I am using the Haoda conformation adapters on my 5D with the Zeiss 28mm 2.8 and 135 2.8 I had to do some filing to get them to clear the mirror, but now they are working fine. I read the adapter section and would like to know what the phrase "specific adapter coded the lens focal length" means. How did you do this and is it something that must be ordered or something that I can do for the Zeiss lenses?
The confirmation "beep" on these adapters is handy, but I find that I often have to slightly touch it up for final focus.

With the HappyPageHK adapters, HappyPageHK will burn the flash chip to have the whatever focal length you want. If want it coded as 28mm F2.8 - then that's what will show in the EXIF.

As far as I know the other companies simply code theirs as 50mm F2.0 - you can check the EXIF data on your files to see if this correct.

In my experience focus confirmation (the camera beeps when focus is achieved and the green light in the viewfinder shows solid) is more precise if the adapter is coded to match the focal length.

I tried a C/Y 135/2.8 and C/Y 35-135 Vario with the an adapter coded at 50mm F2 and experience repeated OOF at 135mm on both lenses. In contrast my C/Y 100/2 has an adapter coded for 100mm F2 and my keeper rate is much higher with that lens - even wide open at F2.

I don't work for Canon and I have no knowledge how their AF system works. That said, their system should incorporate the focal length to determine the proper focus for a given circle of confusion standard / target.

Whew..., HappyPageHK codes the adapters for free and the price is the same as Haoda, so it's pretty much no-brainer IMO.

Oh, and welcome to the forums

John

HappyPageHK's inventory is up and down. If he doesn't have anything listed on Ebay, I click on a Ebay profile and send him a message. He's pretty quick to reply - usually within 24 hours.

Technically and adapter could be 'zapped' with the correct EXIF data if we had the tools. HappyPageHK at one point was going to offer that, but I'm guessing they realized providing software and hardware would lead to whole host of support issues. And/or maybe the pricing wasn't going to be attractive.

Once an adapter has been coded, I guess it's possible to re-code, but it's probably not worth it. Paying for to the place, pay for the re-zap, and pay for shipping back. What I like about HappyPageHK's adapter is he (they, whatever) code each adapter manually. The other sellers just paste the same chip in each one. Whereas HappyPageHK has to custom code each chip and then install into the adapter. Their work is purely custom (unless the buyer goes with the standard 50mm F2 coding). I would like to think that the extra manual work may also lead to higher quality control. I'm probably being naive, but I'd like to think that

You gave me a idea - I'll create a user ID for HappyPageHK and invite him to participate. That's better than me putting words in his mouth