The Myth of Maximum Megapixels

[Suhit Gupta]

<div class='os_post_top_link'><a href='http://www.computerworld.com/action/article.do?command=viewArticleBasic&taxonomyName=mobile_wireless&articleId=9005180&taxonomyId=15&intsrc=kc_feat' target='_blank'>http://www.computerworld.com/action/article.do?command=viewArticleBasic&taxonomyName=mobile_wireless&articleId=9005180&taxonomyId=15&intsrc=kc_feat</a><br /><br /></div><i>"Camera vendors and consumer electronics retailers sell digital cameras as if the pixel count -- the number of pixels a camera's electronics can capture -- is the most important measure of quality. I'm here to tell you that pixel count has become unimportant almost to the point of irrelevance. Megapixels don't matter anymore. Ten years ago, consumer-level digital cameras weren't capable of taking good pictures. The optics were lousy, the electronics were unsophisticated, and the settings were relatively limited. Buying a better camera back then meant spending big bucks for a 2-megapixel model rather than, say, a 1.3-megapixel one. As overall digital camera quality rose, so did pixel counts. Then, a couple of years ago, the industry silently passed an invisible milestone: Affordable consumer cameras reached, then exceeded, the number of pixels nonprofessional photographers could practically use. The current standard is just over 10 megapixels. In an effort to convince you that your camera is obsolete and you need to buy a new one, camera vendors keep harping on the more-megapixels-are-better myth."</i><br /><br />I 100% agree with Mike Elgan, author of this article. Gone are the days when megapixels really did matter, nowadays you have to look at all the supporting machinery and optics when buying the camera. Even the styling matters more. My girlfriend and I were recently contemplating a new point-and-shoot for her and the choice was between a Canon 10MP and a Fujitsu 6MP. The Fujitsu offered the better optics, the better control, the better shots under extreme ISO settings, etc. and this is why I recommended the Fujitsu to her. So note to everyone: megapixels are not only not the most important feature in a camera anymore, they may be one of the least important.

[cameron]

He also missed what, in my mind, is the most important negative of more megapixels - noise.

As you cram more pixels into a constant space, the amount of noise that you capture increases. Now, advances in image processing have blessed us with imaging chips that in many cases do a fantastic job of reducing noise, but it's still a concern.

What the average consumer forgets/doesn't know is that they will never use those pixels. Whether you are printing on an at-home printer or sending files off to a lab, you generally don't need more than 200 pixels/inch (I typically size to 240ppi). As hardly anyone will print their pictures greater than 8x10, this means you need 1600x2000 pixels, or 3.2 megapixels! Anything above and beyond this, for the average joe six pack, is overkill - which he has to pay for in the form of cash and the other reduced performance issues Mike mentions in his article (processing time, size, etc.).

Now obviously if you are going to blow up bigger than that you need to start thinking about how you are going to do that and still maintain image quality, but that problem exists whether you have 3 or 10 megapixels (using 200ppi, 10 doesn't get you to a 16x20, which would require 12 megapixels).

[Janak Parekh]

Suhit, the one thing I will say, though, is that Fujis have that lousy xD. I'd much rather hunt for a Canon 6MP than either of your two choices. ;)

--janak

[Vincent Ferrari]

Well Cameron... I just happen to have a handy dandy wall-chart next to me. Adorama, a place every photographer in New York knows, has a pixel dimension guidelines sheet. Looking at it right, now they say 3000 x 2400 for an 8x10 at 300dpi.

I'm not saying you're wrong here, but if they'll print a picture at 300dpi, I'm going to give them as much data as possible to do it. Every little bit helps, so to a degree, the "more megapixels doesn't help" thing doesn't hold up. It does help. It gives labs more to print with and it gives you more flexibility in cropping a picture. You could make an 8 x 10 out of a crop if you have enough megapixels to make it look decent.

Now granted, for the average person, that means nothing, and they print every picture at 4 x 6 on glossy paper at Wal-Mart. For some people that want to grow, though, it's unfair to say they don't "need" the power. "Need" may be the wrong word, but everyone can benefit.

One thing Elgan is right about, though, is that measurebators don't have a leg to stand on anymore. It isn't just about the number of pixels anymore, and as Suhit noted, there's a hell of a lot more to a good camera than the number of megapixels it runs.

We just went through this with MegaHertz also, didn't we? I mean, my 1.83 Core Duo iMac and my 2.0 Core Duo MacBook smoke my old Winders PC which was running at almost 3 Gigahertz.

It ain't just about the numbers anymore, folks. They're only useful when combined with other specs.

[cameron]

Well Cameron... I just happen to have a handy dandy wall-chart next to me. Adorama, a place every photographer in New York knows, has a pixel dimension guidelines sheet. Looking at it right, now they say 3000 x 2400 for an 8x10 at 300dpi.

Hm...

A camera store telling you that you need more megapixels? Why in the world would they do that??

I'm a B&amp;H guy myself - make it a point to go there everytime I'm in NY (was there on Monday and Tuesday this last week, spent way too much money).

You mean PPI, right? DPI is fundamentally different.

let's say their right and I'm wrong - in that case we've gone from 99% of people buying digital cameras needing 6mp, not the 3 I suggested earlier. Still means they are paying too much.

I have some shots that I've taken to 20x30 from files from a 300D - that's roughly a resolution of 100ppi off a 6mp sensor. You can't do this with every picture, but the 3 I typically take to this size come out just fine.

I love the term measurbator - It truly reflects the attitude on most photography forums at this point.

[Vincent Ferrari]

They're not telling you that you need more to sell you more. In fact, in all my dealings with them, they've never upsold me one time (although I admit I do much more business with B&amp;H and just use Adorama for prints and used equipment).

Yeah, I did mean PPI, not DPI. *sigh* That's what happens when you try to write a thoughtful post on a forum AND your novel at the same time.

I just think the more pixels you can push, the better. If you're the "all I need is a polaroid or a disposable type" which I imagine most people probably are, then even a digital camera is overkill. Hell my mother in law refuses to even look at a digicam and buys $20 k-mart film cameras or disposables, so I guess what you call overkill is relative. Me? I prefer my Rebel XT to any camera I've used for it's size and the huge variety of lenses out there.

For most people, though, my camera would be like swatting a mosquito with a sheet of plywood. Even though it's a prosumer camera, it's not one that most consumers would have any interest in.

[Jason Dunn]

I definitely agree that megapixels matter less and less now, unless you're a crappy photographer and need 6 megapixels extra to crop from. ;-)

I just bought the Canon SD800, and picked it over the higher-megapixel SD900, because the SD800 had better all around features...and I sure don't need 10MP in a point and shoot. Though I would have loved the higher resolution video...I think 640 x 480 videos are "ok", but I won't be really happy until I can shoot 720P...which I know it going to take a long time. ;-)

[Jason Dunn]

You mean PPI, right? DPI is fundamentally different.

How are they different? I always thought that PPI was the measurement in the digital world, and DPI was the measurement in the physical world. They're both about how many pixels are spread out over how much space, resulting in "x" quality.

[Phoenix]

I agree that MP's aren't so important anymore - certainly not at this point. We have more than enough in cameras as it is. Now although the Casio Z1000 takes 10mp shots - I do like the output; it's one of the best PAS's out there, but 10mp needs to be the limit. However, now I heard Sharp developed a 1/1.7" 12mp sensor for PAS's!

I say "Enough already!!!"

Enough with the MP's! Let's focus on better optics and better zoom. Please!

I'm not buying another camera with more MP's. 10mp is it for me. Camera manufacturers need to get the message. If all they do is continue to bump up the MP's and don't do anything bold with the sensors by increasing their size sufficiently (not just by some dinky little increment), and with the optics by integrating better glass and better zoom along with optical IS (not electronic IS), and with the firmware by gracing their cameras with alien-like technology ( :lol: OK, but you know what I mean), then I simply won't buy another camera. Period. Because otherwise, what's the point?

Do they think we're wallpapering our homes with our prints? :P


At any rate, the simplest way I combat noise is to remember that PAS's are not low light cameras; I don't care what brand or model you have. It's about knowing the limitations that all PAS's share, and then adapting. I know it's not always possible, but take photos with a lot of natural light and keep your camera locked at the lowest ISO as often as you can, and with a little bit of photographic knowledge and skill, your shots will look great.

[jeffd]

I knew Mpixles didn't matter when my 2MP A40 was taking better pictures then most 4mp cameras at the time. ;) Even now I have little "drive" to replace my A40 powershot. Id really like to get one of the 12x canon IS cameras for that awesome zoom, but for now the A40 takes great pictures so no need to replace it yet.

Though I would like to find a phone that has a really good quality camera (doesn't need any major lens features, but 2mp would be nice and great quality is a must).

[Lee Yuan Sheng]

How are they different? I always thought that PPI was the measurement in the digital world, and DPI was the measurement in the physical world. They're both about how many pixels are spread out over how much space, resulting in "x" quality.

The difference is going to be quite subtle, but it is there.

Let's use cameron's example: Printing a photo at 200 PPI with dimensions of 8x10 means you're using 1600x2000 pixels of information in the image file to send to print, say to a nice Epson printer.

Now, in our example, what the Epson printer will do is to print that file at 1440 DPI, but since it is a one of those nice 6 colour inkjet printers, each 6 dots of colour from its nozzles will be used to produce 1 pixel of colour information. The end result meaning that your 1440 DPI Epson printer is capable of resolving 240 PPI of image information. Cramming more pixels is going to show diminishing returns after that.

Hence, if you're describing image sizes via pixels, use PPI. Using DPI isn't quite so accurate, since 1 pixel is likely to be composed via more than 1 DPI on the physical printout.

PS. Yes, cameron's example will not maximise the printer's capabilities, but depending on the original file, it can be enough.

PPS. Yes, I know that the new printers advertise some crazy DPI numbers which will correspdond to very high PPI numbers, however many are interpolated numbers. In general 240 PPI is the spec Epson has told photographers, and with good reason too!

[cameron]

To expand a bit - think about how much information is in a pixel versus a dot.

On your computer/camera/etc. a pixel is going to contain anywhere from 24 to 48 bits of color - millions and millions of color choice in each pixel.

On a printer, each dot also represents one color, although the number of colors is greatly decreased. How many inks does your printer have? 3, 4, 9, 11? Even if it had 100 its not capable of reproducing every color in one pixel per dot. It then takes multiple dots to represent the color in each pixel.

I think we're all saying the same thing though - that the focus on megapixels is completely wrong at this point. I shouldn't be complaining about it though - because the more cameras the average guy buys the more that lets the camera manufacturers recover their costs that much quicker, theoretically resulting in lower prices for the rest of us.

[mjmccoy64]

I started with a 2.3mp Fuji. Moved up to a 5.1mp Kodak and now have a Canon Digital Rebel. Every move up has been more megapixels. Better pictures, more control and more options. But where does it all end? How far do we really need to go to get great prints?

[Vincent Ferrari]

I believe the general consensus on "enough" would be the equivalent of film, which, as I understand it, is around 25 megapixels.

Maybe at that point, it'll stop. :roll:

I want these things when I buy a new camera:

1. Higher resolution photos (more cropping control)
2. Less noise.
3. More accurate colors.

I need those three things to buy a camera. Megapixels alone are not the issue anymore. If you'll notice, cameras are touting their ISO now because ISO correlates to low-light which is the one area consumer cams really suck in.

[Phoenix]

I believe the general consensus on "enough" would be the equivalent of film, which, as I understand it, is around 25 megapixels.

I remember years ago, reading an article by John Dvorak. When he set out to find just what the true film equivalent was, a group of engineers (who specialized in this field) told him it was 8mp.

Unless there's new info to suggest otherwise.

What is the true equivalent?

[Lee Yuan Sheng]

I remember years ago, reading an article by John Dvorak. When he set out to find just what the true film equivalent was, a group of engineers (who specialized in this field) told him it was 8mp.

Unless there's new info to suggest otherwise.

What is the true equivalent?

There... isn't really one. :P

To elaborate again: different emulsions will have different resolving power and, also depending on personal taste, certain limits on enlarging.

I believe a fair number of photographers feel that 6mp SLRs are already better than most ISO400 colour print film. I think they might have a tad less resolving power than say, Fuji Velvia, in an actual scene with medium to low contrast details (as opposed to say, silly resolution charts), but the difference in grain and noise structure might lead well to better enlarging.

With black and white film it is a totally different matter. A film like Kodak Technical Pan still might be able to outresolve a true digital black and white, but it is even more hassle than processing RAW files.

In short, there's no real simple one numerical answer, but at this current stage I think most DSLRs are better than film already for most purposes. The versatility even in shooting JPEGs far outstrip what you can get with most colour film, and the current double digit megapixel DSLRs likely have more resolution than most amatuers can need. How often do you all do 20x30 prints?