro Camera Tutorial Videos

MAVEN Filters, Mini Microphone:

Michael’s Maven Straps

#Canon90D #CanonLenses #CanonGreyMarketLens

Canon 24-70mm f2.8L II USM Lens