m4/3 Adapter Question

[Filmkid2003]

Hey everyone. I have a question about the m4/3 adapters for the GH1. Are these adapters kind of like 35mm adapters in the sense that you have to make adjustments once you attach the lens to them? What I mean is, with the 35mm adapters for camcorders, once you attached the lens, you had to make sure the camcorder was zoomed all the way in, then focus on the image being displayed onto the adapter glass, get rid of any vignetting, etc. Is that how it is with these m4/3 adapters or do you just attach the lens to the adapter and start shooting? Hopefully its that easy... Thanks.

 

[AndrewGentle]

You mean like these? There may be some backfocus adjustments but, in general, no, these are nothing like video camera lens converters. Instead of projecting an image onto an intermediate surface, these adaptors allow you to project the image straight on to the image sensor like the native lenses do.

 

[Filmkid2003]

Thanks, Andrew. What exactly do you mean by "back focus adjustment"? What exactly do you have to do when you do a back focus adjustment with these adapters?

 

[AndrewGentle]

You're welcome! Back focus is the distance from the rear element of the lens to the focussed image (on the image sensor). Micro 4/3 has a relatively short back focus distance and this allows a large range of lenses with a longer back focus distance to be mounted in front of the position the original rear element and still produce a focussed image on the sensor. This is the reason why you can't put a Canon lens on a Nikon body, it's not possible to get the lens's rear element close enough to the image sensor to focus to infinity.

If an adaptor has back focus adjustment, it would simply move the lens a little further and closer to the camera to produce the sharpest image when the lens was focussed to infinity.