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Forum: Pentax K-3 10-12-2015, 02:24 AM  
Increasing AF speed on a K-3 : technique or hardware or both?
Posted By awaldram
Replies: 32
Views: 6,006
There a big different between priority and mandatory !!

The only difference between focus priority and shutter priority is the weighting applied to focus Vs shutter

Both will attempt to focus the camera using all the data you provide, In the case of single point and approaching target that would be roughly no data so no accurate focus will occur the same is true for lacking target background separation.

So from this we can establish 1 rule - single point AF does not allow predictive AF

In focus priority the camera will attempt to focus the subject to the detriment of FPS so under low light frame rate will drop drastically as it can take upwards of .7 second for the sensor to correlate multi point AF, Under shutter priority the camera will fire the shutter while it attempts to focus so frame rate around 7.2 will be achieved.

Another rule coming up

Under AF-C focus is not promised as this is a continuous AF mode the camera will always be attempting to follow the moving subject , If you need lock before shutter then AF-S is the mode you should use.

Finally Lens, as AF-c relies on fast reporting from the Phase detectors and positive discrimination of target vs background it easy to see the slower the lens the worse AF-c performance, When light drops the phase reporting takes longer, an f2.8 lens lets in twice the light as an F4 lens so you can see under low light a fast lens is required.

Under good light you will still need a fast lens especially with shorter focal lengths as the DoF can end up so large practically everything is more or less in focus and AF-c is pointless and wont work anyway.

Nothing has changes you still need a 70-200 f2.8 as a starter for indoor sports work (aps-C you can get away with 50-135) for intimate action shooting you need f2.8 or better or your wasting your time.

IMO no lens in the 10-200mm range should be used for indoor sport AF-C work unless it has an open aperture >=f2.8 physics clearly shows you will be disappointed !!

Only when you've met the above requirements is it time to look at body used or lens motor speed.

Of cause in reality you look at both the basics requirements (F2.8 and 200mm) at the same time as lens /body performance, With this in mind and the knowledge that glass control is paramount to good AF-C performance you need high torque low latency lens drive which translates to HSM,SDM,DC in lens drive.

Currently the best current indoor sport solution (basic) for Pentax is
DA* 50-135 + K3ii

the best 2nd hand solution is
Sigma 70-200 OS HSM f2.8 + K3ii

This is only valid for 'general' advice for indoor shooting and is possibly not correct for your sport/conditions.

For example I shoot under mixed lighting in 25 and 50 m Pools sometimes deck side my usual 'arsenal'

25M pools
DA*300 F4 , 70-200F2.8 , 50-135 F2.8 and 55 f1.4
50M pools
DA*300f4 , Sigam 400 F5.6 , Bigma +HD converter

I usually carry the 70-200 @50M pools as sometimes the light is appalling as night comes, Generally 50M pools in the UK are modern and well lit.

---------- Post added 12-10-15 at 10:35 AM ----------



Just thought on your last bit, Getting multiple AF reading is paramount for successfull Predictive AF (sharp image under AF-C) fro this to occur the Photographer must.

1 keep AF wound up
2 accurate track the subject

It may be easier for a beginner to enable back button AF and keep that pressed , That way they can 'squirt' the shutter in bursts without lifting to far and stopping AF tracking. allowing more time to concentrate on keeping the subject on sensor.

---------- Post added 12-10-15 at 10:43 AM ----------



Centre point ? You've disabled predictive AF, so as soon as you lose target or the camera/lens can't keep up with the action you will get OOF images

If you used 9 point expanding you'd get predictive AF and auto handoff if you slightly lost the subject from the centre point during the pan the camera would hold target for you

Admittedly Pentax's 'predictive' AF is pretty crude but works well for linear tracking allowing sharp image as the AF will skip to where the subject will be whilst the shutter is open not lagging behind.
Forum: Digital Processing, Software, and Printing 04-07-2016, 09:50 PM  
Does LR automatically support the K-3 and Pentax lenses?
Posted By stevebrot
Replies: 24
Views: 2,209
It is easy, but not well-documented. The steps go something like this:
  • Under Lens Corrections, Profile tab, check "Enable Profile Correction"

  • If the "Make", "Model", and "Profile" selections are appropriate, there is nothing to do. If not, continue...

  • Under "Make" choose the lens brand

  • With any luck the "Model" and "Profile" selectors will auto-fill. If not, find your lens model and choose the desired profile. If there is no profile for your lens, you are blocked until you can find one online or make one yourself.

  • Having found a profile, you can set it as the new default for that lens by clicking the "Setup" selector and choosing "Save New Lens Profile Defaults"

Note that this does not change how the lens model may or may not be detected on import. Lightroom pulls that information from other fields.


Steve
Forum: Digital Processing, Software, and Printing 08-20-2015, 11:14 PM  
You should delay Windows 10 upgrade!!!!!
Posted By officiousbystander
Replies: 53
Views: 6,606
I've gone from 7 to 8 to 8.1 to 10 and haven't had any problems. Maybe doing individual steps has helped. PSPX7 runs fine. Did yours have the latest updates? BTW beware of the Refresh option. I thought it was the same as the old Repair but it wipes out all your applications which is a little bit more than a refresh in my dictionary. I've done two PCs and one laptop now. The laptop which is 8yrs old went straight from 7 to 10 but it's the kids' so there was nothing at risk there. 10 runs slightly better than 7 on the old hardware.
The really big issue with Windows 10 is privacy:
Windows 10 privacy problems: Here’s how bad they are, and how to plug them.
Forum: Digital Processing, Software, and Printing 03-01-2015, 11:24 AM  
Perfect Effects 9 free
Posted By jmick
Replies: 11
Views: 1,636
Forum: Pentax K-3 02-18-2014, 02:16 PM  
K3 sample shots ... post here !
Posted By normhead
Replies: 11,381
Views: 1,421,052
A few from the weekend...














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