Manual Focus with Sigma T/C

kentster · 10-30-2015, 10:01 AM

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 ?

Adam · 10-30-2015, 10:07 AM

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.

stevebrot · 10-30-2015, 11:35 AM

Originally posted by kentster

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.

Steve

**Canada_Rockies** · 10-30-2015, 05:47 PM

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)

10-30-2015, 10:01 AM	#1
kentster Senior Member Join Date: Jul 2015 Location: Bremerton, Washington Posts: 287	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
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	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. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

10-30-2015, 11:35 AM	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by kentster 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. Steve Last edited by stevebrot; 10-30-2015 at 11:43 AM.

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10-30-2015, 05:47 PM	#4
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	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)