Rolling Shutter Stills?
- Thread starter PhilipD
- Start date
Barry_Green
Moderator
Not sure exactly what you're referencing, but the D90 is an SLR with a mirror and a focal plane shutter when used in stills mode. So when you take a still with it, it's exactly what you'd expect, one discrete moment in time with no "rolling shutter" artifacts.
Michael Erlewine
Well-known member
Here is a question Barry Green:
This will show my ignorance, but that is what these forums are for. I am shooting with the D3s video and then going through the footage looking for still frames I can pull, not on the camera, but in Adobe Premiere. Too time consuming in the camera.
When looking for stills, I find one clearly focused frame every 3-4 frames. Why is this? Is this motion that could be solved by a somehow getting higher shutter speed or is the subject moving too fast for the frames per second? 720p obviously does not mean each frame was separate and in perfect focus, for this appears not to be true. I also looked at pulling frames from the camera and it seems to be the same story. I assume this is just the way it is. I have not pulled single frames before, except to use for making titles, so this is a little new to me.
On the other hand, the sound is great with the external 3.5mm mic jack on the D3s out to an XLr and mic, as you can hear on my video link:
http://www.vimeo.com/7997178
I am encouraged by that.
What I am realizing of late (and I also have a D3x 25MP camera as well) is that I am almost never going to need giant-sized images anymore. Almost all my work goes on the web or at least is fairly small in pixel size (1000 to 1500 px) when it finally gets used. So I am not really needing those pixels, but what I really find I am needing is interchangabbe lenses like this D3s, where I can use a variety of the really great lenses I have collected over the years to good effect.
This will show my ignorance, but that is what these forums are for. I am shooting with the D3s video and then going through the footage looking for still frames I can pull, not on the camera, but in Adobe Premiere. Too time consuming in the camera.
When looking for stills, I find one clearly focused frame every 3-4 frames. Why is this? Is this motion that could be solved by a somehow getting higher shutter speed or is the subject moving too fast for the frames per second? 720p obviously does not mean each frame was separate and in perfect focus, for this appears not to be true. I also looked at pulling frames from the camera and it seems to be the same story. I assume this is just the way it is. I have not pulled single frames before, except to use for making titles, so this is a little new to me.
On the other hand, the sound is great with the external 3.5mm mic jack on the D3s out to an XLr and mic, as you can hear on my video link:
http://www.vimeo.com/7997178
I am encouraged by that.
What I am realizing of late (and I also have a D3x 25MP camera as well) is that I am almost never going to need giant-sized images anymore. Almost all my work goes on the web or at least is fairly small in pixel size (1000 to 1500 px) when it finally gets used. So I am not really needing those pixels, but what I really find I am needing is interchangabbe lenses like this D3s, where I can use a variety of the really great lenses I have collected over the years to good effect.
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Zim
Veteran
Good question really. Also most video goes to the web and DVD so these DSLRs will be great for that. Plus they will get better.
Michael Erlewine
Well-known member
I am such a tech nut that I seldom really dare to ask myself: just what are the photos I am taking going to be used for, and for the most part the answer is simple: web use, advertising some, and that is about it. I don’t frame photos and put them on the wall, ever. Not my style. My history is that of the bleeding edge of digital photography, and that hurts the pocketbook, but opens doors for the mind. The D3s is perfect for documenting ‘stuff’ like, for me, musicians, concerts, recording sessions, portraits, collaterals, etc. I might sell my D3x and get a second D3s…. hmmm. There is a scary thought.
Zim
Veteran
At least you would have two of the same camera. Well you should be able to take stills with that camera and get great pictures. The video will be great for the web and documenting stuff for sure.
Barry_Green
Moderator
Okay, but be aware, the quality of the stills is going to be about 100x better than the quality of a frame grab. These cameras work hugely different in stills mode than in video mode. So if you want high-quality stills, you're not going to find them by taking frame grabs out of the video...
A for why you're finding defocused frames -- I haven't used a Nikon for video but for the very briefest moments, but it's my understanding that they use MotionJPEG recording -- which should meant that every frame is recorded individually. There should be no variation at all.
Are you finding variations even when you're shooting a static subject?
Do you have autofocus active?
Michael Erlewine
Well-known member
A Nikon Camera with bursts of 30-frames a Second
A Nikon Camera with bursts of 30-frames a Second
To Barry Green,
I may have not made myself clear. Of course, the standard stills shot with a Nikon and the great Nikkor lenses are fantastic. I was differentiating between the following:
(1) Stills taken, frame at a time, from the video while the FlashCard is still in the Nikon D3s
And
(2) Stills taken from the video using Adobe Premiere (or whatever) after the footage is copied to the hard drive.
The video is at the following link that I used. There was not a lot of light, so I will have to repeat the test as soon as I can find the time. I am building a light-driven set for this in my studio.
http://www.vimeo.com/7997178
Nikon D3s, Nikkor 70-200 F/2.8 VR II, F/8
But from the above-linked video, everything but the moving subject is in good focus, so the answer would seem to be that it is only the movement of the subject that is being monitored here which is causing the blur.
Then my question for all of us becomes: How do I increase the shutter speed so that every frame is sharp? I am pretty ignorant about some of this stuff.
As for having autofocus active, I am not sure, but will look into this.
This video was an afterthought. I was there trying to take great Nikon stills, as I should, but as it turned out (which is why many of us want to move to hi-res video), from a couple hundred still photos, only a few were any good. As I start to get more into VDSLR video, I can begin to admit to myself (it has always been true) that still photography of moving people is VERY difficult, because unless you take bursts you never know when the good moment will come, much less capture it.
It is much easier to capture everything and extract the stills, when the glint is in the eye and the peak moment of the smile is on the face. I found myself totally fascinated as I went through a lot of other similar footage to what I posted here looking for frames to grab. Here is a sample of a frame grab from one of the videos. How could I ever get this shot using just my Nikons in standard (not video) DSLR mode? Mostly by pure chance!
So, for me, all of this hullabaloo about DSLR video is not just some fad, but a step into the future that will change how we take pictures forever. I have taken roughly 50,000 stills in the last couple of years, most of macro nature subjects. I hate to think how many of those (moving subjects) were not the moment I witnessed, but just fractions of a second too late.
I sold my HVX-200 and a whole set of Redrock Micro gear because the ergonomics of the system and the lack of interchangeable lenses were just too much for me take compared to the clarity of the best Nikkor lenses and the elegance of their bodies. Of course I find myself again on the bleeding edge of technology, which is a pain in the pocketbook and a frustrating wait for technology to blossom. But when I think about it, my whole career has been on the edge. I run the second oldest software company on the Internet, the oldest being Microsoft. I had email in 1979, etc. and etc. It goes on and on.
So, for me, this move to combine the power of video with the state of still photography is not a fad, but a defining moment. I consider my D3s not to be a lousy video camera but a Nikon V-DSLR that takes continuous bursts of about 30 frames a second! The size of the frame images are just not quite large enough for my taste. Perhaps a RED camera with interchangeable lenses will be my future, but I doubt it. Nikon will get it right pretty soon.
If I am honest with myself, almost all of my photographic work ends up on the web in one form or another and even 1280x720 frame grabs are usually enough for that. In fact, I am selling my D3x (24.5 MP) Nikon and buying a second Nikon D3s, so that I can have a 2-camera shoot. As for the 5-minute (2 GB) limit, so what? Real cinema cameras have short takes as well. I will just stagger the two cameras by a short time, so I have continuous footage of my subjects. Instead of zooming (which is getting old anyway), I will just jump from camera to camera in post for now. Anyway, too much yak-yak. I am sure you get my point.
This is a 1280x720 px snapshot of legendary singer/songwriter Robin Lee Berry at a recording session with Grammy Award winning harmonica player Peter ‘Madcat’ Ruth at the Heart Center Studios in Big Rapids, Michigan.
A Nikon Camera with bursts of 30-frames a Second
To Barry Green,
I may have not made myself clear. Of course, the standard stills shot with a Nikon and the great Nikkor lenses are fantastic. I was differentiating between the following:
(1) Stills taken, frame at a time, from the video while the FlashCard is still in the Nikon D3s
And
(2) Stills taken from the video using Adobe Premiere (or whatever) after the footage is copied to the hard drive.
The video is at the following link that I used. There was not a lot of light, so I will have to repeat the test as soon as I can find the time. I am building a light-driven set for this in my studio.
http://www.vimeo.com/7997178
Nikon D3s, Nikkor 70-200 F/2.8 VR II, F/8
But from the above-linked video, everything but the moving subject is in good focus, so the answer would seem to be that it is only the movement of the subject that is being monitored here which is causing the blur.
Then my question for all of us becomes: How do I increase the shutter speed so that every frame is sharp? I am pretty ignorant about some of this stuff.
As for having autofocus active, I am not sure, but will look into this.
This video was an afterthought. I was there trying to take great Nikon stills, as I should, but as it turned out (which is why many of us want to move to hi-res video), from a couple hundred still photos, only a few were any good. As I start to get more into VDSLR video, I can begin to admit to myself (it has always been true) that still photography of moving people is VERY difficult, because unless you take bursts you never know when the good moment will come, much less capture it.
It is much easier to capture everything and extract the stills, when the glint is in the eye and the peak moment of the smile is on the face. I found myself totally fascinated as I went through a lot of other similar footage to what I posted here looking for frames to grab. Here is a sample of a frame grab from one of the videos. How could I ever get this shot using just my Nikons in standard (not video) DSLR mode? Mostly by pure chance!
So, for me, all of this hullabaloo about DSLR video is not just some fad, but a step into the future that will change how we take pictures forever. I have taken roughly 50,000 stills in the last couple of years, most of macro nature subjects. I hate to think how many of those (moving subjects) were not the moment I witnessed, but just fractions of a second too late.
I sold my HVX-200 and a whole set of Redrock Micro gear because the ergonomics of the system and the lack of interchangeable lenses were just too much for me take compared to the clarity of the best Nikkor lenses and the elegance of their bodies. Of course I find myself again on the bleeding edge of technology, which is a pain in the pocketbook and a frustrating wait for technology to blossom. But when I think about it, my whole career has been on the edge. I run the second oldest software company on the Internet, the oldest being Microsoft. I had email in 1979, etc. and etc. It goes on and on.
So, for me, this move to combine the power of video with the state of still photography is not a fad, but a defining moment. I consider my D3s not to be a lousy video camera but a Nikon V-DSLR that takes continuous bursts of about 30 frames a second! The size of the frame images are just not quite large enough for my taste. Perhaps a RED camera with interchangeable lenses will be my future, but I doubt it. Nikon will get it right pretty soon.
If I am honest with myself, almost all of my photographic work ends up on the web in one form or another and even 1280x720 frame grabs are usually enough for that. In fact, I am selling my D3x (24.5 MP) Nikon and buying a second Nikon D3s, so that I can have a 2-camera shoot. As for the 5-minute (2 GB) limit, so what? Real cinema cameras have short takes as well. I will just stagger the two cameras by a short time, so I have continuous footage of my subjects. Instead of zooming (which is getting old anyway), I will just jump from camera to camera in post for now. Anyway, too much yak-yak. I am sure you get my point.
This is a 1280x720 px snapshot of legendary singer/songwriter Robin Lee Berry at a recording session with Grammy Award winning harmonica player Peter ‘Madcat’ Ruth at the Heart Center Studios in Big Rapids, Michigan.
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OK PhillipD, here's the lead. Even with the rolling shutter the D90 video takes, for all intents and purpose it takes - and remember it takes - one frame at a time. For film or photography, any image is a frame, regardless of what shutter mechanism it has and regardless what goes on in the real world. The D90 video has single frame captures for video. That's it. What you do or say post production is up to you. But the D90 has shot 24 frames per second. Period. The image is scanned across the sensor - and here's where the problem begins. Unlike traditional film, which is exposed all at once (sort of) the D90 has a "rolling shutter" - the only import of this being that the sensor is not exposed to light uniformly - hence the wobble of the video. Why does this happen? Does it need to happen? Good questions, but if you have this camera, you'll only drive yourself crazy wondering and trying to circumvent it.
If you can see, you have better eyes than any camera. If you can hear, you have better audio than any audio system. every technology you confront is only a limitation to you. Find out how to make it less of a compromise. Forget rolling shutter and single frames. they are the least of your technological limitations.
Remember that 35mm film also takes one frame (in a single exposure) and if there is any movement, there will be motion blur. Taking frames from film or video is often very useful. On a film shoot, the still photographer is employed to generate the still images. And they do it with a different camera - a very good still camera. But the D90 can do this too, and I've been the stills photographer on a film myself with only this one excellent camera.
If you can see, you have better eyes than any camera. If you can hear, you have better audio than any audio system. every technology you confront is only a limitation to you. Find out how to make it less of a compromise. Forget rolling shutter and single frames. they are the least of your technological limitations.
Remember that 35mm film also takes one frame (in a single exposure) and if there is any movement, there will be motion blur. Taking frames from film or video is often very useful. On a film shoot, the still photographer is employed to generate the still images. And they do it with a different camera - a very good still camera. But the D90 can do this too, and I've been the stills photographer on a film myself with only this one excellent camera.
Michael Erlewine
Well-known member
damonb:
I get it, of course. But taking stills with a Nikon (or whatever still camera) and capturing the whole event with video (and pulling stills) are, as you know, different things. I am trying to find out if there is anything I can do to make each frame in the rolling shutter better. Any ideas, other than shoot still frames?
Thanks,
Michael Erlewine
I get it, of course. But taking stills with a Nikon (or whatever still camera) and capturing the whole event with video (and pulling stills) are, as you know, different things. I am trying to find out if there is anything I can do to make each frame in the rolling shutter better. Any ideas, other than shoot still frames?
Thanks,
Michael Erlewine
Barry_Green
Moderator
Well, first of all, recognize that DSLR video is really far inferior to conventional video camera video. An HPX300 or EX1 is going to deliver still frame grabs that would easily, handily, thoroughly outperform those from any DSLR.
DSLRs are still cameras, designed to take stills. The video aspect is grafted on and frankly it isn't done very well at all. It can look good, or it can look rough, but it doesn't compare in terms of sharpness or dynamic range to what a decent video camera can do.
But, back to working with what you've got -- if you think motion blur is the problem, then yes shutter speed is the answer. Make sure your shutter is at least 1/50th of a second, and if you want crisper footage (at the expense of less-realistic motion blur in motion) you can go faster. 1/60 is reasonable, 1/80 is starting to push it, and anything faster than 1/80 will have a staccato feel to the motion. But, it'll be crisper (less blur) than a slower shutter speed.
Lammy
Well-known member
Not in his case. The D3s has amazing stills that can be pulled from the video. The general image quality is so much more aethetically beautiful than a grab from an EX1/HPX300 (even with an adapter with the same glass), despite the compression and resolution being technically better.
Barry_Green said:
Agreed. Although I really like the 1/80, 1/100 shutter look. It's surreal and everything appears faster.
I've seen the rolling shutter on the d3s isn't as extreme as the d90, so you wont get as much "jello" looking subjects. It'd be best if you experimented and showed us the details =]
On your d3s, set liveview to tripod mode and switch the camera to M mode. Then turn on live view, press the OK button, then change your shutter speed while you're recording.
You can tell if you're on a high shutter when you move the camera around and there's little motion blur.
That should make screen grabs more sharp, at the expense of smooth motion.
Michael Erlewine
Well-known member
BandanDan:
Thanks much! I will experiment and see what is possible. From my point of view, the D3s is the “Little Engine that Could,” or at least I plan to find out if it can. I just put my D3x on sale, and ordered a second D3s. My plan is a 2-camera shoot, offset so that the two cameras overlap enough that one of them is always filming when the other reaches the 5-minute mark.
My experience with my two Sony VX-2000s, an HVX200, and other camcorders that I have (or had) has been less than satisfying so far. I even bought into the whole 35mm adaptor stuff, but my roots are in Nikon primes and their best zooms – clear glass. Pumping the videos through a 35mm adaptor was not worth it for me. I did not like the results. The whole apparatus was just not precise enough.
Thanks much! I will experiment and see what is possible. From my point of view, the D3s is the “Little Engine that Could,” or at least I plan to find out if it can. I just put my D3x on sale, and ordered a second D3s. My plan is a 2-camera shoot, offset so that the two cameras overlap enough that one of them is always filming when the other reaches the 5-minute mark.
My experience with my two Sony VX-2000s, an HVX200, and other camcorders that I have (or had) has been less than satisfying so far. I even bought into the whole 35mm adaptor stuff, but my roots are in Nikon primes and their best zooms – clear glass. Pumping the videos through a 35mm adaptor was not worth it for me. I did not like the results. The whole apparatus was just not precise enough.
Barry_Green
Moderator
Interesting, as that would be a first from a DSLR. Has anyone shot a zone plate or a resolution chart with one? I googled and couldn't find any.
Michael Erlewine
Well-known member
Barry Green:
Perhaps you can explain how to shoot a resolution chart and zone plate and I could perhaps do that and post it here.
Perhaps you can explain how to shoot a resolution chart and zone plate and I could perhaps do that and post it here.
Barry_Green
Moderator
Well, that'd be excellent. Thanks for offering. If you don't have a professional chart, the best online one is the ISO 12233. John Beale has put up some links to some free downloadable charts:
http://www.bealecorner.org/red/test-patterns/
What you'd want to do is print a chart at the absolute highest resolution and largest size that you can. I'd recommend using the 12233 and spreading it out across four sheets of paper. Yes it's a hassle to slice the edges and tape it back together, but printing at the larger size will make the chart a lot more accurate and remove the printer's resolution out of the equation.
Print it out, tape it up against a wall, and then frame the camera up perfectly square to it; you don't want the camera tilted up or down at all, you want the center of the lens to be at the same height as the center of the chart, and you want to be perfectly angled to the chart so that the camera isn't pointing off to the left or to the right at all.
Once you've squared up the camera to the chart, you want to illuminate it flat and evenly. Overhead fluos or daylight can be good for that; it's not so easy to get it flat & even by using tungsten fresnels. A big softbox would help; put it right behind the camera, higher, and tilted down, pointing at the chart, and you should get some nice even flat illumination.
Then frame the chart according to the arrows that are all around it. You want the arrowheads to converge exactly on the frame lines. You don't want to see any gaps between the inner arrows and the edge of your frame, and you don't want to see any of the outer arrows. The arrowheads should line up so that they're perfectly pointing at the edges of the frame. If the arrowheads are cut off, then you're framed too close and your resolution numbers will be wrong, they'll be too generous. If the arrowheads are fully visible and don't run right up to the edge of the frame, then you're framed too far away, and your resolution numbers will be wrong, they'll be too low. So try to frame it as absolutely squarely and perfectly as you can. And this isn't easy with an SLR, because every time you change the zoom, the focus changes a little... and because of lens breathing, every time you change the focus, the lens framing will slightly zoom in or out (even on a prime!) So it's a tricky dance to get perfect focus and perfect framing. Focus is more important than framing, so if you can only get the frame "very close" but you can get the focus "perfect" and you're tired of fiddling with it, well, that'll be good enough.
So, shoot the chart in movie mode and post a frame grab!
Thanks!
http://www.bealecorner.org/red/test-patterns/
What you'd want to do is print a chart at the absolute highest resolution and largest size that you can. I'd recommend using the 12233 and spreading it out across four sheets of paper. Yes it's a hassle to slice the edges and tape it back together, but printing at the larger size will make the chart a lot more accurate and remove the printer's resolution out of the equation.
Print it out, tape it up against a wall, and then frame the camera up perfectly square to it; you don't want the camera tilted up or down at all, you want the center of the lens to be at the same height as the center of the chart, and you want to be perfectly angled to the chart so that the camera isn't pointing off to the left or to the right at all.
Once you've squared up the camera to the chart, you want to illuminate it flat and evenly. Overhead fluos or daylight can be good for that; it's not so easy to get it flat & even by using tungsten fresnels. A big softbox would help; put it right behind the camera, higher, and tilted down, pointing at the chart, and you should get some nice even flat illumination.
Then frame the chart according to the arrows that are all around it. You want the arrowheads to converge exactly on the frame lines. You don't want to see any gaps between the inner arrows and the edge of your frame, and you don't want to see any of the outer arrows. The arrowheads should line up so that they're perfectly pointing at the edges of the frame. If the arrowheads are cut off, then you're framed too close and your resolution numbers will be wrong, they'll be too generous. If the arrowheads are fully visible and don't run right up to the edge of the frame, then you're framed too far away, and your resolution numbers will be wrong, they'll be too low. So try to frame it as absolutely squarely and perfectly as you can. And this isn't easy with an SLR, because every time you change the zoom, the focus changes a little... and because of lens breathing, every time you change the focus, the lens framing will slightly zoom in or out (even on a prime!) So it's a tricky dance to get perfect focus and perfect framing. Focus is more important than framing, so if you can only get the frame "very close" but you can get the focus "perfect" and you're tired of fiddling with it, well, that'll be good enough.
So, shoot the chart in movie mode and post a frame grab!
Thanks!
Michael Erlewine
Well-known member
First Try at the Test Frame
First Try at the Test Frame
Dear Barry Green,
Here it is:
http://www.flickr.com/photos/13655164@N00/4166786921/sizes/o/
Here where I am so far:
(1) Made a large photocopy from the PDF file. Mounted it on a cork board and flanked it by two umbrella lights at 45-degree angles to it.
(2) I tried a couple lenses, and ended up using the Micro Nikkor 60mm f/2/8 lens, which is a flat lens.
(3) I tried to get both the top and bottom and left and right sides of the pattern in my viewfinder, but it did not work. The frame of the camera did not fit the pattern, so I settle on the top and the bottom. Did the best I could, but am willing to try again.
(4) DVXuser would not let me enter the file size or image size, so I put it on Flickr.com, which I don’t use, so I can’t speak to how faithful it is to what we want.
Let me know what I should do to make it better or comment on whatever it is supposed to be showing here.
Thanks,
First Try at the Test Frame
Dear Barry Green,
Here it is:
http://www.flickr.com/photos/13655164@N00/4166786921/sizes/o/
Here where I am so far:
(1) Made a large photocopy from the PDF file. Mounted it on a cork board and flanked it by two umbrella lights at 45-degree angles to it.
(2) I tried a couple lenses, and ended up using the Micro Nikkor 60mm f/2/8 lens, which is a flat lens.
(3) I tried to get both the top and bottom and left and right sides of the pattern in my viewfinder, but it did not work. The frame of the camera did not fit the pattern, so I settle on the top and the bottom. Did the best I could, but am willing to try again.
(4) DVXuser would not let me enter the file size or image size, so I put it on Flickr.com, which I don’t use, so I can’t speak to how faithful it is to what we want.
Let me know what I should do to make it better or comment on whatever it is supposed to be showing here.
Thanks,
Barry_Green
Moderator
There's a lot of the picture missing; there's a whole bunch that should be on the left and right, for example. The full frame should look like this:
Look at the perimeter, at all those arrowheads -- they should be pointing to the exact limits of your frame.
Look at the perimeter, at all those arrowheads -- they should be pointing to the exact limits of your frame.