Q: Legacy Pen F lenses on OMD

[Hibbs]

Just wondering if it is possible to use legacy Pen F lenses on an OMD and (if so) what adapter is required. I'm considering the OMD and wondered if my older lenses are in play.

Lastly, what would be the 35mm equivalent of using half-frame lenses. Is there a FL ratio?

Thanks kindly.

 

[zuiko85]

Yes there is an adapter, try Photodiox. There are no Pen F lenses equivalent to a 35mm AOV for FF if that is what you mean. The shortest Pen F lens is 20mm. That would have about the same AOV as a 40mm on FF.

 

[zuiko85]

Sorry, AOV = Angle of View
FF = Full Frame

 

[zuiko85]

Just checked the Fotodiox site (correct spelling) they have a Pen F to micro 4:3 adapter for $49.99. There are some cheaper ones on E-bay, I don't know about the quality of any of them compared with each other.

 

[bugmenot]

Since you will be focusing using Live View through the viewfinder, the only two things that matter with regards to the adapter is whether the lens is firmly in place with no room for play, and whether your infinity is accurate.

Also, the Pen F lenses were designed to cover a 24mmx24mm image circle, so they will work just fine on m4/3, as well as APS-C mirrorless cameras.

 

[Dwig]

...and whether your infinity is accurate...

Actually, accurate flange distance isn't critical with such adapters unless you intend to rely on the focusing scale on the lens, something that isn't extremely accurate in most SLR lenses anyway.

Most of the inexpensive adapters seem to set the flange distance slightly too short. The only negative to this is that the lens will focus slightly beyond inf (something many SLR lenses to anyway) and that the focusing scale will be slightly inaccurate. Since with an EVF (eyelevel or rear panel) camera you generally focus using the actual image on the sensor there is no focus error when the adapter is slightly too thin.

BTW, I noticed on Amazon/US today (2012-08-24) that they have the Fotodiox for $49 and one from Rainbow Imaging for ~$28. The latter might be a better "cheap" option than one from an unknown source on eBay.

 

[Hibbs]

Thanks for the replies. These adapters are less expensive than the Oly OM to Micro4/3.

As for the field of view, I would think that a 20mm half frame lens is equivalent to 35mm in full frame (film) but is it really 2X when it comes to Micro 4/3?

So my 40mm 1.4 on the OMD is an 80mm 1.4?...or is it more like a 57mm?

Hmmm...my math run away from me.

 

[bugmenot]

The m4/3 crop factor is exactly 2X ... So all lenses give you an angle of view twice their focal length.

 

[rxmd]

The m4/3 crop factor is exactly 2X ... So all lenses give you an angle of view twice their focal length.

Just like the original Pen F's crop factor is 1.4 (actually √2) relative to "full frame"/135 film. The diagonal of the half frame negative is shorter than the diagonal of a full frame negative by √2.

So to take the 40/f1.4 lens: on a half frame camera like the Pen F it gives a field of view like a 57mm lens (40 x √2) on full frame, and on a m4/3 it gives a field of view like an 80mm lens (40 x 2) on full frame.

 

[Dwig]

...As for the field of view, I would think that a 20mm half frame lens is equivalent to 35mm in full frame (film) but is it really 2X when it comes to Micro 4/3? ...

20mm is 20mm is 20mm, regardless of what format the particular lens was designed to be used on.

Crop factors, by default, are used to compare field of view (FOV) to "full frame 35mm" so, yes, there is a 2x crop factor when comparing m43 to 35mmFF. A 20mm lens used on m43 gives a FOV equivalent to a 40mm lens used on "full frame 35mm" regardless of whether is was designed for m43, 35mm Half Frame, or 35mm Full Frame.

Note: crop factors are based on the diagonal field of view, as is the convention in the photo industry. Using this measure the aspect ratio of the various formats can be convieniently ignored. Since the m43 format and 35mmFF have different aspect ratios there is a slightly different crop factors that should be used when comparing either horizontal or vertical coverage.

 

[goamules]

I've been shooting 3 old Pen F Olympus lenses on my G1 m4/3 the past few months. They are very sharp, more contrasty than the Canon RF lenses I was shooting. Here are three from this weekend at the Grand Canyon taken with the Pen F 25/4.0.