Iam thinking of getting the sigma 120-300 2.8 but I've read that some people are saying that the lens needs to be re-chip by sigma to make it work with a canon 1d or 1d mk2. What does re-chipping means really is it to make the AF work with the 1d body or any kind of canon dslr body?
Most new Sigma Lens don't need re-chipping, most of the time it's older lens that need it.
I believe the reason for this is that sigma uses reverse engineering to produce the mounts for it's lens instead of purchasing a liesense from Canon as Tamron and Tokina and other after market lens makers do. This is the reason that they sometimes need to be rechipped.
A rechipped lens should work fine with all current Canon Bodies, Will work with future Canon bodies without a second/future rechipping is another question.
All that being said tons of Canons shooters use Sigma Lens so the process doesn't seem to be that big of a deal.
Mike is right. The lens would have to be on the shelf for a long time to need to be rechipped if you bought it new. If that did happen and it's a current lens then re-chipping is free.
FWIW, I had my 105 EX rechipped by sigma for free. I purchased it 3 years ago and was still covered by the warranty. The shop where I orginally bought it sent it in and was back in a couple of weeks, no charge.
mikeCary wrote:
I believe the reason for this is that sigma uses reverse engineering to produce the mounts for it's lens instead of purchasing a liesense from Canon as Tamron and Tokina and other after market lens makers do.
As I understand it, Canon does not license their lens mount to any third-party lens manufacturers. If anybody has proof that they have done so, please provide a reference. I have seen lots of speculation about this, but it's all anecdotal.
moondigger wrote:
As I understand it, Canon does not license their lens mount to any third-party lens manufacturers. If anybody has proof that they have done so, please provide a reference. I have seen lots of speculation about this, but it's all anecdotal.
I'm begining to come to this conclusion myself. What it looks like is that Tokina and Tamron either engaged in some industrial espionage or did a full and complete job of reverse engineering the EOS protocols. Sigma on the other hand cut a few corners and lenses prior to 2000 had problems with more recent EOS bodies. Sigma fixed this with new chips but whenever anyone mentions Sigma lenses the collective memory rears up and says "Sigma is bad because you need to re-chip them", dispite any recent evidence to this effect.
I once bought an older Sigma 70-210 f4-5.6 that needed to be rechipped. I told them it needed to be chipped for a D30 but I'm not sure if there are different chipping procedures for different cameras. I sent the lens to Sigma and it was ready just a few days later. And free.
Frankly, I have not heard of any 120-300s needing to be rechipped. The lens is relatively new (three years, maybe?). If it were necessary, though, I'd think Sigma would do it for free on that lens.
thanks for all the reply, as a general question on other sigma lens , how would I know that the lens needs re-chipping? the AF just doesn't work? will it break my camera?
Chuck Westfall has stated to Bob Atkins that Canon has never licensed their EF specifications to any 3rd party lens manufacturers. They have had some licensing arrangements with Kodak to produce camera bodies, though, and some of those are still in effect.
Tamron, Sigma, and Tokina all reverse engineer their lenses. This does not involve any espionage, just buying a few bodies and lenses and measuring the heck out of all their operating parameters.
Canon has never changed their EF communications protocol, which is why the very earliest EF lens works as well or better than it ever did on the very newest Canon EOS body. They did make one change: When the Elan 7 was released, Canon lowered the amount of drive power the camera delivered to the lens (to extend battery life). All Canon lenses were already very efficient and didn't need as much power as had been available, so they had no problem with the change. The same was generally true of Tokina and Tamron lenses.
Sigma, however, had some lenses that had some ineffcient chips that required all the power the older bodies delivered. These lenses choked when put on power-stingy Elan 7 and later cameras. The fix was simple--Sigma installed more efficient chips in those lenses.
It was all a matter of Sigma not paying close enough attention to perfect reverse engineering in the first place. I suspect they have learned their lesson, considering they're providing a 6-year warranty with new lenses.
