40D: contax planar 85/1.4 with cameraquest adapter

Hi guys,

First post for me... I am just wondering if someone might be able to explain how I might be able to get around a problem with using my contax planar 85/1.4 on my 40D. I am using a cameraquest adapter alongside another adapter with AF confirm.

The viewfinder and/or AF confirmation focus and the actual image focus do not appear to be the same. The same happens if I use an AF confirm adapter from another company. The camera confirms focus at a given point (say 4 feet away) and an image is captured. The actual image captured is always focussed slightly closer than what the AF said, or what I can see with my eye (by about 8mm).

Am I correct in assuming there is probably nothing I can do to correct this phenomenon? It is incredibly annoying as it boils down to guesswork as to what the accurate focus will be. These problems are with the contax open.

I am not a particularly experienced photographer so please forgive any ignorance I might be showing!

Thanks,

Husky01

Well shooting wide open will give a very shallow DOF. The way to test is use a tripod and focus on a static object, then check the focus with live view at 5/10X magnification.

AF confirm adapters are very hit & miss. I have a number of old MF lenses and only 2 have AF confirm chips. One seems ok, but the other can be a little off, depending on subject distance. I don't bother with chipped adapters anymore. On difficult situations I use the 40D's live view. Another option would be to change the focus screen on your camera for one dedicated to manually focussing.

I have 2 contax zeiss lenses on the way and an adapter mount without AF confirmation. I may have to use Katz eye or Hado Fu's focussing screen for this.