Gerard Maas' Blog

Broken PW TT5 hotshoe

Posted by gerard.maas on October 7, 2011 None comments

Broken PW TT5 hotshoe, originally uploaded by Gerard Maas.

Ouch. It really snapped off from turning upside down on an umbrella shaft.

Leen in backlight

Posted by gerard.maas on October 7, 2011 1 comments

Leen, originally uploaded by Gerard Maas.

This was an experiment with backlight in an old WW2 bunker (‘Fort V’ – Edegem, Belgium). I had this idea since a long time and Leen had the perfect dress to make it work. The location is a fortified tunnel that provides access to the inner part of the fort. It’s cold and humid, so I had to work quickly to prevent my model from catching a cold.

How High Speed Sync flash works – Illustrated

Posted by gerard.maas on October 7, 2011 None comments

I found this image lost in my archives and thought it would be good to share it. I added some explanation to help digesting it .
I think it helps to understand how high speed sync flash works.

High speed sync in action

The initial image shows the camera firing at x-sync speed: 1/125 in the case of the EOS 30E film camera that we are using for this experiment. Our point of view is located inside the film chamber, right behind the shutter speed, seeing whatever the film or sensor will see.

The first row shows how the pulsed flash bursts of the high speed sync function illuminates the subject as the curtains fly across the shutter. Notice how the curtain seems “ghosted” as the burst of flash continuously illuminate the subject while the curtains fly across the shutter. Of course, the faster the shutter speed, the smaller is the slit between the first and second curtain and therefore the dimmer that the image becomes. This the reason why HS Flash reduces the effective output of the flash unit.

As a means of comparison, the row below illustrates the same shutter speed but without FP flash. Here one normal flash is taking place, partially illuminating the subject through the slit between the shutter curtains. Appreciate how small the slit becomes when the shutter speed increases. The part covered by the curtain would become a black shadow in the final picture. This is the behaviour that you would see with e.g. studio flashes or wireless systems that do not support FP flash.

Bigdata on RDBMS

Posted by gerard.maas on June 24, 2011 2 comments

I’ve been investigating the performance of our “big vendor” RDBMS to hold months of sensor data. So far, the results are not really encouraging. I observe a exponential performance drop on the single-index (PK) table holding the data as more records are added. Here’s a plot of the performance of 5K records as records are continuously added to the table. Record addition is done with 5 parallel client threads, each inserting 1K records in batch mode. The client is an optimized Java app, using raw JDBC for the batch inserts. I haven’t found a faster way than that to add records to the relational DB.

Jack vs the Pony

Posted by gerard.maas on June 19, 2011 None comments

So far, this blog has been about photography. And it has been very quite in the last year. That doesn’t mean the end of it, but just a slow down to allow the most scarce of all resources -time- to be invested in other areas. I’ve been busy with some ideas and projects in different technology domains, that, next to my family, use up much of my time.

So whether it is learning Scala, deploying Cassandra, creating Led lamps, trying to make an IOIO board with my Android phone or measuring the energy consumption of the setup box, there are plenty of interesting things I would like to talk about; share with the blogosphere and reach to whoever is interested.

Then comes the question of this entry: keep the blog as One Trick Pony dedicated to photography (and updating it from time to time) *or* let it become a Jack of All Trades covering my different areas of interest.

Analyzing this dilemma brought me also to the thought of whether it’s manageable to cover different areas successfully. So, is proficiency is Scala a goal in itself? or seeing Cassandra run is the end of it? No. They are all means to creation, tools that will help me down the road to realize what this blog, and me, are about: realizing ideas.

How does it fit with photography? Well, having an image in your head, and using the tools, like camera and lights to translate that original idea into pixels is a very concrete example of the concept of idea realization. I realize that in the other areas I will be addressing, that translation step is less obvious and the risk is high of never converging into a particular realization.

The evolution of this blog will be in itself an experiment to see how this all evolves. If we don’t try, we won’t know, right?

Let’s give it a try.

-Gerard.

very low light

Posted by gerard.maas on June 14, 2011 None comments

candles on strawberry cake, originally uploaded by Gerard Maas.

Really liked the facial expression in this low-light image. What otherwise would be an underexposed endeavor got a new dimension and I wanted to share that.

Speedlite Advanced Home Studio

Posted by gerard.maas on November 29, 2010 None comments

Speedlites can be used with a variety of modifiers to achieve professional results. In this home studio setup, we used an Ezybox and an Umbrella box, both from Lastolite, to transform the harsh light of the speedlites into soft illumination for our model.

Delphine - Portrait

Strobist in Nature

Posted by gerard.maas on November 11, 2010 None comments

Nature is a wonderful source of curious subjects. In this case, it was a pristine cicada cocoon hanging on the trunk of a tree. Being under a tree meant no direct light at all, so here is where speedlites come into action.

Empty Cicada Cocoon - Backlighted with one speedlite fitted with a custom grid

Home portraits

Posted by gerard.maas on October 9, 2010 None comments

Elena - xmas portrait

Portrair of Elena: Behind the scenes

Adding a second speedlite to the setup is easy. Just turn the speedlite unit with wireless slave capabilities, to the ‘slave’ setting and to the same channel as the master unit, like for the setup with one slave.

In the setup above, both flashes will equally contribute to the total exposure. To achieve the soft light in the portrait of Elena, one 550EX was set pointing to the ceiling, to “bath” the scene with some soft bounce light, while the 580EX in the sofbox provided additional direction light to the face of the girl.