Re: Official: Sony A7 and A7R Fullframe Mirrorless
sebboh wrote: Samuli Vahonen wrote:
Other topic: I shoot today 1/4000s and 1/8000s images with and without electronic first curtain to get understanding WHY some people claim that mechanical first curtain shutter is needed at high shutter speeds. I look at the images and can\'t find difference. What I should be looking for? Or is it\'s myth/BS that electronical first shutter causes image quality issues at fastest shutter speeds.
Samuli
shooting at higher shutter speeds with EFC on often results in uneven exposure of the frame at least on NEX cameras. it basically looks like there is severe vignetting on only on the bottom of the frame (in landscape orientation). i\'ve successfully used it as a makeshift grad filter by turning the camera upside down.
Yep, it creates uneven exposure and a thin exposure boundary. Here\'s a sample on an NEX-5N (EFSC on left). It starts somewhere between 1/2000 and 1/4000. It\'s likely a rolling shutter reset artifact. The sensor reset associated with EFSC happens very quickly, certainly faster than the time it takes to read the sensor during an exposure. However the reset is probably done on a rolling-row basis (just like an exposure), so while a portion of the sensor is still being reset the portion that has already been reset is already receiving light for the final exposure. This is why the effect looks like a GND - rows that reset first will receive the most light, with subsequent rows progressively receiving less.
Re: Official: Sony A7 and A7R Fullframe Mirrorless
sebboh wrote: Samuli Vahonen wrote:
Other topic: I shoot today 1/4000s and 1/8000s images with and without electronic first curtain to get understanding WHY some people claim that mechanical first curtain shutter is needed at high shutter speeds. I look at the images and can\'t find difference. What I should be looking for? Or is it\'s myth/BS that electronical first shutter causes image quality issues at fastest shutter speeds.
Samuli
shooting at higher shutter speeds with EFC on often results in uneven exposure of the frame at least on NEX cameras. it basically looks like there is severe vignetting on only on the bottom of the frame (in landscape orientation). i\'ve successfully used it as a makeshift grad filter by turning the camera upside down.
Yep, it creates uneven exposure and a thin exposure boundary. Here\'s a sample on an NEX-5N (EFSC on left). It starts somewhere between 1/2000 and 1/4000. It\'s likely a rolling shutter reset artifact. The sensor reset associated with EFSC happens very quickly, certainly faster than the time it takes to read the sensor during an exposure. However the reset is probably done on a rolling-row basis (just like an exposure), so while a portion of the sensor is still being reset the portion that has already been reset is already receiving light for the final exposure. This is why the effect looks like a GND.
Re: Official: Sony A7 and A7R Fullframe Mirrorless
sebboh wrote: Samuli Vahonen wrote:
Other topic: I shoot today 1/4000s and 1/8000s images with and without electronic first curtain to get understanding WHY some people claim that mechanical first curtain shutter is needed at high shutter speeds. I look at the images and can\'t find difference. What I should be looking for? Or is it\'s myth/BS that electronical first shutter causes image quality issues at fastest shutter speeds.
Samuli
shooting at higher shutter speeds with EFC on often results in uneven exposure of the frame at least on NEX cameras. it basically looks like there is severe vignetting on only on the bottom of the frame (in landscape orientation). i\'ve successfully used it as a makeshift grad filter by turning the camera upside down.
Yep, it creates uneven exposure and a thin exposure boundary. Here\'s a sample on an NEX-5N (EFSC on left). It starts somewhere between 1/2000 and 1/4000. It\'s likely a rolling shutter reset artifact. The sensor reset associated with EFSC happens very quickly, certainly faster than the time it takes to read the sensor during an exposure. However the reset is probably done on a rolling-row basis (just like an exposure), so while a portion of the sensor is still being reset the portion that has already been reset is already starting to receive light for the final exposure. This is why the effect looks like a GND.
Dec 14, 2013 at 12:06 PM
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