Having focus accuracy issue with my Canon EOS 1Ds Mark III

[achrisproduction]

While using the EF 35 f/1.4L USM with my 1Ds Mark III, the images often appeared soft (seems focus issue) while I wide opened the lens.  Images taken with my 5D Mark II wide open with the EF 35 f/1.4L USM were sharp and in focus.  Quite disappointed because I have sent the 1Ds Mark III for a AF adjustment earlier but still there's no improvement at all.  

Cheers,

Chris

[Ken Bennett]

Did you send it *with* the lens in question? That helps.

You can do the focus adjustment yourself with a prime lens. There are directions from Canon floating around the web.

[achrisproduction]

Did you send it *with* the lens in question? That helps.

You can do the focus adjustment yourself with a prime lens. There are directions from Canon floating around the web.

First thanks for replying my thread.  I did not send it with my lens because I truly believe it's the 1Ds Mark III's problem as I did the focus check via the focus chart it's always accurate but when I did photography outside if I shot an image for just pressing half shutter for focus once the image would be out focus.  However, if I press half shutter 5 or 6 times the image would be in focus.  Really pushing me mad.  

[Jonathan Wienke]

Always send lens AND body when having focus calibration issues, as both are involved. If the lens is calibrated to front-focus, and the body back-focuses, the result will be correct focus. But when you put the lens on a correctly-calibrated body, you'll get front-focus. The problem might be the lens you didn't send in, and not the 1Ds.

[achrisproduction]

Always send lens AND body when having focus calibration issues, as both are involved. If the lens is calibrated to front-focus, and the body back-focuses, the result will be correct focus. But when you put the lens on a correctly-calibrated body, you'll get front-focus. The problem might be the lens you didn't send in, and not the 1Ds.

thanks for replying.  Yeah, I think I will bring both for them when I return to HK.  

[KevinA]

While using the EF 35 f/1.4L USM with my 1Ds Mark III, the images often appeared soft (seems focus issue) while I wide opened the lens.  Images taken with my 5D Mark II wide open with the EF 35 f/1.4L USM were sharp and in focus.  Quite disappointed because I have sent the 1Ds Mark III for a AF adjustment earlier but still there's no improvement at all.  

Cheers,

Chris

Have you done the micro adjustment? My 1DsmkIII and everyone else's I know of suffered from poor AF. I had mine adjusted and did the micro adjust on return for each lens, I now think it's shooting the sharpest pictures I've ever shot.

Kevin.