The limitation of 6 megapixels

I am still waiting to hear back from the camera store about my E-M1 repair (what, me impatient? Never!). I am really hoping that it coincides with our upcoming trip to Christchurch to meet our new grandchild because a) it would be very convenient to pick it up then, and b) I really want a camera to photograph the new edition to our family! And to make matters worse (or better I guess, depending on how you care to look at it), my Panasonic Lumix 12-35mm f2.8 G lens has now arrived. Yay! Except I don't have a camera to try it out with. Aarrgghh!

Greymouth wharf from Cobden. Nikon D70 with Nikkor 18-55mm. f/8 @ 1/400th, ISO 200

In the meantime, though, I am still using my wife's Nikon D70. And I'm still enjoying shooting with it. I used the camera for a few years when I switched to digital in the mid 90s, so when I pick it up now a certain amount of muscle memory kicks in, and I find it very intuitive to use. Yes, there are a couple of things that 'annoy' me (exposure compensation +/- is flipped around from what I am used to now), but overall the shooting experience is still very enjoyable. And the images still hold-up, even at 6 megapixels. With one exception... cropping.

White Heron. D70 with 18-55mm. f/5.6 @ 1/640th, ISO 200

Most weekends, my wife and I like to go for at least an hours walk together. This usually involves taking a stroll through our local Cobden Lagoon - an estuary that is home to numerous bird life. If we are lucky, one of those birds will be a beautiful white heron.

I usually take my camera on these walks, on the off-chance that something catches my eye, and I'll wan't to take a photograph of it. Most of the time the camera stays draped over my shoulder (or carried in my hand) and I never use it. But sometimes I get lucky, and a white heron (or some other worthy subject) presents itself.

That's what happened last weekend on our walk. We spotted it from across the other side of the lagoon, and from where it was wading I could tell it was very close to a bridge that we would cross eventually. Actually, it's the same bridge from which I captured the image 'Swan River' from my last post.

As we made our way over to the other side of the lagoon, and approached the bridge, I spotted the Heron again - in almost exactly the same position as when we had first seen him. He had hardly moved at all. And because we were slightly elevated up on the bridge, he seemed not to really even notice that we were there. Or if he did, he didn't seem to mind. He was only about 15 meters from us, probably the closest I have ever managed to get to a heron. And would you believe it - all I had was a standard 18-55mm lens!

The smaller image of the white heron, seen above, is the uncropped image - as close as I was able to get with the full 55mm end of the lens. As you can see, even though this was the closest I have ever got, the bird is still relatively small in the frame.

The larger image is cropped from the original. And while the bird is now a bit more prominent, it's still not filling the frame! But this was as close as I could physically get. So I knew I would have to crop in on the image later if I was going to get anything even half-way decent.

And in doing so, we run up against the D70s limiting factor - the 6MP sensor if you need to crop heavily into your image.

Curious Horses. Nikon D70 with Nikkor 18-55mm. f/5.6 @ 1/1000th, ISO 200

Unfortunately, it didn't only happen once, but twice, on this particular walk. Heading home from the lagoon, we passed a paddock with some horses that I hadn't seen in there before. The lighter coloured horse especially caught my eye, and I went over to take a photo.

This scenario was even worse than the heron, since as you can see from the uncropped image at right, the horses were even further away from me, and they weren't that keen to get any closer!

So once again, I took the shot anyway - at the 55mm end of the lens (around an 80mm full-frame equivalent focal length) - knowing that I would have to crop out a lot of the image to feature my subject.

In both images, I've probably only kept around a third of the image, cropping out two-thirds. That's left me with file sizes of around 1MB - not great in terms of resolution. Enough for a sharp 5x7 print, but probably not much more.

Does that mean that the D70 is no good as a camera? No, of course it doesn't! If you don't crop the 6MP files, then you can easily print up to A3 sizes. But, if you do need to crop - heavily - then resolution (and print sizes) will suffer. Dat's a fac u'all.

Bus Barn. Nikon D70 with Nikkor 18-55mm. f/5.6 @ 1/1000th, ISO 200

So what to do? Well, if I was going to be shooting a lot with the D70 (I'm not), then I would invest in a zoom lens. Something like the Nikkor 75-300mm. Then I wouldn't have had any problem filling the frame with the heron, or the horses, and I wouldn't have had to crop-in later. Thereby taking advantage of all those 6 million wonderful pixels! Easy....

And to be honest, the same should be true no matter how many megapixels your camera has. Yes, it will be easier to do a super close crop of a bird from a 50 megapixel sensor and still be able to get a decent A4 print. But should you? There is a reason why bird, wildlife and sports photographers carry around those massive 600mm lenses with them (and newsflash, it's not just to look professional). They need to get as close to their subject as possible, and fill-the-frame so they don't have to crop later on. This gives them the absolute best IQ they can get. I'm sure there is certainly some cropping going on later in post. But they certainly don't all own 100 megapixel cameras and shoot with standard lenses, thinking that they'll just crop-in super tight later on! And neither should you or I. 

I'm not advocating that we all shoot with 6 megapixel cameras and resolution be damned! Of course not. But... we also probably don't need as many megapixels as we think we do either - and we certainly shouldn't be going out with the intention of cropping out two-thirds of every photo we shoot because we couldn't/didn't get close enough. Wildlife photographer's know they will be shooting nervous animals, from a long way off, so they invest in super telephoto lenses. Comes with the territory I'm afraid. 

I'm not a wildlife photographer, and never intend to be. I do know, however, that on the odd occassion, I will want to take a telephoto image or three. That's why the only lens I kept when I was selling all the others to get the 12-35mm f2.8, was my Lumix 45-150mm. A while that's not super-telephoto by any stretch, it does equate to 300mm focal length on a full-frame system. And boy, could I have used a 300mm lens last weekend when I was photographing a white heron and some horses. Maybe next time...