Done with slow focus

Had some friends and family over the other day.  Decided to show my friend again why an actual camera is better than an iPhone for some situations.  I had a k50 in program mode with my 50mm 1.8. Afternoon outdoors.  Kids running around.  My camera could not get focus on the excited kids.  I've played with some recent consumer level Nikon and Canon dslrs and was amazed at their quick focus.  Does anybody have a m43 like gx85 or od m10?  How is the focus speed on moving subjects?  I'd rather ditch Pentax for a m43 than cheap dslr from canon or Nikon.

That's the K-50 for you. It has a ton of features, but they really skimped on AF performance. I'll borrow my dad's Nikon D7200 whenever I anticipate that a bit of action will be taking place. Even his Olympus OMD E-M1 is almost leaps & bounds better at tracking subjects than my K-50. I'm comparing an orange, apple, & a banana here, but the AF performance between the K-50 & the other 2 cameras is ridiculous. I think the lowest Canon or Nikon DSLRs probably have way better AF performance, but they don't have the features that the K-50 has. I've learned to compensate by focusing manually or presetting the focus, but it requires an incedible amount of effort to get some decent photos. Way more effort than using the other 2 cameras. It also defeats the whole purpose of having a modern AF system.

I'd suggest you try a Sigma 17-50mm F2.8 HSM.  Your camera will focus a lot faster with that lens.

The grass is not always greener.

I have the GX7 and GX8 they are very good all round performers, but like any camera system, these do vary in speed and accuracy depending on many variables, including lighting conditions, camera settings and the lens attached. I also have a Q -QS K10, K-01, K07, and just bought the K1. I have to say the K1 with the latest firmware and the appropriate focus points selected beats anything else I have used to date. I am using CF in 9 points selectable and I am amazed at the results even with older screw drive lenses such as the FA SMC 35-70mm. The K1 is performing spot on, fast and accurate autofocus, better than the Panasonics IMHO. I do love the GX7, and the GX8, M43 is great for video and automatic out of camera Panoramas, but I would stay with Pentax if you want the very best stills image performance, the K1 is brilliant.

PS. Have you tried manually focusing or using 'Catch-in Focus' it can be a lot of fun and very rewarding.

I've wondered if a different lens with internal focus control, like the sigma or the Pentax 18_135 would work much better.

My budget is limited.  And I'm past fiddling with technicalities to get a shot or not get a shot.  And my subjects are not keen in accommodating my camera tinkering in the moment.  The canon and Nikon entry level just seemed to work so darn quick in comparison to what I'm used to.  Though I'm sure the Pentax focus faster than those in a heavy rain...

ChiJeff5 wrote:

My budget is limited. And I'm past fiddling with technicalities to get a shot or not get a shot. And my subjects are not keen in accommodating my camera tinkering in the moment. The canon and Nikon entry level just seemed to work so darn quick in comparison to what I'm used to. Though I'm sure the Pentax focus faster than those in a heavy rain...

Entry level nikon are good for center point AF-C, but the 3D tracking is less reliable for small subjects since the D3x00 line have very few af points. If you want to play with 3D tracking I suggest you to invest at least in a D5x00.

Though the K-50 or most Pentax cameras AF isn't stellar, Pentax keeps many advantages in other areas so you may want to keep your K-50 along a Nikon kit for different purposes.

ChiJeff5 wrote:

I've wondered if a different lens with internal focus control, like the sigma or the Pentax 18_135 would work much better.

Simple answer: no.

Don't know about the K50 or the D3xxx, but my D5600 is much better at focus tracking than my K-3 or K-1, though neither of those gave us much trouble with tot shots.

Lyff wrote:

ChiJeff5 wrote:

My budget is limited. And I'm past fiddling with technicalities to get a shot or not get a shot. And my subjects are not keen in accommodating my camera tinkering in the moment. The canon and Nikon entry level just seemed to work so darn quick in comparison to what I'm used to. Though I'm sure the Pentax focus faster than those in a heavy rain...

Entry level nikon are good for center point AF-C, but the 3D tracking is less reliable for small subjects since the D3x00 line have very few af points. If you want to play with 3D tracking I suggest you to invest at least in a D5x00.

Though the K-50 or most Pentax cameras AF isn't stellar, Pentax keeps many advantages in other areas so you may want to keep your K-50 along a Nikon kit for different purposes.

I'm a landscape shooter with a K-1. Its AF is accurate. I can't compare it to other brands due to lack of experience.

I was also frustrated in some situations where the K-1 took too long to focus. Now I have turned it to release priority and this seems to be much better. Certain situations require immediate shooting, and in many cases the camera gets the shot. For example this squirrel, which appeared all of a sudden and I shot at it John Wayne style with the DA300/4. No chance with focus priority.

Lutz

ChiJeff5 wrote:

I've wondered if a different lens with internal focus control, like the sigma or the Pentax 18_135 would work much better.

Faster focusing motor will help.  The 18-135 is not a fast focusing lens.  I did see faster focusing from Sigma HSM lenses compared to Tamron screwdrive on my K30 that I previously owned.  On newer camera bodies that supports it, the Pentax PLM 55-300 is supposedly the fastest focusing lens for Pentax Kmount.

To make it short: AF has improved in the latest models, whatever the brand.

Best AF performance is an expensive differenciating feature that is offered only in top end models

Pentax AF also improved, but Pentax AF-C tracking is still behind Nikon and Canon best cameras.

When comparing with a smartphone or a small sensor compact, dont forget that the depth of field of the smaller sensor is dramatically larger: shooting at f2.8 with a small sensor compact or a smartphone, you will get the same depth of field as when shooting f11 in APS-C. As smartphone only have a wide angle lens, almost everything will be in focus, you loose the bokeh and 3D effect, but it is very forgiving for the AF.

In details:

I have K30, which is same camera as K50, since february 2014.

With K30, the only way to track a moving target in AF-C is to use single point AF and pan the camera to track the target yourself: the camera AF will work only in the Z axis, and it does that well. What it doesnt do well is tracking the target in x and y axis.

On K5/K30/K50, if your target is small, it is better to use only the central AF point, which is cross type and more precise than the other AF points. Other AF point will be prone to mistake on what is exactly your target, pecularly if the background is busy.

That is why last year, after trying my son's K3, I too bought a K3 for its much improved AF.

The 25 cross type AF points in K3/K3-II and KP are much more precise than the 9 points in K5/K30/K50, and I can track moving target in the Z axis with any of them.

Yet the K3 struggles to track by itself in X and Y axis. It is the only true limitation of Pentax cameras when compared with Canon and Nikon DSLR or most recent high end mirrorless.

You asked about the DA 18-135. I have it and it is my most used lens. It wont AF faster on a static target than the DA50 f1.8, but, IMO, its AF-C seems a little more efficient on a moving target. But as DA 18-135 at 50mm is only f4.5, the shallower depth of field when shooting at wider apertures with DA50 f1.8 can also explain a lower hit rate.

The two samples below have been shot during a Carnaval parade in single point AF-C with DA 18-135 fully open to get some background blurr :

They were walking steadily, but very close to me

As these dancers moved faster and were also quite close, I tracked the lady in the foreground  with a rather wide framing, and cropped the shot to my taste in PP, as all AF points are clustered in the center of the frame. That is why, though the K3 has 24MP, there are only around 12MP in the final picture

When comparing with a M43 camera, dont forget that the depth of field is larger on the smaller sensor: it is like shooting at an aperture value one stop closer on APS-C cameras.

I also have a M43 Panasonic GM5, which is very snappy to AF, even in dim light, but not good to track in the X and Y axis.

Also ensure that the AF in your K30 has been fine tuned for every lens you use, and pecularly for large aperture lenses like your DA50: read the manual to understand how to do it.

For ultimate precision, you need to use a tripod and a special AF target, but you can do a very efficient quick fix handheld by shooting with the lens fully open to a far away static target (a textured building about 30 meters/yards away is a good target for this purpose) and comparing the focus both in live view and using the viewfinder PDAF.

The liveview AF works the same as in mirrorless cameras, by maximizing the contrast on sensor: hence, it is always accurate.

But when using the viewfinder, AF is done by a dedicated sensor, as the image sensor is hidden by the mirror.

This is why it may often needs to be adjusted for each lens, using the camera dedicated feature: the focus accuracy through the viewfinder should be the same as in liveview.

If not, you enter a correction value and try again until you reach the value that delivers the best results. Then try again on a close distance target, usually it will be OK. If it needs a different correction, it is up to you to choose which intermediate value suits you best.

Walt_A wrote:

I have and use the OMD-10 quite a bit alongside my K3/K30 and my Canon 7D. My partner uses the Panasonic G7. If you want to do CAF/AF-C to track the OMD-10 is not for you, the G7 is much better, although I believe the newer Panasonic G80 is even better with it's improved Depth from Defocus (DFD) ability. However I shoot wildlife not people so can't say how they would work with active children. You can use the OMD 10 in single shot af with motordrive for active subjects because it is so fast to acquire the subject and with 8fps I can usually get a few more in focus that with my K3/K30. An example of a fast flying falcon is here flying Falcon , a vulture against a cluttered background vulture , and finally a flying dragonfly dragonfly in flight . You do have to approach it differently though with the way you use saf ie don't prefocus then fire but just press the shutter button down all the way in one go. The only olympus that I know does afc well is the EM-1 and it's newer II version as these have phase detect built into the sensor rather than having to rely on contrast detect af (I have no experience with them though).

Shooting on a moving target with K3 and K30, I get best results in AF-C by using back button focus: this way my thumb is dedicated to AF, whereas my forefinger on the shutter release dont bother about AF.

Pentax AF is not good in tracking in x and y axis, but is good in the z axis (depth). I get better results in single point AF-C, trusting the camera for adjusting the focus (in the Z axis) while I track the target by panning the camera.

First of all, make sure you know how to set your K-50 for action. What settings were you using; AF mode, AF point, SR? Did you control the shutter speed in P-mode? Was DOF sufficient to capture what you wanted in focus?

In this scenario I would have used TAv mode, with shutter speed of 1/500s minimum, Continuous Shooting High, AF-C, SR off, and Auto AF point (but with Auto AF you would need to see what the camera focused on before tripping the shutter). Aperture according to the DOF I was after. To isolate one child, f2.8 or f4, more than one child in sharp focus, f5.6 or f8.

I've shot many action images with a K20D, which would be similar to your K-50 in good light (the K20D is horrible in low light). There's no way you should be having trouble shooting children running about outdoors in the afternoon. Delve into the menus of your K-50, practice shooting action, it's worth it.

PS I own a K-3 and Sony a6000. I always choose the K-3 for action shooting because of superior controls. Shooting action with an a6000 is good, if you let the camera decide what it should focus on. The K-3 allows me to select one point of focus and track it. Much better IMO.

Lia25 wrote:

What is release priority? Do you use the AF-A, AF active area, Af assist light or Expanded area AF?

release priority=the camera fires the shutter as fast as it can, without waiting the AF process to be over.

LightBug wrote:

ChiJeff5 wrote:

I've wondered if a different lens with internal focus control, like the sigma or the Pentax 18_135 would work much better.

Faster focusing motor will help. The 18-135 is not a fast focusing lens. I did see faster focusing from Sigma HSM lenses compared to Tamron screwdrive on my K30 that I previously owned. On newer camera bodies that supports it, the Pentax PLM 55-300 is supposedly the fastest focusing lens for Pentax Kmount.

The DA40 f2.8 Ltd pancake on a K-70 is very very quick.