[MightyMike]

Interesting. I always ask about metering settings because in many camera brands it seems to have an influence on AF-C effectiveness. In Nikon, for example, AF-C '3-D tracking' relies on matrix metering to feed subject colour movement into the AF calculations, and centre-weighted and spot just can't support '3-D tracking' AF-C effectively. I believe it's the same with Pentax, particularly those bodies with access to the 86K metering sensor:





Cool. I wish it was easier to move those SEL clusters around. The 4 way controller is a bit awkward for me.

I may be wrong but I don't believe the metering setting choice has any bearing on how the camera uses the metering module for AF tracking. Basically regardless of the metering mode you select the full metering module is being used and its only metering being computed based on the mode you choose. Its not like spot or center weighted metering only activate a portion of the rectangular metering sensor, the whole sensor is active and providing all its data to the camera, then the camera chooses which data to apply to the metering mode the user has chosen. It can simultaneously used the full metering sensor data for AF tracking. Now if its too bright or too dark for the metering sensor to provide ideal data for AF tracking then it will likely fail in that role.

For airshows there is almost no reason to move off center point based tracking so moving the SEL around isn't necessary.

[reh321]

Thanks for this, Mike. Real, honest user reports - especially from someone with experience - are always of more interest to me than bench tests.

In time, when you've processed your photos, could I ask you to consider posting about the overall image quality? I'm sure I wouldn't be the only member here to value your findings...

I'd rather just have the images and make the evaluation myself if I can - I've found that my standards are not always addressed by someone who evaluates them "for me". For example, I'm more interested in live animals in the middle of the image than dead ones on the edge {if Rupert were still here, he would have asked if the photographer had performed CPR on it}. The one exception that comes to mind is astro images, because I'm not really up to taking roll to insure all the stars are present and accounted for.

[MightyMike]

I know you included a "smiley", but this actually isn't a straight forward question. A faster object can be less of a focus challenge than a slower one is if the faster one is farther away, because the real issue is how fast is the percentage distance changing.

Ok so I did some measuring, 10 shots in 2.3 seconds and based on wingspan not taking into account that the plane wasn't perfectly centered (shouldn't alter the values too much) it was traveling at 855km/h (532mph) in the first shot it was 989m (3264 ft) away and in the 10th shot it was 443m (1462 ft) away and in the 11th shot it failed, beyond that it was to big to fit in the frame. This was using the Sigma 500mm F4.5 EX DG. This also doesn't take into account its altitude so its likely approaching even faster, maybe 600mph.

Using the assumption that the DPR bike test targets head is 20cm (10") ear to ear then the cyclist started at 32.5m (107 ft) away and ended after 16 shots (3.6 seconds) at 13.2m (43.5 ft) away. He was traveling at a blistering 19.3km/h (12mph). This of course at a 200mm focal length.

Interestingly each one cleared a little more than 50% of their distance during the burst. 59% for the cyclist and 55% for the jet. However the jet did it 1.6x faster and the lens focal length was 2.5x longer... however a 200mm lens would have to move further in the focus throw over the bike change of distance than the 500mm lens. The percentage of distance change can be described as 59% in 3.6 sec compared to 55% in 2.3 sec... the percentage of change win goes to the F-18. However I suspect the focus throw distance change goes to the bike test at likely 2-4mm vs 1mm or so of the 500mm lens, however throw time into the equation and the change in focus throw gets closer to even.

Another way to look at this is the jet was traveling at least 44x faster at a starting distance of 30.5x further away and don't forget the extra 2.5x the focal length

Take from this what you will, but the K-1 II can effectively track a very fast moving target coming towards you at a realistic distance away, as can many other Pentax cameras though maybe not as effectively.

Have fun!

[LensBeginner]

I know you included a "smiley", but this actually isn't a straight forward question. A faster object can be less of a focus challenge than a slower one is if the faster one is farther away, because the real issue is how fast is the percentage distance changing.

I know that. It was a gratuitous stab at you-know-who.
OP wrote "coming in fast straight towards me with the sigma 500mm ", so I assumed close-ish distance and high magnification.

[redpit]

The photos of this event will come in time, they've yet to be edited.

Really appreciate the feedback Mike! Thank you very much for the detailed report.... You perfectly described airshow results that all of us that have photographed airshow know what you're talking about

I'm thinking of upgrading too, but still haven't decided what to do... I'm expecting some samples too, as I prefer viewing pictures to reading

[MightyMike]

Link to the post with the link for the finished gallery from this event
K-1 II My First Airshow Gallery - PentaxForums.com