K100D AF not focussing

gibikote · 01-17-2009, 11:25 PM

Hi

I recently acquired a used K100D with 2 Sigma lenses (24-70; 70-300) and these really look new/sparingly used. The friend who sent them from overseas has taken a few snaps which look v.good too.

I tried it today, but the lenses are not focussing. I double checked that the switch is on AF, and even reset all custom selections to default. The focus ring on the lenses release (in MF) and tighten on making the MF/AF switch as would be expected. The lenses just dont focus in AutoProgram or any other mode... the exposure continues and I end up with a blurred image.

Warranty does not exist, and I would think of returning rather than chasing repair, as it would be in another city...

All suggestions welcome.

Thanks in advance.
Sridhar

Class A · 01-18-2009, 02:37 AM

Originally posted by gibikote

I tried it today, but the lenses are not focussing. I double checked that the switch is on AF, and even reset all custom selections to default.

Not sure whether AF settings such as the following are reset: One can, e.g., set the OK button to enable focus. Pressing the shutter button halfway then won't activate the AF but only pressing the OK button will.

Make sure it is none of this.

Originally posted by gibikote

the exposure continues and I end up with a blurred image.

Normally, with AF activated the camera shouldn't take a picture unless it detects something in focus.
Is AF set to AF-S?

You could also try to look at the images of your friend and see whether they were taken with AF or manual focus. The PhotoME program can read the EXIF data of images and lets you know.

Hope that helps.

axl · 01-18-2009, 02:59 AM

reseting the custom functions would have sorted out the OK button issue. I'd fiddle with the switch on the lenses, but go through the custom menu again to see if it's set correctly.
Check following:
AF by halfpress: enable or yes
OK button when shooting: choose whichever you like. Setting these two should sort the problem, and try it with different lenses too.
good luck
BR

gibikote · 01-18-2009, 07:47 AM

hi ClassA and axl
thanks for the suggestions...
need to re-check the Custom settings & switch on the lenses (wonder where that is... )
hope to be back later tonight/morrow.

-Sridhar

gibikote · 01-18-2009, 10:03 AM

it was the OK button setting!
(is this really a helpful thing - AF on the OK button? havent used it earlier... need to search through the thread to see how ppl use it).

thanks guys!

KjetilH · 01-18-2009, 02:32 PM

The most important part is the ability to keep SR ready for use with the shutter button half-pressed. Combined with AF-C, OK-AF can be effective for getting faster focus (though with higher risk of defocused images).

Class A · 01-19-2009, 04:04 AM

Originally posted by gibikote

it was the OK button setting!

Hey, that's a lot better than a broken camera.

Glad we could help.

Originally posted by gibikote

is this really a helpful thing - AF on the OK button?

I sometimes use it to decouple focusing from shutter releasing.

In particular when you have to recompose after obtaining focus and want to take several shots (perhaps making slight exposure or other alterations in between) with the same focus, it is nice to not make "half-press" refocus again.

Or when I shoot action and want to separately either obtain new focus or capture the moment.

gibikote · 01-19-2009, 04:07 AM

hi KjetilH
maybe I am asking these too early (before trying)...

* as a general default is AF-C any way better than AF-S (presently my camera is on AF-S)

* if on OK-AF, SR would probably need to be on all the time (from start up). the button is so placed that it would be impossible to move to on position while framing the shot and thumb on the OK.

Thanks!

01-17-2009, 11:25 PM	#1
gibikote Forum Member Join Date: Jan 2009 Location: Vellore, India Photos: Gallery \| Albums Posts: 83	K100D AF not focussing Hi I recently acquired a used K100D with 2 Sigma lenses (24-70; 70-300) and these really look new/sparingly used. The friend who sent them from overseas has taken a few snaps which look v.good too. I tried it today, but the lenses are not focussing. I double checked that the switch is on AF, and even reset all custom selections to default. The focus ring on the lenses release (in MF) and tighten on making the MF/AF switch as would be expected. The lenses just dont focus in AutoProgram or any other mode... the exposure continues and I end up with a blurred image. Warranty does not exist, and I would think of returning rather than chasing repair, as it would be in another city... All suggestions welcome. Thanks in advance. Sridhar

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01-18-2009, 02:37 AM	#2
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by gibikote I tried it today, but the lenses are not focussing. I double checked that the switch is on AF, and even reset all custom selections to default. Not sure whether AF settings such as the following are reset: One can, e.g., set the OK button to enable focus. Pressing the shutter button halfway then won't activate the AF but only pressing the OK button will. Make sure it is none of this. Originally posted by gibikote the exposure continues and I end up with a blurred image. Normally, with AF activated the camera shouldn't take a picture unless it detects something in focus. Is AF set to AF-S? You could also try to look at the images of your friend and see whether they were taken with AF or manual focus. The PhotoME program can read the EXIF data of images and lets you know. Hope that helps.

01-18-2009, 02:59 AM	#3
axl Veteran Member Join Date: Mar 2007 Location: Nove Zamky, Slovakia Photos: Gallery \| Albums Posts: 7,183	reseting the custom functions would have sorted out the OK button issue. I'd fiddle with the switch on the lenses, but go through the custom menu again to see if it's set correctly. Check following: AF by halfpress: enable or yes OK button when shooting: choose whichever you like. Setting these two should sort the problem, and try it with different lenses too. good luck BR

01-18-2009, 07:47 AM	#4
gibikote Forum Member Join Date: Jan 2009 Location: Vellore, India Photos: Gallery \| Albums Posts: 83 Original Poster	hi ClassA and axl thanks for the suggestions... need to re-check the Custom settings & switch on the lenses (wonder where that is... ) hope to be back later tonight/morrow. -Sridhar

01-18-2009, 10:03 AM	#5
gibikote Forum Member Join Date: Jan 2009 Location: Vellore, India Photos: Gallery \| Albums Posts: 83 Original Poster	it was the OK button setting! (is this really a helpful thing - AF on the OK button? havent used it earlier... need to search through the thread to see how ppl use it). thanks guys!

01-18-2009, 02:32 PM	#6
KjetilH Veteran Member Join Date: Mar 2008 Location: Oslo Photos: Gallery Posts: 309	The most important part is the ability to keep SR ready for use with the shutter button half-pressed. Combined with AF-C, OK-AF can be effective for getting faster focus (though with higher risk of defocused images).

01-19-2009, 04:04 AM	#7
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by gibikote it was the OK button setting! Hey, that's a lot better than a broken camera. Glad we could help. Originally posted by gibikote is this really a helpful thing - AF on the OK button? I sometimes use it to decouple focusing from shutter releasing. In particular when you have to recompose after obtaining focus and want to take several shots (perhaps making slight exposure or other alterations in between) with the same focus, it is nice to not make "half-press" refocus again. Or when I shoot action and want to separately either obtain new focus or capture the moment.

01-19-2009, 04:07 AM	#8
gibikote Forum Member Join Date: Jan 2009 Location: Vellore, India Photos: Gallery \| Albums Posts: 83 Original Poster	hi KjetilH maybe I am asking these too early (before trying)... * as a general default is AF-C any way better than AF-S (presently my camera is on AF-S) * if on OK-AF, SR would probably need to be on all the time (from start up). the button is so placed that it would be impossible to move to on position while framing the shot and thumb on the OK. Thanks!