I just got my beginner DSLR (Nikon D3300) and tried to take a photo of a water splash.
I read about aperture, ISO and shutter speed and I know if I set high shutter speed I need to set low aperture (higher number), also I need to set higher ISO.
I set 1/500 shutter speed, ISO about 800 but the photo is still dark.
What do I need to do to achieve this?
[Sorry for my English.]
Czan, I suggest you read up on how a correct exposure is made. It's not a simple "set your camera to x" type of thing. To boil it down, there is an amount of light in a scene, and the proper capturing of that light requires you to set an ISO, shutter speed, and aperture and to understand the constraints that each of these has on the exposure as a whole.
But, to get you started in photographing water drops...
You want to freeze the action of the drop as it bounces off the surface of the liquid. In order to do this, you want to light the scene 100% with flash. (let's keep this easy and not introduce mixed lighting)
In order not to mix ambient lighting with flash lighting, you need to make sure that the ambient light is low. Leave enough light for you to move around in the room, but not much more.
Most of these types of photos are shot with off camera flash where the flash is set to a certain power. ISO is usually set to 100. Aperture is set for the depth of field that the photographer wants. This could be f/2 or f/16. It depends. But, to get you started, try using f/5.6 or f/8.
Now, the tricky part. Shutter speed. The fastest your camera will allow with 100% flash lighting is called the flash sync speed - and it's 1/200 of a second. This is perfectly fine to freeze a water drop.
However, using 1/200 will require you to time the shot far too accurately. You'll have to press the shutter release, the camera will have to drop the mirror, open the shutter, trigger the flash...all while you hope to capture a drop in air.
Instead, you are better off using Bulb mode. Bulb allows you to manually open and close the shutter, on your count. (keep in mind that we still want to avoid ambient lighting, so keep it short). But, the method here is: Trigger a Bulb exposure. This drops the mirror and opens the shutter - now the camera is just waiting for the flash to pop to expose the scene.
Drop your water droplet and manually trigger the flash when you want. The timing is extremely hard - but using this method, you only have to worry about when to pop the flash, as opposed to when to start the sequence of events listed above.
As soon as the flash has popped, stop the exposure. If you're working alone, you will need a remote shutter release. If you don't have one, you can try using a ~3 to 6 second exposure and hustling to do the rest.
You are using 100% flash here to light the scene. So, if it's too bright, decrease your flash power. If it's too dark, increase your flash power. If you've hit the limit on your flash power in either direction, you will have to either open the aperture (let in more flash) or close it (let in less flash). (You could also put diffusers in front of the flash to scatter and absorb some light if the flash is too bright [like a piece of paper] but keep in mind that this will greatly alter your lighting, for good or bad)
Here's a great article on more ways to light and expose these scenes.
Edit to add:
If you don't have a flash and can't follow the advice above, then you need to light the scene with as much light as you can. Get every lamp in the house. You need a shutter speed that is fast, 1/200 or faster. Set the aperture to obtain the depth of field that you want and get the ISO as low as you can, ideally, 100.
Again, I can't tell you exactly what settings to use because they are dependent on how much light you can add to the scene. Ideally, you would want ISO 100 with an aperture between f/2.8 and 11 (depends on the depth of field that you want) and a shutter speed at least 1/200.
As for timing, you'll need to fire the shot to capture the drop at exactly the right time. Look into "Mirror Lockup". This will allow you to set up the shot, lock the mirror up, and then trigger the exposure exactly when you want to. Again, a tripod and shutter release cable are invaluable here.
Trigger the mirror lock up, drop your water, and then trigger the exposure. Rinse and repeat.
I read about aperture, ISO and shutter speed and I know if I set high shutter speed I need to set low aperture (higher number)
You've got this part backward. You want a large aperture, and the size of the aperture increases as the f-number decreases. So, if you're increasing the shutter speed, you can compensate by decreasing the f-number for the aperture setting.
also I need to set higher ISO
ISO is just another option for changing exposure -- you don't necessarily need to change it unless you're out of other options. For example: lets say you get a good exposure with your camera set to 1/125s (shutter), f/4, and ISO 400. If you want a faster shutter speed so that you can stop motion, you set the shutter two stops faster, to 1/500s. 1/500 of a second is only one fourth as long as 1/125s, so it only lets in a quarter of the light that you'd get at 1/125s. To compensate, you can use an aperture that's four times larger, which means changing the f-number two stops from f/4 to f/2. Or, you can make the sensor four times more sensitive by increasing the ISO two stops, from ISO 400 to ISO 1600. Or, you can do a little of each: go down only one stop in f-number, to f-2.8, and up one stop in ISO, to ISO 800.
I set 1/500 shutter speed, ISO about 800 but the photo is still dark.
Somehow, you need to fix the exposure. You can use a larger aperture (smaller f-number), or increase the ISO further, or turn on some more lights in the room, or add light with a flash.
Using a flash is the best option for water splash photos for a few reasons:
First requirement is Use Your flash. A camera flash is called a speedlight because at lower power levels, it can be extremely faster than any possible shutter speed. Plus it can light a f/16 macro situation, and it can override any existing ambient.
Water drops imply macro situations, up close to see it large. That means you have to stop the lens down greatly, at least to f/16 to have any depth of field at all. So you use enough flash power so that f/16 works. That also means the flash overwhelms the ambient light, so it does not need to be dark. Only dim, perhaps even normal room lighting, just "not bright", not as bright as the flash.
Shutter speed is what lets in more ambient, so to keep it out, set shutter speed to the cameras maximum sync speed, very likely to be 1/200 second. And 1/200 second at f/16 (manual exposure) will not expose much ambient (so it need not be darker than just "not bright"). Try one picture indoors at 1/200 f/16 ISO 100 with no flash just to see that it certainly is insufficient exposure of ambient.
But you surely need a larger camera flash than just the camera internal flash. The internal flash probably has a guide number of about 40 (feet, ISO 100). That means f/16 has a range of 40/16 or 2.5 feet. HOWEVER, that assumes maximum power level which will Not be fast enough. So you need a larger speedlight flash (any regular size hot shoe flash) which lets you lower the power level to perhaps 1/32 power, at perhaps 2 feet from the water drop. Possibly you may need ISO 200 or 400, but absolutely not more (more just lets in the ambient). And at 1/32 power, the speedlight duration is probably about 1/20,000 second to freeze the splash. This is how high speed flash photography is done. Speedlights, lower power levels, up close.
See http://www.scantips.com/speed.html for this concept of speed, and concept that dark is not required.
Water splash photos are typically done with off camera lighting, with settings on camera that won't pick up ambient light. Your shutter speed is really only relevant to eliminate that light, and often a long exposure is used in a relatively dark room.
The freezing of the splash action is done by triggering the lights at the right moment instead of the shutter, so only the instant the lights are on is picked up by the sensor.
Edit: I would like to add that when using a flash, lower power = shorter flash duration. I am not sure what duration you need to freeze a water drop, but I would guess 1/500s or faster.
For example - Canon 580 EXII
So you can see from these values, that you would need the flash at 1/2 power or less to get the desired effect (assuming my assumption about the 1/500s is correct).
