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Simen1 · 08-04-2015, 04:13 AM

Originally posted by RonHendriks1966

You only will get the aps-c size cut from the sensor, so you might as well just stick with an aps-c sensor camera.

Is this a guess or something confirmed by Pentax? I will have a menu option to turn off auto cropping when using APS-C lenses on a Pentax FF body. Besides, the camera cant know if the Samyang 8mm f/3,5 is made for APS-C or not. Its a lens without electronic contacts.

---------- Post added 08-04-2015 at 01:20 PM ----------

Originally posted by Mistral75

Er.... no. On-sensor PDAF photodiods are neither some kind of filter nor an add-on in front of the sensor. They are part of the sensor, engraved in silicon.

Its an add-on to the color filter array. Its practically a pair of pixels where half the pixels is blocked (left half of one pixel and right half of the other). The color filter array is between the micro lenses and the silicon sensor. I'm not shure witch side of the color filter array the half pixel shades are, but its not engraved in silicon. Aside from the light loss the PDAF-pixels are constructed just like other pixels. The camera might choose a faster sampling rate of these pixels.

RonHendriks1966 · 08-04-2015, 12:14 PM

Originally posted by Simen1

Is this a guess or something confirmed by Pentax? I will have a menu option to turn off auto cropping when using APS-C lenses on a Pentax FF body. Besides, the camera cant know if the Samyang 8mm f/3,5 is made for APS-C or not. Its a lens without electronic contacts.

With those lenses and old lenses you will use the while sensor and some times get the nice vignetting.

dosdan · 08-04-2015, 12:34 PM

Originally posted by Simen1

Its an add-on to the color filter array. Its practically a pair of pixels where half the pixels is blocked (left half of one pixel and right half of the other). The color filter array is between the micro lenses and the silicon sensor. I'm not shure witch side of the color filter array the half pixel shades are, but its not engraved in silicon.

No, it's part of the sensor layer, not part of the "toppings" (anti-reflection coating, UV filter coating (if used), IR filter coating, AA filter (if used), microlenses, Bayer CFA (if used)) that are placed on top of the sensor.

Image Sensors World: Canon Announces Dual Pixel CMOS AF Technology

You could have Dual Pixel CMOS AF without an CFA.

Dan.

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08-04-2015, 04:13 AM	#46
Simen1 Veteran Member Join Date: Jul 2009 Location: Tromsø, Norway Photos: Albums Posts: 1,031	Originally posted by RonHendriks1966 You only will get the aps-c size cut from the sensor, so you might as well just stick with an aps-c sensor camera. Is this a guess or something confirmed by Pentax? I will have a menu option to turn off auto cropping when using APS-C lenses on a Pentax FF body. Besides, the camera cant know if the Samyang 8mm f/3,5 is made for APS-C or not. Its a lens without electronic contacts. ---------- Post added 08-04-2015 at 01:20 PM ---------- Originally posted by Mistral75 Er.... no. On-sensor PDAF photodiods are neither some kind of filter nor an add-on in front of the sensor. They are part of the sensor, engraved in silicon. Its an add-on to the color filter array. Its practically a pair of pixels where half the pixels is blocked (left half of one pixel and right half of the other). The color filter array is between the micro lenses and the silicon sensor. I'm not shure witch side of the color filter array the half pixel shades are, but its not engraved in silicon. Aside from the light loss the PDAF-pixels are constructed just like other pixels. The camera might choose a faster sampling rate of these pixels.

08-04-2015, 12:14 PM	#47
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	Originally posted by Simen1 Is this a guess or something confirmed by Pentax? I will have a menu option to turn off auto cropping when using APS-C lenses on a Pentax FF body. Besides, the camera cant know if the Samyang 8mm f/3,5 is made for APS-C or not. Its a lens without electronic contacts. With those lenses and old lenses you will use the while sensor and some times get the nice vignetting.

08-04-2015, 12:34 PM	#48
dosdan Pentaxian Join Date: Dec 2007 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 1,741	Originally posted by Simen1 Its an add-on to the color filter array. Its practically a pair of pixels where half the pixels is blocked (left half of one pixel and right half of the other). The color filter array is between the micro lenses and the silicon sensor. I'm not shure witch side of the color filter array the half pixel shades are, but its not engraved in silicon. No, it's part of the sensor layer, not part of the "toppings" (anti-reflection coating, UV filter coating (if used), IR filter coating, AA filter (if used), microlenses, Bayer CFA (if used)) that are placed on top of the sensor. Image Sensors World: Canon Announces Dual Pixel CMOS AF Technology You could have Dual Pixel CMOS AF without an CFA. Dan.

Sony BSI APS-C Sensors

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