[jddwoods]

Hello All

I am looking for feedback from anyone using the DA* 200mm on any camera body. I have noticed the SDM autofocus is slow in a very peculiar way. When I press the shutter release partially down the lens hesitates before the SDM autofocus occurs. Once the autofocus motor starts, it focuses fairly quickly. It works and works all the time, but it hesitates the same way all the time before the motor actually moves. For focusing on stationary objects this is not an issue but for birds and wildlife it results in missing a lot of shots since it involves focusing on moving subjects. I thought it may be due to subject contrast issues (ducks on water) but I switched to my new DA 55-300 PLM it was a totally different experience. Under the same conditions and subjects on the same K-3, the 55-300 autofocus locked focus almost instantly at any focal length but my comparisons were at 200 mm.
Is this delayed autofocus response, or latency normal for this lens? It does not matter if I use AFS or AFC. Clearly this issue shooting the same subjects in the same camera and lighting conditions is no problem at all for the 55-300 PLM.
So my question is: do I have a problem with the lens or is this normal for it? Is there any camera setting I can try that would improve it? I hate to see this lens turn into an expensive paperweight but the difference in autofocus performance means that if I need 200 mm, it will be the 55-300 that will be on my K-3.

Thanks, John

[Driline]

I just tested the DA*200 on my K-3 inside a few minutes ago. If the subject is brightly lit it autofocuses quickly. If it's a bit dark or there is more contrast it hesitates a beat and then focuses similar to what you describe. I think it's just a function of the SDM motor. It's slow period. For birds in flight I use my F*300 with screw drive. The DA*200 is used more for static indoor shots. Others have had success going manual and using catch in focus though so all is not lost.

[UncleVanya]

You can try converting it to screw drive. It does sound like ask hesitation. Back button autofocus plus quickshift can help I'd wager. I recently shot some birds in my front yard with my DA* and it isn't a speedy lens.

[shardulm]

Is there any camera setting I can try that would improve it?

AF-C. But looks like your SDM is under the weather. I have a couple of DA*s that feel under the weather when it is very cold which otherwise perform normally. I think it could be partly because of the tight tolerances or it could be that the SDM is failing. Not sure.

[Na Horuk]

Usually single-point centre point AF.S is the most confident AF. You can do a proper focusing test using a focusing chart at a certain distance, then use MF, Live view focusing, and then the regular PD AF. Then you can compare results to see whether the problem is in the focusing module or in the lens motor. Live view is generally slow, but accurate. PD AF is a bit faster, but might suffer from back or front focusing.

[mikec100z]

I find my 200 is a bit sluggish to respond as well. This is usually on on the first couple shots. I don't use the lens as much as others and I have taken to giving it a weekly workout as these lenses unfortunately have been known to have SDM failure if they sit for a long time. I simply point it at the sky and run it from minimum focus to infinity letting it hunt for a focus point, then i try a number of changes from distance to close up. I am not sure if this will help ward off an SDM failure but it appears that the problem is worse for little used lenses.