[dugrant153]

Hey folks,

I own a K200D and was looking at the DA35 Ltd the other day and testing it in the store. I'm contemplating on replacing my DA40 to get a slightly wider 35mm focal length and considered this DA35... but something wasn't right.

I noticed that as I tried to take some shots, the camera missed focus a couple of times. Most of the time it was on target, but other times it just didn't get it. And there was a situation where it just wouldn't focus at all (silvery grey plastic panel??)...

Is this maybe a defective copy? OR does the 35mm have a tendency to misfocus on indoor shots (tungsten?) or on people shots?

My DA40 Limited is usually dead on, no matter what the lighting... might just keep it!

[keithlester]

AF works on contrast
if there is no, or little texture and/or low lighting level the body may fail to focus your lens. AF is not a lens thing, its a body function. If there is nothing in the field of view for the body to work with, it will fail. The fact that it usually gets focus right shows there is nothing intrinsically wrong with either the body's circuits or the lens mechanism.

[Sean Nelson]

The other thing to remember is that the AF sensors aren't really "points" - they're actually rather large areas in the viewfinder. The AF sensor can lock onto anything within that area, and it may not be the thing you want it to. The diagram below shows the area of the center AF "point" in my K100D Super, measured by trying to get a focus lock on a black dot on white paper at various positions:

[enoxatnep]

It might be the lens or the camera or perhaps both, but if your camera has been great with other lenses, perhaps it was just the lens you were trying out.

In my case, I'm borrowing my friend's DA35 right now and its AF is bang-on in all lighting situations on his and my K20D. I've also tried his DA*200 and DA*300, and DA*50-135 and also had perfect AF. However, my FA 50 f1.4 front-focuses all the time regardless of lighting and the in-camera correction scale isn't large enough to correct it, so I rely entirely on MF for that lens. And my 12-24 is hit-and-miss with AF, but more often 'hit'. So I've concluded that my camera's okay and that my FA 50 is the problem. Maybe that's your situation, too.

[dugrant153]

It might be the lens or the camera or perhaps both, but if your camera has been great with other lenses, perhaps it was just the lens you were trying out.

In my case, I'm borrowing my friend's DA35 right now and its AF is bang-on in all lighting situations on his and my K20D. I've also tried his DA*200 and DA*300, and DA*50-135 and also had perfect AF. However, my FA 50 f1.4 front-focuses all the time regardless of lighting and the in-camera correction scale isn't large enough to correct it, so I rely entirely on MF for that lens. And my 12-24 is hit-and-miss with AF, but more often 'hit'. So I've concluded that my camera's okay and that my FA 50 is the problem. Maybe that's your situation, too.

I would say so. My camera does pretty good with my DA40 Limited (which is a killer lens by the way).

I realize some subjects have a tendency to cause our cameras to go haywire for autofocusing, but I think that in this case it's probably the DA35 lens that may be at fault. But I guess the lesson here is to try out the lens before buying. These days I'm willing to pay the premium in order to try out the lens in case it's a dud.

Case in point: A local store had the FA50 F1.4 (same lens you mentioned) and had two copies. The first one I tried was off and front focused. Second one was way more usable and I bought it.