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05-04-2012, 10:52 PM   #16
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Greetings. My K-5 has worked rather well over the past year, with various DA*, FA and DA Limited lenses. However, tonight I found that neither the DA 16-45 nor the FA Limited 43 could achieve focus on a relatively high contrast subject (hiking boots) about 4 feet away (well within the focus range of either lens). On AF-S, the camera would hunt severely and not lock focus at all, unless I removed the camera from the tripod, backed up 2 more feet, handheld, and tried AF again. Then it worked fine, as normal. Not sure what the deal is.

05-04-2012, 11:30 PM   #17
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What were the lighting conditions? At close range, the AF assist light might properly illuminate the subject. Could also be because only the center point was chosen (rather than all 11), in which case you would have simply been unlucky.

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05-05-2012, 11:34 PM   #18
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K-5 AF hunting issue

Adam,
Thanks for the reply. Lighting conditions were "average", enough to focus on manually, with an exposure of 1/180 @f/8 with flash. I do usually use the Center Point, and 5 AF points. I used the same kit today with Metz 58 AF-2 flash with no issues, but still puzzled as to why the system failed to lock focus with both the DA 16-45 and FA 43 Limited! Steve
05-08-2012, 05:26 PM - 1 Like   #19
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I got a new K-5 yesterday early in the day. Didn't have a look at it until the evening because of work and I quickly noticed something was off/different with the focusing vs. my K-x.

I have done lots and lots of testing in the two days I've had it and so far it seems like AF is affected by light level and/or type, as have been suggested on various pages.

My worst case scenario: I have a rolled up poster (bright) leaning up against a dark wall. The K-5 refuses to archive accurate focus no matter how many times I try - except in LV mode. It's often off by up to 40-45cm, while I was seated approx 3m from the subject/poster - this was using the 70mm ltd @ 2.4.

My K-x on the other hand nails it every single time and performance wise the K-x isn'wasn't really struggling. Is the K-5 not supposed to be better than K-x on this area (AF)? I've been doing comparisons with different targets with both the K-5 and K-x using 4-5 different lenses (all 2.8 except my 70mm Limited which is 2.4), and K-x was by far the clear winner.

Light level: I get a good exposure (photo looks like how I see) @ 1/25th f2.4 ISO 6400.

Ps. it's not a lens FF issue because I can get a good focus in different lighting.

Pps. The k-5 never really struggled. It locked quickly, but way off point.

05-09-2012, 05:14 AM   #20
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QuoteOriginally posted by mxlinn Quote
I've been using my K5 with a newly acquired A f1.2 lens and found couldn't rely on the AF confirmation (red light and beep) for focus accuracy. Anyone please comment if to trust your eye or AF confirmation? Also, has anyone tried Focus Trap/Catch-in Focus on K5, I couldn't seem to able to get the camera to fire automatically once focus is in.
You need a calibrated split focus screen to aid manual focus. Then you won't need the AF confirm nor the CIF. AF confirmation may be a great aid in low light scenes but cannot replace the split screen.

Canon S type is fine, but without the split indicator, that implies that your focusing eye must be perfect to focus correctly.
I prefer the split - far more easier to focus.

The split screen also easier to calibrate.
05-09-2012, 05:54 AM   #21
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QuoteOriginally posted by mxlinn Quote
I've been using my K5 with a newly acquired A f1.2 lens and found couldn't rely on the AF confirmation (red light and beep) for focus accuracy. Anyone please comment if to trust your eye or AF confirmation? Also, has anyone tried Focus Trap/Catch-in Focus on K5, I couldn't seem to able to get the camera to fire automatically once focus is in.
first of all the red light is NOT focus confirmation, this is a green hexagon at the bottom of the viewfinder so you are not using the correct indicators.

Second the red light only indicates which focus sensor is being used, and flashes somewhat irregularly

Third, while the beep is perhaps good, it only indicates when you hit focus, not whether you are remaining in focus, so if you pass through the focus zone it will beep

Only the green hexagon which if lit continually indicates you are in focus, is a true focus indicator.

Then add something (I don't know if I really believe it or not, as I don't have an F1.2 to test it on) but there is the idea that with really fast lenses the focus point shifts between wide open and stopped down. therefore, focusing wide open, and stopping down to shoot causes a shift in the focus point of the lens, but you are not focusing stopped down.

also, the very fast lenses are tough to focus manually due to the very thin depth of field when wide open.

A split image focusing screen might be a better option
05-09-2012, 08:39 AM   #22
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I have for A type lenses, with some experimentation found to focous more accuracy using CIF when you turn the focus ring in a counter clockwise direction! It may sound crazy, but for lenses focused using that procedure can't be wrong....... right! If someone wants to give it a try and comment if it works, or just call me CRAZY!!! This procedure is done while looking through the viewfinder obviously. Most of the time I just hold down the shutter release button while turning counter clockwise slowly and bingo, a sharp shot.
05-28-2012, 03:32 AM   #23
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QuoteOriginally posted by mxlinn Quote
I've been using my K5 with a newly acquired A f1.2 lens and found couldn't rely on the AF confirmation (red light and beep) for focus accuracy. Anyone please comment if to trust your eye or AF confirmation? Also, has anyone tried Focus Trap/Catch-in Focus on K5, I couldn't seem to able to get the camera to fire automatically once focus is in.
Getting back to the OP.

I've also recently acquired a K 50mm f1.2 and they are a real challenge. I've more or less decided that with AF confirmation I've probably already turned the focus ring past the critical focus point before the camera 'in-focus confirmation' flashes and beeps.

I'm beginning to suspect that the problem obtaining spot-on focus confirmation may be due in no small part to the VERY narrow DOF. Even in 'Live-view' with the magnification at maximum, I find it a challenge to get the focus spot on. I figured that camera lag would be the same with CIF so I'm persevering with focussing by what I see in the viewfinder or on the LCD screen at present.

I will keep trying because the bokeh is something to behold, and I reckon when I get it right I'll have some shots to be proud of.

BTW, I am also using a K5.

Hang in there, and if you come up with a magic formula, please post in this thread and I'll do the same.

Cheers

Kevin

05-28-2012, 10:58 AM   #24
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Kevin, I strongly advise you to look into the Canon EE-S focusing screen for K-5 which you can buy from focusingscreen.com. It still will be a challenge with f1.2 due to a very narrow DOF but I can assure you the keeper ratio will be much higher.
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