Posts by tag: strobist

Water Drop Collisions

Posted by Caz on Monday, 7th November 2011

After my recent success with the CameraAxe5 and the Microphone Sensor, I thought I would have a go at some shots using the Valve sensor today.

Here is the Camera Axe setup:

Valve Sensor Setup

Valve Sensor Setup

The valve sensor is plugged into Sensor Port 1 of the Camera Axe. It has the droplet size and delay controlled from the Valve Sensor Menu. The camera is plugged into Device Output 1 – using Bulb mode at f/11 and manual focus. The first flash is plugged into Device Output 2 and is set to go off after a short delay once the first or second drop has left the valve nozzle. The second flash is fired from the first via visual slave mode. Here are some setup shots:

General setup

General setup

Kitchen studio

Kitchen studio

Valve Sensor Details

Valve Sensor Details

Getting Started

First things first – you need to know rough timings for events with just ONE drop coming out of the valve sensor. For my first set of shots, I set Drop1 Size at 40(ms), Drop2 Size at 0 (ie no second drop) and varied the flash delay in 10ms increments between 200ms and 400ms to observe where the drops were during each time frame (dropping from a height of 330mm). The stop-motion animation on the right is composited from one frame taken at each flash time delay value.

This is an important step, otherwise you could be spending ages trying to catch the right moment via trial and error. If we use a bit of maths, however, we can get much nearer the predicted event straight away. There is more of an explanation at the excellent Camera Axe Valve Sensor tutorial page.

Valve Sensor Setup Menu

Valve Sensor Setup Menu

From the frames already taken, I decided that I wanted to have the 2-drop collision take place once the first drop was “on the rebound” and at the top of its “spout”. This gave me a delay value around 32oms. Looking at the motion to see where the second drop should be to collide with it, that gave a value around 230ms. The sums give us:

Pos1 (320ms) – Pos2 (23oms) – Drop1 size (40ms) = Drop2 Delay (50ms)

and

Pos1 (320ms) – Drop2 Delay (50ms) – Drop2 size (40ms) = Flash Delay (230ms)

So, plugging these values into the Valve Sensor Menu (see above) should get us in the right ballpark for a collision. I was desperate to try this out, but just as I’d got the vital numbers worked out, the rechargeable batteries in one of my flashes went flat! Since there was already a set on charge and no spares, I had to nip out to buy some disposables before I could give it a whirl. After taking one shot, I did a little bit of tweaking , as I noticed the flashes were going off a bit too soon for the interesting action. So I upped the flash delay to 245ms. And here we are – my first collision shot!

Valve Setup Menu: D1 (40), D2D (50), D2 (40), FD(245) ms

Valve Setup Menu: D1 (40), D2D (50), D2 (40), FD(245) ms

Getting Creative

Then it was time to play! Vary the delay and see what happens…

Oval Splash

Oval Splash

The Anti-Gravity Hat

The Anti-Gravity Hat

Mushroom And Raindrops

Mushroom And Raindrops

Tilted Sombrero

Tilted Sombrero

So that’s it for the moment. My favourite for the day was Frilly Skirt. I want to concentrate on some better lighting behind the splashes next time, but I need to wait for my new cable to arrive so I can run both flashes via the wireless TX unit. Then I can place them a lot further away from the CameraAxe electronics. But I’m pretty pleased with my first efforts at water splash collisions. Now that I’ve done a few shots, I should be able to get set up and running a lot quicker next time around.

1st MoNovember ’11

Posted by Caz on Tuesday, 1st November 2011

High Key Spring Title: High Key Spring
Location: At home
Camera: Canon EOS 7D / 24-105mm EF f/4 L IS USM
Strobist: 1 x YN560 from camera left with Stofen softbox @ 1/32, 1 x YN560 from camera right with Stofen softbox @ 1/32 on background
Notes: Messing about with a high key look, just for a change. I used two flashes to flood the scene with a bit too much light. A happy accident, or intentional? Not telling! MoNovember has started.

Going Round In Circles

Posted by Caz on Friday, 15th July 2011
Boring Bubbles

Boring Bubbles

Today I took some time to play with a mixture of olive oil sitting on top of water. I used my macro lens and one YN560 @ 1/16 to light the shot from underneath. Not diretly, however, as this gave quite boring results initially [see right].

Also, this shows air bubbles in the oil, rather than the more interesting pool of oil separated from the water. So I had a rethink and came up with a better setup.

Oil and water setup

Oil and water setup

Firstly, this was all done on the floor. I laid down a large piece of white card and then on top of that placed the wrapping paper. The far side of the card was curved over to make a reflective surface to bounce back the light from the flash at the opposite side.

Then placing two plastic storage boxes and a sheet of glass, I made a makeshift table. The little bowl with the oil and water mix was placed on top of this.

Once again, even though there was quite a lot of light in the room, I was using ISO 200, 1/250 s and f/16 to give a black frame without flash. Once the softbox and flash were fired from the wireless triggers, this gave a nice exposure on the wrapping paper.

My 60mm EF-S f/2.8 USM macro lens was on manual focus and I moved myself about above the dish to compose the best shot and get into focus.

Here is a selection of the best shots from the session:

The Planets

The Planets

Fatal Attraction

Fatal Attraction

Resizing

Resizing

Three At The Edge

Three At The Edge

Circles Of Colour

Circles Of Colour

Planetary Surfaces

Planetary Surfaces

My favourite from the shoot made it as Day #1292 – Circular Motion. There are plenty more shapes and colours out there – why not have a go yourself?

Soap Opera

Posted by Caz on Monday, 11th July 2011

I’m easily distracted from household chores, especially where the washing up is involved. So it was no surprise that I got sidetracked into photographing soap bubbles this evening. It’s a very simple setup:

Soap Bubbles setup - one softbox from the side

Soap Bubbles setup - one softbox from the side

I started off with a small glass full of water, and added plenty of washing up liquid. Bubbles were blown in this with a straw, producing a rather nice head.

Once again, I’m using 1/200s shutter speed, ISO 200 and an aperture of f/20. Without flash, this gave a black frame. The bubbles were lit from one side, very close, by my DIY sotftbox @ 1/32. I had my macro lens on manual focus and shot in hand rather than on a tripod – I was able to react much more quickly to the rapidly changing (and popping!) bubble structures. The low flash power meant the exposure was very short, (of the order of 1/20,000s) so I didn’t have any worries about hand-holding the camera.

Here is a small selection of the best images:

Soap Spheres

Soap Spheres

Underground, Overground

Underground, Overground

Bubble Study

Bubble Study

Soap Film Abstract

Soap Film Abstract

Compared to my recent water splash images, these are pretty easy to take technically, you just have to watch the bubbles carefully and see what’s interesting. My favourite made it for Day #1288.

Crowning Glory

Posted by Caz on Sunday, 10th July 2011

I had been hoping to get some crowns with my water splash shots but hadn’t had much luck making any. But I asked around on the High Speed Flash group on Flickr and got some good tips, so thought I would have another go.

Setup shot from the front

Setup shot from the front

This time, I was using skimmed milk with red, green or blue food colouring. It was dropped from 40-60cm with the pippette, onto a sheet of opaque perspex. I used one YN560 @ 1/64 with my new DIY gridded snoot to throw light onto the droplet landing zone.

Setup shot from side/behind

Setup shot from side/behind

This was lit from behind with one YN560 @ 1/16 through my DIY softbox and opaque perspex sheet, which gave a nice even illumination. As before, I was using ISO 200, 1/200 and f/16 which gave a blank frame without firing the flash.

Crowns weren’t evident with every drop, but I was getting them reasonably regularly. Still there was a lot of patience required though! Here are some of the best images from the session:

Almost A Double Crown

Almost A Double Crown

Mini Crown And Reflection

Mini Crown And Reflection

Beginnings Of A Crown

Beginnings Of A Crown

Low Profile

Low Profile

Blue Crown

Blue Crown

Into the drop zone

Into the drop zone

I’m pleased with these considering they were timed by hand, but I still need to be able to hold the pippette in place – I’ve just ordered a retort stand and some clamps from eBay which should help.

My favourite was one of the red images for Day #1286.