Originally posted by Ed Hurst I have got both the 67 300mm EDIF and the 67 400mm EDIF and both are superlative lenses when used on the 645Z (I have also had brilliant experience using the 300mm EDIF on the 645D and a Nikon D800E). No issue whatever with their performance on a smaller than 6x7 sensor.
In terms of comparisons with the 645 alternatives, it is close, but IMO the 67 EDIF lenses edge it.
By the way, I would say that the 67 300 EDIF is slightly better than the 67 400 EDIF, but not by enough to use the former when the longer FL is needed.
Thanks Ed...
I've thought about a few of the 35mm lenses in the 300mm focal length as well, like the Canon 300 f4 L and the Nikon that you mention. I know the Canon 300 f2.8 will cover the 33x44 sensor, so I suspect most 300's will cover as long as there isn't a substantial baffle in the lens to cut the IC down.
Those lenses come in at about the same price as the Pentax 645 300 ED, so they are good options as well as long as they don't suffer in the corners.
I also have a Mamiya 645 300mm f5.6 here that was too cheap to ignore trying out. It's really small and since I have a Mamiya adapter for the GFX anyway for a few other lenses, I felt it was worth trying.
---Michael