Sharpness of DA35 Macro at Infinity Focus

[scorpioh]

I realised it is not as sharp as my DA40 or even my sigma17-70 at (35-40mm) when focused at infinity, at the same aperture. I had also tried adjusting through all aperture sizes but the peak performances, from about f5.6 to f12 still cannot match with the former two. Any experiences? Is it normal or am I just anal?

 

[fengwei]

Which camera are you using? I heard the lens might have some focusing problem w/ K10D ...

 

[scorpioh]

Which camera are you using? I heard the lens might have some focusing problem w/ K10D ...

Ha, I am using the k10d. I was kinda pixel peeping when I was doing the comparison. My da21 is even less sharp at infinity focus, but I think cos its wider.

 

[fengwei]

Ha, I am using the k10d. I was kinda pixel peeping when I was doing the comparison. My da21 is even less sharp at infinity focus, but I think cos its wider.

DA21 is also known to have some AF problem on K10D ...

I think it's time for you to upgrade to a K20D :bsmilie:

 

[scorpioh]

But its not really an auto-focus issue. Cos I set it on manual and turn the focus ring to its maximum. I still love my k10d. It's serving me very well. Thanks for your inputs, fengwei.
OT: Can't wait to get my hands on the da15!!!

 

[Gengh]

But its not really an auto-focus issue. Cos I set it on manual and turn the focus ring to its maximum. I still love my k10d. It's serving me very well. Thanks for your inputs, fengwei.
OT: Can't wait to get my hands on the da15!!!

Don't some lenses have the ability to focus "beyond infinity"? Could that be what's causing your pics to go OOF when you turn the focusing ring to its maximum?

 

[scorpioh]

Don't some lenses have the ability to focus "beyond infinity"? Could that be what's causing your pics to go OOF when you turn the focusing ring to its maximum?

Hmm, makes sense. I'll try again during the day. Thanks!

 

[scorpioh]

Just tried out. And you are correct. A very slight turn from the max (auto-focused by the camera itself) did make the image sharper! Million Thanks.

 

[hjbyeo]

what's beyond infinity in photography context?

 

[Gengh]

what's beyond infinity in photography context?

I'm not confident of this... but I think in the event that you use a lens mount adaptor (eg. M42 to K mount) that is not well made, the lens may be mounted a little too far forward. The lens would then focus a little closer than it ought to, as if it's on a little extension tube, and at infinity focus it would still actually be focusing at somewhere closer. When a lens can focus "beyond infinity" it will be able to correct for that.

Phrased more generally, it's a little extra focusing allowance the lens has to accommodate slight differences in the lens-to-sensor distance.

Do correct me if this is all rubbish.... I've not actually had to use "beyond infinity" before. :bsmilie:

 

[alanswan]

That sounds like a pretty good explanation.
I didn't know about this before, though I have experienced it.
Focus being sharper at infinity just before max focus turning, that is.

 

[sleepz]

I also have this problem with my K10 and DA35.
Had to use the russian debug program to adjust the BF on my camera to make the DA35 focus correctly at infinity distances.
Unfortunately, the compensation affects my other lenses too, so think i'll have to bring all my lenses and k10 down to shiro for adjustments soon.

Anyone has any idea how long this will take and the cost (out of warrranty)?