[Robert S Donovan]

I'm adding 5) Don't use it for things it wasn't intended for, like human faces.

As I said a moment ago I was merely trying something that had been suggested. Not my preferred (or recommended method)

[Rondec]

I have to say, I think that auto focus is as much lens dependent as it is body dependent. I have a DA 35 mm as well and find that due to its macro function, it is a very slow focusing lens. Don't get me wrong, it is extremely sharp, but it often takes forever to get a focus lock. On the other hand, my DA* 50-135 f2.8 is much faster. I have heard others say that the DA 40 mm is a very fast focusing lens as well.

I think that if you use a cheaper consumer zoom, you have more DOF by definition, because you can't shoot at under f4, therefore of course it looks your focus accuracy is better. I have to say that if I want to have sharp photos in low light settings, I use a flash and the lens at f4.

[ajuett]

What I want is a lighting fast center focus point so I can focus, recompose and shoot before the shot gets away. This technique has worked for me for a very long time. I just struggle sometimes with my K10D...

Being realistic I thought I needed the same. Going into the opposite direction of film and fully manual lenses I still catch my kids. They are about the fastest things I photograph! With MF you learn to relax and get a good shot most, if not 90% of the time instead of "spray and pray". I'll take half a dozen shots and they come out just great. When I shot AF and digital I'd take dozens of shots and rely on the machine, not my instincts for timing. MF is easier and faster than you think, just practice and you'll feel more of a reward when capturing subjects, imho.

[pingflood]

@Gruoso,
Thanks for joining in

Your experience pretty well mirrors mine. The only difference is that I rarely use anything other than the center focus point. The only camera I have used to date that even comes close to having perimeter focus points that are accurate enough is the Nikon D3. The problem there is that there are so many of them it becomes quite tedious to select the right one shot-to-shot. You can leave it in auto but... how does the camera know what I'm trying to do with my composition? Typically, it does not.

I don't know about the D3, but on my 1DsII I have some options for point selection. In single shot mode, I can either leave it on AFPS (auto) where it'll attempt to pick the right ones (and frankly does a half decent job if I want to hand it over to somebody to use), or manually pick one of the 45 points, or set it to being able to select between 11 or 9 points. Narrowing down the points that can be selected does help to speed things up. (It also lets me tie spot metering to the selected AF point if I want which can be useful sometimes.) It also has a somewhat curious mode where you can enable AF point expansion; when it can't find something to lock on under the selected point it'll expand and search the surrounding AF points for something it can grab onto. I'm guessing the D3, being a much newer camera than mine, has similar options for configuration.

[pingflood]

Being realistic I thought I needed the same. Going into the opposite direction of film and fully manual lenses I still catch my kids. They are about the fastest things I photograph! With MF you learn to relax and get a good shot most, if not 90% of the time instead of "spray and pray". I'll take half a dozen shots and they come out just great. When I shot AF and digital I'd take dozens of shots and rely on the machine, not my instincts for timing. MF is easier and faster than you think, just practice and you'll feel more of a reward when capturing subjects, imho.

When I read posts like this I wonder why people equate autofocus with careless machine gunning of the shots. The autofocus system is a tool, it doesn't MAKE you blast away at 10fps in hopes of a good picture. What you get with a good AF system that cooperates with you is the ability to NOT worry about manual focusing, and you can spend more effort on the other components of the image like framing and content. You can still carefully compose and shoot each frame, you just get some assistance in the manual labor department. Not sure why that's such a bad thing -- nobody bitches about autoexposure do they?

[*isteve]

@Gruoso,
Thanks for joining in

Your experience pretty well mirrors mine. The only difference is that I rarely use anything other than the center focus point. The only camera I have used to date that even comes close to having perimeter focus points that are accurate enough is the Nikon D3. The problem there is that there are so many of them it becomes quite tedious to select the right one shot-to-shot. You can leave it in auto but... how does the camera know what I'm trying to do with my composition? Typically, it does not.

What I want is a lighting fast center focus point so I can focus, recompose and shoot before the shot gets away. This technique has worked for me for a very long time. I just struggle sometimes with my K10D...

Focus recompose and shoot is NOT always accurate for critical focus on nearby subjects at widish apertures - on a face for instance, you can be focusing up to an inch further away than you should be. I always use off centre points in a studio so I can compose and focus at the same time, and I always use it on a tripod when shooting scenery.

Canon's off centre FPs are pretty useless IMO (I think they are tuned more to detecting off centre motion) and on the 5D (and all other FF cameras) they are too close to be of any use for what I use them for.

Pentax, at least the K20D is as accurate and fast in low light using off centre points as it is using the centre one, and there is enough spread for me to be able to use it on a tripod.

Plus, and I know no-one will accept this but, Pentax will often keep trying to lock focus even in really low light where some cameras (notably Canon XSi's) give up altogether.

So Pentax AF is not fastest (though in good light with many lenses its adequate) nor is it the best at tracking, but for what I need a camera for it has advantages over just about every other camera.

So thanks for your blog. I'm sure Pentax will appreciate the 100,000'th person telling them what they already know, and I'm sure it wont cost them toooo many sales.

[ajuett]

When I read posts like this I wonder why people equate autofocus with careless machine gunning of the shots. The autofocus system is a tool, it doesn't MAKE you blast away at 10fps in hopes of a good picture. What you get with a good AF system that cooperates with you is the ability to NOT worry about manual focusing, and you can spend more effort on the other components of the image like framing and content. You can still carefully compose and shoot each frame, you just get some assistance in the manual labor department. Not sure why that's such a bad thing -- nobody bitches about autoexposure do they?

My comments were (and I should have stated this) to users who rely on they 'spray and pray' methods. Personally I can't see how photography could be enjoyable in that case. Ciphering through dozens of images to find the 'right one' is not exciting. I don't worry about manual focusing, not one bit, to me it's a part of the process.

Like someone else who replied to this thread said, 'I'm bored so I'll chime in'. I guess I have some time on my hands as well and I should be doing sometime more constructive then this topic.

[kenyee]

Focus recompose and shoot is NOT always accurate for critical focus on nearby subjects at widish apertures - on a face for instance, you can be focusing up to an inch further away than you should be.

I didn't believe this initially but now do as well...even w/ the 77ltd at 2.4, it matters and is noticeable.

Robert: if you use AF-S w/ AF-ON, you can also release the shutter whenever you want (it acts like AF-C except AF-C keeps trying to focus). Just another mode to try if you're bored

[user440]

Sorry, the continual comments about embracing manual focus are kind of tired and laughable. Shooting sports, manual focusing is not always possible or appropriate. It seems like many times people that are waving the 'manual focus' flag shoot static objects 90% of the time. The Pentax AF system is flawed, they need to fix it to keep people from jumping systems.

[Robert S Donovan]

Being realistic I thought I needed the same. Going into the opposite direction of film and fully manual lenses I still catch my kids. They are about the fastest things I photograph! With MF you learn to relax and get a good shot most, if not 90% of the time instead of "spray and pray". I'll take half a dozen shots and they come out just great. When I shot AF and digital I'd take dozens of shots and rely on the machine, not my instincts for timing. MF is easier and faster than you think, just practice and you'll feel more of a reward when capturing subjects, imho.

If you check my photos on Flickr you'll see that 90% shot in the last six months were with a manual focus SMC-A 50mm f/1.7 lens. I post less than 1% of my photos on Flickr

AF is the part I like least of my Pentax system. When Pentax gets AF right—hopefully in their next bodies—I'll have a truly great system... lenses and camera.

[Robert S Donovan]

...So thanks for your blog. I'm sure Pentax will appreciate the 100,000'th person telling them what they already know, and I'm sure it wont cost them toooo many sales.

Here's where you are mistaken. We all have a choice in what cameras we shoot. I could easily decide to switch to Canon, Nikon, Olympus, or Sony if Pentax wasn't cutting it for me. However, I love Pentax. I feel that they get it by making cameras that think like photographers do. I don't think it is lost on my readers that, while I may point out flaws, I still choose to shoot Pentax.

This discussion has pointed out a number of counterpoints and has offered up numerous solutions for making the most out of Pentax cameras and lenses. Without this type of healthy and passionate debate camera shoppers would likely never be exposed to these great cameras and all that they can do (and the great people who own them).

This is grass-roots marketing at its best. Being honest and open about the products' features, benefits and short comings works much better at building brand loyalty than plastering glossy photos in magazines of the kinds of pictures one can take with (insert camera model here) or parading pop culture semi-icons on TV using said product.

No, I don't work for Pentax. Though, if they're listening I'm open to talk

[Robert S Donovan]

AF is the part I like least of my Pentax system. When Pentax gets AF right—hopefully in their next bodies—I'll have a truly great system... lenses and camera.

Excellent point!

[OregonJim]

Sorry, the continual comments about embracing manual focus are kind of tired and laughable. Shooting sports, manual focusing is not always possible or appropriate. It seems like many times people that are waving the 'manual focus' flag shoot static objects 90% of the time. The Pentax AF system is flawed, they need to fix it to keep people from jumping systems.

Of course it's possible. What do you think sports photographers have been doing for the last century or so before AF was invented?

Granted, it can be convenient, just like autoexposure, but certainly not necessary.

[Jonson PL]

short summary of blog entry: Pentax double check is annoying. Canon Rebel is faster. Canon 1DmkIII can track ticks hopping on dog

As I mentioned in a comment on the blog entry, try running w/ AF-ON or AF-C mode to bypass the double check...you have to time it though...fire the shutter at the initial swing but not the 2nd check. Your DOF has to be big enough to hide the partial focus.
Not the optimal solution but seems to be the best that can be done for now...(and yes I've played w/ a D700, D300, D80, Rebel, 1DmkIII, and A700...there's a reason the 1DmkIII adn D700/D300 are used for sports... :-)

Thanks for the tips.

I've also considered the K20, since the AF should be better than my K10