20 August 2007

 

Megapixels are meaningless

That's right. If you have a camera with a sensor that captures more than 4 to 6 megapixels, you probably don't need them all, and would almost certainly benefit from spending the money on better optics or electronics. My Nikon D50 is a 6-megapixel DSLR, and I don't even always use it at maximum resolution.

Then again, there are people for whom spending $8000 USD on the new crazy crazy 21-megapixel (!) Canon EOS 1-Ds Mark III will be worthwhile. I just don't know any of them.

UPDATE: You should read the excellent discussion in the comments, as well as Ken Rockwell's very good articles about megapixels and the related controversial issue of sensor sizes.

LATER UPDATE: Hell has frozen over and Nikon has released a full frame DSLR, the new D3. It's smart enough to scale down its sensor resolution if you attach a DX-format non-full-frame lens, which is an interesting compromise. At full frame it only has a little over half the pixels of the Canon 1-Ds Mark III, but it also costs $5000 USD, a little over half the price. So does it reinforce my point? Hard to say. I didn't think I'd see Nikon do this, though.

Labels: , ,


# 9:22 AM

Comments:

That's only because I don't shoot Canon. Besides, my 39-megapixel digital back has been on backorder for the last 2 months.
# posted by Blogger Alastair : 20 August, 2007 09:44
 
I completely disagree. the higher the MP the bigger crop you can make on your original photo while maintaining your suggested 4mp resolution. Cropping ability means light and day between photographs. With the new 1Ds MarkIII you could essentially take one photograph, split it 4 ways and have 4 5mp photos which could each be printed 20x30 with very nice results.

I will admit that the average consumer needs nothing more than 4 or 5mp, the new 1Ds is hardly targeted at the average consumer.
# posted by Anonymous Randy A : 20 August, 2007 10:41
 
I agree with Randy - the higher resolution - provided that the quality is good - allows for cropping without resolution problems.
# posted by Anonymous Eric Grondorf : 20 August, 2007 10:58
 
I was being deliberately a bit provocative. But I think that most people don't crop very often or all that much, and that they don't make use of the 7 or 10 megapixels in their point and shoot cameras, considering the lenses and electronics that work with them.

Personally, I think I *could* find a use for a 21-megapixel image (or, more realistically, something like a 10 or 12-megapixel sensor), but even then only on rare occasions. I'd like to encourage people to look at something other than the megapixel rating when choosing a camera, particularly a point and shoot model.
# posted by Blogger Derek : 20 August, 2007 11:03
 
I should also note that Alastair above is one of the only people I know who might consider the 1-Ds Mark III, but he uses digital backs for his Hasselblads instead.

But just watch, I'll have a 32 MP camera in five years or something.
# posted by Blogger Derek : 20 August, 2007 11:05
 
For me, the biggest issue with this camera is storage - I already have 12GB of cards and for my 10MP Nikon it's a days' worth of shooting. Even compressed, a 21.1MP file is going to be HUGE - you'll burn through a TB or two in no time.

And as for megapixels, more is definitely not necessarily better - I think it would be a valid concern as to whether or not the Canon glass (as good as it is ) can adequately resolve ALL those pixels crammed on that little, tiny 24x36mm chip.
They were having enough trouble with wide-angle lenses on the 1DsII, which is only 16MP.
# posted by Blogger Alastair : 20 August, 2007 12:14
 
With the WFT-E2/E2A accessory, you can hook the 1-Ds Mark III up to any external USB storage, including a hard drive.

Of course the whole rig weighs as much as a small car, but since when did that stop anyone?
# posted by Blogger Derek : 20 August, 2007 12:57
 
How does this all work in not so much cropping but zooming in the event that your optical zoom is limited.
In theory, if you had an 8 MP camera, could you zoom 200% and maintain quality of a 4 MP camera?
I have a Canon A80 with 4 MP and (I think) 3 X's optical zoom and was thinking about a higher MP point and shoot camera just for the purpose of being able to zoom in on something that my zoom couldn't get close enough to without bulking myself up with a larger camera with lenses and such.
# posted by Anonymous Simon James : 20 August, 2007 13:03
 
Digital zoom is the same as cropping, so theoretically yes, but in general you should do cropping on the computer rather than in the camera -- I always disable digital zoom on cameras that have it. DSLRs don't at all, so I don't have to worry about that now.
# posted by Blogger Derek : 20 August, 2007 21:07
 
I'm with Derek on the zoom/crop thing. As well, cameras are designed to use the sensor they have, and when you start cropping or zooming in-camera, often the image quality suffers greatly.
You're much better off cropping after the fact and carefully sharpening.
# posted by Blogger Alastair : 21 August, 2007 08:48
 
I think that attention to exact focus is more important than the total number of pixels. The automatic focussing features on most digital cameras tend to take an "evaluative" approach to focussing (in a sense, an "averaging"). Being ever so slightly out of focus will swamp any advantage gained by a high pixel count. This is especially true of objects near, but not quite at infinity; it implies that a lens is capable of resolving very fine detail is needed to achieve the best any CCD can deliver. So, I tend to agree that optical quality has a large effect, at least equal to pixel count.
# posted by Blogger Karl : 21 August, 2007 10:39
 
Similar focus issues can arise at close distances too, especially at wide apertures. If you look at the full-size crop of a recent photo of mine, for instance, you'll see that the subject of the photo, the diamond, is slightly out of focus, even though the ring it's on is clearer.

The sort of focal precision you need at wide apertures like that is very difficult to achieve (I focused the shot manually, and still got it wrong), and having more pixels only magnifies the size of the error. Certainly there is a place for very high resolution images—check out these guys—but today, most people should be looking at almost anything except pixel count to decide which camera to buy.
# posted by Blogger Derek : 21 August, 2007 11:24
 
It is excellent to see you are on the mend Derek.

I would consider a DS Mk III, if not for a lack of money. I am semi-pro and think that the people who would want a camera like this would consider all of the options including good quality lens, etc.

I have noticed that no one has mentioned that with the increased pixels, a larger print size can also be obtained before pixalation comes into affect, which is better for some commercial work.

I think people need to be educated better for the digital camera world, for example composing the image correctly to start with rather than croping, although in some cases un avoidable. Things like the use of lenses, what makes a good lens.

Anyway, it probably just comes down to what you want to do with the camera.
# posted by Anonymous Nick Young : 21 August, 2007 13:39
 
Check the update to my original post to a couple of great articles by Ken Rockwell.
# posted by Blogger Derek : 21 August, 2007 15:23