Enquries on how to DIY rechipping for old Sigma lens to new Canon DSLR

[rhino123]

Hi bro and sis,

I am about to bid for an old Sigma 400mm f5.6 lens in EF mount (because I cannot afford a Canon 400mm f5.6L), I read in reviews that the lens will not work for new Canon bodies such as my 7D and I wouldn't mind manual focusing however, it was stated that the lens couldn't even manual focus because when attached err 99 message will come up and it will freeze on my camera.

Anyway, I know that the lens needed to be rechipped, however because that lens is pretty old and not sure how much it will cost to get Sigma to rechip it. So I am wondering could I actually just do it myself, by removing the contact on the lens and reinstall an EMF AF confirm chip that I can easily find in the ebay? Was it the same thing as rechipping the lens by Sigma? And the lens could retain all its AF capability after that, or do I have to go manual?

 

[daredevil123]

Hi bro and sis,

I am about to bid for an old Sigma 400mm f5.6 lens in EF mount (because I cannot afford a Canon 400mm f5.6L), I read in reviews that the lens will not work for new Canon bodies such as my 7D and I wouldn't mind manual focusing however, it was stated that the lens couldn't even manual focus because when attached err 99 message will come up and it will freeze on my camera.

Anyway, I know that the lens needed to be rechipped, however because that lens is pretty old and not sure how much it will cost to get Sigma to rechip it. So I am wondering could I actually just do it myself, by removing the contact on the lens and reinstall an EMF AF confirm chip that I can easily find in the ebay? Was it the same thing as rechipping the lens by Sigma? And the lens could retain all its AF capability after that, or do I have to go manual?

It is not just the af chip.... when i tried a old sigma lens on a nikon camera, tye problem is exposure....

 

[ageha]

It is not just the af chip.... when i tried a old sigma lens on a nikon camera, tye problem is exposure....

Isn't that related to the focus distance? If the lens doesn't communicate the distance the camera will be in trouble.

 

[rhino123]

Hmm... look pretty complicated. Haiz... guess I better forgo that option. Anyway, I just bought a Russian 3M-5CA 500mm f8 mirror lens off ebay. I read lots of reviews saying that this lens is well known for its sharpness... although not too contrasty, but I could easily rectify that problem with photoshop (woo hoo!).

Anyway, I hope the russian lens is good enough for the time being when I save up for a 400mm f5.6L.

Thanks guys.

 

[daredevil123]

Isn't that related to the focus distance? If the lens doesn't communicate the distance the camera will be in trouble.

Not sure actually. Spot meter and center weight average is just fine. Just matrix meters under exposes by 0.7 stops. Works fine on a D70, screws up on the D300.