To IBIS or not to IBIS, that is the question


It’s been a while since I’ve put a photography related post here, but having been mulling over an upgrade to my ageing Lumix GH1 for the past few weeks, I thought it might be worthwhile explaining my rationale for not shifting my allegiance to Olympus, sticking with Panasonic, and deciding to pull the trigger on a GX1.

The micro four thirds format is still in its’ relative infancy, and it is only really in this last year or so that we have started to see interesting developments in the way of native and third-party lenses. The fast 12-35 f/2.8 zoom from Panasonic is starting to ship now, along with a 35-100 f/2.8 expected later in the year, while Olympus have some interesting large aperture primes (45mm and 75mm) either available now or shipping soon. One of the nice things about the mirrorless format is that with the correct adaptors, you can fit virtually any old lens to the front of your camera body. I personally have had a lot of fun experimenting with various older Canon FD-mount lenses on my GH1, but in all honesty, I prefer at least having the option of autofocus. It’s wrong, I know, but I’ve said it now…

Everybody is entitled to their own opinions when it comes to design and styling, and many will have staunch brand allegiances, although this is neither the time nor the place for a Canon vs Nikon debate. There will of course always be the “in vogue” camera of the moment too – I’m thinking of you OM-D E-M5 – and the latest greatest feature or art filter that you simply must have. However, if we can cast all personal preferences, fashion and marketing fluff aside for the moment, there is one key difference between the micro four thirds cameras offered by Panasonic and Olympus which might well affect your next purchasing decision (and indeed mine), and that’s how each manufacturer implements image stabilisation.

Panasonic have opted for ‘in lens’ Optical Image Stabilisation (OIS) stabilisation, whilst Olympus have chosen to go down the route of In Body Image Stabilisation (IBIS). Not understanding the fundamental differences between OIS and IBIS might perhaps cloud your judgement and prohibit you from making a sensible, informed choice over which is better for you (or your wallet), but even more importantly, understanding that you don’t actually need either form of image stabilisation will I hope help you with your next purchase!

Modern cameras like the GX1 and E-M5 are clever bits of kit that allow you to be an extremely lazy photographer who simply points the camera in the right direction, frames the shot and clicks the shutter button, leaving the computer inside the camera to automatically work out the correct exposure. I know someone who takes photographs in this way and frequently ends up with blurry pictures, which brings me nicely to the reasons why image stabilisation might not be as big of a deal as you thought.

The very first lessons I learned about taking good pictures – and by that I mean sharp, un-blurry pictures with the subject in focus – was to have good technique (i.e. to hold the camera steady with the lens supported in my left hand, elbow in), and to remember the simple rule that to avoid hand shake, you need to shoot with a shutter speed of at least 1/focal length (in 35mm terms).

My first camera was a Canon EOS film camera with standard kit lens, which I bought to ensure I had beautiful photographs of our soon to be born at the time first child. The camera did a very good job of calculating exposure such that the shutter speed was at least 1/60th of a second – which I read was the slowest practical speed that avoided problems of hand shake and human subject movement – but it became clear as our daughter grew and started moving about that 1/60s was completely inadequate when it came to freezing a moving subject… kids can move fast!

Without going into the nitty-gritty of exactly how stabilisation works, it essentially allows you to shoot 2 stops slower – sometimes more – than the aforementioned shutter speed = 1/focal length rule of thumb. That’s all well and good if you only shoot static subjects, but when the subject is moving, well you’re probably going to have to increase the shutter speed way beyond the point where the stabilisation is effective anyway. So what’s the point?!

Of course my point is that image stabilisation is both completely unnecessary and extremely valuable at the same time. It will let you hand-hold wide angle shots at ridiculously slow shutter speeds, which might well be extremely useful if shooting landscapes or architecture and don’t want to resort to, God forbid, the use of a tripod! Equally, that 300mm zoom lens in your bag could yield sharp hand-held results at 1/80s and maybe even slower (as long as you’ve not been overdosing on the caffeine). A slow shutter speed may not always be the right choice, but sometimes a slower than appropriate shutter speed is necessary, either because of the shooting conditions, the relative slowness of your lenses, the poor high-ISO performance of your camera or indeed a combination of all three.

Ordinarily, one would expect optically stabilised lenses to offer improved stabilisation performance over in-body stabilisation at the expense of, well, expense! At least that’s the theory – in micro-four-thirds telephoto land, you’ve only really got the choice between the Panasonic 100-300mm (with OIS) and Olympus 75-300mm (non-stabilised) lenses, and guess what, the Panasonic lens is actually less expensive (and I have read optically superior too).

Having in-body stabilisation of course means you’ll be able to shoot hand-held at slower shutter speeds with whichever glass you choose to affix to the front of your Olympus body – great if you’re using older manual focus lenses – and indeed the latest IBIS on offer in the new OM-D E-M5 is apparently superb.

So if you’re shooting static subjects, don’t want to carry a tripod, need to shoot in low light situations, or don’t have particularly steady hands, then image stabilisation is going to be a very useful feature to have. In-lens or in-body? At the end of the day, it doesn’t really matter – just remember that whether you chose OIS or IBIS, it won’t necessarily stop you getting blurry pictures. The only cure for that is to stop being a lazy photographer, think about what you’re pointing your camera at, and check that shutter speed before you click. Simples!

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