[DARK_M3]

Specifically, I am trying to shoot some rings and other heavy, small items in water using strobes.

The problem I am encountering is that once the item is dropped, it's blurred from the speed of decent.

Question: Is it possible to capture a crisp, clear image given the nature of the objects? Or is it only bouyant objects that photograph well because they sort of "stop" once they hit the water long enough to be photographed clearly?

Thoughts?

Example 1. A .40 mm cartridge dropped into the water tank with manual settings at: shutter-160 f/14. Lens is my 100mm f/2.8 mounted to my 50D. The strobes are about half power (I've tried lowest power and highest power... all the same thing) I've tinkered with the shutter speed but it's not really the camera stopping the action, it's the strobes and besides, the shutter starts to creep into the shot at 200 or higher.



Notice the shell is blurred as it's on it's way down gaining speed as it goes.




These two shots are only a comparison between two different lens's AND using an object that floats demonstrating that it stops it's decent right as I click the shutter and viola... in focus. Both are unretouched photos straight out of the camera except for resizing. The first shot is my 100mm f/2.8 shot at f/14 with shutter @ 160:




The next shot is with my 17-85mm f/4-5.6 attached. It's focal length set at 50mm and the same f stop and shutter speed apply:




I was just interested in seeing what the difference was as far as clarity goes. As you can see, not much. Strobes kind of even things out in that regard.

A shot of the setup:
Simple setup
-1 small soft box
-1 barn door w/ grid
-camera with tripod
-small aquarium with about 1/2 water
-stand holding a black board behind aquarium (or white, whichever)



Any help is appreciated!

[rodi]

the speed at which the flashes are on should be much faster than the speed in the water. something is weird.
so you're saying the markers are in focus, but when you use the cartridge, it's out of focus with the same exact settings?

[oneintheory]

you'll want to make the flashes full-power or at least 3/4 for starters. a more powerful flash has a shorter duration. now, if you have access to speedlites and can do high-speed sync, that would be even better. try increasing flash power and increasing the aperture size to f/10 or so.


how powerful are your lights?

[Weebl]

You want lots of natural light but set your flashes at the lower end of power so they don't flash so long. High speed sync helps and lots of patience.

Google produced this:
"To actually get an "exposure", a flash is fired. The flash light duration will now become the actual

exposure time.

SO now we need to see how long does it takes the flash to fire. It turns out that the output power of the flash, actually affects the duration of the light, so to get exposure times. If you need exposure faster than 1/6000 seconds, the output needs to be reduced. For more information on the light duration please see the test I ran on my Sigma EF-500 flash." http://www.diyphotography.net/light_...s_output_power

You need enough background light and flash to illuminate your object and nothing else, otherwise you are wasting power. I'm not sure but I think this is where a large guide number will help. As you decrease the power the range decreases and eventually will fall short of your bowl of water but you will have a very high effective shutter speed.
I think....

[The1]

high speed sync should be able to get you to 1/200 or 1/250 depending on the flash if you have such flashes. That extra little bit might just be enough to get it to where you want it.

otherwise, use bright lamps instead of flashes, then you'll have a constant high light source and enough to get the shutter speed you want. Also alowing you to bump the ISO up to help you get higher speeds.

[DARK_M3]

Originally Posted by rodi

the speed at which the flashes are on should be much faster than the speed in the water. something is weird.
so you're saying the markers are in focus, but when you use the cartridge, it's out of focus with the same exact settings?

Yes same settings.

Originally Posted by oneintheory

you'll want to make the flashes full-power or at least 3/4 for starters. a more powerful flash has a shorter duration. now, if you have access to speedlites and can do high-speed sync, that would be even better. try increasing flash power and increasing the aperture size to f/10 or so.


how powerful are your lights?

Well the ones I was using are only 250 watts. I do have another set of 2000 watt lights however these were already set up so I thought I would give them a shot.

Originally Posted by Weebl

You want lots of natural light but set your flashes at the lower end of power so they don't flash so long. High speed sync helps and lots of patience.

Google produced this:
"To actually get an "exposure", a flash is fired. The flash light duration will now become the actual

exposure time.

SO now we need to see how long does it takes the flash to fire. It turns out that the output power of the flash, actually affects the duration of the light, so to get exposure times. If you need exposure faster than 1/6000 seconds, the output needs to be reduced. For more information on the light duration please see the test I ran on my Sigma EF-500 flash." http://www.diyphotography.net/light_...s_output_power

You need enough background light and flash to illuminate your object and nothing else, otherwise you are wasting power. I'm not sure but I think this is where a large guide number will help. As you decrease the power the range decreases and eventually will fall short of your bowl of water but you will have a very high effective shutter speed.
I think....

Very good info. Thank you. Further experimentation is in the works.

Originally Posted by The1

high speed sync should be able to get you to 1/200 or 1/250 depending on the flash if you have such flashes. That extra little bit might just be enough to get it to where you want it.

otherwise, use bright lamps instead of flashes, then you'll have a constant high light source and enough to get the shutter speed you want. Also alowing you to bump the ISO up to help you get higher speeds.

This is actually what I was going to try next. I have some 200 Watt bulbs somewhere. Either that or I can just use my 2000 Watt Dynalite's.

[DARK_M3]

Alright so I switched it up completely and am shooting without strobes. I'm using a LOT of incandecent light. See pic below (lights off in pic)...




Here's a shot at 1/4000 sec @ f/2.8
I think the cartridge is still a bit out of focus but that could be due to the low f stop and me dropping it either a hair too close or too far from the focal point. (or the damn thing is being dropped in the right spot but once it hits the water, it moves on it's own out of the focal point). Either way, the shot was pretty dark @ f/2.8 but if I move either the f stop up or increase the shutter speed, it really goes into dark/black territory.



Starting to get better. Much better than the strobes anyway. I will continue to work on it until I have it perfected.

[Weebl]

What did Capt. Kirk say?
"We need more power".
More speed too, it looks like blur vs focus. A higher F stop will help as if moves around in the water and if you have a platform to let the cart. roll off the focus point won't change as much as being hand held.

[The1]

Originally Posted by Weebl

What did Capt. Kirk say?
"We need more power".
More speed too, it looks like blur vs focus. A higher F stop will help as if moves around in the water and if you have a platform to let the cart. roll off the focus point won't change as much as being hand held.

big improvement. I would say it's now down to your focus point. How far away from the case are you?

if really close, definitely stop down the aperture and open up your DOF

It's definitely not speed anymore at 1/4000 That would get a hummingbirds wings at a dead stop

[The1]

your splash out of the water is out of focus too, so it pretty much has to be your DOF the case is probably at an angle towards or away from the camera and causing the blur. the back of it seems pretty crisp in comparison to the tip.

Might also be your focus point at the water edge?

[Weebl]

Originally Posted by The1

big improvement. I would say it's now down to your focus point. How far away from the case are you?

if really close, definitely stop down the aperture and open up your DOF

It's definitely not speed anymore at 1/4000 That would get a hummingbirds wings at a dead stop

Been there and it did not do that.

[The1]

Originally Posted by Weebl

[/COLOR]

Been there and it did not do that.

crazy.... I'll have to find my old humming bird shots and see what speed I was shooting....

those buggers are fast.

[DARK_M3]

I'm givin it all she's got Captain!! Haha...

Alright so the camera's approx 6' away from the tank. Bear in mind that I have the 100mm attached.

I will adjust f stop and report back

[DnA Diesel]

Is your flash synch set to rear curtain?

[DARK_M3]

Originally Posted by DnA Diesel

Is your flash synch set to rear curtain?

Lemme check that..

[The1]

Originally Posted by DARK_M3

Lemme check that..

If you don't know, and you bought the camera new, its likely on first curtain.

[DnA Diesel]

Originally Posted by The1

If you don't know, and you bought the camera new, its likely on first curtain.

Yes. I don't know why, but the default (at least for Nikons) is front curtain synch.

I'm by no means a pro, but I think that less light on the strobes and rear curtain would sharpen things up, particularly that first shot with the cartridge.

Cheers
D.