Olympus Zuiko 45mm focal length shoot-out

With both kit zooms and the 45mm f1.8, I've got this focal length covered with all 3 lenses. So should I have bothered with the 45mm f1.8 at all? Isn't it a bit redundant with the other two lenses in my bag? How good is it compared to the kit lens offerings? Couldn't I just use them instead when doing portraits? These are the questions I wanted answered when I nabbed my son Joshua to go out for an impromptu photo shoot to test all three lenses. What conclusions did I come too after looking at the images I took? Read on McDuff...

First up, the 12-50mm f3.5/6.3 kit zoom that I figure will be on my camera 80% of the time. The widest it can go at 45mm is f6, so not a great lens for blurry out-of-focus backgrounds (bokeh). Shooting the 45mm at f6 as well, it looks to be a little more contrasty, a lot sharper, and perhaps just a hair more blurry in the background. The 12-50mm at 45mm is ok, but the 45mm at the same f-stop is fractionally better. So even shooting at these large apertures, it might be worth swapping to the 45mm when I get to that end of the range on the kit lens? Having said that, the 12-50mm at 45mm isn't 'bad' - it's just ok.

Next up it's the turn of the 40-150mm f4/5.6 to go head-to-head with the 45mm at its widest opening of f4. Once again, the 45mm prime has a bit more contrast and 'pop', is sharper, and also has a creamier bokeh in the background even at the same f-stop. Same conclusion here as above - the 40-150mm is 'ok' wide open at the 45mm end, and sharpness is acceptable. But the 45mm prime is better (surprise, surprise).

What about the other focal lengths for the 40-150mm? Well, there's good news and bad news. The good news? If you can get decent separation between your subject and the background, then bokeh actually isn't too bad. You definitely get some 'pop' with portraits at 150mm wide open (f5.6), and the quality of the bokeh is actually quite decent and not too 'busy'. The bad news? Everything gets notably 'soft' wide open from 100mm onwards - so you probably want to stop down from wide-open to get a sharper image. Oh well, you win some you loose some :-)

Which brings us to the Olympus Zuiko 45mm f1.8 prime. Bokeh at f1.8 is gorgeous - and very nice at f2.8. Subject sharpness certainly increases when you open up to f2.8 or f4 (where it is excellent), but the great news with this lens is that wide open at f1.8 is very useable, and sharpness is very good. I wouldn't hesitate to use this lens at f1.8 if bokeh was my main concern, although f2 or f2.8 might be a decent compromise if subject sharpness and bokeh are equally important. For prints up to A3 I would shoot wide open all day. For anything bigger, stopping down to f2.8 might be advisable?

So can the kit lenses compete with the 45mm f1.8 prime lens and replace it as a portrait lens? Well, no, of course not. They are what they are - which is actually pretty decent for what you pay for them. But the 45mm f1.8 is several notches above, both in terms of sharpness and contrast, at the same apertures. And of course, it goes where the other two can not go - to wide open f1.8 bokehlichousness :-)

Luckily, the 45mm f1.8 stands out enough from the kit lenses that it's definitely worth having in my bag. Compared to the likes of the 12-40mm f2.8 though? Well, that's another story...