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10-30-2015, 10:01 AM   #1
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Manual Focus with Sigma T/C

Any ideas why the focus confirm doesn't work with the T/C on?

Is there a setting that I need to enable to allow it to let me know when a shot is in focus when using manual focus ?

10-30-2015, 10:07 AM   #2
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It could just not be working as reliably due to the loss of light.

If you want to use catch in focus, there's a menu setting that needs to be enabled.

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10-30-2015, 11:35 AM   #3
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QuoteOriginally posted by kentster Quote
Any ideas why the focus confirm doesn't work with the T/C on?
Focus confirm with your K-3 should work regardless of the lens/TC mounted or whether AF is turned on or off. Catch-in-focus, on the other hand, requires that the menu item (referenced in Adam's comment above) is set, AF switched on, and that the lens/TC have a conductive base. For some unexplained purpose, the camera does a check for electrical continuity between the data pin on the body and the lens mount face. If that check fails, catch-in-focus is disabled.

As Adam noted, there is the outside chance that the TC or aperture (manual aperture actuation) setting cuts the light to the AF system below the -3 EV(100) supported by your K-3. I would try again in bright light and with the lens wide open. Visually confirm that the lens is not stopped down as an additional check.


Last edited by stevebrot; 10-30-2015 at 11:43 AM.
10-30-2015, 05:47 PM   #4
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I have used CIF with the M 400/5.6. DOF is hair thin at 10 meters or less. It is very easy to overshoot before the camera has time to react. If doesn't work at all if I add the AFA 1.7x to the mix. (Wide open is f/9.5)


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