Is it true that lowering the camera's resolution will achieve a sharper picture?

I was reading Ken Rockwell's guide to the 5D III. He says using a lower resolution than the native resolution will result in sharper picture because of no bayer interpolation and they cheat to interpolate to its native resolution.

I haven't had a chance to test his theory yet because I'm away from home now without my camera.

Um, that makes no sense what so ever. Maybe you misunderstood what ol' Ken was trying to say. There is no way to lower the resolution of the sensor and no way around the need for the bayer interpolation. You can lower the resolution of the final image but all you are doing is tossing out information thus lowering the ultimate resolution of the image.

I found it:

"No one needs 21MP. All it does is slow everything and clog your hard drive.

Try shooting your 5D Mark III at its M (11MP) or S (5MP) settings. If you look at your images at 100%, you'll see that the lower resolution shots are sharper pixel-by-pixel!

When I'm photographing family and friends, I shoot at SMALL JPG. Even SMALL is good enough for great 20x30" prints.

The smaller-sized images out of the 5D Mark III are spectacular. They are much, much sharper and cleaner than images from cameras on which that is their native resolution. When you start with over 20MP, it looks pretty good if you use all those to make 11MP or 5MP......"

Sorry, but half of what Rockwell says is baloney. The other half is still suspect.

That might actually be the same thing as just downsizing in post. Now the lens on the other hand, that's a different story. If the lens resolution is great enough, just shoot full quality.

I'd really take what he says with a grain of salt. I wouldn't be surprised if he's replaced his cameras with iPhones considering his standards.

Using a smaller resultant file means that the image has been downsized - probably by averaging - somewhere during its transit. This has the effect of obscuring things like aberrations, motion blur, and focus problems. The image, after this downsizing, is of course less sharp in absolute terms, but hiding image defects may give the visual impression of a better image. But since you can do it yourself in post with 100% control over the process, why would you throw away part of the image permanently at the beginning? If you can't afford a large hard drive to store your files, you probably can't afford that camera either.

garycoleman wrote in post #17500871
I was reading Ken Rockwell

Ah, there's your problem.

Do... second guess just about everything he says or writes.

Another KR victim...

... and here is the Joker: https://vimeo.com/1205​46894#at=5

I was reading Ken Rockwell's guide to the 5D III.......

APRIL FOOLS!

Pixel for pixel, the results will be "sharper" because with fewer pixels.

If you have a bad lens and a sensor with a lot of megapixels, the image will appear blurry at 100% magnification on a computer screen.

But if the image was a 5MP image, at 100% you're not out resolving the amount of detail the lens has, so there is less blur when looking at 100%.

While technically true, we do know that the higher resolution sensor will capture more detail. It just won't look as good at 100% on a computer display.

lellololes wrote in post #17503316
Pixel for pixel, the results will be "sharper" because with fewer pixels.

If you have a bad lens and a sensor with a lot of megapixels, the image will appear blurry at 100% magnification on a computer screen.

But if the image was a 5MP image, at 100% you're not out resolving the amount of detail the lens has, so there is less blur when looking at 100%.

While technically true, we do know that the higher resolution sensor will capture more detail. It just won't look as good at 100% on a computer display.

Generally when printed, or otherwise reproduced at the same enlargement factor (thats optical enlargement factor, not screen % factor) then the higher resolution image will NEVER look worse than the low resolution image. Usually it will actually be superior, very rarely it will be the same but never worse. That is of course when comparing the full image from two physically same sized sensors.

Alan

Yes, which is why I specified at 100% on a computer display.

The answer is no, even if you use your monitor as a basis. That is because the camera's internal resizing algorithms are inferior to imaging packages capabilities.

Good question. So to rephrase. Are smaller pictures sharper? One to one zooms may appear sharper at lower resolution but you will have less content (detail) and a smaller picture. You will not be zooming as deeply onto the image. Try something a little different. Pick an object in your image. Crop for the object and zoom in on it. Push that object to full screen, one to one, or as far as possible. That is where you should see the advantage of more resolution.

Mike

Heya,

It's not true.

What is true, is that a smaller, lower resolution image will appear sharp relative to the viewing size. That's all.

Is it a good idea to shoot at lower resolution? People have reasons. If it's just for facebook or low quality print where quantity is more important to the shooter than quality (this is true for some reporter types who upload literally as they shoot, so they shoot lower resolution JPG to make mass transfer faster from a wifi source in the field), then it doesn't matter. But for someone wanting to keep the best original image they can and downsize, etc, later, then there's no sense in shooting anything other than the largest, most information containing image you can. It's not like space is costly or limited these days.

Very best,