Reduced sensorsize use during moviefunction: K-01 (and K-30?)

RonHendriks1966 · 07-22-2012, 12:10 PM

I noticed this before, but had some time to look into this. During movie recording the K-01 (how is that with K-30?) doesn't use the whole width of the sensor, but cut's off a part of it.

So I set up my camera infront of my screen (googled a grid) with 40mm lens that would fit all three formats:

This is a picture, jpg in 3:2:

This is a picture, jpg in 16:9:

This is a jpg extracted from a movieclip in 16:9:

No exact measurement, but it seems that it uses only 90 % off the sensor width.

Anyone an idea about how and why? Or is this old news I missed? Is this the same with the K-30?

The only thing I can think off is less heat development during the movierecording.

Last edited by RonHendriks1966; 07-22-2012 at 01:53 PM.

vladimiroltean · 07-22-2012, 12:22 PM

Maybe it has to do with shake reduction, edges will be cropped out with the sensor moving, so they decided to cut some slack and minimize the effect of moving frame.

Na Horuk · 07-22-2012, 03:28 PM

You can also just set the camera to P mode and 16:9, and then turn the mode dial to the video camera and see that the image on the LCD screen gets cropped (or enlarged or whatever)
It sort of makes sense that the camera doesn't use the whole sensor when doing video, because video is only 1080p. On the other hand, its odd that they would cut off the edges, since that becomes a pretty big crop, compared to FF lens focal length number.
Don't know which parts of the sensor other brands use for video, though. Would be an interesting comparison.

RonHendriks1966 · 07-23-2012, 07:56 AM

Originally posted by Na Horuk

On the other hand, its odd that they would cut off the edges, since that becomes a pretty big crop, compared to FF lens focal length number.
Don't know which parts of the sensor other brands use for video, though. Would be an interesting comparison.

Well they don't crop extra on the K-5 moviefunction. The cropfactor for lenses in moviefunction (if interesting at all) to compare with full frame is about 1,7x.

Canon does a crop size for moviefunction on the 1Dx, don't know how much, but it was kind of APS-H sized.

GabrielFFontes · 12-11-2012, 09:33 AM

I know this is an old thread, but if anyone still cares about this, the edges are cropped because the Shake Reduction in the K-01 and K-30's movies is electronic, and NOT sensor based. With that in mind, to do the image stabilization with the software, you have to stretch the image and/or move the frame, so the edge cropping is done so no "black border" appears

mbp · 05-10-2013, 07:46 PM

I wonder if the image is not cropped during movie function if the SR on the k01 is turned off....

mbp · 05-19-2013, 09:47 PM

Just found another post that answered my question.
Video is still cropped, even when SR is turned off. Bummer

.
https://www.pentaxforums.com/forums/pentax-k-01/203814-about-k-01s-stabilizer-video-mode.html

RonHendriks1966 · 05-20-2013, 02:57 AM

Originally posted by mbp

Just found another post that answered my question.
Video is still cropped, even when SR is turned off. Bummer

.
https://www.pentaxforums.com/forums/pentax-k-01/203814-about-k-01s-stabilizer-video-mode.html

Yes and I found the answer in the why - apparently it is due to the SR-functioning that is different then with stills.

07-22-2012, 12:10 PM	#1
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	Reduced sensorsize use during moviefunction: K-01 (and K-30?) I noticed this before, but had some time to look into this. During movie recording the K-01 (how is that with K-30?) doesn't use the whole width of the sensor, but cut's off a part of it. So I set up my camera infront of my screen (googled a grid) with 40mm lens that would fit all three formats: This is a picture, jpg in 3:2: This is a picture, jpg in 16:9: This is a jpg extracted from a movieclip in 16:9: No exact measurement, but it seems that it uses only 90 % off the sensor width. Anyone an idea about how and why? Or is this old news I missed? Is this the same with the K-30? The only thing I can think off is less heat development during the movierecording. Last edited by RonHendriks1966; 07-22-2012 at 01:53 PM.

07-22-2012, 12:22 PM	#2
vladimiroltean Veteran Member Join Date: Dec 2010 Location: Bucharest, Romania Photos: Gallery Posts: 1,465	Maybe it has to do with shake reduction, edges will be cropped out with the sensor moving, so they decided to cut some slack and minimize the effect of moving frame.

07-22-2012, 03:28 PM	#3
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	You can also just set the camera to P mode and 16:9, and then turn the mode dial to the video camera and see that the image on the LCD screen gets cropped (or enlarged or whatever) It sort of makes sense that the camera doesn't use the whole sensor when doing video, because video is only 1080p. On the other hand, its odd that they would cut off the edges, since that becomes a pretty big crop, compared to FF lens focal length number. Don't know which parts of the sensor other brands use for video, though. Would be an interesting comparison.

07-23-2012, 07:56 AM	#4
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675 Original Poster	Originally posted by Na Horuk On the other hand, its odd that they would cut off the edges, since that becomes a pretty big crop, compared to FF lens focal length number. Don't know which parts of the sensor other brands use for video, though. Would be an interesting comparison. Well they don't crop extra on the K-5 moviefunction. The cropfactor for lenses in moviefunction (if interesting at all) to compare with full frame is about 1,7x. Canon does a crop size for moviefunction on the 1Dx, don't know how much, but it was kind of APS-H sized.

12-11-2012, 09:33 AM	#5
GabrielFFontes Veteran Member Join Date: Jul 2011 Location: Rio de Janeiro, Brazil Posts: 647	I know this is an old thread, but if anyone still cares about this, the edges are cropped because the Shake Reduction in the K-01 and K-30's movies is electronic, and NOT sensor based. With that in mind, to do the image stabilization with the software, you have to stretch the image and/or move the frame, so the edge cropping is done so no "black border" appears

05-10-2013, 07:46 PM	#6
mbp Junior Member Join Date: Sep 2012 Photos: Albums Posts: 39	I wonder if the image is not cropped during movie function if the SR on the k01 is turned off....

05-19-2013, 09:47 PM	#7
mbp Junior Member Join Date: Sep 2012 Photos: Albums Posts: 39	Just found another post that answered my question. Video is still cropped, even when SR is turned off. Bummer . https://www.pentaxforums.com/forums/pentax-k-01/203814-about-k-01s-stabilizer-video-mode.html

05-20-2013, 02:57 AM	#8
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675 Original Poster	Originally posted by mbp Just found another post that answered my question. Video is still cropped, even when SR is turned off. Bummer . https://www.pentaxforums.com/forums/pentax-k-01/203814-about-k-01s-stabilizer-video-mode.html Yes and I found the answer in the why - apparently it is due to the SR-functioning that is different then with stills.

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