Can anyone explain this

Can anyone explain this
0

My vote is also for the lack of the anti-aliasing filter… not sure why but rarely does a camera NOT have that unless you specifically buy that model, and we’ve not really seen this nifty phenomenon before!

Any way you can go back to the spot in similar conditions? I’d see if I could borrow a Nikon from a friend that has the filter and shoot both that day. I would also record 60fps video on your camera so you can slow it down and see what’s moving/arcing/jumping, lol. You always want your shutter speed in video to be double of the framerate you are shooting, so in your case it’d be 1/125 sec, then you pick as F-stop (5.6-8 should work in this case) and adjust ISO to get the right exposure. It’d be interesting to compare that to the images.

Side note, those are the settings you want for ANY video work if anyone does that… shutter is double your FrameRate (I shoot 24FPS so I use 1/50), pick the aperture to fit the art (2.0 for a portrait, etc), and adjust ISO for exposure. If I want to shoot f2.8 in bright sunlight I can’t achieve that with a 1/50 shutter speed so I pull out an ND filter or even a CPL in a pinch. You can’t change shutter speed. I know, off topic, just wanted to explain why I mentioned the settings above. :wink:

Nice observation. Calls for an explanation. I’ll give it a try.

My suggestion about the origin of the segments is the following. I’ll concentrate on the upper trail and make some crude approximations.

1 I do not think it has anything to do with the camera. We are seeing about 20 segments in 0.3 seconds. That does not seem to be related to the speed of internal processes of the camera.

2 If this were a single streak of water broken into droplets then their distances are almost equal which is imo not very likely. Moreover during 0.3 seconds they apparently moved over say 1 cm giving them a speed of 3 cm per second which is rather slow.

3 From the previous I conclude we are seeing the path of only one droplet. (It covered a distance of about 50 cm in 0.3 seconds then its speed was 1.5 m per second, which seems reasonable to me.) When the flowing water hits a stone the flow becomes irregular and droplets get detached from the main mass of water. They are launched with a certain amount of energy, part in the motion of its center of mass part in oscillations of its shape. At rest the shape will be a sphere due to electrostatic forces holding it together. At launch time the shape is almost certainly not a sphere so when free its shape starts to oscillate. Thus its shape changes when travelling. As a result the reflecting surface towards the camera changes in size, this will result in dark and light parts along the path of the droplet. Reflected light is usually polarized. So with a polarizer filter in front of the camera (a landscape photographer surely uses one…) the effect will be even stronger.

It would be interesting to see similar pictures with different shutter settings, even using flash for extremely short exposure times.

Added later: The frequency of the oscillations would then be about 60 Hz (20 segments in 0.3 sec), I do not know whether that is a reasonable number.

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