[Derwin]

>>software shake reduction<<

??

The K30s video mode is almost certainly not using the physical shake reduction mechanism that is used to stabilise the sensor when taking stills. The results bear far more similarities to the kind of software based image stabilisation that is possible in post rather than, for example, footage shot with an image stabilised lens.

[Steve.Ledger]

I don't own a K-30, but I do own a K-7, K-01 and Q. All of which use the same sensor shift stabilization during video. It would surprise me if the K-30 used digital image stabilization.

The K-30 captures photos and Full HD video with its 16 Megapixel CMOS sensor, and image blur is reduced via a sensor-shift image stabilization system

► Pentax K-30 Review | Digital Camera Resource Page

[Derwin]

I don't own a K-30, but I do own a K-7, K-01 and Q. All of which use the same sensor shift stabilization during video. It would surprise me if the K-30 used digital image stabilization.


► Pentax K-30 Review | Digital Camera Resource Page

Hmmm... I'm going to have to do a partial climb down on this. Have just recorded a couple of samples on my K30 with the 1.04 firmware and I can most definitely hear the shake reduction mechanism in operation during live view and movie recording. So, it appears sensor shift is used in movie mode. This is not what I remember of my earlier attempts with he K30 (not that my memory can be relied upon for much beyond the occasional staggering inaccuracy these days), so I wonder if anyone running 1.01-1.03 can test for the same? Can you hear the SR mechanism during movie recording?

What I'm still unable to square away is the type of visible evidence of shake reduction in some of the footage I've seen from the K30. With sensor shift, if you were going to see any evidence of the shake reduction in your footage it might be expected to be across the full frame (moving the sensor as it does), but many of the K30 clips - including some shots in the TCS clip at the start of this thread - exhibit area-specific warping and distortion which is more consistent with software shake reduction (crop the frame and use information from the surrounding area and a bit of guesswork in between to fill in any gaps). Would be interesting to know what firmware version Jordan's K30 was running when they filmed that clip.

Could it be that the K30 is now using some combination of both physical and digital image stabilisation?

Higher bit-rates and lift the ISO3200 cap in the next firmware update. Come on Pentax, we know you're lurking, :P

[Steve.Ledger]

What you might be seeing is the rolling shutter effect coupled with the sensor shift stabilization and is likely one of the reasons it is often suggested that SR be disabled for video.

[Derwin]

What you might be seeing is the rolling shutter effect coupled with the sensor shift stabilization and is likely one of the reasons it is often suggested that SR be disabled for video.

It must be. Strange that in-body should be so different to in-lens for movie recording. I wonder if it's Pentax's implementation or if other manufacturers who use in-body stabilisation have the same problems with movie recording? Any Olympus owners care to chime in?

[kadajawi]

What you might be seeing is the rolling shutter effect coupled with the sensor shift stabilization and is likely one of the reasons it is often suggested that SR be disabled for video.

I have tried a K-30 when I wanted to buy a new Pentax, and I'm pretty certain it is using software SR. There is no rolling shutter effect when you use sensor shift stabilization, because the image on the sensor itself stays perfectly stable. Try a K-5 and you'll see what I mean, there is really NO rolling shutter whatsoever when you are shaking a bit (even with a 200mm lens handheld there is no wobbling! You do get the rolling shutter when shooting without SR (looks the same as a K-30 without SR) or when panning fast).

On the K-30 you do get rolling shutter with SR (and even worse than without SR) because the sensor is picking up the full, unstabilized wobbly video, and then they stabilize it according to the top most line. But since the lines below have not been taken at the same time it will move around. You can also check it by looking at the frame coverage. A 18mm lens gets turned into a lets say 22mm lens when shooting video, which means they are cropping so they have enough space to move around.

Also, from what I have seen from the K-01 here it seems to me as if it, too, has the same crappy digital image stabilization. I have no clue what Pentax was thinking there, at least they should have given us the option to pick what stabilization we want. The noise from the SR system isn't so bad, and can be removed with an external microphone.

[Steve.Ledger]

There is no rolling shutter effect when you use sensor shift stabilization, because the image on the sensor itself stays perfectly stable.

As far as I know, the 'rolling shutter' effect has nothing to do with SR.
It's caused by CMOS scanning and electronic shutter (in movie mode there is no mechanical shutter)

► Rolling shutter - Wikipedia, the free encyclopedia

[kadajawi]

As far as I know, the 'rolling shutter' effect has nothing to do with SR.
It's caused by CMOS scanning and electronic shutter (in movie mode there is no mechanical shutter)

► Rolling shutter - Wikipedia, the free encyclopedia

Yes, sorry. What I meant was that the K-30 amplifies the effect, the K-5 reduces it. Rolling shutter is indeed created by reading the sensor line by line as opposed to one frame at a time. You will only see the effect when there is movement in the frame, when the frame has moved between the time you start reading it until the time you stop reading it. The K-30 and K-5 should have pretty much the same sensor (thus a similar rolling shutter effect), but:

In the K-5 the sensor is moved around when you are shaking, in an attempt to get a stable image. What then arrives on the sensor itself is a stable image, with no movement (within the limits of the sensor shift system of course). As if the camera was mounted on a tripod. Thus there is no wobbling around (coming from small random movements left, right, up and down). The only way to get a visible rolling shutter effect is to either have a fast moving object (like a train) move through the image or by panning fast. If you look for it you'll see it, but it is not very irritating. Movements need to be pretty fast, and the amount at which lines tend to lean is pretty stable.

In the K-30, and probably K-01, the sensor stays where it is. That means all the time when you shake the camera (i.e. handheld usage) the image area has moved before a single frame has been read. This happens randomly, so where it wobbles to also changes, sometimes it is to the left, to the right, or the video is stretched or squeezed, and everything in between. You can see it on most of the Canon and Nikon DSLR videos, unless they use things like a steadicam or a stabilized lens. Now this is pretty irritating, but since the whole frame shakes anyway that disguises the effect a bit. But when you activate SR in the K-30 it does make use of the sensor that is used for the sensor shift SR system (making it superior to those pure software ones), however it only stabilizes according to the top most line, it takes the final frame/crop based on that line. However due to the rolling shutter effect the lines below that have moved on. So you do get a half way stabilized video, where the top part of the frame stays perfectly stable. But the rest of the frame... nope. Moves around. And THAT is seriously irritating.
And that's not the only problem with this sort of digital image stabilization that simply crops a part out of the sensor and moves around the part of the sensor. You might be able to eliminate this effect by selecting a different part of the sensor for each line (this could also work for the rolling shutter effect in general), at least when it comes to panning, though it would introduce a rolling shutter effect if you actually follow a driving car for example. However when your shutter speed isn't very short you do get motion blur when you move the camera when shaking. Again, since the sensor is recording an unstabilized frame, that's it. You can't avoid it. And again, if you don't stabilize at all it is perfectly acceptable, and even concealing the camera movement to a certain degree, making it more acceptable. But the K-30 picks a part of the sensor for the frame, thus stabilizing it more or less. Then you have a stable video that a) has the bottom of the frame move around randomly and b) gets blurry sometimes, with motion blur going in different directions, randomly (especially weird when there are bright spots of light).

The K-5 as I said before doesn't get any of these negative effects because what sensor sees is perfectly stable, or at least only moving in one direction, smoothly.

[Steve.Ledger]

All of which means turn off SR for videos as is universally recommended.

(I actually have SR off all the time, even for stills - only switch on when my shutter speed falls much lower than my focal length.)

[kadajawi]

All of which means turn off SR for videos as is universally recommended.

(I actually have SR off all the time, even for stills - only switch on when my shutter speed falls much lower than my focal length.)

Only with the K-30. It works EXTREMELY well with the K-5. I'd buy a K-5 over say a 7D for video, just because of this feature. I can easily shoot with a 200mm lens, handheld, while getting a pretty stable video. I can walk around with a 50mm or 18-55mm at 18mm and get non jerky video (especially with the 50mm) that looks pretty smooth... there is a bit of up and down motion, but other than that no problem. I barely ever see a rolling shutter effect (and I even notice it in big budget movies), and never do I see any wobbling effect. You can sometimes see the lens flare move around like mad, while the video itself is stable.

I don't see any reason at all why you'd want to deactivate SR on the K-5, unless you WANT a Michael Bay shaky camera look.

[Steve.Ledger]

Yes, I have the K-7 and the sensor shift SR is very good, but I still almost always have SR off.
The small amount I have done with the K-01 is also better with Movie SR turned off in my opinion, but then I use a tripod.
But to be honest, I do very little video with Pentax cameras as I have a HiDef Camcorder with insanely good optical (lens) stabilisation.

[kadajawi]

I have several camcorders (older ones though), and none of them can reach my K-5. I have also tried a pretty expensive consumer Panasonic HD camcorder with 3D and all, the footage out of it just doesn't look as good as what my K-5 produces (the only advantage is that it is easier to use (AF...) and it produces 50p instead of 25p. It simply doesn't have anywhere near the dynamic range the Pentax has (obviously, with a much smaller sensor), the colors aren't as good, ...

Hm. Any reason why you have turned off the SR in the K-7? Does it actually do sensor shift stabilization? Can you hear the mechanism? Maybe you can put a long lens (as long as possible) on the K-01 and on the K-7, and try to shoot handheld. You should see what I described, if the footage from both looks the same, with the artefacts I described then they both don't have proper sensor shift stabilization.

After 10 or 20 seconds I knew I wouldn't buy the K-30 because of the stabilization, 10 seconds after I started trying the K-5 I was very impressed. The difference should be very obvious.

[Steve.Ledger]

Any reason why you have turned off the SR in the K-7?

Of course there are reasons, I wouldn't chose to do so for no reason at all
I have SR off all the time (unless I have need to switch it on). As stated earlier, I always shoot stills at a shutter speed at or higher than the focal length, so SR is just not necessary and having it enabled actually more often than not results in softer images. This is a widely known drawback of mechanical SR.

If I do shoot a vid with the dSLR or the MILC, I use a tripod and SR is always off for tripod work. I don't have any reason to shoot hand held with a dSLR, I prefer that the subject should be doing all the moving rather than the camera (except for panning scenery of course).
You can listen to pros such as Philip Bloom to explain why SR should be off for tripod work.

Does it actually do sensor shift stabilization?

Of course, the K-5 is an updated version of the K-7 - identical build newer sensor. The K-7 has full SS SR in movie mode.
The K-01 does not. I'm not nearly as impressed with the video capability of the K-01 as some people are, but that might be my fault.


I apologise to the OP for shifting his thread a little off topic.

[kadajawi]

Of course there are reasons, I wouldn't chose to do so for no reason at all
I have SR off all the time (unless I have need to switch it on). As stated earlier, I always shoot stills at a shutter speed at or higher than the focal length, so SR is just not necessary and having it enabled actually more often than not results in softer images. This is a widely known drawback of mechanical SR.

If I do shoot a vid with the dSLR or the MILC, I use a tripod and SR is always off for tripod work. I don't have any reason to shoot hand held with a dSLR, I prefer that the subject should be doing all the moving rather than the camera (except for panning scenery of course).
You can listen to pros such as Philip Bloom to explain why SR should be off for tripod work.


Of course, the K-5 is an updated version of the K-7 - identical build newer sensor. The K-7 has full SS SR in movie mode.
The K-01 does not. I'm not nearly as impressed with the video capability of the K-01 as some people are, but that might be my fault.


I apologise to the OP for shifting his thread a little off topic.

Ah yes, I see your point. I usually don't bother with turning off SR, I can only be bothered to carry a tripod when doing a paid assignment anyway. When shooting video on a tripod there's no point in using SR. But yeah, my tripod is way too heavy IMHO (but I do need the stability cause I'm shooting HDR panoramas with a nodal point adapter).

Personally I simply almost never shoot video with a tripod, but I do want some smoothness, while being mobile and in motion. And the K-5 SR works great for that sort of use.

Anyway, yeah, sorry for the OT.

Also I agree with Derwin. There are quite a few issues with the K-30, which makes it even a step down from the K-5, and most of it is firmware stuff only. I doubt it takes them more than a few switches and maybe porting software from the K-5 to the K-30 to make it possible to switch between software SR, hardware SR and no SR. To give the K-5 and perhaps the K-30 a video recording button... just optionally. If you want to use it, you can, if not, then don't. Just make it possible to assign one of the buttons (Fx for example) to start/stop video recordings. To give the K-5 manual controls. Or even to just activate MJPEG on the K-30. It can do h264, so it surely should be able to handle MJPEG too, which is much lighter on the hardware. Just make it optional. There are many things that could be done, that would probably just require one of their software guys to sit down for a day or two. But Pentax can't be bothered it seems...

[paranoia23]

I don't own a K-30, but I do own a K-7, K-01 and Q. All of which use the same sensor shift stabilization during video. It would surprise me if the K-30 used digital image stabilization.

surprise surprise ... neither the k01 nor the Q use they sensor shift in video mode ... finally people care about this design failure