The recent spate of lens and camera releases has given me the chance to spend some time with the Olympus M.Zuiko Digital ED 45mm F1.8 'Family Portrait' lens.

We've been asking manufacturers to make a proper portrait lens for as long as we can remember. APS-C may have become the de-facto standard sensor size, making up the majority of interchangeable camera sales, but you'd never know it to look at the lens ranges current available from most camera makers. There are very few prime lenses specifically intended for APS-C and fewer still that offer the classic combination of large aperture and the circa 100mm equivalent focal length that film users used to enjoy (though some people use 85s or less perfectly, 50s to give something around 135/85mm equivalent on APS-C).

So we were understandably delighted when Olympus announced a lens that fitted this definition almost perfectly. And still more encouraged when we discovered they were asking a fairly sensible amount of money for it. It doesn't have the 12mm F2's beautiful all-metal build and clever manual focus engineering but we'd much prefer a price tag that will see it end up in more people's kit bags.

What about the faithful 50s?

All my film shooting was done with slow-ish kit zooms so my first real experience of playing with depth-of-field came with a 50mm F1.8 on APS-C. It's a fun combination and one of the only really affordable ways to play around with the low-light and shallow depth of field capabilities of your first DSLR (it's no surprise that cheap 50s are sometimes seen as 'gateway' lenses, leading to addictive fast-glass buying habits).

Ultimately, though, it's not a focal length I enjoy shooting. Subsequent experience has led me to prefer a 35/40mm equiv. for all-round shooting (and sacrifice some of that depth-of-field control at sensible working distances), and yearn for something a touch longer for shooting people. There are 60mm F2.8 Macros, of course, but they're optimised for quite a different purpose and their list prices are often $600 or more.

Using the 45mm

There's always a risk of disappointment when you finally get the thing you've been hoping for, but I haven't found that to be a problem with the 45mm. The PEN Mini isn't the obvious body to mount it on - a model with little direct control, aimed squarely at a demographic that tends not to buy additional lenses - but it's still an Olympus, so buried away in there somewhere are all the customization options in the world. A few minutes spent enabling the Super Control Panel and toning down the noise reduction and sharpening left me with a seriously compact combination set up to produce very likeable JPEGs.

The lens looks nice on the Mini but it makes more sense, visually, sitting flush to the body of an E-P3, rather than out on a protruding mount (mounting it on the Panasonic GF1, meanwhile, emphasises the retro design cues of both to give a combination with serious camera-geek appeal).

Just because it's promoted as a portrait lens doesn't mean you have to use it as one

In use the 45mm is an absolute pleasure. Its autofocus is extremely swift - at least as fast as any DSLR/50mm combination I can think of. Critical focus fine-tuning isn't quite as immediate as using an optical viewfinder and a lens with manual focus override, but the PEN Mini is intelligent enough to magnify the selected focus point if you turn focus ring. This 10x magnified view gives better precision than an APS-C viewfinder affords. And, of course, the Mini's choice of 35 AF points and Face Detection gives more control over AF positioning than most DSLRs allow.

But what about the pictures?

Obviously it doesn't matter how a lens feels to use if the image quality is indifferent. From a technical point of view, I've been more than happy with the results I've been getting from the 45. Even at F1.8 it is sharp enough to give plenty of detail in subjects' eyes. Just as importantly, at sensible working distances, it gives a usefully shallow depth of field on the Four Thirds format and renders out-of-focus regions rather pleasantly in the samples I've shot so far. Obviously all this will be covered in more detail in the forthcoming lens review but the noises coming from the testing studio are similarly positive.

And, beyond the pixel-peeping potential, I've been really pleased with the results from a creative perspective. I found I liked the shallowness I was getting at F1.8 for head-and-shoulder shots, and can more easily imagine myself wanting to stop down a little than wish the lens was faster. Just as I said that 50mm F1.8s often turn out to be the key to unlocking the creative potential of APS-C DSLRs, I feel the 45mm/1.8 is likely to do the same for Micro Four Thirds users. And, just because it's touted as a portrait lens doesn't mean it can't be used for other things - a moderate telephoto isn't a bad lens to have to hand.

Sometimes shooting with a new focal length can be a challenge - getting used to 'seeing' the photographic opportunities in front of you - but having a proper portrait lens has been genuinely reinvigorating. I wouldn't claim to have suddenly become a great (or even particularly good) portrait photographer but spending a couple of weeks shooting with the 45mm has helped me enjoy photography (and the results I'm getting), more than in a long time. Definitely worth the wait.

Click here to see our 45mm F1.8 preview samples gallery