Comments on: The megapixel myth – a pixel too far?

By: majid

majid — Wed, 13 Oct 2010 01:41:10 +0000

Thank you for your comments.
1) Yes, microlenses improve the effective size of pixels by hiding circuit traces and other overhead circuitry on the chip. So do backlit sensors. That’s why I put the caveat “for a given generation of cameras”. My Canon 10D has 2x the pixels of my D30 yet better SNR. Unfortunately the rate of improvement is stalling, and the Canon 50D or 60D have worse performance than the 40D.
2) I am distinctly underwhelmed by the LX3, S90/S95. The only small-sensor compacts that were halfway decent in my book were the late and lamented Fuji F30 and F31fd. Many of the current compacts apply excessive noise reduction at the cost of detail. The only decent compacts in my book are the Sigma DP series, the Panasonic GF1, Leica X1 and Sony NEX.
3) In my experience the Panasonic GF1 almost always selects f/1.7 in full-auto program mode when the 20mm is mounted. On a good lens, the optimal aperture is only one stop lower than wide open. The very best ones, e.g. Leica APO-Summicron-M 90mm f/2, are diffraction-limited and the optimal aperture is in fact wide-open.
4) Many of the compact rangefinders of the 70s to 80s like the Canonet had a f/1.7 lens. Stabilization won’t compensate for motion blur, only lens shake.
5) The Foveon-powered Sigma DP2 has exceptional image quality. Sadly, the sluggish autofocus lets it down.

By: Collin Zeng

Collin Zeng — Wed, 13 Oct 2010 01:23:56 +0000

1) Photo absorption can be improved with better microlens design.

Canon upped the MP count on one of their DSLRs by 2 but got away without shrinking each photosite by a significant amount by making the microlens gapless – the entire sensor is covered in microlens with no gaps.

2) Older cameras with lower megapixel counts aren’t worth it. Newer cameras that are targeted at enthusiast are much much better because older sensors are inherently nosier. The D90 is a stop better than the D80, despite the two extra megapixels. New enthusiast cameras under 400 worth a look include the Canon S90/S95, Panasonic LX3/LX5, the Canon G11/G12, and the Samsung TL500. The Nikon P7k should also be considered, but it does have a laundry list of problems people have been reporting related to the lens mechanism.

3) As for cameras with fast apertures – fast apertures are a double-edged sword.

Lens generally don’t perform their best at their max apertures. Nonetheless, having f/2.8 can be useful for shots that otherwise would have been ruined entirely by noise and blur (due to camera shake, not lens softness).

E.g. the Panasonic m4/3rds 20mm f/1.7 is terrible wide open in terms of vignetting. Probably don’t want to use it during the day – looks like storm clouds are closing in from each corner of the frame!!

But f/1.7 is more useful in the dark, where further darkening of the corners probably won’t be noticed as much.

4) Sure, lens today are slower than the lens on compacts of yesteryear. But are they that much slower? Today, the slowest lens I could find start at f/3.5. Yesteryear all lens used to start at f/2.8 if not faster.

F/3.5 is 2/3rds of a stop slower than 2.8. But the availability of image stabilization on nearly every camera now provides 2-3 stops if not more of correction.

My Kodak DX7590 with its 10x zoom and impressively fast f/2.8-3.7 lens doesn’t have IS. I often get blurry shots, even with the lens wide open at f/2.8 below 1/8th of a second. IS would help tremendously.

5) Fujifilm and other manufactures may use clever loopholes to exploit the minds of consumers. I don’t blame them as a Fuji SuperCCD camera will trump all other compacts. So will a Foveon camera.

By: Howard Phillips

Howard Phillips — Fri, 04 Jun 2010 09:44:10 +0000

Thank you for these updates. It is very hard to wade through the swamps of misinformation out there to find just a few truffles of wisdom and good sense.