Tuesday, July 31, 2007


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Meyer-Optik Görlitz Lydith 30mm f/3.5


Saturday, July 28, 2007

Meyer-Optik Görlitz Lydith 30mm f/3.5

And later marketed as Pentacon 30mm f/3.5

(Little Zebra)

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10 aperture blades for decagonal out of focus highlights

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Simulation of Fuji NPH 400 using Alien Skin Exposure. Note the grain visible in the large image

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Thursday, July 26, 2007

Updates on the author

I’m alive, as the photo post below suggests. The occasional bouts of existential crisis have upgraded from intermittent flashes to a concentrated beam not unlike the lonely intense beam that a lighthouse projects out to the foul tempered seas.

Ok, it’s not that bad; I just liked that sentence.

Last Friday was eye opening. I was in the correct state of mind to contemplate the importance of my existence. It is not important.

My latest fetish is the book “Fundamentals of Futures and Options Markets” pinched from The Accountant.

The current price war between international budget airlines will probably cause me to go home when the company closes for a fortnight over Christmas, and then take a week off for Chinese New Year. I have enough leave days for CNY, just.


Rialto Tower- Melbourne's second tallest building

Colours calibrated for cathode ray tube monitors.

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Cosina 19-35mm f/3.5-4.5 with Fuji Superia 200

Cosina 19-35mm f/3.5-4.5 with Fuji Superia 200


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Aww, I Love You Too...


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Sodium River

The Bolte Bridge

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Saturday, July 21, 2007

Receding Horizon

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Super-Takumar 50mm f/1.4 - aren't those lines straight?


Friday, July 20, 2007

The Mask of Silence

My publicity consultant would probably suggest I add the subtitle "Based on a true story"


“Come, young boy. Come behind me, and I will shield you from the prying eyes of the world.”

I gingerly held up the mask. It was made of a lightweight metallic material, a solid feathery substance that shimmered gently in the light. From the front, it looked as featureless as a slab of granite. There were no eye slits, no nose protrusion, nothing at all to suggest that it should go on a face.

I turned it around, and looked at its inside. Aha, there are eye slits, just not visible from the front! And the nasal orifices were cleverly hidden as a series of invisibly tiny holes.

“Go on, try me on. Keep your weaknesses to yourself; the world needs not see them.”

I put on the mask and its surfaces morphed to fit my face perfectly. It was comfortable behind the mask.

The mask was a blessing. From then on, I was no longer to be read like an open book. I was not even encrypted; there was simply no emotion to be seen on my blank face. I was pleased to be able to watch people react while not having to show myself- this was the ultimate poker face.

Initially, I used the mask whenever I had cause to hide my expressions. Then I became more and more dependent on it, and it was not long before the mask became a permanent fixture.

Since no one could not see my emotions, people around me were no longer directly affected by them. With an incomplete feedback loop, my emotions started to atrophy. Anger, sorrow, joy, disappointment, hope and love evaporated steadily. Month by month, I resembled an automaton more and more. In short, I was turning into a machine.

I was inseparable from my mask. Physically, it was possible to take the mask off; but that action was as unthinkable as parading my naked and unmasked self in the streets.

Two months ago, I lifted the mask a crack. The unfamiliar sensation of fresh air stung my cheeks. I allowed it to sting, savouring the sensation of having a sensation. A light breeze blasted against me, carrying with it an intense smell of coffee, rain drops and gunpowder. I left that little crack open.

Of late, my outlook appears to change subtly when I am with a particular accuaintance. I carefully inspected my psyche, and discovered that love was not dead. Perhaps I am not dead yet.

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Sunday, July 15, 2007

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Notice the trend? They all happen to be sky shots. And something from today, again with the sky:


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My name is Tan Yee Wei

I probably need a credit card for the odd transaction or two, such as car rental, access to porn websites and online purchase of optical instruments.

I tried an online application for a credit card; filled electronic form meticulously.

Given Name: Yee Wei
Middle Initial:
Family Name: Tan
Sex: weekly


“There was an error in the form.”
“Special characters may not be used in the Given Name field.”

Ta ma de, the space is now designated a special character. What now, am I supposed to break my name up into Yee W. Tan? Also note that the surname gets pushed rather violently to the end of the line.

Pfft. I’ll download and print the application form, then fill it in as I like.

Light Well

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The financial year is over, and this is the period when first time income earners start worrying about taxation rates. Amusingly, yesterday morning was spent in consultation with an accountant (graduate, not yet Certified Practicing or Chartered) discussing the error function (tax returns) associated with linearised tax payments and the actual, piecewise-linear taxation rate.

The field of elementary micro and macro economics contains a measure of calculus, but the power of explicit calculus is not required in solving linear problems, and thus calculus is shoved aside.

Take the word ‘marginal’, for example. Marginal always implies the first derivative. The marginal cost of producing the 51st can of worms is the cost of producing one additional can of worms after the 50th can has been produced. It is also the change in total production cost associated with the changing the output from 50 to 51.

Thus it is the rate of change of total production cost (denoted C) with respect to total output (denoted x). The marginal cost (denoted M(x)) of producing the n-th can of worms is nothing more (or less, depending on your point of view) complicated than M(x) = dC/dx at x = n.

Working backwards, the total cost of producing n cans of worms is the definite integral of M(x) with respect to x, with the limits of 0 to n.

You’re still reading? Congratulations!

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Saturday, July 14, 2007

Fresh Mint

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Jupiter-9 85mm f/2.0 over an extension tube


Wednesday, July 11, 2007

Photography of stars

Ever since I took my first photo of stars, I have wanted to capture better and better photos of the night sky. Cleaner sensor, faster lens, sharper optics… the race for light collection never ends. At the moment, I’m nearing the practical limit of light collection using photography equipment. The next step for improvement in light collection would be the Canon EF 50mm f/1.2 L, which costs 4 digits.

From this dodgy photograph taken 9 months ago,

...I have graduated to this:

Starz II

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Super-Takumar 50mm f/1.4 over a Canon EOS 300D. ASA 200, f/1.4, 30s.

See, it's true- some stars burn hotter (blue/ white) than others(yellow).

Note, that mass of light is not sensor noise. The 100% crop below shows that they all have the same trail characteristics, indicating that the bright spots are all from celestial objects, the light smeared over the sensor as the earth rotated during that 30s of exposure.

The universe is big isn’t it?


Tuesday, July 10, 2007

Wilson's Promontory- birds

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Super-Takumar 135mm f/3.5 with a short extension tube, uncropped
Subject to lens distance: ~2m

The bulu-test

100% crop from the preceding image

"Albert mentioned that the test for a lens' sharpness would be the bulu-test, where you see if the sensor is capable of resolving the individual strands of pubic/facial or head hair." - from tanyeehou.blogspot.com

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Super-Takumar 135mm f/3.5

"Shit in my camera bag, and you'd wish I was never born."

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Super-Takumar 135mm f/3.5

Interestingly, we are starting to see some JPEG compression artefacts. The sharp boundary between the subject in focus and the bland, defocused background causes a boundary layer of stray pixels to adopt the colours of the subject.

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Monday, July 09, 2007

Dancing with a baby elephant

The weekend was spent on an overnight trip to Wilson’s Promontory, a national park that also happened to include the Australian landmass’s southernmost point. Jean, The Architect, Another Architect (The Architect’s coursemate) and I rented a car on Saturday and took a 3-hour drive.

We (or more accurately, I ) had a grand plan to rent the Toyota Prius for this trip. However, this fantasy of driving a soundless ghost-car was shot to bits by the fact that the discount for Melbourne University students does not apply to this fuel sipper. The next best choise was an ugly, ugly Toyota Camry with a 2.4L VVTi engine. It was huge, chunky, and appears to be styled after a slab of pork chop. Fortunately it was white.

The Camry is so ugly we need a rainbow to distract the eye

The drive out of the park was exhilarating (The Architect drove in). The road was a mix of short straights, hairpins, swooping curves and chicanes with a variety of camber and elevation changes.

With a car full of dozing passengers, my objective was to fly though this road as smoothly as possible. This means making use of as much width of the road as possible, including the opposite lane when safe and visibly clear.

A sign recommended 20 km/h for an upcoming left hander, the low speed suggesting a tight hairpin. From 100 km/h, ease onto the brakes and slip deep into the wrong side of the road, tyre walls brushing the grass verge. Gently get off the brakes and slowly start turning in early, balancing the decrease in brake force with an increase in steering angle. Let the other tyre walls rumble on the crumbled inside edge of the road, timing the events precisely so that this was the instant of maximum steering input and zero braking. The speed is now 40 km/h, 20 over the recommended but still not uncomfortable owing to the huge turning radius. Past the apex, gradually open the throttle while letting the steering wheel slowly unwind itself. Balance the unwinding rate so that the car just touches the far edge of the tarmac when the car straightens out.

I was obviously lost in my memories. It’s not as high adrenaline nor fast as setting hot laps, but it was just as technically challenging. There are different parameters to consider- visibility of the opposing lane, balancing (de)acceleration force with comfort and optimising input rate of change to be as undetectable as possible.

Taking a slab of pork chop-like car through that 20 minute dance out of the park was the best drive I’ve had in a while. The passengers slept soundly throughout, until I made everyone play a car-pushing game. We’ll talk about that another day.

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Thursday, July 05, 2007

Some weekdays, when I wake up fuzzy-minded and slit-eyed, when I do not have enough sleep and when the weather is cold and miserable, I suffer from a momentary bout of existential crisis.

Do I need to drag myself to work? What am I working for?
What is the purpose of my life?

Obviously my work is paying more than required to fund a single guy’s bare necessities. There’re no car instalments to worry about, no petrol price to bug me, my wife does not exist, my daughter does not need school fees (bless her), my son lives in my imagination, my fetish for optical equipment is generally limited to cheap manual focus lenses and most importantly, I have no social life to speak of.

Perhaps I should stir up some trouble for myself, just to rid myself of this blasted existential crisis. You know, buy a car with absurd fuel consumption, get married (anyone out there? Females only, must be over 18. Email me- early bird gets the worm), adopt a child, start smoking… the usual things.


This evening at the gym, I chanced upon transcendence. A man showering with the cubicle door wide open, God knows why. And he was facing out too – again, only The Deities know of his intentions.

The Deities were kind to me. A flash enlightenment came over me, and I realised a truth:
The penis is a remarkably ugly thing. Or less elegantly, penises are fugly.

Nestled in a bed of pubic hair with a pair of bagged orbs for company, the human penis is generally located on the pelvis between two of the human body’s largest bones (the femurs) and posterior of a potentially bloated belly.

Compared to its surrounding anatomical features, the penis is ridiculously small. Now tell me, who hasn’t seen Michelangelo’s sculpture of David and went, “hehehe, what’s that lump between his legs?”

Viewed as an individual entity, the penis lacks the homogeneous elegance of a pair of breasts, the intricate depth seen in eyes, nor the heart-warming joy of a smile. Proportions between various dimensions of the penis do not appear to fit the Golden Ratio.

The design (intelligent or otherwise) of the human penis can thus be said to be utilitarian, with no attention given to aesthetics. The penis is a tool to direct liquids to where they are intended, and is not designed for viewing.

So put that nasty thing behind some pants, the world does not want to catch a glimpse of it.

And a brief reminder to email me, as the early bird gets the worm.

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Tuesday, July 03, 2007

A brief histogram-based qualitative comparison between the Panasonic FZ-30 and entry-level DSLRs

The objective of this investigation was to compare the dynamic range of the Panasonic FZ-30 with entry level DSLRs. Lens flare is also briefly discussed.

Introduction of concepts
In general, cameras are devices that record light brightness values in the form of a continuous bounded spectrum of dark (black) to light (white). On typical (film or digital) cameras, dark areas are rendered as black while light areas are rendered as white.

The black and white areas represent the limits of the sensor- the sensor cannot detect light levels less than the black areas, and light levels more than the white areas. The ratio between light levels required to produce black and white areas on the sensor is known as the dynamic range of the sensor.
Dynamic range explained

Dynamic range is typically quoted in units ‘stops’. One stop represent 2 times of difference in light intensity; two stops represent 4 times; three stops, 8 times; 4 stops 16 times; 5 stops 32 times…

At first glance, it may appear odd that the dynamic range is quoted in multiplicative form (8 times, or 3 stops) instead of additive (3 lux, 4 lux, 5 lux…). The logic is demonstrated in the following example:

A hypothetical sensor would be black if 5 photons or less hit it, and would be white if 160 or more photons hit it. Once can see that the dynamic range is 160/5 = 32 times, or in a more conventional notation, 5 stops.

Consider two light sources giving out 5 photons per second and 3200 photos per second. Exposing a sensor to each of these sources for a second would expose them to give black and white, as the sensors would receive a total of 5 and 3200 photons respectively in that one second of exposure.

However, let the light sources be brightened significantly, so that the dim light now throws out 5000 photons per second, and the bright light is worth 3,200,000 photons per second. Exposing the same sensors to these light sources for a short period of time, 1/1000 second, would still result in 5 and 3200 photons on each sensor, again giving us black and white.

In both cases, the ratio of light intensities between the bright and dark sources is the same:
3200 photons per second / 5 photon per second = 32
3.2 million photons per second / 5000 photon per second = 32

However, the difference in intensity is not identical:
3200 – 5 = 3195 photons per second
3195000 photons per second

Thus the multiplicative manner of describing dynamic range makes more sense than additive.

Description of Cameras

The Panasonic FZ-30 is a regarded as a prosumer point-and-shoot superzoom camera with a fixed lens (7.4-88.8 mm f/2.8-3.7) of Leica design.

Entry level DSLRs used were the Nikon D40 and Canon 300D, both using their respective kit lenses (both 18-55 mm f/3.5-5.6).

Methodlogy and results

A scene with excessive highlights and shadows was captured at various exposure settings using all three cameras. The exposures were calibrated to be exactly the same: ISO 100, f/5.6 and exposure times of 1/200, 1/400, 1/800, 1/1600. In the case of the Nikon D40, it does not have the ISO 100 setting, so exposure times were halved to compensate for doubling the sensor’s sentivity.

The exposure corresponding to ISO 100, 1/800s and f/5.6 was arbitrarily chosen as the baseline exposure (0).

The captured images were cropped to contain approximately identical portions of the scene. The cropped scenes are presented in the figure below.

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The histogram for each scene was observed in Photoshop CS2, and captured by using the Print Screen function. Distinct peaks (corresponding to large areas of similar darkness) were marked.
Histograms explained

Histograms show the frequency of various darkness levels within the image. The horizontal axis shows the darkness of pixels (dark on the left, bright on the right) and the vertical axis shows the quantity of pixels corresponding to each darkness level.

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As the marked histograms show, the Panasonic FZ-30 has a remarkably narrow dynamic range. The main indicator is that where the DSLRs can accommodate 3 distinct peaks in the first two exposures, the FZ-30 is unable to do so even in the final one where the green peak is pushed closest to the left.

Curiously, the histograms from both DSLRs show that certain brighness levels are not represented (the histogram having zero height between the green and blue peaks) while the Panasonic one does not fall to zero.

Further investigation shows that this is due to lens flare. Internal reflections from the intense sunlight were not well controlled, resulting in light hitting the sensor where it should not.

A region of the scene was further cropped so that it contained a portion of the dark foreground and a bit of the bright sky. Ideally, the horizon should be a sharp division between the dark foreground and bright clouds. A histogram of this cropped region should have two sets of peaks- a dark one corresponding to the dark foreground, and a light one corresponding to the clouds.

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The histogram from the Panasonic FZ-30 shows that some of the light from the sun has spread into the dark foreground, resulting in a gradual drop off in brightness instead of a sharp transition.

Summary of results
Compared to entry level DSLRs, The Panasonic FZ-30 has a sensor with comparatively low dynamic range and lens which suffers from noticeable flaring.

Concluding remarks
The results are not surprising.
The Panasonic FZ-30 has a very small sensor (approximately 7.4 mm across) while the DSLRs have much larger sensors (approximately 24 mm across). The resolution is of these sensors not remarkably different. The DSLRs’ larger sensors allows each pixel to have a larger area and collect more photons. As a result, large signal amplifications is not required, and noise is well controlled thus allowing usable data to be extracted from regions with low light.

The FZ-30’s 12x larege aperture (f/2.8 - 3.7) zoom lens requires more compromises in terms of various design objectives compared to the 3x zoom (f/3.5 - 5.6) on the DSLR kit lenses.

Overall, these are the inherent drawbacks of having a high resolution sensor and large zoom range on a relatively small camera body. The Panasonic FZ-30 serves as a general purpose camera which does many things (macro, wide, long telephoto) with a small, lightweight package. It lies in a different category and has a different target market from DSLRs.

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