flawed megapixel experiment

NY Times tech columnist David Pogue tried to prove that 13mp does not
yield better results than 5mp, but in a flawed experiment. What was his
technique? He took a 13mp photo, then downsized it to 8mp and 5mp. He
printed all three on a 16x24 inch poster and had people try to figure
out which was which--they couldn't.

Pogue insists that his test is valid because he wanted to isolate
megapixel as the sole factor (rather than optics and electronics).
Anyways, read his article and see if you can convince him of his flawed
experiment.

http://pogue.blogs.nytimes.com/2006/...ogues-posts-2/

"Bucky" wrote in message
oups.com...
NY Times tech columnist David Pogue tried to prove that 13mp does not
yield better results than 5mp, but in a flawed experiment. What was his
technique? He took a 13mp photo, then downsized it to 8mp and 5mp. He
printed all three on a 16x24 inch poster and had people try to figure
out which was which--they couldn't.

Pogue insists that his test is valid because he wanted to isolate
megapixel as the sole factor (rather than optics and electronics).
Anyways, read his article and see if you can convince him of his flawed
experiment.

http://pogue.blogs.nytimes.com/2006/...ogues-posts-2/


Who says the experiment was flawed?

Rudy Benner wrote:
Who says the experiment was flawed?

Plenty of the comments on his blogs.

His article implied that a 5mp camera will produce an equivalent 16x24
inch print as a 13mp camera, so don't bother getting a 13mp camera.

When actually all that his experiment implied was that a 5mp image
downsized from a 13mp camera will produce an equivalent 16x24 inch
print as a 13mp image from the same camera. There's a big difference
between the 2 conclusions!

There are lots of factors to consider, but fundamentally I find that when
testing high pixel density sensor cameras, resolution is impressive at the
lowest ISO setting, but to keep noise under control at higher ISO settings
you will lose resolution. High pixel density sensors are less sensitive and
this reduces their dynamic range, so unless shooting conditions are ideal,
you will get poorer shadows and highlights, details that will show up in
large prints.

In comparisons I have done, comparing, say, ISO 800 with a 5-6MP DSLR with a
ISO 800 shot from 10MP DSLR (both similar APS class sensor sizes) will show
pretty similar resolving capability, but the 10MP cameras will be much
stronger at 100 or 200 ISO.

Ian

Digital Photography Now
http://dpnow.com

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"Bucky" wrote in message
ups.com...
Rudy Benner wrote:
Who says the experiment was flawed?

Plenty of the comments on his blogs.

His article implied that a 5mp camera will produce an equivalent 16x24
inch print as a 13mp camera, so don't bother getting a 13mp camera.

When actually all that his experiment implied was that a 5mp image
downsized from a 13mp camera will produce an equivalent 16x24 inch
print as a 13mp image from the same camera. There's a big difference
between the 2 conclusions!

Bucky wrote:
NY Times tech columnist David Pogue tried to prove that 13mp does not
yield better results than 5mp, but in a flawed experiment. What was his
technique? He took a 13mp photo, then downsized it to 8mp and 5mp. He
printed all three on a 16x24 inch poster and had people try to figure
out which was which--they couldn't.

Pogue insists that his test is valid because he wanted to isolate
megapixel as the sole factor (rather than optics and electronics).
Anyways, read his article and see if you can convince him of his flawed
experiment.

http://pogue.blogs.nytimes.com/2006/...ogues-posts-2/


It certainly justifies a narrower conclusion
than the one he draws - the NUMBER of pixels
needed for a print is lower than many people
think.

However, the number of pixel sensors in a camera
is part of a complex set of factors in the
information gathering capability of that camera.

So his larger conclusion is NOT justified.

In the current market, it strikes me
that P&S cameras *should* have a sensor
with around 5-6 Mpixels on a moderately
large sensor.

This would give "enough" resolution
(as per the article) but with improved
ISO sensitivity and/or noise.

BugBear

His article implied that a 5mp camera will produce an equivalent 16x24
inch print as a 13mp camera, so don't bother getting a 13mp camera.
It's this piece of logic where I see the flaw. Even if the prints obtained
by a 5mp camera are just as good as those produced by a 13mp, the latter
gives you more flexibility to crop and zoom in post processing.

Whether or not this is an advantage depends upon how you use your camera.
Many people won't ever do any post processing but, equally, many will.

So for some people it may indeed be true that there's no point getting 13mp
but it's an over generalisation to advise all users that it's not worth
while.

Having said that, I am firmly in the camp who believe megapixels are
overrated. Whilst they might be on my list of purchase criteria they
certainly wouldn't be near the top. For a long time I used a 2.1Mp camera.
It had a 10x stabilised optical zoom so I was nearly always able to frame my
shots exactly as I wanted and hardly ever did any retrospective cropping.
Never once did I yearn for extra megapixels.

The trouble with megapixels is that you can count them, so the marketing men
have latched onto this figure as a universal index of how good a camera is.
Unfortunately a large section of the buying public have swallowed this
concept hook line and sinker.

Recently I upgraded to a new camera because the old one was too bulky. My
latest purchase boasts 6mp - not a lot by moderns standards but more than
enough for my modest needs. I have recently discovered an unforseen
disadvantage of all those extra megapixels. With my old camera, all the
photos I wanted to keep in any one year fitted, conveniently, onto a single
CD. I therefore have a cupboard of CDs with labels such as "photos 2005"
etc. With my new camera they don't. It's too much hassle to have to split
the year up so suddenly I am in the market for a DVD recorder. Yet more
expense!

Keith

On 22 Nov 2006 00:04:19 -0800, Bucky wrote:
NY Times tech columnist David Pogue tried to prove that 13mp does not
yield better results than 5mp, but in a flawed experiment. What was his
technique? He took a 13mp photo, then downsized it to 8mp and 5mp. He
printed all three on a 16x24 inch poster and had people try to figure
out which was which--they couldn't.

Pogue insists that his test is valid because he wanted to isolate
megapixel as the sole factor (rather than optics and electronics).
Anyways, read his article and see if you can convince him of his flawed
experiment.

http://pogue.blogs.nytimes.com/2006/...ogues-posts-2/

I read that post, and a bunch of comments, yesterday. Did he ever get
around to saying what camera was used? If it was an DSLR, what lens?
You have to wonder whether his test photo was resolution-limited by the
optics rather than the sensor.

-dms

Bucky wrote:
NY Times tech columnist David Pogue tried to prove that 13mp does not
yield better results than 5mp, but in a flawed experiment. What was his
technique? He took a 13mp photo, then downsized it to 8mp and 5mp. He
printed all three on a 16x24 inch poster and had people try to figure
out which was which--they couldn't.

Pogue insists that his test is valid because he wanted to isolate
megapixel as the sole factor (rather than optics and electronics).
Anyways, read his article and see if you can convince him of his flawed
experiment.

http://pogue.blogs.nytimes.com/2006/...ogues-posts-2/

I have seen people do this before. Of course the flaw is that a 13mp
image down sized to 8 will be much sharper then an 8mp photo taken with
an 8 MP camera. Almost any digital camera image and be down sample to
about 70% to 75% of it starting pixels count and loose almost no
detail.

Problem number 2 is portraits tend to need far fewer pixels then
landscape photos, he should have done a scene with a lot more detail in
it.

Problem number 3 is we have no way to know how well focused the photo
was, did he use a f/1.4 lens wide open. The difference between 13 and
5 will not be huge when the 5 is a down sampling of the 13 but it
should be clearly visible, but only if the 13MP was sharp to begin
with.


Scott

"Daniel Silevitch" wrote in message
...
On 22 Nov 2006 00:04:19 -0800, Bucky wrote:
NY Times tech columnist David Pogue tried to prove that 13mp does not
yield better results than 5mp, but in a flawed experiment. What was his
technique? He took a 13mp photo, then downsized it to 8mp and 5mp. He
printed all three on a 16x24 inch poster and had people try to figure
out which was which--they couldn't.

Pogue insists that his test is valid because he wanted to isolate
megapixel as the sole factor (rather than optics and electronics).
Anyways, read his article and see if you can convince him of his flawed
experiment.

http://pogue.blogs.nytimes.com/2006/...ogues-posts-2/

I read that post, and a bunch of comments, yesterday. Did he ever get
around to saying what camera was used? If it was an DSLR, what lens?
You have to wonder whether his test photo was resolution-limited by the
optics rather than the sensor.

-dms

I doubt it. I recently resolution tested a 10MP Casio Exilim EX-Z1000
compact p&s and it out-resolved the ISO resolution test target at ISO 100.
At higher ISO the softening of the image to suppress noise did severely
compromise the resolving power though.

Ian

Digital Photography Now
http://dpnow.com

*** Extra 40MB of storage space on DPNow's free photo gallery until the end
of November, don't miss it while it's there! http://galleries.dpnow.com

Scott W wrote:
I have seen people do this before. Of course the flaw is that a 13mp
image down sized to 8 will be much sharper then an 8mp photo taken with
an 8 MP camera. Almost any digital camera image and be down sample to
about 70% to 75% of it starting pixels count and loose almost no
detail.

On a tangentially related point, has
anyone else noticed that recent TV
programs recorded in HD look better -
even on normal TV's ?

BugBear