Fotomacher Loc: Toronto

I do not believe that the statement is ridiculous at all. Lenses have a optical characteristics that are not widely discussed. One is the T stops which is the measure of the actual light transmission of the lens rather than the F stop which is merely a calculation based on the focal length and diameter. The optical quality of a lens (i.e. resolution) will most definitely produce final images equal to or less than the maximum resolution of the camera sensor. Compare the image quality of the Nikkor "kit" lenses and their pro quality glass. If the kit lenses were capable of maximizing image quality we'd never spend more money to buy better glass. For my image capture I always use Nikkor lenses, from AI-s lenses, AF-D and newer AFS units. For those who want to save money, you can either buy Sigma/Tamron/etc or buy used Nikkor. Nikkor lenses will hold their value over many years while other (off brand) lenses will see their values drop like stones. Sorry for the length of this opinion.

MT Shooter Loc: Montana

Obviously you declined to actually read the referenced statement.

Apaflo Loc: Anchorage, Alaska

Other astute replies to this comment have suggested correctly that it is nonsense or worse. It is a troll using pseudo geek bait. On multiple occasions he has run out his misunderstanding and proceeded to get a lot of desired attention, but the real technical facts get ignored.

His false statement is arrived at by assuming that a meta concept from DxOmark called "Perceptual MegaPixels" can be compared with a physical count of real pixels. That is the first of two fake notions. The second is his repeated assumption that any given lens reduces the resolution of a 36 MP camera but not the resolution of a 24 or 12 MP camera.

Reality: take any specific lens and measure DxO's Perceptual MP on a 36 Mp camera necessarily gives a figure lower than 36 MP. But on a 24 MP camera that lens will measure less than 24 and on a 12 MP camera it will measure less than 12. Those "Perceptual MP" values can only be compared to each other and not to physical pixel counts. The perceptual value from a D810 will always be greater than the value from a D750 which will always be greater than the value from a D3s because the higher physical pixel count camera is always higher resolution! Thus the original claim by member Dan De Lion, comparing apples to oranges, is pseudo geek speak.

That has been demonstrated to him previously, with hard facts using DxO data.

selmslie Loc: Fernandina Beach, FL, USA

Although his statement is not literally correct - you still end up with a 36 MP file - you end up with a 36 MP image that is not very sharp. Dan De Lion is correct about the actual effective resolution.

What DxOMark is telling us with the "Perceptual MegaPixels" is that the lens in question produces the sharpness in the image equivalent to a 10 MP camera with a perfect lens. We all [should] know that there is no such thing as a perfect lens.

If all you can get is effectively 10 MP on a 36 MP camera, that lens is not so hot. It would probably degrade any camera's resolution in proportion to the 10/36 figure and result in approximately [sensor MP]x10/36=[ effective resolution], for example, about 6.7 effective MP on a 24 MP camera.

It is easy to see that the best zoom lenses do not match the performance of decent prime lenses. All you need to do is look at the DxOMark Perceptual MegaPixels ratings for lenses and compare them to the camera's on which they were tested.

The best lenses have Perceptual MegaPixels closest to the MP of the camera on which they were tested.

Apaflo Loc: Anchorage, Alaska

He is totally wrong because he simply doesn't understand what DxO's "perceptual megapixel" figures are.

You have also in the past tried to equate the DxO meta concept to real pixels. They are not the same, and doing so produces invalid results.

The simple fact is that a D810, with 36 MP, provides higher resolution with any given lens that the same lens provides on any camera with fewer pixels. It doesn't become a 10 MP camera that isn't as good as a D750 with 24 MP.

selmslie Loc: Fernandina Beach, FL, USA

It's obvious that you don't understand this topic. Dan De Lion and I know exactly what is going on. Perceptual megapixels is just a way to compare lens sharpness. It's easier to understand than MTF curves - at least for most, maybe not for you. You don't understand either concept or you would not be arguing about this.

I have never related DxOMark's perceptual megapixels to actual pixels. It is not a pixel count. It is a measure of relative sharpness. On a D810 with a poor lens you get 36 MP of poor image quality.

On a D810, an $1800 Carl Zeiss Milvus 1.4/85 ZF.2 resolves the equivalent of 36 MP. That's very good, especially if you want an 85 mm focal length.

My $600 Tamron SP 35mm F1.8 Di VC USD has the sharpness equivalent of 29 MP or about as good as it gets for 35 mm and it's a lot of bang for the buck, especially since it is my favorite focal length.

The best zoom on the list is the $1699 Tamron SP 70-200mm F/2.8 Di VC with the sharpness equivalent of 28 MP at a focal length of 100 mm. The best zoom that covers the 35 mm range is the $950 Tokina AT-X 24-70 F2.8 PRO with a sharpness equivalent of 27 MP at 24 mm.

So not only are prime lenses sharper than zooms, zooms are best at only one of the focal lengths. And primes are less expensive, lighter and have wider maximum apertures.

In terms to which you might be able to relate, if your recording system can handle all the way from 20 Hz to 20,000 Hz but your microphone performs poorly below 200 Hz or above 2000 Hz, your recordings will suck. You will need a better microphone.

Apaflo Loc: Anchorage, Alaska

Obfuscation by blathering volumes of non sequiturs won't improve your track record...

selmslie Loc: Fernandina Beach, FL, USA

It should have been clear to you by now that the resolution of the sensor can only be achieved with a "perfect" lens. If you understood that you would not have been arguing about perceptual megapixels.

I can only hope you have finally learned something new today.

Apaflo Loc: Anchorage, Alaska

Nobody has this perfect lens that only you need. But many of us have fully appreciated 36 mp cameras, and in the future will no doubt work well with even higher pixel counts!

Your argument suggests you lost it when 6 mp sensors were introduced... : - )

selmslie Loc: Fernandina Beach, FL, USA

I guess my hope that you would learn something new was wasted on you. You will probably never know how poor lens quality can degrade sharpness.

Go ahead and blow your money on a 50+ MP body. It's never going to help you until you understand the relationship between sensor resolution and lens resolution.

I'll just add lens resolution to the list of topics you still need to learn about.