While focusing for stills and video, the lens mechanisms of both lenses are so quiet that you have to hold your ear up to the lens to hear the faint whirring of the motor.

So what’s inside the Panasonic lens to make it so much larger? Well, it has a more complex optical design with 14 elements in 10 groups compared to nine elements in eight groups on the Olympus. The more complex design of the Panasonic is in some part required for its macro capabilities and optical stabilization, but don’t forget the Olympus is optically brighter. In terms of build, the extra weight of the Panasonic lens inevitably lends it an air of greater confidence, but I having carried both for several months around the World I don’t believe it’s any stronger, and neither sport any kind of weather-sealing. The Olympus 45mm f1.8 M.ZUIKO Digital Lens is a short-telephoto prime designed for Micro Four Thirds compact system cameras. With its equivalent range of 90mm on a 35mm film camera and large f/1.8 aperture, the lens is ideal for a variety of applications, including portraiture, interior work, low-light shooting, and everyday snapshots. I am replacing my Pany 45-175 with this lens. I know both of different leagues, but even at pixel level this is so sharp, I better get objects (focused) cropped out of the image, besides I also got 100-300mm Pany. 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 pleasantlyin 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. Furthermore I didn't want to preempt the review, which will be based on much more extensive use and testing, so have made very few comments about IQ.To me, vignetting is desired in portraits, but nonetheless it doesn’t show up on this lens, probably due to the in-camera correction. The Olympus M.Zuiko 45mm f/1.8 is a lens that I never leave the house without. (No exaggeration; my everyday camera bag consists of an Olympus PEN E-P7, Olympus M.Zuiko 14-42mm Pancake, and an Olympus M.Zuiko 9mm Body Cap lens). It's an absolutely fantastic portrait lens that's also adept at day-to-day photography if you know how to use it. So while this is mainly one for the headshot hunters, it's more versatile than it seems –and if you want to try your hand at portraiture, it's such low price and great value that you can't really go wrong.

To sum it up – I find it very difficult to name a clear favourite. What matters most to me is the pure joy of taking pictures and I get that from both lenses. However, if I had to choose one of the two lenses at gunpoint, the price might be the deciding factor. Both lenses are vulnerable to flare and ghosting even though they feature a lens coating (Z Coating on the PRO lens and ZERO on the 45mm 1.8). It usually takes the form of a series of polygonal shapes or veiling flare, and occurs if you shoot directly into the sun. Flare with the M.Zuiko 45mm f/1.2 PRO (shot at f/2.8) Flare with the M.Zuiko 45mm f/1.8 (shot at f/5.6) Chromatic Aberration, Vignetting and DistortionFalloff of illumination towards the corners is very well controlled, especially so for a fast aperture lens. At f/1.8 the corners are only 0.76 stops darker than the image centre and visually uniform illumination is achieved at f/2.8. While it has an effective focal length of 90mm, this is still a 45mm optic –so you get the same depth of field as you would with a 45mm f/1.8 lens on a full frame camera (or, alternatively, you get the same effective depth as you would at 90mm f/3.6 –but note that this phenomenon only extends to depth of field; the lens still gathers f/1.8 of light, so you don't lose any transmission).

Tipping the scales at just over 115 grams and measuring only 46x56mm, the M.Zuiko Digital 45mm f/1.8 is a truly small and lightweight lens that fits easily in the palm of your hand.In the past I never used lenses pouches with my larger lenses, but with these smaller rangefinder like lenses, I put all my lenses into pouches before they go into my bag. This is one disappointment I have with Olympus which Panasonic is one step ahead with even their Leica lenses. Hood and Pouch should be included in the price of this.

The 42.5mm f1.7 defends itself quite well against its big sister, the Nocticron 42.5mm f/1.2, although the latter has more sharpness. I often heard that wide-angle lenses have trouble delivering sharp images all the way to the very edges. With the M.Zuiko 17mm, I barely notice that, apart from really deep zooms while editing. But to be honest, I am not a pixel-counter. My philosophy is that it is much more important a picture is coherent in terms of content and design than technically perfect. A nice but purely cosmetic touch is the ability to choose the colour of the foremost part of the lens housing to match the colour of the host body. Equally cosmetic is what Olympus calls a metal-like exterior design. The previously-reviewed 12mm has a genuinely metal-bodied construction but the 45mm is merely matched for appearance. Similarly, there are no distance and depth-of-field markings on the 45mm lens. Sample images Of course, the 45mm f/1.8 isn’t without its merits. Because it is so small and light, it is much easier to transport and can suit any Micro Four Thirds body in the range. It is also four times cheaper than the PRO lens, so unless you regularly shoot portraits and require the best quality Olympus has to offer, it (or its sibling within the Panasonic Lumix range) may prove a more tempting proposition.Also related to the f/1.2 aperture is the fact that you can work in very low light conditions without worrying about excessively high ISO values or low shutter speeds. This isn’t to say that f/1.8 is unacceptable for low light work but f/1.2 certainly does provide some added latitude in these situations. 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). While photographing the Cor Meibion Bro Dysynni‘s 50th Anniversary Party, for example, I used the 45mm PRO at f/1.2 for most of the evening, which allowed me to maintain a shutter speed of 1/100 to reduce motion blur and set the Auto ISO to a maximum of 1600. The optimal sharpness wide open makes it the perfect choice for an entire evening of shooting at f/1.2 and the extra stop also helps you isolate your subject better when shooting at a longer distance. E-M1, 1/100, f/1.2, ISO 800 – M.Zuiko 45mm PRO E-M1, 1/100, f/1.2, ISO 640 – M.Zuiko 45mm PRO E-M1, 1/100, f/1.2, ISO 250 – M.Zuiko 45mm PRO