02-09-2012, 10:05 PM
[quote name='youpii' timestamp='1328816544' post='15762']
Thanks for the review. Very nice lens indeed.
But I'm very puzzled by the current trend of full manual lenses (Samyang & Cosina). Even M42 had automatic aperture...
[/quote]
Hi youpii,
On a mirror less, the non-automatic aperture is less of a problem than on a SLR. Unless it is really dim, the amplifiers in the camera will make up for it and show a reasonably bright image on the screen or in the EVF.
I don't think there is any trend here. Samyang is selling non-AF lenses for a couple of mounts incl. Canon EF and Nikon F. Typically the price is low enough to make up for it. The Voigtländers are about extreme speed. Focussing of these lenses involves moving extensive optical systems and not just a single or a few light weight optical elements inside the lens. I think there is a technical reason, why this can not be done with the current technology in a contrast AF setting.
From Panasonic and Olympus there is a permanent trickle of AF lenses. Also the recent Sigma offerings have an AF. Remains to be seen how quick the Sigmas will be focussing.
J.
Thanks for the review. Very nice lens indeed.
But I'm very puzzled by the current trend of full manual lenses (Samyang & Cosina). Even M42 had automatic aperture...
[/quote]
Hi youpii,
On a mirror less, the non-automatic aperture is less of a problem than on a SLR. Unless it is really dim, the amplifiers in the camera will make up for it and show a reasonably bright image on the screen or in the EVF.
I don't think there is any trend here. Samyang is selling non-AF lenses for a couple of mounts incl. Canon EF and Nikon F. Typically the price is low enough to make up for it. The Voigtländers are about extreme speed. Focussing of these lenses involves moving extensive optical systems and not just a single or a few light weight optical elements inside the lens. I think there is a technical reason, why this can not be done with the current technology in a contrast AF setting.
From Panasonic and Olympus there is a permanent trickle of AF lenses. Also the recent Sigma offerings have an AF. Remains to be seen how quick the Sigmas will be focussing.
J.
enjoy