Freezing the action: Splashes and Flows

The captures made using high speed photography techniques, which are used to freeze the time, are truely amazing and inspiering. The spilt of a second is hard to experience from the naked-eye (actually it might not that hard to see nice frozen moments in a disco party). Therefore, most photographers  keen to capture the exact moment, exact action which can be admired by almost all the people. There is a vast collection of such photos and tutorials on above technique is available in the internet. Inspired by their work, I decided to work on mine and share my experience. May be you have known this before, or even mastered it. Yet I just want to share this with you.

The equipment I used are,

• Nikon D3100 camera.
• Tamron AF 18-270mm f/3.5-6.3 Di II VC LD Aspherical (IF) MACRO lens.
• Nissin Di622 Mark II speedlight.
• 30 cm $latex \times$ 30 cm softbox made by myself.

I know they are not the best, but they are more than enough for get the job done. At the moment I am using D3100 built-in popup flash to trigger the off-camera Nissin speedlight.

Splashes:
The setup is illustrated in the  figure below.

• Use a colored paper or wall as the background. It will add a nice flavor to the water.
• The glass is filled with water and I used to drop grapes to make the splashes. Water will be spilling all around. Therefore, make sure to use this setup in a proper place.
• Take the speedlight with the softbox close to the glass as close as possible. Moreover, make sure to cover them with a water proof transparent sheet. You do not want mess them with the water.
• Set the camera with a safe distance which avoid the spilling water.
• For camera settings, I used Manual mode with,
• Shutter speed: flash sync speed (1/200 for D3100). If you have high speed sync capability, you may try it. I have no experience with it.
• Apeture: make it small (f-8 to f-11). Henceforth, you can make sure that everything is focused.
• ISO: some lower values (100-200).
• focus: auto focusing at the begining. Then switched to manul in order to avoid refocusing issues under low light.
• Try to use a remote trigger to operate the camera. It will avoid shaking the camera. If you do not have a remote trigger or it just got skrewed like mine, you can use the self timer.

Drop the objects. Shoot them several times. Results will be rewarding :)

Flows:
Here, we need a nice white background. Therefore, I am using my speedlight to light the background (wall). From the camera settings, I overexpose the background and make it looks like a white (almost) back drop. The setup is as follows:

Side view

Top view

The rest of the steps are quite similar to 'Splashes' scenario.

• Camera setting follows the same. However, the aperture needs to be adjusted such that the background is overexposed and produces bright white pane.
• I used colored water to have a contrast between the flow and the background.
• Start pouring the water, and shoot them.
• Finally, grab the glass from the top and lift it up, take one photo of its base. This is used to add the base during the post-processing.

Water drops:

This is captured about a year ago when I do not have the speedlight. I used camera's built-in pop-up flash as the light source. It lights up the background and, using a black cover I cut out the direct light on the water container. It ensured that the water drops are illuminated by the reflected light from the wall which avoids unnecessary bright reflections.

The rest of my shots can be found here. Just want to say that "practise makes perfect".

Courtesy of: SnapKnot

Some EPS figures for communications diagrams.

TeX is a type setting system which is widely used among the scientific writers. The capability of producing complex mathematical expressions accurately is the main reason for such popularity. Although working on TeX environment is not comfortable as working on well-known word processors coming from MS-Office, iWork, Open-Office, etc., once you get used to it, it becomes more easy to work around with it. Moreover, the ability of producing high-quality outputs, especially vector based documents, will be able to hold you with the TeX environment (for most cases).

One major issue of working with TeX is the need of eps or pdf type figures whenever you need to produce loss-less documents. There is number of applications which can be used to produce the vector graphics, but not everybody going to happy with working on them. On the other hand, applications such as Visio and Smart Draw are not only providing vast collection of arts for diagrams and flow charts, but also provide the facility to produce impressive diagrams even for novices. Thus, such applications are very popular among everybody.

However, the main limitation of such applications is to convert such diagrams to TeX compatible formats without losing their qualities. I have tried working on both Visio and Smart Draw to produce high resolution figures and diagrams, yet once the file conversion takes place (save as pdf, save as eps, jpg/png to eps), diagrams looks (slightly) blurred in the final TeX output. Another disadvantage is when creating flow diagrams; the equations written in Visio/Smart Draw are not neat as the rest of the equations in the TeX.

Therefore, I moved to Inkscape and Ipe for all kind of drawings which are required for my work. It was/is a pain working on such environments, yet the outputs are so blessed – and I am happy about the struggle with Ipe and Inkscape. A flow chart containing equations accurately and a diagram with loss-less vector format are shown below. Ipe needs additional adjustments in order to obtain the fonts and symbols according to the IEEE format. I did include that tip here.

      

- Flow diagram with equations -

      

- Vector graphic based figure -

I was managed to reproduce few of shapes related to communications in Ipe. The original shapes are coming from Visio. It was quite a time consuming process to produce them all + I was not familiar with all those tools. However, I manage to produce them with a certain level of satisfaction, and I thought to share them with you.

The EPS figures of above shape can be found here. The Ipe drawing project can be downloaded from here.

I will add more shapes whenever I produce.

Nice fonts for text and equations in IPE.

Ipe uses the TeX interpreter. Therefore, it is a nice solution for producing vector based graphics along the equations with accurate format. However, the default formatting may not be the best. Especially for the IEEE based documents, it would be more convenient to use the standard fonts for both text and equations.

In order to obtain such nice format, you just need to follow few more steps.

1. In Ipe, access the document properties via ‘Edit’ menu. Alternately, you can use the key combo: ctrl + shift + P (for windows) or cmd + shift + P (for mac).
2. In Ipe document properties dialog window, add following lines under the section named ‘Latex preamble’.
• \usepackage{amsmath}
• \usepackage[T1]{fontenc}
• \usepackage{times}
• \usepackage{dsfont}
3. Click Ok and compile your document (ctrl + L).

There you go. The sweet IEEE format.