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-   -   Slow motion of birds in flight? (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/34632-slow-motion-birds-flight.html)

Per Johan Naesje November 8th, 2004 12:55 AM

Slow motion of birds in flight?
 
I have tried several settings filming small birds like titmouse, sparrow etc. Playing back in slow motion I would like to see the wing as sharp as possible.
The stroke of the wings are very fast and I find it hard to figure out the right settings for shutter speed, aparture etc., what record mode to use: TV, AV, Manual..., frame rate 50i or 25p (PAL), to get the best result with XL2 and 20x lens.

Have anybody tried this and what settings did you use? I know that light conditions are of importance!

Apreciate any recommondation!

- Per Johan

Marty Hudzik November 8th, 2004 10:40 AM

I am wondering if what you are trying to achieve is even possible for the XL2. Typically high speed cameras would be employed to capture something of this nature. At the end of the day the most you will ever capture with the XL2 is 60 temporal images a second and that would be field based. I don't know the facts for sure but a hummingbird, for example, probably flaps its wings at that speed if not faster. In essence you probably can't get real good slow motion of something that fast without shooting at several hundred frames per second.

Pete Bauer November 8th, 2004 11:07 AM

Adding to what Marty wrote, if there are adequate -- that is to say, bright -- lighting conditions, you can open your aperture and speed up the shutter to get sharp images on each field / frame. But you won't get smooth, sequential, flowing slow motion because there are too few frames compared to the movement of the wings.

The best you might hope for is an effect something on the order of the wheels of a forward-moving car seeming to stop or rotate backwards on film/video. Maybe if you shoot enough takes, you'll get lucky and the timing of the wingbeats and the video fields will line up adequately. But that would be a combination of patience, luck, and very bright lighting to allow the very fast shutter speeds needed.

You can shoot something that moves more or less linearly, eg a pan left-to-right, but unless someone has a real trick up their sleeve, rapidly rotating or oscillating objects can't really be done in true super-slow motion on any equipment that most of us can afford.

Greg Boston November 8th, 2004 11:33 AM

Here's a thought. Don't know if it will work but you could perhaps use the 'clear scan' mode used for shooting computer screens. It says it's adjustable from 60hz to 202.5hz. Maybe the 202.5 coupled with a fast shutter speed would get more of the motion.

I may have to test this out.

=gb=

Marty Hudzik November 8th, 2004 12:24 PM

<<<-- Originally posted by Greg Boston : Here's a thought. Don't know if it will work but you could perhaps use the 'clear scan' mode used for shooting computer screens. It says it's adjustable from 60hz to 202.5hz. Maybe the 202.5 coupled with a fast shutter speed would get more of the motion.

I may have to test this out.

=gb= -->>>

I think clearscan is the shutter speed! IN other word it is essentially matching the shutterspeed to a monitor or tv. I don't think this will help out much. Especially since the actual shutter settings go way faster.....1/1000 and up? You still will only end up with 60 1/2 res images that are really tight with little motion blur because of the high shutter speed.

Lauri Kettunen November 8th, 2004 12:27 PM

Per, In my view your question makes sense although as Marty already says the Xl2 is not an optimal tool for this. Anyhow, this is what to do: Set your camera into progressive mode (50p) and select as short shutter speed as you ever can.

To minimize the shutter speed add gain, and if you do not mind about noise, put gain to maximum, and in addition, you may want to try the Noise reduction from the menu setting.

I've been filming hawks, and it's amazing how much the wing moves in a 1/300s.

Per Johan Naesje November 9th, 2004 04:34 AM

Thanks everybody for your response!
Lauri: I gonna try your suggestion

- Per Johan

Rob Lohman November 9th, 2004 04:36 AM

I would shoot at interlaced with a high as shutter speed as you
can (given the light), this should give you the least amount of
motion blur and the highest resolution both temporal (ie 50
samples per second instead of 25).

Lauri: the camera does not have a 50p (progessive mode), but
25p or 50i (interlaced). I would not go with 25p in this case since
the chip will sample 50% times less in a second. Yes, in interlaced
the spatial resolution is also reduced in half, but the XL2 has a
lot of this (and sharpness), so in my guess slowing the footage
down by 50% and converting it to progressive at the same time
should yield excellent results (for the lack of a real high speed
camera).

Lauri Kettunen November 9th, 2004 05:28 AM

<<<-the camera does not have a 50p (progessive mode), but
25p or 50i (interlaced). I would not go with 25p in this case since
the chip will sample 50% times less in a second. Yes, in interlaced
the spatial resolution is also reduced in half, but the XL2 has a
lot of this (and sharpness), -->>>

Rob, thanks, a mistake, I meant of course 25p.

What comes to progressive/interlaced mode, Per wants to view birds in slow motion. In my experience, if the camera is set to interlaced mode, you do not have a single sharp picture of a bird (unless the bird is staying steady). Instead, you get one half of the image on the first half frame and the other on the latter half frame. If the shutter speed is 1/50s, the motion is blurred, and if the shutter speed is short, then, say in every second line the wing appears in the upper part of the image, and every other line has the wing in the bottom part. The composition (i.e., the frame) makes no reasonable image, and playing it slower does not improve the situation.

The progressive mode is closer to taking photos with a high speed SLR camera --say 10 frames per second-- and I think this is what Per wants to do. And indeed, one can easily make beautiful animations of SLR pictures representing flying birds. So, if you have 25 frames per second in the Xl2, all the better.

Amount of light is obviously a problem in getting fully stopped images of birds.

Rob Lohman November 9th, 2004 05:36 AM

Lauri: that's true, but depends on your viewing media. If the
output is TV or broadcast then you will not have this. Since Per
indicated he wants to do slowmotion you can do this better with
interlaced material since you have 50 (half) frames per second to
work with instead of 25.

So if you are going to slow your footage by 50% then you will
convert it to progressive and you will not have the problem you
have described and you should have a clearer picture of the
action. Ofcourse keep the shutter high with such shoots!

Converting interlaced to progressive with slow motion has been
discussed a lot of times on this board already. If you do not want
to do slow motion and you need still frames then by all means
use progressive.

Robert J. Wolff November 9th, 2004 06:43 AM

Per,

I have shot Hummingbirds at 1/15,000 down to 1/4,000 of a second with excellent results, using my XL-1s. They were done in bright sun conditions. I would suggest that it would be dubious footage, in any other light condition.

I shoot in movie mode.

Depth of Field is catch as catch can, since you are dealing with subjects of just some several inches (centimeters) in breth and width. Therefore, I don't worry much about what f-stop is necessary. The shutter speed mandates that.

I white ballance for the scene, and, than, await my subject(s).

I find that shooting cross light as best, since it tends to dispay the irridesence of bird feathers to their fullest. I carry a small white window shade to use as a fill light.

I am not computer literate enough to send you a minute or so. But at the top, center, and bottom of the birds wing motion, feathers are almost stilled.

I repeat the term: almost. (I would guestimate that 1/60k or better would be needed to do the job). The hummer's wing motion are hundreds of times faster than the birds that you are shooting. And they fly foreward, backward, instant up/down & sidways!

With a slower wing motion such as you are shooting, I can't understand why you have not achived your goal.

On the other hand, if you are only having your subject fill 1/3 or less of the frame, you will not have enought image detail, captured by ANY mode that you use, to satisfy your needs. It just isn't there. Off hand, it's about the only case where film does beat out video.

How about sending me some of your shoot settings? Maybe I can help out.

Lauri Kettunen November 9th, 2004 07:52 AM

<<<-- Converting interlaced to progressive with slow motion has been discussed a lot of times on this board already. If you do not want to do slow motion and you need still frames then by all means use progressive. -->>>

Rob, got your point now. Indeed, I was implicitly thinking of creating the slow motion with cross dissolve not by slowing down the progressive mode. In this particular case, I think, cross dissolve creates a better outcome.

Rob Lohman November 9th, 2004 08:57 AM

Cross dissolve? How are you creating slow motion with a cross
dissolve?

David Lach November 9th, 2004 10:29 AM

Even though slow motion is best acheived with interlaced footage, for shooting fast paced movement that would not only be seen on regular TVs, I would still use the progressive mode, in order to get sharp picture like frames without interlacing artifacts. Just shoot in TV (shutter priority) mode and increase the shutter speed number to a value that is optimal for continuity of movement and definition. Great slow motions can be acheived out of such footage with plugins like Twixtor.

Of course, ideally, you'd want to shoot with a high speed camera that does 50p / 60p or more, but since it is not possible here, I think this is your best solution.

BTW, if you find the shutter speed needed is bellow 1/200, I would try Greg's idea. Using the Clear Scan feature will let you tweak the shutter speed much more precisely than you normally could with the regular manual shutter speed setting.

Lauri Kettunen November 9th, 2004 11:07 AM

<<<-- Originally posted by Rob Lohman : Cross dissolve? How are you creating slow motion with a cross
dissolve? -->>>

Rob, Just think you had a sequence of still photos. How would you create an animation of them? Just make a cross dissolve transition from one still photo to another and you'll end up with an animation (with slow motion).

Barry Green November 9th, 2004 12:09 PM

Quote:

Even though slow motion is best acheived with interlaced footage, for shooting fast paced movement that would not only be seen on regular TVs, I would still use the progressive mode, in order to get sharp picture like frames without interlacing artifacts.
You guys are missing Rob's point -- since the footage is going to be slowed down to slow motion, each interlaced field will be converted to a full frame. There won't be *any* interlace artifacts, there will be 50 frames per second.

If you want to capture as much motion as possible, you have to use interlaced mode. Progressive will capture 25 motion samples per second, interlaced will capture 50 per second. And after slowing down to 50% playback speed, there won't be any interlace artifacts, each field will be converted to a full frame and it'll look like film that was shot at 50 frames per second (although lower vertical resolution).

Rob Lohman November 9th, 2004 12:11 PM

Okay, but how would you (seriously) do this with a video file?
Have you done it? In what program? The idea is that if you slow
footage down the program you do it in creates the inbetween
frames through a process known as interpolation. There are
various algorithms and thus varying degrees of succes. It sounds
like your describing something like this, although in an unusual
fashion (for me at least).

If you slow down interlaced footage 50% the program has half
a frame for every new frame and does not need to interpolate
the full frame (like it needs to do in progressive), but only half
with information from the surroundings.

And what Barry said (thanks!)... <g>

Lauri Kettunen November 9th, 2004 01:06 PM

Rob, Barry, I think I understand your point, but ...

To minimize confusion, I put some sample frames (tif-files)available at

www.luontovideo.net/Birds.html

Now, could you download the Black woodpecker frames(progressive mode) and the Common kestrel or Siberian jay (interlaced mode) frames. That will give us some common ground to share our experiences.

If I understood Per properly, he wanted to have images like the Black woodpecker and show them in slow motion (say something like 2-4 frames per second).

David Lach November 9th, 2004 03:55 PM

<<<-- Originally posted by Barry Green : You guys are missing Rob's point -- since the footage is going to be slowed down to slow motion, each interlaced field will be converted to a full frame. There won't be *any* interlace artifacts, there will be 50 frames per second.

If you want to capture as much motion as possible, you have to use interlaced mode. Progressive will capture 25 motion samples per second, interlaced will capture 50 per second. And after slowing down to 50% playback speed, there won't be any interlace artifacts, each field will be converted to a full frame and it'll look like film that was shot at 50 frames per second (although lower vertical resolution). -->>>

I'm aware that 50i will allow for more samples per second, but you will be losing half the resolution, which is a lot. When using progressive mode, you do not lose any resolution, but the extrapolated frames are farther apart. If you're only going to use the slow down feature in Premiere, the end result will look jerky. However, if you're using a morphing technique to create the extra in between frames, you'll keep both your resolution and smoothness of motion.

That being said, those morphing techniques have their limits and if the motion is too complex, the end result will look odd. Maybe not the best for bird shooting, as the movement might be too fast and therefore the difference between each frame too great, but it's worth a try. I always do sample tests when planing for slow motion and I try different techniques to decide which provides the best results. It's always a case by case decision.

Per Johan Naesje November 10th, 2004 12:13 AM

Well, I think the discussion is moving towards technical aspects of video editing programs, plug-ins etc.
My initial question was: Settings on the camcorder to achieve the best “raw-film” result!

My biggest problem now, is that light conditions here in Northern part of Europe is hard, lots of bad weather, rain, snow…, Lauri: you agree with me?
Whish I could move, what about Hawaii?

- Per Johan

Lauri Kettunen November 10th, 2004 03:03 AM

<<<-- is that light conditions here in Northern part of Europe is hard, lots of bad weather, rain, snow…, Lauri: you agree with me? ... - Per Johan -->>>

Luckily enough there was last night bright skies for couple hours and at the same time there was a magnificant Aurora borealis. Got the best footage (sharp and colorful, very little noise) I've ever managed to have Northern lights. So, I'm quite happy of being here right now, in fact!

Rob Lohman November 10th, 2004 06:52 AM

<<<-- Originally posted by David Lach : I'm aware that 50i will allow for more samples per second, but you will be losing half the resolution, which is a lot. When using progressive mode, you do not lose any resolution, but the extrapolated frames are farther apart. -->>

This is true when you are just converting interlaced to progressive,
but that is NOT the case here. It is clearly stated that this is to
be used when ALSO DOING SLOWMOTION. Let me draw it out:

click here for difference between progressive and interlaced

Now if you convert this to 50% slowmotion it will be converted
to progressive. Look at the following:

click here for conversion to 50% slowmo

Now look at the difference. The resolution stays exactly the same
in both cases since all fields/frames are kept. However, the
information with interlaced is distributed across two frames instead
of one frame, thus each frame is constructed of less interpolated
material. Ofcourse these fields also have a slight temporal shift
which gives extra clarity on the moving object (and might even
allow you to get away with a bit lower shutter speed in case
you don't have a "enough" light, although not much).

> If you're only going to use the slow down feature in Premiere,
> the end result will look jerky. However, if you're using a

That might be, that depends on the algorithms they use. I can
imagine that it isn't geared towards a good end product for these
conditions like a specialized product does.

> morphing technique to create the extra in between frames,
> you'll keep both your resolution and smoothness of motion.

And how would one "activate" these "morphing techniques" in
a program like Premiere?

> That being said, those morphing techniques have their limits
> and if the motion is too complex, the end result will look odd.

ALL slow-motion algorithms that need to create inbetween
information (as is the case with our fixed rate camera's) use a
form of "morphing" (or as it is usually called: interpolation) to
create the missing information. The longer these gaps, the more
difficult and bad it will look.

> I always do sample tests when planing for slow motion and I
> try different techniques to decide which provides the best
> results. It's always a case by case decision.

That is definitely true and something everybody should be doing.
A technique that might work wonders one time might produce
bad results with some other footage and vice versa!

Just as a side note: we are talking about XL2 progressive mode
here which is a "true" progressive scan mode, not a faux one like
the XL1S. In that case different rules apply.

David Lach November 10th, 2004 12:35 PM

Quote:

click here for conversion to 50% slowmoNow look at the difference. The resolution stays exactly the same
in both cases since all fields/frames are kept. However, the
information with interlaced is distributed across two frames instead
of one frame, thus each frame is constructed of less interpolated
material. Ofcourse these fields also have a slight temporal shift
which gives extra clarity on the moving object (and might even
allow you to get away with a bit lower shutter speed in case
you don't have a "enough" light, although not much).
I think this is true on a theoritical level only, one I'm agreeing with from the start. It's obvious that you don't end up with more pixels captured by the XL2 over the entire footage using one method or the other. So in a way, yes, the resolution remains the same.

But, and your drawings there kind of point towards that direction, if you do a frame by frame analysis, you see that every slowed down frame in interlaced mode will only contain one half of the real world capture, hence my 50% lower resolution comment, whereas with the progressive scan, which on the PAL XL2 is the equivalent of taking a full frame photo every 25th of a second, you will have one frame out of two that will be entirely created from scratch and one full unaltered frame.

So unless I'm understanding this wrongly, and it is a definite possibility, the progressive mode, out of every 2 frames, will allow for one full unaltered 100% resolution frame and one in between frame created frome that full frame. The interlaced slow motion, on the other hand, will have each frame created with half the "reality" of what has been captured. Now of course I might not be understanding properly how the software recreates that other missing field for slowing down interlaced footage, but if it's from blending, you're definitelly losing resolution, where in progressive mode, there will be one frame out of two with no "captured reality" in it, but it will still have been created from one full resolution and unaltered image nonetheless.
Quote:

And how would one "activate" these "morphing techniques" in
a program like Premiere?
Like I said in an earlier post, I use the Twixtor plugin from Revision Effects. Premiere alone does not do any kind of sophisticated morphing. Only frame blending, which isn't the same, or at least it isn't as advanced.
Quote:

ALL slow-motion algorithms that need to create inbetween
information (as is the case with our fixed rate camera's) use a
form of "morphing" (or as it is usually called: interpolation) to
create the missing information. The longer these gaps, the more
difficult and bad it will look.
That's true. But what I call a morphing program is software that will not just blend the 2 frames together, but will look at the content (often you'll need to draw mattes around unmoving subjects to avoid background distortion), will calculate the motion vectors for literally each pixel and will draw the in between movements based on that analysis.

Marty Hudzik November 10th, 2004 03:01 PM

I hate to jump in here so late but in general slowmotion created in editing software will first deintelace the footage to get 50% slow motion and if you slow it down more it will begin to just repeat frames to give the illusion of slower motion. I have been applying slow motion to wedding videos for 5years using all known versions of premiere and if you slow it more than 50% say to 33% you will see frames just blatantly being repeated. This could be considered slow motion.

But what I think we are all assuming is that the original poster was trying to achieve a "high speed" photogragphy look. Twixtor and Retimer are 2 plugins that will emulate this but to put it bluntly....they are expensive and a pain in the *** to use. It is not easy by any means.

There is just no affordable camera that will shoot 200-300 frames per second to achieve this effect. We have to cheat.

David Lach November 10th, 2004 03:16 PM

<<<-- Originally posted by Marty Hudzik :

Twixtor and Retimer are 2 plugins that will emulate this but to put it bluntly....they are expensive and a pain in the *** to use. It is not easy by any means. -->>>

That's true. I wouldn't recommand using Twixtor if you don't have a LOT of time on your hands. I use it mainly for fictional stuff and it is very time consuming, but it can emulate the look of expensive high speed cameras when you know how to use it and most importantly, when to use it.

Rob Lohman November 11th, 2004 05:27 AM

I think we are all sort of agreeing in the end. It all works or fails
with the quality of the algorithms being used and as we all
understand this can have a huge impact on how the reconstruction
is done and with what quality you end up with.

David: your points are certainly valid and are the same as mine,
the idea (and this has been tested) is that with a good slow-
motion algorithm (ie, not the Premiere included one) the inter-
laced method is usually giving smoother motion results (due
to the more even distribution of time). But as said earlier, test
, test, test and test <g>


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