[danielchtong]

The Forster's Tern are great birds to shoot. Here are few shots taken in MF while having the AF in auto-select focal points. All are MF and cropped from a distance. SR are off in all shots

[center]



As much as I like MF on the lens with Pentax F* 300mm f/4.5, I missed quite a lot of shots due to focus errors without the trap-focus, the above are some of the keepers.

Thanks,
Hin

Hin

Awesome. White feather fast birds are difficult to focus .

Keeper rate is low but all you need is one of many to catch the right moment.

I easily mis-focus when the dog come too close.

That is the most challenging situation if the subject is running/flying towards you. It fills very little of the frame thus confusing any AF detection/locking. Try to position yourself sideway

Keep up with the good work


Daniel

[palmor]

Something else that may help is to AF with the button in the back instead of the half shutter press. The theory is that since you aren't using the shutter button the AF will pick up faster in that in between state of pressing the shutter and then half pressing again to re-achieve focus.

Great photos in this thread btw


John

[GeneV]

Great thread, both for the tips and the shots!!

[hinman]

Great thread, both for the tips and the shots!!

Gene, thanks for the comments. I should have saved some bad photos so that I can share the tips and experience in a better form. Sometimes a bad photo tell us more than a good photo. I need to pick up and learn from my mistakes and make the best use of the AF available to us.

Something else that may help is to AF with the button in the back instead of the half shutter press. The theory is that since you aren't using the shutter button the AF will pick up faster in that in between state of pressing the shutter and then half pressing again to re-achieve focus.

Great photos in this thread btw

John

John, That is something that I attempted. My good friend Mis, Justin, Migol, and few others use the AF button and they probably disable the half-press for AF. I tried it once and for the life of me, my fingers and brain are not coordinated to adjust to the changes easily.

I currently go for the opposite:

• half-press is the default AF -- use default setting
• AF is set to cancel AF -- weird but I need that for F-1.7x AFA to work with M42 lens for no AF after stopping down

I use AF as cancel for the occasionally need to cancel AF when the frantic AF starts to bother the tracking or when I don't want AF to function after stopping down the lens. I have to make that change for AF-as-AutoFocus-cancel for the manual lens with Photosniper Tair-3 PhS 300mm f/4.5 in M42 mount so that I can use the magical F-1.7x AFA on it.

But you have a valid point that the AF button may be faster and more reliable than half-press. Also, when I disable SR, I hope the AF is actually faster than when SR is turned on. Not tested but just a common sense thinking.

When shutter speed is faster than 1/1000 sec, I find SR off is better in panning motion of birds as in bird in flight. But turning SR off has its caveats in between shots as I am more likely to take some still shots. And sometime I simply forget to turn it back on when I lower ISO for still shots.

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Last edited by hinman; 05-14-2009 at 10:44 AM.

[hinman]

Here are two sets of mallard pictures in different days of BIF practice shooting. Not great samples as I am way too far from the mallard pair and it is sunset lighting with clouds in the 1st set. First set has SR off while 2nd set has SR on. Both are in AF.C with center focal point. All are shot in a sequence in single drive mode.

Pentax F* 300mm f/4.5 BIF practice

First set -- SR off
cloudy day

#1
1/1250 sec, f/5.6, 300mm, 640 iso, 0 Ev, SR off, AF.C



#2
1/1250 sec, f/5.6, 300mm, 640 iso, 0 Ev, SR off, AF.C




#3
1/1250 sec, f/5.6, 300mm, 640 iso, 0 Ev, SR off, AF.C



Second set -- SR on

#4
1/4000 sec, f/5.6, 300mm, iso 1000, SR on, AF.C




#5
1/4000 sec, f/5.6, 300mm, iso 1000, SR on, AF.C




#6
1/4000 sec, f/5.6, 300mm, iso 1000, SR on, AF.C




#7
1/4000 sec, f/5.6, 300mm, iso 1000, SR on, AF.C

If you pay attention to the 2nd set as in #5, #6, #7, I start noticing double edges in the wings. It goes as if the SR works against my panning motion to the right and shift the sensor to the left.

Anyway, I am still toying the idea of leaving SR ON or OFF as a default for panning, but I am all for trying something out for a difference and learn as I go.

Thanks,
Hin

[danielchtong]

When shutter speed is faster than 1/1000 sec, I find SR off is better in panning motion of birds as in bird in flight. But turning SR off has its caveats in between shots as I am more likely to take some still shots. And sometime I simply forget to turn it back on when I lower ISO for still shots.

Great shots above Hinman.

With practically all of them done faster than 1/2000s , SR is really pointless.

One thing I have found out is that I need sp setting for either bif or stationery shots. I can never mix it up as the former needs high shutter and iso setting and no SR.

Geese or mallard on the ground are a lot less interesting than when they are in flight. They can be very graceful indeed.























If you look at the exif you will know that they were all done in Av which does slow the burst to only 1fps not 3. So anyone using AF should use manual exposure which does not impede the focus lock. Other time saving setting are iso 800 (that is a must or higher for bif ) and no SR






Daniel

[danielchtong]

To find a cute moment of non in flight shot is relatively easy. It does not come that frequent though with this heavily cropped image.

Auto select without spot focus is ok in this circumstance










As it is not fast 1/200 is quite ok for a SR shot



Daniel

[hinman]

Daniel,

Thanks for the great photos. I especially like the shot with three geese rising together. It is a breath taking shot. I don't have your skills on MF and I wish I can manage to switch between MF and AF at ease and achieve photos easily.

I went back to same location to shoot the Forster's terns a 2nd time, the foul up on AF is nailed this time. It comes from AF not picking up any spot when I pan the bird flying over sky that has low contrast as in partially white bird over white clouds. The problem is less when I pan the bird over water. The foul up happens so often that I have to switch from AF.C to MF.

It is very disappointing because when AF.C with auto-select works, the results are quite spot on for me. It is almost insane to shoot completely in AF.C and auto-select as I don't find the combination to work satisfactory due to the frequent foul up on AF that refuses to lock on any target. It is very unsettled feeling to use K20D to picture the terns in flight. The terns are crazy for one as they don't fly in a straight pattern. The AF is not responsive enough to focus on the bird upon first half-press.

Changing to MF make the job less insane due to the less noise from the AF motor and no foul up from the AF. Unfortunately, I get lots of focus errors especially when the bird are farther away in a distance and I have to guess on MF from the default focusing screen

Daniel, are you using a katz-eye focusing screen or something similar for your MF work? I am hitting an area that both my skills and the AF responsiveness in Pentax have much rooms for improvements.

Thanks,
Hin

[danielchtong]

Daniel,


Hin

I am starting another thread on MF and its pros and cons