Megapixels and Actual Sharpness vs. Percieved sharpness

So I just finished reading a Thom Hogan article on the D2x randomly, and he states that a higher MP count (well, 12 isn't that high anymore) will lower the perceived sharpness and will make it more difficult to achieve truly sharp images.

So, with that said, does a lower MP camera have images that appear sharper when viewed as a full image? Or is this occurrence only going to happen at pixel depth viewing? For example, if you have a 12mp sensor and a 6mp sensor, shot through the same lens, would the 6mp look sharper than the 12mp, when viewed at the same size on your monitor?

 

No, he is wrong. I have noticed sharpness differences related to 5 meg. vs. 8 meg. vs. 14.2 meg. vs 21 meg. when used on the same or similar scenes.

skieur

 

This probably means little for those who'll take a totally tekkie approach, but I read a paper on pixels and sharpness not long ago which stated that, once you hit 10 MP, the next level at which the human eye can detect any real difference is at roughly 18 MP. True? Don't know. However, I don't doubt it.

It's just a continuation of the never-ending sharpness debates during the film days and which lenses delivered, which did not, etc. My opinion then, as it is now, is that when someone looks at my work, I don't hand them a loupe at the door before they step into my home where it's upon the walls.

If it looks sharp, it is sharp.

That being said, shall we commence to discussing what lenses deliver the best bokeh?

 

That's easy, the ones with the most, and roundest, aperture blades. The Nikon 85mm f/1.4 Cream Machine comes to mind as a fine example.

 

My d70 pics look sharper from the camera on screen than my d200 pics. 6.1 vs 10.2mp

 

All I can say is that I usually shoot with a 40d ... and recently rented a 5d mkII ... and I was blown away by the sharpness!!

So much so .. that I've been crazily saving for one. Of course, now that the 7d has been announced, I have no idea if I'll end up with one ... but the difference between 21 and 10mp was amazing to me ...

Sue
Sue Bruce Photography

 

Can you explain? Are you saying more MP equals sharpness, or vice-versa?

 

Same with my D700, at the per-pixel level, it's softer.

I loved shooting RAW with my D70 and in ACR or C1, images were SHARP SHARP SHARP!!!

I've thought about removing the AA filter on the 700 so it would be sharp like the D70 is, but concluded that it would be a waste of time and money.

 

How did you come to that conclusion? I like the D700/D3 look just fine, especially when used with the 85 f/1.4, or very sharp lenses such as the Sigma macros, or the 14-24mm f/2.8 ...but it is significantly softer at the pixel level than the 24.5 megapixel Nikon 3DX (from the tests I saw online & in magazines)

However, if what Thom Hogan said is true (I don't think it is), the 3DX would have a lower "perceived sharpness".

 

I don't see any technical basis for his assumption other than he has a crap lens and when cranking up the megapixels the faults of his lens are showing. Honestly try tell 45mpx medium format shooters that their images aren't as sharp as bog standard Aps-C, you'll be laughed out of the room.

The point at where this madness stops is that when lenses are sharp enough to be truly diffraction limited, and the sensor has high enough resolution to resolve this level. At this point anything more megapixel wise just reduces sharpness and you may as well just upsample in photoshop.

 

To put it a little differently, with a 5 meg camera flower petals may not look soft but with 10 meg camera you can see the surface texture of the petal. With a 14 or 21 meg, you can see sharp edges and detail in distance shots that blend together using a 5 or 8 meg.

skieur