[ddamski]

Well ddamski, I do hope you will succeed to solve your autofocus accuracy problems with your FA77.

But as DSims highlighted above, a good lens is much more than just about sharpness. But it appears that many these days evaluate a lens primarily based on sharpness.

Well, if a particular lens is having actual focus issues or construction problems, leading to unacceptable softness, then yes, you do have a problem on your hands.

But if that is not the case, then sharpness is merely one aspect of a lens' overall performance.

Other things come to play, eg the colour rendering, 3D effect, microcontrast, bokeh character, image 'purity' and so on. These aspects are often overlooked (or unappreciated perhaps). To some extent, an over-reliance on laboratory-based lens testing is contributing to this problem. Test charts do have their usefulness but there is much more to a lens, which can only be detected through actual field usage and experience using the lens to understand its character.

Therefore, to evaluate a lens purely on lab test results, in particular shaprness, is quite dangerous and can well miss the whole point of the lens.

hello kdafa,

thanks for your answer. I know that also other criterias are important. But imagine how i felt, wenn i went for vacations, took some pics with my 77 and found out that it had an focusing issue In the moment i dont have focusing issues, i fine tuned it through my K5 to a +10. (even though a 12-13 would be better if it was possible). But my thread was mostly a comparison. For me it was quite interesting checking the bokeh and the sharpness. Just for info and not burning the DA40mm i want to mention that i had a wrong fine tune adjustment of +6. This lens works better with 0. So my previous foto samples of the 40mm are not focused accurately.

Which Sigma zoom is that? I have the old EX DG II 70-200/2.8 HSM macro (not OS) and it fares *much* better than this. Consensus has it that the newer (OS) version is much better.

It is the first of the Sigmas 70-200, non Macro, Non DG. I also know that this lens performs better than the new ones. My copy is just not the sharpest at 2.8. After 5.6 it is doing very well.

That Sigma doesn't look so bad on the 200mm end. That's usually the weakest of all the 70-200s. It's a bit weak on the 80 end though. As Sandy says - some of the Sigma 70-200s aren't that great.

I also had the Tamron 70-200 and i think it is sharper than the Sigma i have now. But i didnt liked always the color rendition of the Tamron. Maybe in the future i have a Pentax tele lens

[slip]

My sigma 70 - 200mm f2.8 is quite soft at 2.8 at long distance and has FF. Once dialed in it is very sharp at 3.5 and up.It could be a soft copy in your case but using it in sports like indoor volleyball I don't see the softness at 2.8 as much as I do when, for example, I am taking a shot of a deer 100 yards away.
If speed of auto focus is a important issue, then a siggy wins hands down
Great thread!!

Randy

[ddamski]

My sigma 70 - 200mm f2.8 is quite soft at 2.8 at long distance and has FF. Once dialed in it is very sharp at 3.5 and up.It could be a soft copy in your case but using it in sports like indoor volleyball I don't see the softness at 2.8 as much as I do when, for example, I am taking a shot of a deer 100 yards away.
If speed of auto focus is a important issue, then a siggy wins hands down
Great thread!!

Randy

Hi Randy,

yes the autofocus is indeed very fast. Do you use more your DA 50-135 or the Sigma?

[savoche]

I agree with VisualDarkness on the 40mm. Sharpness isn't everything. Depending on what you shoot, of course - a macro lens should be sharp - but if the 40 is your favourite, don't be too eager to get rid of it.

Test charts have their uses, but don't let them take the fun out of photography

[ddamski]

after finding a new Pentax DA*300 with a reduced price, i bought one and sold my Sigma 70-200.. there is quite a difference! unlucky for me, that my Cullmann tripod just broke and the screw cant hold the middle tube...
My best Buy until now!

[DVaughan007]

Wow ddamski pic 2 is going to give me nightmares haha. Nice shots though !

[joe.penn]

Which Sigma zoom is that? I have the old EX DG II 70-200/2.8 HSM macro (not OS) and it fares *much* better than this.

The OS FLD version is as sharp wide open as the 105 macro is.

after finding a new Pentax DA*300 with a reduced price, i bought one and sold my Sigma 70-200.. there is quite a difference! unlucky for me, that my Cullmann tripod just broke and the screw cant hold the middle tube...
My best Buy until now!

The above mentioned at f/4 is quite a bit sharper than the *300 at f/4, stopping both down to 5.6 there are about equal.

[ddamski]

The OS FLD version is as sharp wide open as the 105 macro is.



The above mentioned at f/4 is quite a bit sharper than the *300 at f/4, stopping both down to 5.6 there are about equal.

The OS FLD version is as sharp wide open as the 105 macro is.



The above mentioned at f/4 is quite a bit sharper than the *300 at f/4, stopping both down to 5.6 there are about equal.

well my copy of Sigma APO EX was not so sharp. As i said before this is not my only criteria, in color rendering the Pentax DA 300 exceeds either way :-)

here two comparisons from both lenses @F/4.

first the sigma



and the pentax DA 300