Megapixel Mania
The photo equipment news of the week — actually, if you've been following the press and forums about it, of the month and maybe the year — is the arrival of the Sony NEX-7. Buzz, buzz, buzz, buzz all over the Internet. For the life of me, I can't figure out why. Is it all about the 24 megapixels? That's what it appears like to me. And I guess this is where I get stuck. I haven't the foggiest idea what I would do with all those pixels. A 6000 x 4000 array offers prints up to, what, 11x16" if you use 360ppi? If you squeeze down to 300ppi, you can make a 13x20" print. These are not huge, by any measure. I've been making image files that are much larger than 4000x6000 all year — doing a little stitching with my 12 megapixel cameras. I know, I know, stitching is not the same and has limitation, but that hasn't stopped me one bit.
I don't want this to seem like I'm ragging on the Sony NEX-7, because I'm not. It looks like a fine camera and I have no doubt that it will be a popular and productive model for both Sony and its consumers. Instead, I want to draw attention to the two competing trends, moving in opposite directions, that amuse me.
- Camera makers are pushing higher and higher pixel counts.
- Consumers are more and more using devices that don't need them.
An example: The ever-popular iPad has a display that is 1024x768. That a whopping 0.7 megapixels. If you want to make an iPad the final destination for your work (I suppose someone, somewhere might), then anything above a 0.7 megapixel camera is wasted — except maybe for cropping. Not too many of us see the iPad as the ultimate destination, however, because it's too small for many uses — a paltry 7.75x5.8" electronic "print." I'll round this to 5x7 for purposes of this photographic discussion. Pretty small for a final destination.
Well, let's say you want to exhibit your work on your 60" LCD television. That requires an image that is 1920x1080 pixels — and underwhelming 2 megapixels. Here again, anything more than 2 megapixels is wasted in this 29x52" electronic "print." I've never made a paper print even close to 29x52" and I never will. I will, however, show my work on a large monitor and can even see this as an important part of my photographic future.
I don't want to push this point too far because I don't want to appear silly, but as more and more people look at photographic images on some type of electronic screen, the need for ever-increasing megapixel cameras seems sillier and sillier. The need for all that resolution is tied only to our insistence that a photograph is a printed thing. Well, for many of us (me included) it is a printed thing — at least some of the time. Hence, more megapixels can make sense if you are a print-oriented photographer.
But, there is slightly more to this train of thought. What kind of print?
What if the ultimate destination for your work is a book, rather than a gallery wall? Look at some numbers. A very large book would be 12"x16". If an image was full bleed on that page, you ideally would need a digital file that was 4800x6400 (at 400ppi, so 24 megapixels) but could probably get by with 2/3 of that, say 3200x4200 pixels, about 13 megapixels. If book publishing is your medium of choice, the largest file you would ever need could be provided by a 12-16 megapixel camera. The largest!
What about a more normal sized art book — say in the range of 10x13" with images roughly 8x10"? In our imaginary normal-size art book, we would need (at 400ppi) image files of 3200x4000 — here again, covered nicely with a 12-16 megapixel camera. (By the way, how do most of you know most of the photography you can see in your mind's eye? The great masters of photography, that is. Isn't it though book publication? Just a thought.)
So, all this leads me to conclude that the only reason to lust after a 24 megapixel (or higher) camera is because you want to make giant wall art. Lots of you do and good for you. You'll need all the megapixels you can afford. If you have an Epson 9000 series printer and want to make 42x60" prints, you'll need 326 megapixels if you want to print at 360ppi without any upres interpolation. Good luck on that.
If you want to regularly make 13x20" prints for the wall, then I can understand the lure of the 24 megapixel camera. Makes perfect sense.
For the rest of us — web images, iPad presentations, large digital displays, book and magazine publication, folios, and even reasonable size 11x14" prints — any camera in the 12-16 megapixel range is all you need. In fact, what I've found is far more important is low-noise sensors and the quality of the lenses you can slap on the thing.
Knowing what it is that you want to produce and a bit of applied reverse engineering can lead you to the camera you need — rather than the camera the manufactures tell you that you need. For me and my needs, 24 megapixels is a waste, so no NEX-7 in my future.
