are AF sites actually smaller?

kenyee · 10-08-2013, 01:24 PM

If anyone has a preproduction unit, could you do the black cross on the wall test and see how big the sensors are?

They look huge from this photo of the AF sensor:

jaad75 · 10-08-2013, 02:20 PM

25 cross points are fitted on the same area as 9 before...

twitch · 10-08-2013, 02:28 PM

This is exactly what I'm wondering about. Sure there are more focus points, and we all assume focus points don't overlap one another, but is that true? I can live with K-5 focus speeds, but the massive size of the K-5 points causes a lot of mis-focused shots with AF grabbing something in the background. If the only improvement with the K-3 focus is to shrink the AF points to half or less their current size, then that would be enough for me to buy a K-3.

jaad75 · 10-08-2013, 02:35 PM

I don't know what you people do to have that issues... Never had a single problem with that - with accuracy and low light focusing - yes (before I bought the IIs), with AF-C - of course, but focus points size? It's just a matter of proper technique and knowledge how big they really are.

twitch · 10-08-2013, 02:39 PM

It doesn't take that much imagination to work out why very large AF points are a problem in certain situations no matter how good your technique is. Hint: your target is smaller than the AF cross point, with extra difficulty if your target is moving around, and extra extra difficulty if they are moving around against a contrasty background.

derekkite · 10-08-2013, 02:40 PM

Originally posted by jaad75

I don't know what you people do to have that issues... Never had a single problem with that - with accuracy and low light focusing - yes (before I bought the IIs), with AF-C - of course, but focus points size? It's just a matter of proper technique and knowledge how big they really are.

Not my experience.

jaad75 · 10-08-2013, 02:44 PM

Originally posted by twitch

Hint: your target is smaller than the AF cross point.

And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance?

snake · 10-08-2013, 02:45 PM

Originally posted by jaad75

I don't know what you people do to have that issues... Never had a single problem with that - with accuracy and low light focusing - yes (before I bought the IIs), with AF-C - of course, but focus points size? It's just a matter of proper technique and knowledge how big they really are.

The problem definitely exists. In fact, the focus area is even outside of the point's indicated boundaries. I can guarantee I'm shooting in more demanding situations than you are, and there is an issue with their size more than anything else.

derekkite · 10-08-2013, 02:49 PM

Originally posted by jaad75

And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance?

I guess the idea of focusing on the eye of something wouldn't work for you. There are many many situations where people want to focus on a specific thing that is smaller than the focus point on the K-5* AF system. In fact, considering how large it is, probably the majority of shots. Sometimes it doesn't matter much, a deep DOF and a subject without much depth, but many times it does.

twitch · 10-08-2013, 02:51 PM

Originally posted by jaad75

And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance?

Not sure why you are picking a fight, I'm not interested in one. There are many people with similair experiences to me, maybe read some of those threads.

from one of those threads....

JinDesu · 10-08-2013, 02:55 PM

7D sensor - Also APS-C (well actually a little smaller than APS-C), with 20 AF points. And supposedly the 7D has pretty small AF points and really really good AF.

Originally posted by jaad75

And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance?

I suppose you don't do full body portraits? Or attempt to shoot that little bee in a flower, and expect to crop to fill? Heck, do you even crop at all?

jaad75 · 10-08-2013, 03:05 PM

Originally posted by derekkite

I guess the idea of focusing on the eye of something wouldn't work for you.

The idea works for me very well - it's just a matter of subject size, distance and DOF combination. On the APS-C camera if the eye is so small that you can have troubles to focus precisely on it, it probably means, that DOF is so deep that you don't have to be that precise.

Originally posted by twitch

There are many people with similair experiences to me, maybe read some of those threads.

People tend to have many problems with many simple things...

krebsy75 · 10-08-2013, 03:26 PM

twitch: I get pretty good results focusing with the 11 point system. I suspect you're using it in more demanding situations than I am. In other words, I don't dismiss what you are saying. I just haven't really experienced it myself. I'm more of a casual shooter.

derekkite · 10-08-2013, 03:28 PM

What if the eye is on a dog, with a longish nose? What I ran across all the time is a bird on water that isn't smooth. There are dozens of contrast points in that shot within a depth of 6 feet either way. This is the way I use my camera; many of those shots are simply identification shots, not for show. If they aren't in focus on what I want, they are useless.

It really depends on what you shoot. The problem is simple. The AF points are too large as well as unpredictable when there are multiple contrast points within the AF point.

There are styles of shooting where it doesn't matter. There are styles where it really does. And it is more than technique. I can get birds in flight with my long manual focus lens, 1 in 50 shots on a good day. If you wonder about my technique, I was out shooting with a friend who at the time had a D7000 with their very nice 300 2.8 lens. He didn't get clear shots of the owl, but I did in manual focus. My K-5 is better, maybe one third to one half will be reasonably sharp as long as the light is very good and there is something contrasty to shoot. When following a target I have to move it around the focus point area to get it to catch, and then hold it there. I didn't try the K5II, which I understand was better. I'm hoping this body will be better again.

I'll be buying this body if it lives up to it's promise for that reason alone. The other improvements are just gravy.

kenyee · 10-08-2013, 03:50 PM

This is what I mean...the current AF points are huge and don't match the display in the viewfinder. Ever wonder why Pentax keeps releasing f/1.8 or slower lenses? I think the inaccurate AF was a big part of it, though cloaked in marketing speak of "we want smaller lighter lenses".

Someone a while back who had a lot of Pentax f/1.4 lenses said the AF system just wasn't accurate enough (he was a practicing pro who did a lot of narrow DOF natural light stuff, not Benjikan's studio stuff)....you couldn't lay the focus point on an eye in a portrait and expect focus exactly at that point...it'd be FF/BF a bit instead. That pro switched over to Nikon and was a lot happier.
So it really depends on what you shoot and what lenses you have.
I've personally had the "focus on background randomly" issue w/ my old K10D just shooting an event where I lay the focus point on people's faces.

10-08-2013, 01:24 PM	#1
kenyee Veteran Member Join Date: Mar 2007 Location: Boston, PRofMA Photos: Albums Posts: 3,026	are AF sites actually smaller? If anyone has a preproduction unit, could you do the black cross on the wall test and see how big the sensors are? They look huge from this photo of the AF sensor:

10-08-2013, 02:51 PM	#10
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	Originally posted by jaad75 And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance? Not sure why you are picking a fight, I'm not interested in one. There are many people with similair experiences to me, maybe read some of those threads. from one of those threads.... Last edited by twitch; 10-08-2013 at 03:05 PM.

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10-08-2013, 02:20 PM	#2
jaad75 Veteran Member Join Date: Sep 2007 Location: Cracow Posts: 457	25 cross points are fitted on the same area as 9 before...

10-08-2013, 02:28 PM	#3
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	This is exactly what I'm wondering about. Sure there are more focus points, and we all assume focus points don't overlap one another, but is that true? I can live with K-5 focus speeds, but the massive size of the K-5 points causes a lot of mis-focused shots with AF grabbing something in the background. If the only improvement with the K-3 focus is to shrink the AF points to half or less their current size, then that would be enough for me to buy a K-3.

10-08-2013, 02:35 PM	#4
jaad75 Veteran Member Join Date: Sep 2007 Location: Cracow Posts: 457	I don't know what you people do to have that issues... Never had a single problem with that - with accuracy and low light focusing - yes (before I bought the IIs), with AF-C - of course, but focus points size? It's just a matter of proper technique and knowledge how big they really are.

10-08-2013, 02:39 PM	#5
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	It doesn't take that much imagination to work out why very large AF points are a problem in certain situations no matter how good your technique is. Hint: your target is smaller than the AF cross point, with extra difficulty if your target is moving around, and extra extra difficulty if they are moving around against a contrasty background.

10-08-2013, 02:40 PM	#6
derekkite Pentaxian Join Date: Sep 2011 Location: Nelson B.C. Posts: 3,782	Originally posted by jaad75 I don't know what you people do to have that issues... Never had a single problem with that - with accuracy and low light focusing - yes (before I bought the IIs), with AF-C - of course, but focus points size? It's just a matter of proper technique and knowledge how big they really are. Not my experience.

10-08-2013, 02:44 PM	#7
jaad75 Veteran Member Join Date: Sep 2007 Location: Cracow Posts: 457	Originally posted by twitch Hint: your target is smaller than the AF cross point. And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance?

10-08-2013, 02:45 PM	#8
snake Banned Join Date: Jun 2012 Location: NY/Germany Posts: 1,183	Originally posted by jaad75 I don't know what you people do to have that issues... Never had a single problem with that - with accuracy and low light focusing - yes (before I bought the IIs), with AF-C - of course, but focus points size? It's just a matter of proper technique and knowledge how big they really are. The problem definitely exists. In fact, the focus area is even outside of the point's indicated boundaries. I can guarantee I'm shooting in more demanding situations than you are, and there is an issue with their size more than anything else.

10-08-2013, 02:49 PM	#9
derekkite Pentaxian Join Date: Sep 2011 Location: Nelson B.C. Posts: 3,782	Originally posted by jaad75 And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance? I guess the idea of focusing on the eye of something wouldn't work for you. There are many many situations where people want to focus on a specific thing that is smaller than the focus point on the K-5* AF system. In fact, considering how large it is, probably the majority of shots. Sometimes it doesn't matter much, a deep DOF and a subject without much depth, but many times it does.

10-08-2013, 02:55 PM	#11
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	7D sensor - Also APS-C (well actually a little smaller than APS-C), with 20 AF points. And supposedly the 7D has pretty small AF points and really really good AF. Originally posted by jaad75 And? Are you going to fill your frame with it? If not, why put it on the photograph? There is nothing to focus on, big enough in the same distance? I suppose you don't do full body portraits? Or attempt to shoot that little bee in a flower, and expect to crop to fill? Heck, do you even crop at all?

10-08-2013, 03:05 PM	#12
jaad75 Veteran Member Join Date: Sep 2007 Location: Cracow Posts: 457	Originally posted by derekkite I guess the idea of focusing on the eye of something wouldn't work for you. The idea works for me very well - it's just a matter of subject size, distance and DOF combination. On the APS-C camera if the eye is so small that you can have troubles to focus precisely on it, it probably means, that DOF is so deep that you don't have to be that precise. Originally posted by twitch There are many people with similair experiences to me, maybe read some of those threads. People tend to have many problems with many simple things...

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10-08-2013, 03:26 PM	#13
krebsy75 Veteran Member Join Date: Jun 2010 Location: Chester County, Pa. Posts: 804	twitch: I get pretty good results focusing with the 11 point system. I suspect you're using it in more demanding situations than I am. In other words, I don't dismiss what you are saying. I just haven't really experienced it myself. I'm more of a casual shooter.

10-08-2013, 03:28 PM	#14
derekkite Pentaxian Join Date: Sep 2011 Location: Nelson B.C. Posts: 3,782	What if the eye is on a dog, with a longish nose? What I ran across all the time is a bird on water that isn't smooth. There are dozens of contrast points in that shot within a depth of 6 feet either way. This is the way I use my camera; many of those shots are simply identification shots, not for show. If they aren't in focus on what I want, they are useless. It really depends on what you shoot. The problem is simple. The AF points are too large as well as unpredictable when there are multiple contrast points within the AF point. There are styles of shooting where it doesn't matter. There are styles where it really does. And it is more than technique. I can get birds in flight with my long manual focus lens, 1 in 50 shots on a good day. If you wonder about my technique, I was out shooting with a friend who at the time had a D7000 with their very nice 300 2.8 lens. He didn't get clear shots of the owl, but I did in manual focus. My K-5 is better, maybe one third to one half will be reasonably sharp as long as the light is very good and there is something contrasty to shoot. When following a target I have to move it around the focus point area to get it to catch, and then hold it there. I didn't try the K5II, which I understand was better. I'm hoping this body will be better again. I'll be buying this body if it lives up to it's promise for that reason alone. The other improvements are just gravy.

10-08-2013, 03:50 PM	#15
kenyee Veteran Member Join Date: Mar 2007 Location: Boston, PRofMA Photos: Albums Posts: 3,026 Original Poster	This is what I mean...the current AF points are huge and don't match the display in the viewfinder. Ever wonder why Pentax keeps releasing f/1.8 or slower lenses? I think the inaccurate AF was a big part of it, though cloaked in marketing speak of "we want smaller lighter lenses". Someone a while back who had a lot of Pentax f/1.4 lenses said the AF system just wasn't accurate enough (he was a practicing pro who did a lot of narrow DOF natural light stuff, not Benjikan's studio stuff)....you couldn't lay the focus point on an eye in a portrait and expect focus exactly at that point...it'd be FF/BF a bit instead. That pro switched over to Nikon and was a lot happier. So it really depends on what you shoot and what lenses you have. I've personally had the "focus on background randomly" issue w/ my old K10D just shooting an event where I lay the focus point on people's faces.