Friday, April 18, 2014

Digital Zoom

DMC-LX5, GIMP G'MIC Kodachrome 64 Film Emulation
There are quite a few things that speak of "Spring" - like the first Robin, or Crocus flowers popping up through the dead grass, and through much of North America, Spring was long over-due this year. But nothing speaks of spring quite as much as a flock of sheep with new-born lambs. These pics were captured near Memramcook, NB from quite a long distance due to some surrounding flooded, soggy ground, not to mention that it was private property. This flock of sheep and their babies were well beyond the 3.8X Optical Zoom limits (or 90mm  Equivalent lens) of "the only camera I had with me" - and so I went with one of my Custom Settings, which includes having the Digital Zoom turned on. In fact, for most of these, I was near the limit of 20X Combined Zoom (480mm Equivalent when the 90mm Optical Zoom is combined with the Digital Zoom), and quite frankly, I was very impressed with the results. "Digital Zoom" is something that serious photographers don't talk about much, because it supposedly is something that runs contrary to good photography, to artificially go beyond the limits of what your lens can actually give you. A DSLR camera does not provide Digital Zoom - if you need to be shooting at 480mm Telephoto, then with a DSLR, you need to attach a Telephoto lens that will reach that far. And so, the Digital Zoom feature is something that is only found on fixed zoom lens compact cameras, such as the DMC-LX5.

I should explain what it is, and how it works - and this won't take very long. Digital Zoom is simply the imitation of a long Telephoto Zoom lens, accomplished within the camera by cropping down to the centre part of the image, and then enlarging it. It is exactly the same thing as opening any picture on your computer with photo editing software (like Photoshop Elements or GIMP), then cropping-off a lot of the picture, and enlarging what's left. I did make the comment above about how a DSLR doesn't provide it - well, this is one way of achieving it, even with a DSLR - simply crop and enlarge the picture using computer software (or an "App"). With a Compact Camera, Digital Zoom is simply the camera doing this crop-enlarge for you.

There is a huge disadvantage to it, which is why "serious photographers" won't even talk about it. The disadvantage is - you loose a lot of MegaPixels, which equates to loosing a lot of resolution. Simply put, you are cropping a lot of your resolution right into the digital dust bin. If this were film photography, it would be the very same thing as taking a pair of scissors and cutting away most of your print, and then re-enlarging what's left. Certainly it wouldn't look nearly as good as using a long Telephoto lens to have taken the original shot to begin with. I should also mention that smartphone cameras use nothing but Digital Zoom - their tiny lenses are not capable of any Optical Zoom.

But I must say, I am very impressed with the results I got with the Lumix DMC-LX5, even near the maximum limit of Digital Zoom, these pictures still look like they have plenty of resolution, even though by using it I've in fact reduced my camera's native 10 MegaPixels down to 2 MP. The camera is built with what Panasonic calls "Intelligent Digital Zoom" - and I really don't know what that means exactly, but somehow it allows the camera to retain a great deal of it's resolution even when zoomed to the max. I'm sure what really helps this along is that it has one helluva good lens, made by Leica.

I'll also say it again - don't be fooled by MegaPixels. It's a black art. you might wonder "the newest smartphones now have 16 MegaPixels, and here I am bragging up a camera that only has 10?" Even the LX5's successor, the LX7, also only has 10 MP. For the same reason that my "old" Canon EOS 5D DSLR only has 12.8 MegaPixels, I can get better quality photos from it than from a newer camera with 20 MP or more. I am certainly getting better pictures with the 5D than I was getting from the 18 MP EOS 7D (worst camera I've ever owned!). Panasonic is keeping the Pixel count down on this, their top of the line Compact for a good reason - "Pixel Density". The more Pixels (which are made up of Photo-Diode Arrays) that get crammed on a camera's image sensor, the less light each individual Pixel can handle, because each Photo-Diode has to be smaller, and crammed closer to the adjacent ones. In general, more MegaPixels = higher pixel density = lower image quality. The only thing you gain from having more MegaPixels is that you can make larger prints - and "only" 10 MP will print a 30"x20" no problem. Now, take this back to my digital-zoomed sheep - they look great on a computer screen, but as they've been cropped to only 2 MegaPixels, a more realistic maximum print size would be 5"x7".

Allow me just one more technical point, and then I'm through. Things are in fact changing for the better. Recall above what I said about newer smartphones having a lot more MegaPixels? This is an advantage, given that they can only do digital zoom - there's no optical zoom with a smartphone. If you do a 4X digital zoom with a 16 MP smartphone, you still have a reasonably healthy 4 MegaPixels. The new Nokia Lumia 1020 has 41 MegaPixels!!!  This is so they can accomplish digital zoom in a whole new way, and this is leading the way for the evolution of digital cameras. Nokia has come with a method of using this huge Pixel count in a way that provides great digital zooming, and at the same time combining Pixels into groupings to increase Pixel Depth - very ingenious! The idea of Digital Zoom now deserves conversation among even the most elitist of photographers, I would say. Having a huge Pixel Density like this only makes sense if the camera is designed to do the right thing with them, and it appears that Nokia has cracked the code and changed the game completely - bravo!
Yet, at the same time, HTC is sticking with only 4 MP, but on a much larger Sensor, and calling it "ultrapixels" - in Marketing babble, because of the phenomena I've referred to above.

Now enjoy the lamb, and remember the Lamb of God this Easter weekend!

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