[kamisu]

Hi,

I love my K5 except for the AF sensor size and accuracy. It misses focus many times when there are high contrast objects in the background, even if the subject in the foreground is not really small. So I am considering upgrading my K5.

I know advantages of K3 over K5ii (K5iis), but most of them are not that important to me (two sd cards, higher resolution, better AF-c) as my main problem with K5 is AF accuracy.

Is there any difference in AF-s performance of K5ii and K3 ?

Thanks.

[jatrax]

Yes. With the k-5 I routinely took 2, 3, 5 shots to make sure one was solidly in focus. With the k-3 I soon realized I had 2, 3, 5 shots that were all solidly in focus. The difference was quite noticeable to me. However, that is primarily product, people and landscape shots. I do not shoot anything that moves.

AF tracking is a completely different subject and I have no experience with that except to say posts I have read indicate a minor improvement in tracking from k-5 to k-3 but not a dramatic one.

[chrisfer]

I have the K-5 II and the K-3 (with f2.8 optics), I often use center focus point in AF-S mode, oudoor or indoor I don't notice any difference in performance or size...

[TER-OR]

It's hard to separate variables from K5 to K3, in field macro my keeper rate is greatly improved, but experience plays a part.

The K3's screwdrive is noticeably faster than the K5's. That's a nice change.

[Adam]

In viewfinder mode, there should be no significant difference between the K-5 II and K-3 for single frames, but there is between the original K-5 and K-3 thanks for the increased low light sensitivity in the new bodies.

However, in live view the K-3 family is quite a bit faster thanks to the faster screwdrive motor and new algorithms, and more accurate, as you have more options for the AF area and a better processor.

[jpzk]

Another piece of feedback:

I have both the K5 and the K3 .... still use them regularly for just about everything.
The K5 does not focus as "rapidly" as my K3 but once I get the focus, it is usually bang on!
The K3 seems to pick focus (AF.S) faster and holds it better than the K5and "seems" to be more accurate ... but that is an opinion, not a science fact.
AF.C, for both cameras, isn't great ... so I stick with spot focus and AF.S pretty much all the time.

[kamisu]

Thanks all for the replies.

Reading this post by fotogaffer: Autofocus accuracy - K3 vs K5II vs K5 ? - Page 4 - PentaxForums.com ,he said "after having previously shot with both the K5 and K5 IIs, especially for birding. I think that the smaller focus points on the K3 make a huge difference for capturing birds especially in cluttered surroundings ...".

Is this just about K3 vs K5, or the focus points on K3 are smaller than those on K5II too?

[jpzk]

Thanks all for the replies.

Reading this post by fotogaffer: Autofocus accuracy - K3 vs K5II vs K5 ? - Page 4 - PentaxForums.com ,he said "after having previously shot with both the K5 and K5 IIs, especially for birding. I think that the smaller focus points on the K3 make a huge difference for capturing birds especially in cluttered surroundings ...".

Is this just about K3 vs K5, or the focus points on K3 are smaller than those on K5II too?

Not quite sure about this statement or maybe it's just me but it sure did not make a "huge" difference to me for this particular type of shooting (birding/BIF).
A difference, yes, but not that "huge".
Go to my Flickr (see my signature) ... lots of birding shots there with several Pentax cameras: K10D, K20D, K7, K5 and K3.

[starbase218]

I'm not sure the AF points in the K-3 are smaller than those in the K-5. They actually seem to overlap.

[mikesbike]

I have both the original K-5 and then in the last few years, also the K-5IIs, which I find has definitely more accurate AF than the original. This is more noticeable with some lenses than others. I've been very happy with it. Your K-5 might be just a tad better for lower noise at high ISO with fine detail preservation than the K-3. Since the K-5 series is no longer available new, the K-3 II is what remains in that style of design, but it has no built-in flash to make room for its built-in GPS. A replacement is expected within 6 months or so. If you don't do much burst shooting, therefore not needing the deeper buffer, you might consider the more lightweight but still having metal construction KP, which is outstanding in higher ISO use, and has the latest AF improvements. Not as many dedicated on-body controls, nor top LCD, but it has a new, unique programmable control set similar to the K-1, and a tilt-out back LCD screen.

Incidentally, I also have noticed a slight increase in fine detail with the K-5IIs over the K-5, which I believe is due to the lack of AA filter with the "s". I use both with sharpening bumped up one notch, and "fine" sharpening employed. The newer model Pentax cameras also lack AA filters, but now have a switchable anti-moire system instead of the AA filter.

[chrisfer]

I think that the smaller focus points on the K3 make a huge difference for capturing birds especially in cluttered surroundings ...".
Is this just about K3 vs K5, or the focus points on K3 are smaller than those on K5II too?

The center Point have the same size on K-5 , K-5 II and K-3. K-5 II and K-3 are more sensitive and more accurate with luminous optics.
On the K-3, the surrounding focus points are smaller.
Focus point on K-5 and K-5 II have all exactly the same size.

Have a look here : "Based on subjective tests, it is our impression that the K-3's autofocus points are smaller than those of its 11-point predecessors, with the exception of the central AF point. If you don't already have a K-5 II (i.e. you have a K-5 or earlier), the K-3's PDAF improvements will be more noticeable in practice."
Read more at: Pentax K-3 Review - Autofocus | PentaxForums.com Reviews

and Here : "Overall, the autofocus in the Pentax K-5 II feels more decisive than that of the K-5, but this difference does not become noticeable until one is shooting in relatively low light."
Read more at: Pentax K-5 II / IIs Review - Autofocus | PentaxForums.com Reviews

[starbase218]

The center Point have the same size on K-5 , K-5 II and K-3. K-5 II and K-3 are more sensitive and more accurate with luminous optics.
On the K-3, the surrounding focus points are smaller.
Focus point on K-5 and K-5 II have all exactly the same size.

Ah, that explains it. I only looked at the center AF point. Still, that's the one I use most of the time.

[kamisu]

The center Point have the same size on K-5 , K-5 II and K-3. K-5 II and K-3 are more sensitive and more accurate with luminous optics.
On the K-3, the surrounding focus points are smaller.
Focus point on K-5 and K-5 II have all exactly the same size.

I always use center focus point in AF-s mode, and the problem with K5 is that it picks something in the background to focus on (in day light, not low light conditions).

So for such a problem, is K3 a better choice than K5ii or they perform the same?

[chrisfer]

Center focus point in AF-S mode perform the same on K-5 II or K-3.