Have you ever noticed that in the days of film cameras zoom lenses become popular late in the time? What did photographers use until that period of high performance lenses?
They used primes, so how many did they use? Often not more than three. And why just three? Because it works and it will still work in digital times. They used a wide angle lens a normal lens and a slight tele lens. So on a film body something like a 28mm or 35mm, a 50mm and something between 85 and 135mm.

If you have a look on the Sigma Art lenses you will find the 19mm (38mm on film), the 30mm (60mm on film) and a 60mm (120mm on film). All lenses have a constant aperture of f1:2.8 in terms of brightness this performs really well in terms of blur in the background you just have a 1:5.6 equivalent. On the 60mm this will give you still nice blur (Bokeh). You can get each of the lenses used between 100 and 150€. When you compare that with the Olympus 12-40mm f1:2.8 you spend about the half for a nice range. But honestly this Sigma trinity lacks on the wide end. 19mm is nice but compared to 12mm of the zoom it is long. What could you do to keep cost down? You could replace the 19mm with a Panasonic 14mm f1:2.5 you get extra reach and also some more light. Replacing it with the Olympus 12mm F1:2.0 or even the brand new Panasonic 12mm f1:1.4 will brake the bank.

28Well when I started in the m43 System some weeks ago I did some research wht lenses to buy and I found out that I won't start with the 12-60mm because I am used to shoot on my Pentax with prime lenses and like to keep that.
So my choice  is:
1. Panasonic 14mm f1:2.5 (28mm f1:5)
2. Panasonic Leica 25mm f1:1.4 (50mm f1:2.8)
4. Olympus 45mm f1.8 (90mm f1:3,6)
All lenses deliver grate image quality and a good value for money.

 Since tow years I have a DSLR system from Pentax. I tested a  lot of lenses and finally I found my trinity with the following lenses:
1. Pentax Limited 15mm f1:4 (22,5mm f1:6)
2. Pentax FA 35mm f1:2.0 (52,5mm f1:2,8)
3. Pentax FA 50mm f1:1.4 (75mm f1:2)

Normally everybody tells you that m43 lenses are much smaller than the APS-C equivalent. Well in the Pentax case that is not really an advantage and the reason why I shoot Pentax. The lenses are nearly equal in size. Honestly comparing the Pentax 15mm with the Panasonic 14mm is not fair. The better Pentax lens would be the 21mm but I sold this lens some weeks ago because the 20-40mm zoom lens from the Pentax limited series does the job well for me and I don't have a prime any more.

When writhing this I found out, that I prefer to take a 4th lens with me. The fourth lens is a special use lens. This lens is vary from what I shoot. On my Pentax system I have more opportunists than on my M43 system.
Pentax:
a.) 8mm Fish-Eye for landscapes or some special sport pictures
b.) DFA 50mm f1:2.8 MACRO for macros :)
c.) DA 70mm Limited for classic portraits

Micro four thirds
a.) 7,5mm Fish-Eye for landscapes (I really like that effect)
b.) Sigma  60mm f1:2.8mm Art lens for classic portraits
I really miss a macro lens on m43, but I could adapt the DFA50mm on the OM-D

Well, that is not from me, but Chelsea and Tony are doing a perfect job.
In fact this was inspiring me to give the micro four thirds system a try.
After about 4 weeks with this system I don't regret the decision to have a compact & light camera for hiking.
The main advantage over my previous Pentax Q7  is the availability of many lenses on the one side and of coerce the larger image sensor of the m43 system.

3 weeks ago a Olympus OM-D went in my camera bag. I decided to sell my loved Pentax Q and give the micro four thirds system a try.