Thanks, it does seem to be known as 'focus shift' and mainly affects rather old view camera lenses (i.e. 80 years old) and plain poor design/build, from what I could gather after some googling.
"focus shift is the result of uncorrected zonal spherical aberrations. Spherical aberration results from the fact that rays of light from the periphery of the lens are brought to a focus at a different point than rays of light from closer to the optical axis. As you stop down, you eliminate the rays from the periphery of the lens and this zone of focus shrinks. The actual point of best focus doesn't really change, it is just overlaid with out of focus rays from the periphery of the lens and this leads to a larger zone of focus and an apparently better focus - it's partly an optical illusion. If you judge the point of best focus by contrast, you are likley to experience focus shift."
From: http://photo.net/bboard/q-and-a-fetch-msg?msg_id=005H2c&tag=
Has anyone actually experienced problems with H lenses and 'focus shift'? I suspect the effect is not noticeable on these lenses or any other modern MF lenses, so this isn't a problem that needed to be fixed.
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I personally don't believe any of this has anything to do with an H-3 and the 28mm.
I don't get fringing or ca on my leaf files using a 35mm Zeiss or even twisting a 45mm Ukanian tilt shift, or using pentax and hasselblad lenses on my Contax.
Everyone is aware that Hasselblad/Imacon is way behind in Medium Format back sales and they need to find something to allow them to compete.
It must be frustrating to have the #1 camera but be #3 or #4 in back sales, so this was their solution.
Obviously it would do them good to not always be a generation behind Leaf and Phase in features, such as iso and frame rate.
As I mentioned before, Imacon had some lousy samples they presented and early one some awful skin tone color. This along with some of the demonstrations mentioned here and in other places pretty much sums up why they are #3 or #4, that and the fact Hasselblad seems to be very bad at getting thier message out.
For the photographer none of this really mean anything.
JR