high shutter speed images

[Chippintuff]

Fantastic diagnostic tool.

WA

[Zuma]

I have a new camera that has shutter speeds up to 1/16000ths. These are stills from 4k video shot at that speed. This may have use in tuning, as it shows the timing of arrow flex. I believe that the shutter is opening on the top first and scanning down leading to the unbalanced look of the string, limbs and fletching.

Just curious. Are the shingles on the house gable correct in the last photo.
I am not sure but if that is a distortion can it effect other parts of the photo??
I have seen a lot of similar distortion on older digital camera photos.
Zuma

[aaron]

That is really interesting. I'm glad you mentioned that it is scanning the picture(I didn't know they worked like that) as I would have thought that a lot of weird stuff was happening. I drew a couple of lines on the picture where I think think you released(top) and where the bow stopped (bottom). In between those lines is like a movie(sort of). If the shutter speed is 1 16,000 of a second does that mean that the time between the two lines is about 1 32,000 of a second? I noticed that the bottom limb looks straight on the inner half. Would that also be from the scanning?

yes, I think your're right-  that the lines you drew are 1/32,000ths apart, or the top line was recorded at one moment, and the bottom line was recorded about 1/32,oooths later. In other words, the very top of the photo was recorded when I was at the moment of release, while  the bottom part of the photo was recorded a bit later. By the time the bottom of the photo was recorded, the bow had almost reached brace. the straight section on the bottom limb could be caused by this I guess. If this is true, it tells us that a bow goes from full draw to brace in 1/16,000ths of a second give or take. If I had more math and less beer in me, I could check this against a ballpark speed of 125fps which is about what the bow probably shoots.

[aaron]

Just curious. Are the shingles on the house gable correct in the last photo.
I am not sure but if that is a distortion can it effect other parts of the photo??
I have seen a lot of similar distortion on older digital camera photos.
Zuma

haha, no the shingles on the gable really do look like that!

[DC]

That is really interesting. I'm glad you mentioned that it is scanning the picture(I didn't know they worked like that) as I would have thought that a lot of weird stuff was happening. I drew a couple of lines on the picture where I think think you released(top) and where the bow stopped (bottom). In between those lines is like a movie(sort of). If the shutter speed is 1 16,000 of a second does that mean that the time between the two lines is about 1 32,000 of a second? I noticed that the bottom limb looks straight on the inner half. Would that also be from the scanning?

yes, I think your're right-  that the lines you drew are 1/32,000ths apart, or the top line was recorded at one moment, and the bottom line was recorded about 1/32,oooths later. In other words, the very top of the photo was recorded when I was at the moment of release, while  the bottom part of the photo was recorded a bit later. By the time the bottom of the photo was recorded, the bow had almost reached brace. the straight section on the bottom limb could be caused by this I guess. If this is true, it tells us that a bow goes from full draw to brace in 1/16,000ths of a second give or take. If I had more math and less beer in me, I could check this against a ballpark speed of 125fps which is about what the bow probably shoots.

I did some "rough" calculations and unless i made a mistake in 1/32,000 of a second the arrow would have only gone a half inch. It's gone about 8-10 inches in the picture. Something doesn't add up. Probably me.

[upstatenybowyer]

That is so cool. 

[willie]

DC,
I think that the camera is capable of 1/16000, but that does not mean that the shutter speed is fixed at that rate like it would be if selected for a still photo. the video frame rate will allow a much longer exposure, and given the high quality of the photo, I think the camera program chose a longer exposure.

[Chief RID]

I love the physics but I still suck at the math. Thanks so much for sharing. I learned so much.

[BowEd]

I used to take hundreds and hundreds of pictures of my coon dogs at the tree barking.Back then I used 35MM film from a Minolta camera.I used to have to use at least 400 speed film to catch them at the right moment barking with their mouth open and the foam a flying.Many times that would take 24 pictures or a whole film roll to get just a couple pictures the way I liked them.
Don't know if that's related to this and I know cameras are a lot more sophisticated now,but it's fascinating seeing on yours the difference of how much the limbs move alternately between the time it takes for the shutter to open and close.

[Del the cat]

The string doesn't do that...!
It's an artefact* of either how the shutter moves or how the charge is scanned from the CCD array.
I was discussing this with my Brother and came up with a good analogy.
Imagine the CCD is a chess board with the pieces set out in the middle of a game.
To scan the image you have to write down what is in each square going along each row one at a time...
No problem...
Except, now imagine that whilst you are wringing it down, the game is till actually progressing!
So as you write down the last line, some of the pieces have been moved!
Del
*search for artefacts in digital photography

[DC]

You're right Del but it gives you a snapshot of the game sorta. Because it took time you can interpret what was going on. By the shape of the string you can see how it initially accelerated to a maximum speed and then decelerated. You can see just below the bottom red line how it overshot the brace position and returned to normal. What is interesting me is that the string seems to reach it's maximum speed right about the middle of his arm and then starts to decelerate. I would have thought that it would accelerate until it was back to brace height. What do you think is slowing it down? Maybe because the bow is just running out of horsepower. If that's the case is it possible that the arrow could leave the string before it reaces brace height? If the string is slowing down faster than the arrow that could happen. Hmmmm

[aaron]

DC,
I think that the camera is capable of 1/16000, but that does not mean that the shutter speed is fixed at that rate like it would be if selected for a still photo. the video frame rate will allow a much longer exposure, and given the high quality of the photo, I think the camera program chose a longer exposure.

nope, this camera allows me to set everything manually. I believe all these are at 1/16oooths.

[aaron]

here are a series of 5 images covering one shot of an arrow. if you download these to your desktop and view in quick succession, you can see the shot unfold. I believe these are 1/16,oooths exposures and 60 frames per second.

[aaron]

...

[BowEd]

Pretty cool aaron.