SAF Front Focus and CAF/SAF Focus Comparisons with the 300mm f4 – E-M1s.

Started 3 months ago | Discussions thread
Gary from Seattle Veteran Member • Posts: 5,421
Re: SAF Front Focus and CAF/SAF Focus Comparisons with the 300mm f4 – E-M1s.

drj3 wrote:

Interceptor121 wrote:

Something is going on with the programming of the functionality here. I doubt it is a hardware problem

I am convinced it is the CDAF algorithm. It has a slight bias for the closer area within the focus points. As long as the user is aware of this issue, it is easy to avoid the problem.

It would rarely be a problem when one uses a single or limited focus area. I almost always use SAF and a single focus point with my 12-100mm f4 lens unless I am photographing a moving target or a small target at minimum focus distance.

It can be a problem when you have a very shallow DOF with very long telephoto lenses when photographing close targets or a very fast lens of any focal length photographing close targets. It is typically a difference in focus around the chosen focus point since the focus point would generally be within the DOF.

I have thought about this with S-AF and CAF. I wonder though if the chosen array/single target pattern makes a difference with CAF+Tr? I am currently using a five target cross on CAF+TR. Would I do better if I used a single small target? I haven't been doing that as I am not sure that I can consistently be that accurate in targeting; or would it make no difference in CAF+Tr because the camera essentially takes over in matching bird shapes and eyes in AI?

 Gary from Seattle's gear list:Gary from Seattle's gear list
Olympus E-M1 Olympus E-M1 II Olympus OM-D E-M1X Olympus Zuiko Digital 1.4x Teleconverter EC-14 Olympus M.Zuiko Digital ED 75-300mm 1:4.8-6.7 +5 more
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