Re: Quote for the day (on fast lenses)
On 18 Dec 2004 at 9:55, Mark Erickson wrote: The SMC-K 50mm F1.2 talk reminded me of a good Dante Stella article on the subject of fast lenses at: http://dantestella.com/technical/fast.html After a lengthy discussion of technical issues related to transmission vs aperture, Dante ends the article with the following quote: But admit it, superspeed lenses are cool Boy that's more stoked with supposition than his normal rants, hasn't the guy ever heard of lens hoods? Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: Quote for the day (on fast lenses)
Good read - and true, like all Stella´s stories. But speed is not everything. Without proper coatings flare is even bigger problem. Many pre-war superspeed lenses had a minimum aperture of something like f:8 because flare made them unusable beyond that - seems like the diaphragm reflects so much light back that multicoating makes a lot of difference. All the best! Raimo K Personal photography homepage at: http://www.uusikaupunki.fi/~raikorho - Original Message - From: Rob Studdert [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sunday, December 19, 2004 1:12 AM Subject: Re: Quote for the day (on fast lenses) On 18 Dec 2004 at 9:55, Mark Erickson wrote: The SMC-K 50mm F1.2 talk reminded me of a good Dante Stella article on the subject of fast lenses at: http://dantestella.com/technical/fast.html After a lengthy discussion of technical issues related to transmission vs aperture, Dante ends the article with the following quote: But admit it, superspeed lenses are cool Boy that's more stoked with supposition than his normal rants, hasn't the guy ever heard of lens hoods? Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: Quote of the Day
Why a new physical mount, then? Surely they could do the electronics with a serial protocol, which would require, at minimum, ground, power, and signal: three contacts. As I understand it, the EOS mount is much different mechanically from the old FD mount. Wider throat. Are other factors at work? Mark Roberts wrote: The real reason for the new lens mount (for Canon in the change to EOS and for Nikon if this latest rumor proves to be based on fact) is the change to completely electronic control of all lens functions - aperture, zoom, focus and anything else they decide to add (image stabilization, for example).
Re: Quote of the Day
Lon Williamson [EMAIL PROTECTED] wrote: Why a new physical mount, then? Surely they could do the electronics with a serial protocol, which would require, at minimum, ground, power, and signal: three contacts. I've thought of that too, but apparently they don't use a serial protocol - at least judging by the number of contacts used. I have no idea why. Anyone know the pinout designations for EOS mount? As I understand it, the EOS mount is much different mechanically from the old FD mount. Wider throat. Are other factors at work? Well, a wider throat allows them to put the electronic contacts at the base of the lens extending radially, rather than using the axial contact orientation that Pentax uses. It also gives more freedom in lens design because the rearmost element can be larger - like a 50mm f/1.0, for example. -- Mark Roberts Photography and writing www.robertstech.com
Re: Quote of the Day
Lon Williamson [EMAIL PROTECTED] wrote: If a radial contact layout has some advantage, what is it? I don't think there is an advantage. It's neither better nor worse, just different. That said, the radial arrangement does get the contacts out of the lens mount itself, which is steel (in better lenses, anyway) and requires all kind of insulating spacers and bushings in Pentax's lens mount. These insulating bits can be eliminated if the contacts are mounted in plastic substructures in the lens and camera. I'm wondering if the elimination of the aperture simulator in the Pentax lens mount is to provide room for some radially-arranged contacts in that spot some time in the future. I realize that a larger throat lets you produce lenses that might otherwise be impossible. On the other hand, if I can't get an available light shot with a 50mm 1.4, then what the hell. Yes, but having an 85/1.2 or a 50/1.0 in your product line is as much about marketing as it is about taking photographs. You could argue that's it's *more* about marketing than photography. -- Mark Roberts Photography and writing www.robertstech.com
Re: Quote of the Day
I don't think so. IIRC, the 0.95 mounted to an outside breech lock on the 7 7S, it did not fit the inner 39mm Leica mount, nor the earlier cameras. Also, the SLR lens has to be mounted ahead of the mirror housing which requires a larger diameter mount. Plus, the EF mount has a shorter film to flange distance than the FD. That was so FD lenses could be used with an adaptor, there were adaptor for several other manufactures mounts also. The Pentax K mount had the same philosophy to start with, but it came out a good decade before the Canon EF when electronics was not yet a consideration. Ciao, Graywolf http://pages.prodigy.net/graywolfphoto - Original Message - From: Peter Alling [EMAIL PROTECTED] Canon produced a f 0.95 lens in Leica screw mount, so I don't think the size of the FD throat was a limitation on making an F1.0 normal lens.
Re: Quote of the Day
Bruce quoted: From photo.net: Can anyone think of a single valid reason why a new lens mount should be necessary? Ask Canon or Minolta. They did such a stunt and made a lot of business sense. -- Pål Jensen snipIf some of you are old enough you might recall that Pentax also had to change their lens mount system in the mid to late 1970s snip -- Ellis Vener , June 13, 2003; 01:49 P.M. Eastern I know Len knows who Ellis is. REPLY: I believe a new Nikon lens mount may be a smart move. They can keep smaller than 35mm sensors for the their current line up + film being able to offer competitive DSLR and competing head on with Canon on price. They could then make a new system for larger CCD's; it could even be larger than 35mm and thereby beat Canon in absolute quality consistently. A new digital only system could be taylored for the its intended use; digital. Pentax is in a good position. They have three slr platform that all can be converted to digital in due course. Pål
Re: Quote of the Day
And as a serious comment. Canon does a lot of business because they always have the right product at the right time, with the right technology and performance, not because they changed camera mounts. REPLY: Really? So Canon EOS has nothing to do with the lens mount? The technology and performance would have been impossible without the mount changes. Pål
Re: Quote of the Day
Caveman: Minolta also changed mounts, but that did not prevent them to be now in such a poor shape that they're looking for a buyer for the company (I hear they're in talks with Konica). REPLY: Minolta changed mount and sold 2.000.000 AF cameras of one single, expensive model in 2 years. Nobody have managed to repeat that performance since. Pål
Re: Quote of the Day
What was it about the old Canon mount? Too narrow? Too far from (or too near to) the film plane? Have Nikon and Pentax been able to keep cobbling along because their mount dimensions were more generous? Somewhere this must have been written about, but I've never seen an article or discussion. -Lon Michael Perham wrote: Bruce Rubenstein wrote: From photo.net: Can anyone think of a single valid reason why a new lens mount should be necessary? Ask Canon or Minolta. They did such a stunt and made a lot of business sense. -- Pål Jensen Actually, when Canon changed their mount, it was ostensibly to accommodate new and upcoming technology; today, Pentax and Nikon are not making that assertion. They are simply changing the mount to reduce manufacturing cost by allowing electronic control of the aperture as opposed to a mechanical control, which is more expensive to produce. Now, I dnk whether or not Canon's rational was an accurate statement or simply a spin to appease the owners of old FD class lenses and in fact was just a way of forced obsolescence of the old lenses. At least with Nikon and Pentax old lenses can still be used, although with reduced functionality. That's how I see it anywaycheers! Mike.
Re: Quote of the Day
Throat diameter is just one thing. What Canon did was to system engineer an entire SLR system from a fresh start. This means that folks sat down, figured out what they wanted the system to do and then figured out the best way to do it. They determined that electronic control of the lens was best for what they wanted. Once they knew the largest diameter they would probably ever need to optics, they included all the electrical contacts they might need. From this, they were able to figure out what the lens mount diameter had to be. (Standard system engineering practice.) Pentax didn't keep cobbling their mount, they changed from screw to K, with no backwards mechanical compatibility to use a K mount lens on a screw mount body. Pentax and Nikon have been enhancing the control/command, lens/body interface to add new functions. The problem is that they've have made a series of changes, sometimes taking different directions (Nikon AIS). They are classic evolved systems, rather than engineered ones. BR [EMAIL PROTECTED] wrote: What was it about the old Canon mount? Too narrow? Too far from (or too near to) the film plane? Have Nikon and Pentax been able to keep cobbling along because their mount dimensions were more generous? Somewhere this must have been written about, but I've never seen an article or discussion. -Lon
Re: Quote of the Day
Lon Williamson [EMAIL PROTECTED] wrote: What was it about the old Canon mount? Too narrow? Too far from (or too near to) the film plane? Have Nikon and Pentax been able to keep cobbling along because their mount dimensions were more generous? Somewhere this must have been written about, but I've never seen an article or discussion. The real reason for the new lens mount (for Canon in the change to EOS and for Nikon if this latest rumor proves to be based on fact) is the change to completely electronic control of all lens functions - aperture, zoom, focus and anything else they decide to add (image stabilization, for example). -- Mark Roberts Photography and writing www.robertstech.com
Re: Quote of the Day
And as a serious comment. Canon does a lot of business because they always have the right product at the right time, with the right technology and performance, not because they changed camera mounts. Really? So Canon EOS has nothing to do with the lens mount? The technology and performance would have been impossible without the mount changes. I agree with Pal here. The original Canon manual focus mount was a mess. The Pentax K mount was a much cleaner design. I don't see how Canon could keep upgrading their old mount like the K mount. regards, Alan Chan _ MSN 8 with e-mail virus protection service: 2 months FREE* http://join.msn.com/?page=features/virus
RE: Quote of the Day
Bruce Rubenstein wrote: From photo.net: Can anyone think of a single valid reason why a new lens mount should be necessary? Ask Canon or Minolta. They did such a stunt and made a lot of business sense. -- Pål Jensen Actually, when Canon changed their mount, it was ostensibly to accommodate new and upcoming technology; today, Pentax and Nikon are not making that assertion. They are simply changing the mount to reduce manufacturing cost by allowing electronic control of the aperture as opposed to a mechanical control, which is more expensive to produce. Now, I dnk whether or not Canon's rational was an accurate statement or simply a spin to appease the owners of old FD class lenses and in fact was just a way of forced obsolescence of the old lenses. At least with Nikon and Pentax old lenses can still be used, although with reduced functionality. That's how I see it anywaycheers! Mike.
Re: Quote of the Day
Bruce Rubenstein wrote: From photo.net: Can anyone think of a single valid reason why a new lens mount should be necessary? Ask Canon or Minolta. They did such a stunt and made a lot of business sense. -- Pål Jensen How typical. Paal is more interested in the financial well being of the camera manufacturers than in his own one. And as a serious comment. Canon does a lot of business because they always have the right product at the right time, with the right technology and performance, not because they changed camera mounts. Minolta also changed mounts, but that did not prevent them to be now in such a poor shape that they're looking for a buyer for the company (I hear they're in talks with Konica). cheers, caveman
Re: Quote of the Day
Minolta also changed mounts, but that did not prevent them to be now in such a poor shape that they're looking for a buyer for the company (I hear they're in talks with Konica). cheers, caveman Konica and Minolta announced their merger in January 2003. Ed _ STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail
Re: Quote of the Day
You guys should read this: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=005ICtunified_p=1 It's about that nikon new mount. The fun part is to see the nikonians at work. Instead of trying to find out if the news is accurate or not, they're debating if talking about it is spamming or not, some moderator acknowledged that he actually deleted the threads about it (because that was spam) and so on. Really weird guys. cheers, caveman
Re: Quote of the day
You don't get a second chance on first impressions. ...unless you're Bill Murray on Groundhog Day.
Re: Quote of the day
Ah, yes. Caught in a temporal loop. How like the PDML sometimes. At 06:48 AM 3/5/2003 -0500, you wrote: You don't get a second chance on first impressions. ...unless you're Bill Murray on Groundhog Day. Outside of a dog, a book is man's best friend. Inside of a dog, it's too dark to read. --Groucho Marx
