Best lenses for Micro 4/3rds Mount

After the news that Blackmagic Design intended to release a micro 4/3rds mount version of their camera, I'm curious what wide-angle lens options this opens up for owner/operators.

As far as fast wide angle lenses, I'm aware of the SLR Magic 12mm lens, the Voigtlander 17mm, 21mm (announced), and 25mm. What lenses are you planning to use to fill out the wider side of this camera?

I have Samyang 24-35-85 f1.4 eos mount and a Takumar 50 f1.4 m42 mount. I am gonna using them with an EOS to MFT adapter.

I think Voigtlander's are too expensive than I planning to get a SLRmagic 12mm f1.6 (it's wider than I want but I don't have a better choice I think.)

And maybe later I would Like to buy a 70-200 f2.8 eos lens or a Porst 135mm f1.8 m42 mount to use with an adapter as well

I just bought the two voigtlanders(17.5 and the 25mm), I will go for sure for the 12mm SRL Magic. I have a 50mm but I'm not sure what will be the best 50mm(Not looking at the SRL Magic cine, is out of my budget).

So quick question to anyone, do the adaptors that you'll need to use to get all these lenses to work mean you'll end up with an even bigger crop factor? Also will you also suffer from a loss of light? Or is it only a case of you will some adaptors ad not with others depending on the mount conversion?

So quick question to anyone, do the adaptors that you'll need to use to get all these lenses to work mean you'll end up with an even bigger crop factor? Also will you also suffer from a loss of light? Or is it only a case of you will some adaptors ad not with others depending on the mount conversion?

Crop factor has nothing to do with the adaptor. It's based on the size of the actual sensor. So a 50mm Canon EOS lens will give you the same field of view as the 50mm SLRMagic MFT mount lens.

You'll only be able to use manual lenses, like the SLR Magic, Voitlander and Samyang, on the Blackmagic MFT camera. So any EOS lens will have no aperture control. There are no adaptors that will control the aperture as there are no electronic contacts on the Blackmagic MTF camera.

You can get adaptors that will let you control the apertur on Nikon G lenses tho because the aperture is mechanical.

You should have no light loss with an adaptor unless there is a lens in it to correct infinity focus. I'd not bother with any of those as you are adding an additional glass element into the equation and so will inevitably degrade the optical quality of the image unless it is a very precise optic (which would make the price very high)

Mostly asking as I was looking at the adaptors for the old FD to EOS but the main adaptor I found had an extra element and added a 1.3 crop factor plus a loss of light as well. So I was just wondering if their was certain adaptors for certain lenses that did this or was it a general rule.

If the flange focal distance of the camera the lens was designed for is longer than the flange focal distance of the camera you want to adapt the lens to, the adaptor will need an element to correct the lens to reach infinity focus.

Here is a good list: http://en.wikipedia.org/wiki/Flange_focal_distance

FD lenses will work well on the MFT mount but are no good on the EOS mount. As you have discovered.

There are other things you need to consider too, like the image circle of the lens and the physical space needed for the rear of the lens to fit.