Olympus OM Lenses on Four Thirds Cameras.

There are so many question comes up in the photography forums.
#Can you use OM system 'Legacy' lenses on the 4/3 system camera?
#Must i purchase the expensive Olympus MF-1 adapter ?
Also is it true that Olympus does not recommended using OM system lenses on 4/3 system for e.g in my case I'm using Olympus E620 DSLR.

This image taken with Olympus E620 using Zuiko OM lens 50mm f1.8

I started to use OM lenses in my 4/3 system camera for the past few weeks ago and I bought an inexpensive adapter (third party brand).The adapter is well constructed and its work very well with my DSLR and with my OM lenses.

The Cobbler shoot with 50mm f1.8 OM lens

I read about the MF-1 adapter which is nicely constructed and quality, but I feel it is too much to pay for an adapter that gives no different results from an inexpensive one. After all, it is just a hunk of finely machined metal. Most adapters will allow the lens to focus past infinity. This is to ensure that you can focus to infinity, given the slight variations in adapters and lenses. In practice, it means for a given lens, you may have to focus to infinity and then back up a little bit to bring distant objects (infinity) back into focus. I do not find this objectionable with my lenses.

 Olympus recommended not using most OM lenses because they consider their performance substandard compared to designed for digital lenses. You may experience some exposure variation with lenses under f/2.8 and blooming wide open.

 Here's what you need to know to get started using legacy OM-system lenses. You will need to focus manually and use stopped down metering. Legacy glass requires using aperture priority. None of the automatic exposure modes on your E-system camera will work with lenses mounted through an adapter. All the other modes require the camera to make aperture adjustments. This is not really a drawback because the lenses work fine with aperture priority and you will likely be wanting to exercise creative control over aperture if you are shooting with old glass.

 Using your manual focus lens on the E-System camera requires stopped down metering.

• Set the camera to Aperture Priority mode.
• Open the aperture to its widest opening. (Turn the aperture ring on the lens to set aperture.)
• Turn the focus ring on the lens to focus.
• Close the aperture to the desired opening. (The camera will select the shutter speed for correct exposure.)
• Trip the shutter. 

Why do photographers use manual focus lenses when auto focus lenses are available? Creativity. They like to differentiate their work from others, explore new ways of making images, choose lenses with unique characteristics imparting special qualities to images. Nostalgia also plays a role for those who got their start in the film era, and curiosity for those who didn't. Sometimes they want a faster lens than is available with their kit zooms or is affordable. 
Have fun!.