[tibor]

Hi fellow Pentaxians,

It's my first post in this great forum. I have a previous experience with Pentax film and digital cameras (a reliable Super A and later K10D).

With my new K-5, I am rediscovering the real joy of photography. The new body gives me much more confidence especially in two important fields - AF speed and high ISO capabilities.

Honestly, I can not blame the K-5 for an occasional sub-optimal final result... It is usually me who made an error

I have probably only one technical "issue" and it's the absolute focus accuracy with fast FA limited primes up to about F=2.8. My K-5 has still minor tendencies to FF or BF under different light conditions (wave lengths). Again, we are talking about extremely shallow DOFs here and in case of hand-held shotting the user error, caused by movement, can be actually bigger then this small AF inconsistence...

When I want to achieve a higher focus consistence shotting with FA limiteds wide open, I usually switch to manual focusing, switch OFF both acoustic and visual focus indicators (very distractive) and... I simply trust my eyes (like in good old film SLR days...).

I am attaching few photos of my 6y old daughter - high ISO shots, low light conditions. Enjoy, your comments are of course very welcome

Tibor

[jbinpg]

Gorgeous photos! Thanks for posting.

[Ole]

Welcome to the forum!

If you want to shoot at f/1.8 you may have to resort to manual focus as you have discovered. AF isn't 100% accurate - that's just how it is. At smaller apertures the error is usually masked by the increased depth of field.

[tibor]

Thanks for your nice comment, much appreciated!

Tibor

[techmulla]

At smaller apertures the error is usually masked by the increased depth of field.

you mean larger apertures. I always confused this bit too.

smaller number = larger aperture.

smaller number = less DOF

btw .. nice pics.

[tibor]

Ole,

Thanks for your replay, you are of course right. The focus accuracy of my K-5 from f/2.8 up is excellent - the percentage of keepers is really much more driven by my photographic skills and composition than my great new camera's abilities.

Thanks again,

Tibor

[pefoto01]

Тибор,да разбирам ли,че твоя К-5 няма с ФА Лимитеди ФФ или БФ?
Или проблема е от АФ + малкия ДОФ?
Салют!

[vievetrick]

Great shots !! I think I need to break out the 77 tomorrow. Well done

[tibor]

Hi pefoto01,

I would say that a super small DOF in case of using f/1.8 - 2.8 can not always hide the small FF BF issues caused by AF's current technical limits and you can sometimes get less than 100% sharp result. To go out of DOF, the lens focus ring sometimes needs to turn by less than a half of millimeter!!!
I am getting a higher percentage of 100% sharp results using manual focusing under these extreme conditions. I am quite sure that there is no problem with a camera - it is simply the limit of current AF technology.

Tibor

[tibor]

Vivetrick,

Thanks for comment, much appreciated!

Oh well.... the 77 is the last boy from those three I do not have and it is sometimes reeeeally missing here...
Well, will try to run a bit of negotiation with my wife and than maybe Santa........ :-)

Tibor

[pefoto01]

Тибор,благодаря за отговора!
Ти можеш да направиш корекция за фокуса на обектива от менюто.
Аз искам да съм сигурен че АФ на К-5 е по-точен от на К-20,преди аз да купя К-5.
Желая успехи!

[dgaies]

Тибор,благодаря за отговора!
Ти можеш да направиш корекция за фокуса на обектива от менюто.
Аз искам да съм сигурен че АФ на К-5 е по-точен от на К-20,преди да купя К-5.
Желая успехи!

You can certainly make adjustments to the AF for the FA limited lenses, but at very large apertures, especially under artifical light, it is nearlly impossible for the AF system to nail the focus 100% of the time no matter how well you try and calibrate the lenses to the body. This is true of the K20D, the K-5 and pretty much any other DSLR out there.

[Ole]

At smaller apertures the error is usually masked by the increased depth of field.

you mean larger apertures. I always confused this bit too.

smaller number = larger aperture.

smaller number = less DOF

btw .. nice pics.

Sorry, but I meant what I wrote. Smaller aperture (larger number) gives more DOF and masks the AF errors.

[joelR]

These are great pictures. Perhaps this is one reason why (compared to other camera/lens makers) Pentax lenses seem to have great color/contrast but are not as fast.

For example the Nikon 35mm 1.8 vs. DAL 35mm 2.4 and the fact that (I believe) the only f1.4 lens currently made by Pentax (who unlike Canon, Nikon, and Sony are 100% APS-C) is the 50mm. I did read somewhere that FF sensors handle the faster lenses better than APS-C cameras. Now I wish I could find the link to that source . . .

[sean]

DA*55 is 1.4 too. I really like mine.