I'm writing a short review for this great little macro lens. If you have any questions, feel free to post or mail me!
I have had this lens for quite a while, but seldom used it for some reason. That changed since I'm starting to share my equipment with my girlfriend. Of course, being the gentleman I am, she get's the best stuff (in the case of macro work, the 70-300mm) and I started to play around with the 35mm.
That said, I found the 35mm to be surprisingly good.
On the pro side, the lens is incredibly light and small.
Copied from the 4/3 website
Dimensions = φ71 x 53mm / φ2.80 x 2.09 in.
Weight = 165g / 5.8 oz.
In addition the lens features an image aspect ratio (don't know if this is the proper term) of 1:1, which would be 2:1 if compared to full frame models from canon and nikon. As a comparison, the famous ZD 50mm macro 2.0 has only 1:2 as well as the ZD 70-300mm.
This means a huge difference in practice.
On the con side, the 35mm has a very close focussing distance - and by close I mean close. You have to nearly touch your subject if you want those 1:1 pictures.
So, how does this lens work in practice?
Surprisingly good. Once you have mastered to sneak onto your subjects (most insects don't mind you getting on touch with them as long as you do no rash movements), the 35mm really shines. 35mm * 2 means that you need 1/70 s to make a photo without blur by shaking - even less with image stabilisation on. This is a huge advantage compared to the 70-300mm (which would have 1/600s - stabilisation) and a bit of an advantage against the sigma 105mm and 150mm. Taking macro shots often demands a closed aperture even beyond f8 and this means longer shots - the 35mm does well in this regard.
On the other hand, taking shots of bees and other fast flower changing insects is nearly impossible - you just can't follow them fast enough. In that regard, lenses with a longer working distance (like the 105mm and 150mm Sigma lenses) might be better, but are more expensive and, in the case of the 150mm, weight much more.
I think the ZD 35mm is a great lens and you won't get more lens for this money and this weight from any other manufacturer.
Check out the sample shot found in the lens gallery