Look what happens on release !

[Watch_Man]

Taking some photo's of archery_mum at a training session tonight I captured the following image just after release. I found it interesting to see the difference in the string below the arrow. The string above the arrow seems hardly to move but below it is nearly invisible. This photograph is not retouched in any way.

[clickerati]

that's brilliant!

[grimsby archer]

Originally Posted by Watch_Man

Taking some photo's of archery_mum at a training session tonight I captured the following image just after release. I found it interesting to see the difference in the string below the arrow.

I feel this is very similar to my comments about string pattern immediately following release in the photos you published here recently. Welbeck was it?

[Anna K]

Does that mean that the bottom cam is going faster than the top?

Very cool picture

[Watch_Man]

Originally Posted by grimsby archer

I feel this is very similar to my comments about string pattern immediately following release in the photos you published here recently. Welbeck was it?

Yes it reflects the pattern. I have a couple of images from tonight illustrating this (someone you know ) but what I was not aware of from the Welbeck photos was how the string seemed to remain above the nock point. It looked like the string went into the shape but as it travelled away from the archer. This seems to show that the bottom section accelerates much faster.

[Watch_Man]

Originally Posted by Anna K

Does that mean that the bottom cam is going faster than the top?

Very cool picture

Anna it is common across all bows I have photographed including recurve (see the photos I just added) I would like someone to explain why it happens as there must be a scientific explanation.

[grimsby archer]

Originally Posted by Watch_Man

Yes it reflects the pattern. I have a couple of images from tonight illustrating this (someone you know ) but what I was not aware of from the Welbeck photos was how the string seemed to remain above the nock point. It looked like the string went into the shape but as it travelled away from the archer. This seems to show that the bottom section accelerates much faster.

Thats what I was jumping up and down and waving my arms about.
Your photos from Welbeck were the first time I had ever seen this and I feel that it HAS to be significant.
I can see a reason for it in that the arrow is positioned above the center of the string, that is to say there is more string below the arrow than above, so youd maybe expect a bigger resonance curve in the bottom part of the string.
I never expected the difference to be so huge though. Id always thought that the bottom limb or cam would pull the string down/forwards in a straight line, towing the arrow behind it. Now it looks like the middle of the bottom half of the string is actually being catapulted forward of the arrow and bottom limb.
We need more photos and some really clever physics guys. This could be the biggest breakthrough in archery since the bowstring.

[renniks]

Originally Posted by Watch_Man

Anna it is common across all bows I have photographed including recurve (see the photos I just added) I would like someone to explain why it happens as there must be a scientific explanation.

20 odd years ago I worked on early generations of CCD cameras on my university placement at EEV, but I doubt the principles have changed much.
The image is scanned pixel by pixel e.g top left to bottom right and processed sequentially. So there is a time delay between the top and bottom of the image, which I had thought would have been negligble on your previous (excellent) photos.
Perhaps you could experiment with the camera turned through 90 degrees, or even upside down to see whether the effect in the first picture can be reproduced, or reversed with the top limb in advance.

[Anna K]

Originally Posted by Watch_Man

Anna it is common across all bows I have photographed including recurve (see the photos I just added) I would like someone to explain why it happens as there must be a scientific explanation.

That's really interesting that it is the same in the recurve too (not just limited to one specific bow). It definitely suggests that the bottom limb (or cam) is travelling faster than the top. Is it designed like that though or is this to do with the height of the nock. The arrow is very rarely (if ever?) going to be in the very centre of the string.

[worthipa]

Originally Posted by grimsby archer

there is more string below the arrow than above

Therefore you'd think it would move slower surely, heavier mass and so on, both limbs being equal ....

Originally Posted by grimsby archer

We need .... some really clever physics guys.

Hmm, not me then!

[geoffretired]

I can't explain it Watch_Man, but it does look as if the two halves of the string are curved but in opposite directions. That reminds me of a physics lesson on music and plucked strings. First harmonic has two parts like an S. Each half string length is half phase out from the other. To create the first harmonic you pluck the string at some point or other away from the mid point. Our arrows are away from the mid point too. That could all be very wrong, but it sounds good don't you think??
Seriously. That is a very unexpected result. Brilliant photos. I still want our club to buy one of those EX-F1's

[Watch_Man]

Originally Posted by renniks

20 odd years ago I worked on early generations of CCD cameras on my university placement at EEV, but I doubt the principles have changed much.
The image is scanned pixel by pixel e.g top left to bottom right and processed sequentially. So there is a time delay between the top and bottom of the image, which I had thought would have been negligble on your previous (excellent) photos.
Perhaps you could experiment with the camera turned through 90 degrees, or even upside down to see whether the effect in the first picture can be reproduced, or reversed with the top limb in advance.

If the weather holds then I will try this tomorrow night

[Flying Whale]

Originally Posted by renniks

20 odd years ago I worked on early generations of CCD cameras on my university placement at EEV, but I doubt the principles have changed much.
The image is scanned pixel by pixel e.g top left to bottom right and processed sequentially. So there is a time delay between the top and bottom of the image, which I had thought would have been negligble on your previous (excellent) photos.
Perhaps you could experiment with the camera turned through 90 degrees, or even upside down to see whether the effect in the first picture can be reproduced, or reversed with the top limb in advance.

Sounds like a very simple experiment to try. I would go with upside down if possible.

[Tony_zelah]

Ok guess work here. But could it be caused by the fact that arrows are not nocked in the exact center of the string. Mean the upper half is a fraction of a second slower to move because of the extra weight (arrow nocking point peep sight) it has to propel

[Hidden Hippo]

My guess would be that it is caused by the fact that the peep sight adds weight to the string (not much, but it could be significant), as well as the nocking point not being completely central.