# Water drop HSS



## Robin_Usagani (May 26, 2013)

This is in response to this thread.  If you pay attention in your physic class in HS or college, you should be able to follow my calculation.
http://www.thephotoforum.com/forum/macro-photography/326634-captain-america-water-drops.html






Now let's just assume we are not using a flash.  Is derrel really saying you cant use the mechanical shutter to stop the motion of the water that is only 5.48 miles/hour?  Give me a break.  Of course you can use HSS to stop a water drop.  It is not going that fast.  If you are talking about a spinning tool, then of course HSS or ambient light is not going to cut it (High Speed Shutter vs. Ordinary Flash Sync).  Usain Bolt average velocity is 23.4 mph.  Is derrel really saying you can't stop motion of Usain Bolt?  Fire away.  I am just really sick of getting picked by derrel.  I understand derrel is full of knowledge but he is not right all the time.   Let the flaming begin.  I was going to set up off camera HSS to shoot waterdrop to proof it (with tripod, constant drip, constant focus point), but I figured a simple physic calculation should do it.


----------



## Derrel (May 26, 2013)

Robin_Usagani said:
			
		

> Here are a few I just did. Hand held, focus was all over the place, HSS, shutter was 1/2000 or faster. Unfortunately since this is handheld, I had to burst the shot so I had to lower the flash power so I can fire it consecutively. Because of that I had to bump up the ISO. If I had used a tripod and keep adjusting the focus, I can probably shoot it at lower ISO and get better timed shots. I have no idea what derrel is talking about.
> 
> View attachment 44292
> 
> ...



In your last picture you show us a nice *stroboscopic* effect, but it does not stop or freeze the motion...just as I said it would not. HSS is a series of very rapid flash micro-bursts, up to 199 flashes per second, according to the Canon website. You can see here that no motion has been "stopped", or frozen. Exactly as I stated. I can see 15 discrete background images here...this water is not frozen, as you stated it would be using HSS. It is rendered exactly as I predicted...a series of very,very rapidly-paced micro-flashes were emitted, turning this into over an inch-long rendering. "stroboscopic rendering"

You calling me an ass in the Captain America Water Drops thread, as well as your beginning of this new, separate thread with some calculations, but none of these blurred photos to support your calculations...just wow Robin, all in all weak sauce.

Your photos above proved that I was right, and you were incorrect. Sorry, but your very own photos demonstrate that your technical knowledge and understanding of Canon HSS flash is faulty.

HSS flash is sequential, micro-burst flashes that a fired over a relatively looooooong duration, in order to make the flash last for the entire duration the mechanical focal plane shutter is traversing the film plane. 

What a person wants to do in trying to render high-speed motion utterly stopped, as in *frozen*, is to use a SINGLE, very brief-duration flash. This is normally accomplished by using AUTO-thyristor flash, fired at low fractional power, usually between 1/16 and 1/128 power, which fires a very short,duration flash of as brief as perhaps 1/64,000 second. Your first two, blurry images prove that I was correct, and you are not fully aware of how HSS actually works, *in the real world.*


----------



## Robin_Usagani (May 27, 2013)

Here you go derrel.. I shot a few more just for you.  I use tripod this time.  Are you really saying I cant stop an object that is going 6 mph with my shutter?  Give me a break.


----------



## Ballistics (May 27, 2013)

So... did you find out whose is bigger yet?


----------



## Robin_Usagani (May 27, 2013)

gosh.. the exif is stripped.. not sure why.. brb.


----------



## Robin_Usagani (May 27, 2013)

Ballistics said:


> So... did you find out whose is bigger yet?



Only one way to find out.


----------



## Gavjenks (May 27, 2013)

This is solvable by math, but you didn't do enough of it to arrive at a conclusion.

Size a water drop can be while still circular = roughly 2mm
Number of pixels in diameter the guy wanted a drop to take up for the captain america thing = roughly 200 pixels (see the printed dimensions of the shots compared to drop size)
Amount that the drop can move in frame during the exposure to see essentially ZERO blur = Maybe a few pixels.  3-4? Subjective, but that's already pushing it.

Thus, the distance in real life that the drop can fall during exposure to see no blur at best = 4 pixels / 200 pixels = 2% of its diameter = 0.04 millimeters

At 1,223 mm/s fall speed (your math was wrong for 1 foot of fall), the time it would take to fall 0.04 millimeters = *about 1/30,000th of a second*





However, why on earth would you wait for the drop to fall a full FOOT before photographing it?  that's just making your life much harder. The drops break into individual spheres much much earlier than that if you set it up right.  In the linked photos above, you can see pretty round drops in less than an *inch *of fall (after many shots, you should be able to luck out and get one nearly perfect).  This would yield a velocity of 0.353 m/s instead.

Which yields a required exposure of *about 1/8500th of a second.*




*Conclusion: HSS should just BAAAAARELY be capable of getting the image with less than a few pixels of motion blur by using a higher end camera body capable of 1/8000th shutter speeds. * But everything would have to be just right, and still, you're really pushing it... if you try to make the drop too big in frame people will absolutely notice blur. Even just 200 pixels like in the captain america example may be too large.

*You are much better off by doing the following*, which doesn't even require any additional equipment to be bought (assuming you were using flash to go at full HSS previously):
1) Set up your normal professional quality (e.g. nikon or canon modern) speedlight
2) Set it at its lowest power (1/64th or 1/128th or whatever). lower power yields shorter flash durations.
3) Set up in a dark room, with almost no ambient light.
4) Have focus manual and pre-adjusted, obviously.
5) Fire at a shutter speed of 1/200th or 1/250th of a second or however fast you can go on your camera JUST BEFORE HSS flash turns on (the max speed of your shutter without requiring both leaves of the shutter to be in motion at once) something (so that HSS does not engage). You may need to look up what this threshold is for your camera body.

Using for example a typical Nikon SB-800, set at 1/128th power, the duration of the flash is a blistering 1/41,600th of a second.  Since you have no ambient light, none of the rest of the exposure matters, and you can capture the water drop without even a single pixel of blur at 1 inch of fall.

Vastly superior than trying to use HSS flash at your camera's max shutter speed.


----------



## Gavjenks (May 27, 2013)

> Here you go derrel.. I shot a few more just for you.  I use tripod this  time.  Are you really saying I cant stop an object that is going 6 mph  with my shutter?  Give me a break.



You're not following your own requirements, dude.  That drop in the photo is OBVIOUSLY not a foot below the point of being dropped.  it looks closer to about half an inch to me. So it's not going anywhere close to 6 miles per hour. more like 0.5 miles per hour. (Note that even at 1 foot, it isn't going 6 miles per hour, because you did your math wrong.  A drop at 1 foot = about 3 miles per hour.)

Also, your drop is not circular, and it's even smaller than the captain America ones (yours is 170 pixels top to bottom). Smaller images on the sensor make it easier to capture without noticeable blur, so this is also cheating.



What you have proven is that at 1/6400th of a second, you can capture a drop (charitably speaking -- it is very wobbly) that is *smaller *than the original thread's drop, and is only going *0.5 miles per hour.*

You still have 5.5 miles per hour and another 30 pixels in diameter in the image to go to prove your point.


----------



## Robin_Usagani (May 27, 2013)

Where did I mess up my calc Gavjenks?  I checked everything.  You are right, it can be shot sooner than 1 ft (even slower velocity).  It was just an assumption.  I understand that the best scenario is to use zero ambient and go with smaller power (shorter tail), I never denied that.  What I am trying to prove is that it really isnt going that fast.  I still think at 1 ft it is at 2.45 m/s (2450 mm/s).



Gavjenks said:


> This is solvable by math, but you didn't do enough of it to arrive at a conclusion.
> 
> Size a water drop can be while still circular = roughly 2mm
> Number of pixels in diameter the guy wanted a drop to take up for the captain america thing = roughly 200 pixels (see the printed dimensions of the shots compared to drop size)
> ...


----------



## Robin_Usagani (May 27, 2013)

gavjenks, i will use a cup with a hole next time.  I used a faucet and it made the drip looked a little weird.


----------



## Gavjenks (May 27, 2013)

I assume you miscalculated time.  I don't really want to worry about how, because you never even needed to calculate time in the first place, when you can just use the equation for velocity directly from displacement:

V = sqrt(2 * g * d) / 2
V = sqrt(2 * -9.8 * 0.305) / 2
V = sqrt(-5.978) / 2
V = 1.223

Edit: It was your velocity from time equation.  V = 1/2 *  g * t.   Left out the 1/2


----------



## Gavjenks (May 27, 2013)

Robin_Usagani said:


> gavjenks, i will use a cup with a hole next time.  I used a faucet and it made the drip looked a little weird.



But you also need to make it actually fall an entire *1.5 meters* before photographing it (distance it takes to get to 6 miles per hour), instead of what looks to be about half an inch in your photo, if you want to prove your point that your shutter can capture an object at 6 mph at that level of magnification.


----------



## Robin_Usagani (May 27, 2013)

i didnt leave it out.  it is d=1/2 g t^2  .  I am confident with my calc.  It is stuck in my head since HS.


----------



## Robin_Usagani (May 27, 2013)

Gavjenks said:


> Robin_Usagani said:
> 
> 
> > gavjenks, i will use a cup with a hole next time.  I used a faucet and it made the drip looked a little weird.
> ...



1.5 meters??  It is going 5.48 miles per hour at .305 meter!  Is it really that hard to get a sharp photo of a car going 5.5 miles/hour?  No.


----------



## Gavjenks (May 27, 2013)

Robin_Usagani said:


> Gavjenks said:
> 
> 
> > Robin_Usagani said:
> ...



No... as I just pointed out above, your math was wrong, and at 0.305 meters, it is going 2.74 mph

At 1.5 meters, it is going 6.1 mph.



And  the car is completely different.  You normally would take a photograph  of a car with your entire frame, and then you'd put the entire frame  onto your final print.
Here, however, you are taking a 200 pixel wide drop and magnifying the image to the point where *only 2% of your sensor is showing up on the final print*  (above, your images are 400x600, and your camera can do 3,000x4,300).   This makes motion blur extremely more visible at slower speeds.

It's the equivalent of something going 40-50 miles per hour at normal magnification (print uses your full frame)... without you tracking it.


----------



## Robin_Usagani (May 27, 2013)

sorry dude.. my math is correct.  I dont know what you are talking about.  MY image above is barely cropped.  I used a macro lens.  I could have shot it closer but then depth of field will be a problem.


----------



## Robin_Usagani (May 27, 2013)

gavjenks.. it is really hard to have this conversation with you.  You edit your responses all the time.    At one point you said your calc was wrong, then you edited it again.


----------



## Gavjenks (May 27, 2013)

Sigh... I already explained why your math is wrong.
You did: velocity = gravity constant * time
The correct equation is: *1/2* * gravity constant * time.


And your image as displayed on the forum is 400 x 600 pixels = 240,000 pixels
Your Canon 5D is capable of producing 2912 x 4368 pixels = 12,719,616 pixels
Which means the image is only as large as *1.8%* of the number of pixels your sensor is able to capture.

Last time I checked a 99.2% crop/scale is not "barely cropped"


----------



## Gavjenks (May 27, 2013)

> At one point you said your calc was wrong, then you edited it again.



Here's a double post for you instead of an edit then.

To be precise, I wrote that MAYBE you were right, because I found three websites with different equations, and none were very official.  Then I went and looked it up in the physics textbook on my shelf, and confirmed that my initial formula was correct and yours was not. Then I edited my post again, because you weren't maybe right anymore.

In any case, it doesn't matter.  The laws of physics do not warp depending on what I post on thephotoforum.com.  It is absolutely v = 1/2 * g * t, and you forgot to divide by 2, or were using a bogus equation from somewhere.


----------



## Gavjenks (May 27, 2013)

if you hadn't cropped and rescaled at all, then your image would be representing the entire sensor plane

The difference between your sensor's full length and the portion you showed here is a factor of 7x (along just one dimension, since motion is one dimensional)

Which means that capturing 6mph without motion blur at your current cropping is approximately equivalent to the difficulty of capturing *42mph* without motion blur for an uncropped normal photo displayed at the same size on the screen as yours in the OP. For instance, one of a car.


Edit: Also, when you take a photo of a car, you would normally PAN the camera to follow it, which reduces its speed from 42mph to essentially just whatever your error is in hand shake and panning skill.  Here, however, you cannot pan the camera to track the water drop.  So you're at a major disadvantage compared to the car. You also cannot take advantage of horizontal tracking image stabilization in your lens.  Taking all this into consideration, capturing 6mph at that cropping *may actually be more difficult than capturing 100-200mph* with no cropping + camera panning being possible.


----------



## BlkdOutGsxr (May 27, 2013)

This is an odd thread to read... @OP I don't think that anyone is saying that you 'cannot stop motion' of a water drop well enough to photograph it using the technique that you mentions, but I think the point was that it's not the preferred or 'best' method of doing a shot like this. As for the nonsense over the calculations, I don't see what anyone is trying to accomplish by focusing on that part of the post; Whether it is 3mph or 6mph the OP's point was that he thinks even at 6mph he should be able to stop the motion of the water well enough for the effect he was trying to get. I'm not sure what the epeen battle is about beyond that.


----------



## Gavjenks (May 27, 2013)

> @OP I don't think that anyone is saying that you 'cannot stop motion' of  a water drop well enough to photograph it using the technique that you  mentions


That is exactly what I am saying, and I _believe _what Derrel was saying too.

At 6mph, I am claiming it is almost completely impossible to freeze the motion of a drop of water using only your camera shutter (up to 1/8000th of a second, assuming normal commercial grade cameras), if it is magnified to the size shown in the OP or in the original captain america water droplet thread.

At 1/8000th of a second, the 200 pixel image would still have upwards of 15-25 pixels of blur even under completely optimal and lucky conditions, which is still going to be completely obvious.


----------



## BlkdOutGsxr (May 27, 2013)

Gavjenks said:


> > @OP I don't think that anyone is saying that you 'cannot stop motion' of  a water drop well enough to photograph it using the technique that you  mentions
> 
> 
> That is exactly what I am saying, and I _believe _what Derrel was saying too.
> ...



I think what your arguing about is actually what you consider 'well enough to photograph it' was the point I was trying to make. Which I went on to say that I think you are trying to say there are better ways; ie closer to what you deem 'frozen'.


----------



## Gavjenks (May 27, 2013)

Note that I am NOT saying it is impossible to capture ANY water drop with only your shutter.

For example, using only your shutter, you very well might be able to freeze the motion of any of the following:
1) A water drop that has just left the faucet and only fallen half an inch. This would be moving at 0.5 mph, not 6mph, and thus could be captured without noticeable blur.
2) A water droplet that was sprayed into the air and is photographed at the top of its trajectory, where it is almost completely still. You might even be able to capture the motion of such a drop with as slow as a 1/500th of a second shutter, depending on circumstances.
3) A water droplet in freefall along with the camera (for instance, in space, or if the camera and droplet are both inside of a plane that is taking a nose dive)
4) A water droplet in a vacuum, where size is not determined by air resistance, and where a drop can be much larger and thus require less magnification.
5) A water drop that takes up a much smaller portion of your final print. For example, if the photo is a picture of children playing in a sprinkler, and the droplet only takes up 2 pixels, then its blur would only be 0.2 pixels of blur, which wont even be rendered. The fact that it is much smaller in the final print makes it easier to freeze its motion even at higher speeds.
6) A water drop that is so predictable that the camera can be made to pan downward (for example using a computerized stepper motor) and track its movement. This would reduce the relative movement from the point of view of the camera, effectively making the droplet act as if it were moving slower.  With perfect tracking, you could potentially freeze motion with 1/50th of a second...
7) Who knows how many other situations?

But this is not about any of those.  This is about the situation at hand: a drop of water that has fallen 1.5m (6mph), and is being magnified to take up 200 pixels in the final image.



> I think what your arguing about is actually what you consider 'well  enough to photograph it' was the point I was trying to make. Which I  went on to say that I think you are trying to say there are better ways;  ie closer to what you deem 'frozen'.


Frozen simply means "few enough PIXELS of motion blur (in the case of a quantum, digital image) in the final, distributed version of the image that the viewer cannot notice the blur."

For most people, this is going to end up being maybe 2-4 pixels of blur, tops, for it to be seen as frozen. That simply cannot be achieved for the given situation using shutter speed alone.


----------



## Gavjenks (May 27, 2013)

In case my explanation was unclear about why a photograph of a car is different:


In the image above, I applied some motion blur to the circles on the bottom.  I then copied and pasted them at a smaller size into the upper image.  Notice that the blur on the bottom is very visible, but the blur on the top is not.  This is because on the top, the blur only takes up 1 maybe 2 pixels, and becomes pretty much invisible to the human eye, whereas 8 pixels or so of blur on the bottom is quite noticeable.

This is why magnification matters, and why a water droplet expanded to be the main subject of a photo is just as hard to photograph as a non-magnified or cropped car is even if it were traveling many times faster than the water droplet.

Pixels of blur in the final image is what matters, not speed in the real world.  And pixels are based on *relative *magnification and *relative *speed to the film plane.


----------



## Nahin (May 27, 2013)

I understand you promote such an stunning example, but relation btw calculation and figured. Actually couldn't perceive... :er:


----------



## Robin_Usagani (May 27, 2013)

Gavjenks, you brought up good points, however:
1. My calc is correct. You got your formula wrong. Gravity Velocity Equations for Falling Objects by Ron Kurtus - Succeed in Understanding Physics: School for Champions

2. I only cropped a little bit to level. The size of water is like the size of a car in a frame when I shoot a car.

I told the OP of the other thread to kill the ambient light (which was the problem) or go to quicker shutter and hss.  You are correct gavjenks about the cropping. You would need sharper stop motion if you had shot it with non macro which was something I didnt consider.   In fact, when I made the point about hss, I assumed OP used a macro lens (the post was in macro section). 

Thanks for having an intelligent conversation with me, that is exactly what I want.


----------



## Robin_Usagani (May 27, 2013)

Gavjenks, i agree with you 100% about the pixel blur. But do you also agree with me if it was shot with macro, it would have been ok too?  I think we were arguing different things.  Major cropping was never in the original discussion. Derrel was simply saying I was wrong while photographers all over the world are going crazy over hyper sync (freezed by mechanical shutter).  I see so many high speed action freezed by hyper sync.  I was just making my point water drop is no difference. You could have done it with no flash out in the sun (macro).


----------



## slow231 (May 27, 2013)

Gavjenks said:


> > At one point you said your calc was wrong, then you edited it again.
> 
> 
> 
> ...



lol what? your final velocity is absolutely g*t (assuming you stat from rest).  if you increase speed at a rate of 9.8 m/s-per-second, after 1 second you'll be going.... 9.8 m/s. if you just thought about it rather than blinding using a formula you'd realize this.  your *average *velocity over that time period (again assuming you start from rest) would be half that though, and that's probably where your equation is coming from.

you can also look at his from an energy perspective. falling d distance gives a potential energy change of m*d*g, ending in kinetic energy is 1/2*m*v^2, so v=sqrt(2*d*g).  and again robin is right.

i don't have much issue with you being wrong, it's more that you're adamant about something that you obviously don't have a very strong grasp of.


----------



## o hey tyler (May 27, 2013)

ur feet secrete almost 1/4 a cup of sweat every day tell me that aint ****ed up


----------



## pixmedic (May 27, 2013)

What is the air speed velocity of a coconut laden swallow?


----------



## Overread (May 27, 2013)

pixmedic said:


> What is the air speed velocity of a coconut laden swallow?



Too fast for HSS of course


----------



## Derrel (May 27, 2013)

Overread said:


> pixmedic said:
> 
> 
> > What is the air speed velocity of a coconut laden swallow?
> ...



Interestingly, a friend of mine has a bird feeder in his back yard. A few years ago, he called me up and referred me to a photo he had done of a black-capped chickadee coming in to the feeder...he could not figure out why the bird's wings were blurry. He was perplexed. He had used High Speed Sync flash on his Canon d-slr with a telephoto lens. The multiple,rapid-fire pulses of the HSS flash pulse caused the bird's wings to be...blurry.


----------



## Overread (May 27, 2013)

Aye HSS is good for bird and wildlife photography for giving fill light to bump up shadows, but not main light.


----------



## Judobreaker (May 27, 2013)

This calculation doesn't take subject distance into account...

The reason a car is less easily blurred at 5 mph than a drop of water at 5 mph is because the car is further away.
Why is camera shake so much more of an issue in macro photography than it is in landscape photography? Because the landscape is much further away. It's really the same story.


Now I'm going to use the metric system as the imperial system is just weird to me... 

Say we've got a water drop falling at 8 km/h (5 mph) and we're using a standard 50 mm lens on a 16 MP crop sensor (my D7K for example).
The focus is as close as possible (roughly 50 cm) which will give us roughly 15 cm in the frame. That's 15 cm for the drop to pass the frame at 8 km/h.0

Some calculation steps:
Drop speed in mm per hour = 1,000,000 * 8 = 8,000,000 mm/h
Drop speed per second = 8,000,000 / 3600 = 2222 mm/s
Drop time past frame = 150 / 2222 = 0.0675 s

So, in roughly 1/15th of a second the drop will pass that frame.
That frame is roughly 4900 pixels long. I will make the assumption that to freeze motion we'll need a maximum movement of 5 pixels (let's not be picky).

Some calculation steps:
4900 / 5 = 980
980 * 15 = 14700

The time it will take that drop of water to pass the maximum of 5 pixels is 1/14700th of a second.
That's pretty damn fast... 

Anyways, at a shutter speed of 1/8000 you'd get the following movement on the sensor.
1/8000 / 1/14700 = 1.8375
1.8375 * 5 = 9.2 pixels.

Because HSS will light the entire frame evenly during shutter movement this means we will get the full motion of the water drop. The only way to freeze motion using HSS is with your shutter speed, NOT with your flash (which would be the case in a standard flash burst).
Yes, I think you might have a hard time freezing that drop with HSS.

Is it impossible? No.
How can we do it? Quite simple... Back up. The larger your subject distance, the less motion blur. The drop will just be a lot smaller so you'll have to crop more.


I'm afraid I'm going to have to agree with Derrel here.


----------



## Derrel (May 27, 2013)

Getting back to the 'controversy' Robin wanted to address in this thread, and in another thread, this morning I did a quick web search for some of the suggestions from "famous water drop photographers". Here are suggestions on *how to properly* do high-speed water droplet photography. Since this is the Beyond The Basics section, I decided to look for world-class water drop photographers on Google, and see what they had to say about high speed water drop photography.


Somewhat interestingly the advice I have been giving here on TPF comes from information I learned years ago from a local TV show's segment profiling one of the world's most well-known water droplet photographers, who lives right across the river from me. His name is Martin Waugh. His process and his recommendations are somewhat well-known among the photographic community right here in our little corner of the world. His portfolio of images is without peer. Here is the tutorial that Martin Waugh recommends on his website. It pays to listen to people who actually know what they are talking about.


You can see Mr. Waugh's amazing work here:http://www.liquidsculpture.com/  and  get additional, expert, knowledgeable, accurate tech info here:
Martin Waugh Father, engineer, artist


A very brief quote from Martin Waugh: 
"I am currently using a Canon 5D and a 180mm macro lens, but other equipment works, too.I use fairly typical high-speed photography techniques."


"I leave the shutter open for a relatively long time (in a darkened room) and use a flash to illuminate the splash. The flash needs to be of a fairly short duration to stop the motion well. I use something like a 50 microsecond flash. &#8220;Speedlite&#8221; flashes (as opposed to studio strobes), control the amount light output by varying the flash duration. Not surprisingly, the shorter the duration, the less light (many studio strobes are the opposite!). So, you can get a short duration by setting the flash for low power (1/16 or 1/64). I get this by modifying the photo sensor circuit on Vivitar 285HV flash (a bit more detail) ."


Here is the tutorial site that Martin Waugh recommends to hobbyists, photographers, and teachers interested in doing true, stop-motion flash photography: HiViz - Tools - Flash Characteristics


Again: the true experts in the field realize that the camera's shutter is far too slow to *stop* water droplet motion. In fact, one of the world's leading experts (Martin Waugh) prefers to use LONG shutter speeds, in darkened rooms, and use ULTRA-brief, *single-pop* electronic flash, by using auto-thyristor flash power reduction, in other words fractional flash power settings, like 1/64 or 1/128 power.


If you want long, stretched-out, or blurred, or, stroboscopically-rendered water, rendered as inch-long blobs, or oval droplets, HSS might be just the ticket. However,the world's foremost experts suggest using single-pop flash of exceedingly short duration; durations so,so,so brief that there is no mechanical device that can even come remotely close to the brief time units that such flash pops span.


----------



## Ballistics (May 27, 2013)

If only this much effort,thought and exposure went into critique threads. You would think that it would in a photography forum,
those would be the threads that receive this much attention, but no. Discussions about the physics behind something so trivial,
or why a video is or isn't interesting, are what keeps TPF turning. The best(worst) part about this argument is, that proof is being presented
in paragraph form, not in real world image form (with the exception of the OP).


----------



## Overread (May 27, 2013)

Ballistics you do realise this thread is an extension of a critique thread. Furthermore why is it bad that we are discussing a core process of the photography world? The debate and discussion on HSS is very valid. 

If you're concerned that critique isn't enough, well, only thing you can do is right that problem yourself. Well thought out and constructive critique given encourages it further.


----------



## Ballistics (May 27, 2013)

Overread said:


> Ballistics you do realise this thread is an extension of a critique thread. Furthermore why is it bad that we are discussing a core process of the photography world? The debate and discussion on HSS is very valid.
> 
> If you're concerned that critique isn't enough, well, only thing you can do is right that problem yourself. Well thought out and constructive critique given encourages it further.



There are more philosophers and physicists than there are photographers in this forum. That's my point. And the longer discussions are almost always an argument about who's more right
and it's usually started by a passive aggressive member who implements subtle insults which carries this crap out further.

This is not an extension of anything but the same argument in the original thread. It's got nothing to do with critique. But I'm being more general in my first post regarding the trends of TPF
as a whole.


----------



## Gavjenks (May 27, 2013)

> Gavjenks, i agree with you 100% about the pixel blur. But do you also  agree with me if it was shot with macro, it would have been ok too?


No, it only has to do with the number of pixels that the object takes up in the final image.  And the number of pixels that it moves over the course of the light exposure.  Macro vs. not macro, lens focal length, etc. etc. should all just be intermediate details that get you in different ways to what matters: pixels in size and pixels of movement in terms of the final image.

In fact, if somebody used a macro lens to not just capture the same image, but to cause the water drop to take up a little less than the entire frame of the sensor (2000 pixels or so), then it would be 10x MORE difficult to freeze its motion, because the tolerances would become much tighter.  In order to get within 2 pixels of blur, you'd have to have it move no more than 0.1% of its diameter during exposure, instead of 1%.



> [being too adamant about gravity stuff, something something, the quote is on a different page]


Fair enough.  You're right, I don't have a strong grasp on it, and it doesn't really matter for the thread, so okay, I give up on that, with more than one person disagreeing.

Still, it's not anywhere close to 6mph at like half an inch away from the faucet, by any formula.



> Again: the true experts in the field realize that the camera's shutter is far too slow to *stop* water droplet motion.


Derrel, just because all the experts use longer exposure and instantaneous flash in a dark room, that doesn't necessarily imply that a shutter wouldn't be POSSIBLE.

Experts will always try to use the best method.  But "best" could simply be a matter of 10% better.  "Best" doesn't necessarily mean 100% better or that any other method will completely fail.



I think that both the math and the shots in the OP show that it is indeed *possible *to capture water drops with shutter only. It would be really annoying, and that the parameters are pretty constrained as to WHEN it could work at all (including the original ones here), but it can. 

 You could have captured motion with shutter only with an old mechanical camera with only 1/500th or 1/1000th or so (and flash bulbs not any faster), even.  You might have to do something like attach the camera to a moving track to match the speed of the drop.  Or spray drops upward so that they are suspended at almost no speed at the top of their trajectory, or whatever.  But you could do it if you set it up right. It's even POSSIBLE to freeze the motion of a water drop at like... 1/10th of a second in outer space =P

It's just that the slower you go, the more ridiculous hoops you have to start jumping through, so anybody with a better means would surely use it (unless they just wanted the challenge).  You can't just use the shutter to casually capture droplets without thinking about it at all or putting forth any effort besides pointing and composing and shooting a bunch. But that doesn't make it not possible.


----------



## Overread (May 27, 2013)

IF some people enjoy the physics of light and photography then more power to them. You won't see me discouraging them from discussing the topic - I might not understand it but I won't stop them.

Just as the gearheads can chat gear
and the macro addicts shoot macro and try to guess things
and the bird photographers shoot birds
etc...

TPF has multiple overlapping communities and it is unfair to tar one with not being worthy of being here just because you don't like them/they don't post stuff you find interesting/don't post in places you want to see them post etc... That is a foolish and stupid way to approach a forum and if you do you'll only set yourself up for endless disappointment.

Now that's enough derailing for one thread - if you want to discuss this further start a new thread up on the topic if you must.


----------



## Derrel (May 27, 2013)

Overread said:


> Ballistics you do realise this thread is an extension of a critique thread. Furthermore why is it bad that we are discussing a core process of the photography world? The debate and discussion on HSS is very valid.
> 
> If you're concerned that critique isn't enough, well, only thing you can do is right that problem yourself. Well thought out and constructive critique given encourages it further.




Yes, I agree with Overread: this is an extension of another critique thread entitled Captain America Water Drops. This is the Beyond The Basics segment of TPF, where we talk about more-advanced techniques. I have a friend, and one of his friends works at The Oregon Zoo, after a 25-year career as a staff photographer for The Oregonian newspaper, he shifted focus somewhat to nature/outdoor/insect photography, and he now holds a nice position at the zoo. He specializes in insect and high-speed, stop-motion photography. I have some insight into how high-speed, stop-motion flash is being done by a few different people.

As you can see from the above links, for a long time the Vivitar 283 flash has been a "standard tool", for the fact that it is low-cost, AND it is very,very easy to access the plug-in flash sensor module, as well as very easy to tinker with that module, as well as to simply plug in a paper clip into two of the connector holes, and thus short-circuit the AUTO-thyristor sensor and thus achieve INSANELY brief, almost microscopic, ULTRA-high-speed flashes. The "standard" high-speed,stop-motion flash unit among my two friends is three, or four, or even five Vivitar 285 HV flash units, wired together, and mounted inside of a PVC pipe, fitted with a large Fresnel lens, and each flash is dialed down to 1/4 or 1/8, or 1/16 power, or set to a specific AUTO-thyristor setting, so as to achieve the power level of a single flash, but with the motion-stopping ability that ONLY comes from one, single, ultra-short flash. Steve has produced utterly astounding 4x6 foot prints of wasps and bees flying inside of long PVC tubes, with artificial,colorful "nature" backgrounds just behind the insect, behind a plexiglas rear compartment door; this is very much like the water drop/oil and water pyrex/colorful background/backlighted flash setup so many hobbyists use. The wasps and bees fly through optical beam triggers, and the flashes only fire when the insects are in "the crosshairs" of a camera's pre-focused spot. This is high-magnification, single-shot, single-burst, ultra-high-speed photography. My friend, Steve's buddy, uses his 4-unit, 283+ Fresnel lens tube-flash for high-speed hummingbird photography. He's a birding "nut".

The crux of the matter here is that Robin was suggesting, in the first thread, that a camera's focal plane shutter is fast enough to freeze motion on water droplet work. The top speed of 1/8000 second sound fast, but as you can see from this link, fractional-power speeds from common flashes are in the 1/35,000 second range, with NO modifications to the flash. 
The Rod And Cone: Flash Durations for Canon 580EX II and Vivitar 285HV

Canon 580EX II -- Distance from Flash to Sensor: 2 feet
1/128 power = 1/52718 seconds Flash Duration ---- SCALED to REPORTED DATA
1/64 power = 1/38845 seconds
1/32 power = 1/26887 seconds
1/16 power = 1/18626 seconds
1/8 power = 1/13039 seconds
1/4 power = 1/8447 seconds
1/2 power = 1/5006 seconds
Full power = 1/871 seconds

Of course, there are methods of measuring flash out which incorporate not just the peak of output, but also the long, low-output "tail" section  of the burst, which can easily give 'unscaled' measurements that are 4 to 5 times longer in duration than the above figures. The thing with photography "Beyond The Basics" is that it's complex, and can't be handled in two or three sentences, like a portrait C&C can be. Please read the above link for additional insight.


----------



## Olympus E300 (May 27, 2013)

If nothing else, this thread is quite educational!  We have some very smart people amungst us!  Gavjenks, you support a very strong argument.  I'm probably enjoying this thread more than I should.  Then again, I always did like science...

Carry on.


----------



## Majeed Badizadegan (May 27, 2013)

http://weknowmemes.com/wp-content/uploads/2012/12/yeah-science-*****-meme.jpg


----------



## jamesbjenkins (May 27, 2013)

tl;dr. @ pretty much every post on this thread.

You guys need to shut up and go take a picture of something.


----------



## TimothyJinx (May 27, 2013)

Sorry, I couldn't resist.




Derrel, Robin - I appreciate you both so no disrespect intended. Since I kinda started this whole thing this is just my feeble attempt to be funny and lighten the mood.


----------



## Robin_Usagani (May 27, 2013)

Is it pay pay per view?


----------



## vintagesnaps (May 27, 2013)

Jason are you suggesting that coconuts migrate?? (or is it water droplets that migrate?)






You bunch o' water piddlers... 
Edgerton Center: Water Piddler

"The strobe uses an electronic flash... ." "The flashes at different time intervals make the drops look like they are standing still..."
drops & splashes « Harold "Doc" Edgerton


----------



## Robin_Usagani (May 27, 2013)

Once again let me repeat I never disagreed that the best way is to kill the ambient and use the flash to freeze the motion.  In fact that is what I suggested first. I have done calculation and freeze it with my shutter.  What more do you need? Seriously.. Do this shot on full sun and macro lens, no problem.  I have been saying it over and over, it is not that fast.


----------



## pixmedic (May 27, 2013)

vintagesnaps said:


> Jason are you suggesting that coconuts migrate?? (or is it water droplets that migrate?)
> 
> 
> 
> ...




The swallow may fly south with the sun or the house martin or the plover  may seek warmer climes in winter, yet these are not strangers to our  land?


----------



## Gavjenks (May 27, 2013)

Robin_Usagani said:


> Once again let me repeat I never disagreed that the best way is to kill the ambient and use the flash to freeze the motion.  In fact that is what I suggested first. I have done calculation and freeze it with my shutter.  What more do you need? Seriously.. Do this shot on full sun and macro lens, no problem.  I have been saying it over and over, it is not that fast.



I still feel like you are using "fast" incorrectly here.  Speed in the real world by itself is unrelated to ability to freeze motion.  It is 100% relative to magnification.

Imagine you have an electron microscope, and all you can see is a single virus in your field of view.  If you expose at 1/8000th of a second, and those molecules are moving at even just one millimeter per second or whatever, you will probably get motion blur.

At the same time, if you are photographing a Russian space satellite with nothing but a 200mm lens, it could be moving several miles per second, and you could easily get no motion blur at all with shutter alone.



So *there is no such thing* as "not that fast" by itself in terms of freezing motion photographically. water drops exist on a level of detail and magnification very different than standard photography, and therefore you cannot apply any normal intuitions or rules of thumb about how fast is too fast when judging how easy it should be.


----------



## Robin_Usagani (May 27, 2013)

But I shot it and delivered.  Sigh.....


----------



## o hey tyler (May 27, 2013)

electricity travels at 186,000 miles per second think about that the next time you flip a switch homeboy


----------



## jowensphoto (May 28, 2013)

Flickr: Maianer's Photostream <- fun stuff.


----------



## amolitor (May 28, 2013)

Imagine, if you will, that you are taking a macro photograph of a snail. Let us say, of its eye stalk. The eye stalk can move.. some distance in 1/100th of a second, right? I don't care what distance. Not very far. Call that distance x.

Macro in there until you're right up close to it, so stuff in the frame is 1/2 of x wide. x is pretty small, so you're really close, but it can be done, right?

Now set the camera to 1/100th second shutter speed.

You gonna be able to get a sharp picture of that eye stalk, or not?


----------



## BRN1 (Jun 1, 2013)

amolitor said:


> Imagine, if you will, that you are taking a macro photograph of a snail. Let us say, of its eye stalk. The eye stalk can move.. some distance in 1/100th of a second, right? I don't care what distance. Not very far. Call that distance x.
> 
> Macro in there until you're right up close to it, so stuff in the frame is 1/2 of x wide. x is pretty small, so you're really close, but it can be done, right?
> 
> ...



It is possible.


----------



## Gavjenks (Jun 1, 2013)

BRN1 said:


> amolitor said:
> 
> 
> > Imagine, if you will, that you are taking a macro photograph of a snail. Let us say, of its eye stalk. The eye stalk can move.. some distance in 1/100th of a second, right? I don't care what distance. Not very far. Call that distance x.
> ...



No, it isn't.  Not with the situation he set up in the post you quoted.  on an 18 megapixel camera, you would have approximately 20 pixels of motion blur at 1/100th of a second, which is a huge amount. That's an amount of blur that you could see in the LCD preview easily and might erase before you even got home.

It would be possible to freeze the motion of the eye stalk at that level of magnification with shutter only, but you'd have to go to 1/2000th of a second or higher probably.


----------



## DGMPhotography (Jun 2, 2013)

I couldn't read past the 3rd page... But I will say Gavjenks is a genius, and derrell is the man (plus we share the same name). Why don't we argue with facts instead of equations that we can't seen to agree on. Prove your point with images and exif data! If you did and I missed that, my b, ignore me, but let's just all be friends!!


----------



## Gavjenks (Jun 2, 2013)

DGMPhotography said:


> I couldn't read past the 3rd page... But I will say Gavjenks is a genius, and derrell is the man (plus we share the same name). Why don't we argue with facts instead of equations that we can't seen to agree on. Prove your point with images and exif data! If you did and I missed that, my b, ignore me, but let's just all be friends!!



Thank you! As to your request, if you look in the Opening Post, there are currently some photos he took that show fairly decent freezing of motion at 1/6400th of a second, shutter only.

However, they are only about 1/2 an inch from the faucet and not very spherical looking (this should get better with more time and speed per drop).  Both of these things severely limit what could be done with such water drops artistically, because wobbly drops aren't as pretty, and slow falling speeds wont make things like nice pretty splashes (plus it's hard to crop out the trail of water above it and the faucet).

The OP suggested that the spherical issue could be improved by using a pinhole in a cup instead of a faucet.  Probably true.

The speed issue is harder to solve.  The camera is already almost maxxed out on shutter speed, and yet a drop falling at proper splashing speeds would be moving up to 10x faster probably than the one photographed here.




Whether it can still be done with a more typical setup like splashing or a drop suspended further down in mid air is an open question.  I don't think it's possible to do these things with a simple shutter on a static camera, but maybe I'm wrong.  Also, there are other ways to "cheat" potentially, like somehow panning and tracking the drop as it falls, or launching a drop upward so that it is at almost zero speed at the top of its arc, etc.

Feel free to give it a try yourself if you like!


----------

