all Nikon's cameras AF very quickly and accurately for a huge portion of my landscape and other work. given that, i'll choose an AF lens over a manual lens of the same quality every time because it is one less thing to interfere with my composing a capture. only when the MF lens offers some significant advantage do i bother with a MF lens. Zeiss lenses have that significant advantage.
Herb...
fkhfineart wrote:
i dont shoot sports so i cannot say for that, but i found the autofocus always slower and talking too much into my work.
Lotusm50 wrote:
(...) the Contax brand (which apparently, sometime last year, reverted back to Zeiss). (...)
Whoa, that sounds interesting !
What is the source of these good news ?
Do you have any link to a source for this information or assumption ?
I so much hope it is true, it would mean new hope
Please elaborate.
Edited on May 12, 2008 at 11:19 AM
May 12, 2008 at 11:17 AM
Andre Labonte Offline • • • • • • Upload & Sell: Off
Chris Langer wrote:
I do not know much about AF and lens formula's but I am sure if you put AF or other modern new features, the glass will have to change its formula which could cause less quality from the Zeiss. Just a thought.
Chris
Not really. It's a matter of setting a motor to turn the focus ring instead of your hand. AFS is a little different, but not much.
Avi B wrote:
Why would the optical design be the same for an AF lens
How is an autofocus lens optically any different from a manual focus lens with appropriate mechanics (motors, gears, etc) so the focussing can be done under the camera's control instead of by your fingers? Autofocus lenses can be focussed manually with no difference except that the focussing mechanics are a bit looser so the motor doesn't have to work so hard.
How about just because the simple fact that Nikon does not want to lose its market share to the would-be better Zeiss AF (Nikon mount) lenses than their curent line up.
HerbChong wrote:
a lot of the larger lenses have been reformulated to IF for faster AF.
Herb...
I thought the reason for IF was better balance and better seal against dirt. Are you saying that if Nikon were, for some reason, to introduce a new high-end manual focus lens today it would NOT be IF?
plnelson wrote:
How is an autofocus lens optically any different from a manual focus lens with appropriate mechanics (motors, gears, etc) so the focussing can be done under the camera's control instead of by your fingers? Autofocus lenses can be focussed manually with no difference except that the focussing mechanics are a bit looser so the motor doesn't have to work so hard.
But I was thinking more along the lines of longer lenses (although I didn't say it)... The AF for teles seem like it would require a redesign to get the AF to work faster, and to possibly move less glass for the AF operation. I always try to think of boundary cases and teles would possibly require redesign to allow the AF motor to move a smaller/lighter piece of glass than the MF equivalent.
If the licensing is an issue so why Tamron, Sigma, Tokina got theirs easily? and if Zeiss not a Japanese company but in this case I think it is own by Japanese company right? Kyocera? plus they have the license for the manual focus line so why no AF? ever since Nikon has no interest or perhaps they already on mass production for the newer prime lenses which I'm sure we all hope they would do so. Again the market for AF users is pretty big out there and I know Manual focus is sort of Niche market for Zeiss advantage.
IF is to reduce the amount of glass that moves. the rest is secondary. if there isn't much to move anyway, there is no need for the complexity.
Herb....
plnelson wrote:
I thought the reason for IF was better balance and better seal against dirt. Are you saying that if Nikon were, for some reason, to introduce a new high-end manual focus lens today it would NOT be IF?
Edited by HerbChong on May 12, 2008 at 04:48 PM GMT
Steen Bondo wrote:
Whoa, that sounds interesting !
What is the source of these good news ?
Do you have any link to a source for this information or assumption ?
I so much hope it is true, it would mean new hope
Please elaborate.
Has anyone else heard about this or read about this ??
Andre Labonte wrote:
Not really. It's a matter of setting a motor to turn the focus ring instead of your hand. AFS is a little different, but not much.
Let's be clear, a given optical formula is present in the zeiss line. The optical formula relies on the fact that the user can supply a large amount of turning power relative to the weight of the optics, thus the optics can be kept tight, heavy and extremely high quality. To get the same movements for AF function, you either have to have a super slow focusing AF (to move the same heavy elements) or you have to change the optical formula to allow for an AF motor to move them. In point of fact, AF lenses are further complicated by the fact that the elements that move are restricted to provide responsive AF functionality.
Why would anyone want to take a razor sharp lens lens like the Zeiss line and then guestimate the focus with an autofocus camera that makes every shot a crap shoot? You would do better to invest in a manual aided focus screen like a Katzeye, autofocus was invented so that SLR makers could sell expensive cameras to non hobbyists. Yeah, I know they come in handy shooting sports with long lenses but for most other pix , if you had a split image with a micro prism collar you, could put that plane of focus right where you want it even if the center sensor is hot and the two people in the pix are standing on the left and right .
Let the flames begin.
just because you know better where you want to focus than the camera doesn't mean you're more accurate. people claim to take razor sharp images without a tripod too.
Zeiss has stirred some retro spirits of late. Yeah some folks would like to shoot film again ( enough with this digital crap ) and how about putting a manual stearing on a space shuttle.
As I mentioned I was intrigued by high iq of zeiss but could not accept two limitations.. fixed focal length and lack of af. Instead went for the best nikon has to offer, 60mm afs ..yet!
HerbChong wrote:
just because you know better where you want to focus than the camera doesn't mean you're more accurate. people claim to take razor sharp images without a tripod too.
Herb...
MF works a lot better and a lot faster than waiting for a logarithm to read your mind
and compare contrast. I was a staffer on a large newspaper for 28 years and rarely ever missed focus until I got AF cameras issued to me. knowing where to put your point of focus is just part of the craft. Razor sharp photos are possible without a tripod (though I don't recommend it) assuming a high enough shutter speed and not too long lens.
By the way, one of my "blind without his glasses" colleagues now embraces AF with good reason. I guess I am lucky to have better than 20-20 peepers even as I approach 60!
molson wrote:
Those are mostly re-badged Tamron lenses... the Zeiss lenses for the Nikon mount are made by Cosina.
Wrong. Tamron only makes a few of the lower/mid Sony branded lenses, and those Tamron's are updated with circular aperture blades and other mechanical changes before being labeled Sony. Nikon and Canon also farm out some of their lower end stuff.
I think the licensing is a big part of the lack of AF Zeiss for Nikon. There has been speculation that Sony already had the Zeiss AF 85mm and 135mm designs in their arsenal before the Minolta buyout, and adapted those lenses to A-mount when they decided to buy Minolta rather than starting their own, new mount. It makes senses to me, because why would Sony redesign the classic and highly reviewed Minolta 85G if they hadn't already developed the Zeiss (some Sony lenses, like the expensive 70-200G, are Minolta rebadges?) You can bet that Sony will hold on to the AF exclusivity as long as they can, seeing it's a major draw into their system.
i've been at it for long enough to know better, just as many other people here are. the only DSLRs that use contrast detect AF are the D3 and D300 and only in LiveView mode. the rest of the time, the D3 and D300 and everyone else uses phase detection. DSLR AF in the here and now, even at the bottom end, is faster than any human can possibly be when it makes the right decision on what to focus on and that is far, far more often than you seem to have ever experienced. given how many people are successful at regularly producing shots that were essentially pure luck in the MF-only days, i'd say that a lot of luck to be flowing in only one direction. there are plenty of reasons to consider a Zeiss. superior focus control is one of them. superior speed is bogus.
Herb...
Agentile wrote:
MF works a lot better and a lot faster than waiting for a logarithm to read your mind
and compare contrast. I was a staffer on a large newspaper for 28 years and rarely ever missed focus until I got AF cameras issued to me. knowing where to put your point of focus is just part of the craft. Razor sharp photos are possible without a tripod (though I don't recommend it) assuming a high enough shutter speed and not too long lens.
and teles would possibly require redesign to allow the AF motor to move a smaller/lighter piece of glass than the MF equivalent.