Extracting Maximum Data From Your Images

The photograph above was taken at an abandoned row of heritage style houses at Bukit Nanas in Kuala Lumpur. The image has a tremendous amount of detail in terms of light, shadow, colour and texture and I think highlights the amount of information or "data" that can be extracted from a photograph (or in this case a series of photographs) to create a final image that is close to what we perceived in reality with the human eye. I wanted to take this image as an example and describe a little of the process I use to extract this information from the raw images and create the final image above.

The Problem

I'm sure I am not alone when after taking a photograph of a scene which captured our attention we are disappointed with the resulting image which did not really capture or show the essence or mood of what we actually saw with our eyes. A scene with subtle colours and perhaps bright highlights or deep shadows comes out as a bland, rather flat image and does not come close to what we originally perceived with our eyes.

The fact is that our eyes can see a dynamic range in the order of 10 to 14 f-stops. This figure relates to a "static" view by the eye (i.e. looking at one area with no pupil movements) whereas in real life our pupils are constantly and dynamically adjusting for light, similar to a video camera, so in reality our human eye has a dynamic range closer to 24 f-stops.

Our human eyes create a mental image of the scene which is a combination of what the eyes see when they are focused on various parts of the scene as depicted above.

Camera film can capture a dynamic range in the order of 14 f-stops. Modern digital camera sensors can usually capture a dynamic range of 5-7 f-stops and some high end DSLR cameras such as the Canon 5D MkIII can capture a dynamic range of about 11.7 f-stops and the Nikon D800 can capture a dynamic range of around 14 f-stops. So there are indeed some limitations with the camera sensor itself in what it can record and capture.

The Solution

So how do we circumvent this problem? One method is to take a range of bracketed photographs of the same scene and blend these into a composite image which captures the best pixels of all the individual images. - somewhat akin to what the human eye is doing. This technique is referred to usually as high dynamic range or HDR photography. Once a set of brackets images have been captured software is required to merge the images together and "choose" the optimum pixels from each bracket - a technique known as tone mapping. By doing this you can extract a lot of additional information from the shadow areas of the image and also minimise any blown out or overexposed portions of the image from the very bright portions of the image, such as the sky.

Using the image at the start of this post as an example let's step through the process I use to capture, edit, post-process the images to maximise the amount of detail and information from the scene.

Image Capture

When taking a series of bracketed photographs for HDR post-processing it is inherently obvious that the camera needs to be in the same position, as does the lens setup and settings. Ideally the camera should be setup on a stable tripod in a position to best capture the scene with the appropriate lens. Depending on the dynamic range of the scene you can take anything from 3 bracketed images, to 5, 7 or even more bracketed images. If the scene has very bright highlights (e.g. bright sunshine) and very dark shadow areas the more brackets should be taken to cover this dynamic range. 

I initially set up the camera on the tripod in the best location and frame the image as required. Then I would set the camera for  the optimum exposure (shutter speed and aperture) and use this as the mid or middle bracket (0EV) I can then use the appropriate number of brackets needed to capture the dynamic range of the scene - you can check the histogram on your camera to make sure you are doing this and covering the complete range of the scene. I maintain the same aperture setting for all the brackets - in this case f/8. For the image in question I took a series of 7 brackets (-3EV, -2EV, -1EV, 0, +1EV, +2EV, +3EV) as shown below.

The 0EV or middle bracket is the usual or normal exposed image you would take if just taking a single image and is shown below.

Although this image is well exposed and actually captures a fair amount of detail both in the bright areas and the shadow areas there is a lot we can do to extract more information and fine detail from this scene.

Image Editing

Once downloaded to the computer we can start the image editing process. I use Aperture as my main photo catalogue system, editor and for basic image post processing. I start by doing some simple editing on the image such as straightening, cropping. You may want to do some other things such as white balance, etc depending on your specific image. I keep the basic edits simple as we may have to do some more once the HDR post processing has been done such as colour adjustments and sharpening which will be done at the very end of the workflow.

HDR Post Processing

For the HDR processing I use Photomatix Pro and I have this installed as a plugin for Aperture which makes it very efficient as the final HDR image is then saved back into the Aperture library, where I like to maintain all my raw and processed images. I have a variety of my own preferred settings for Photomatix but basically what I am trying to do is to create a balanced, well exposed image with maximum information, i.e. retain detail in the highlights and bring out details from the dark shadow areas, without making the image too extreme which many HDR images can tend towards if you are not careful.

The resulting HDR processed image is as below.

Although the image does have more detail in it there are still areas which are a little too dark such as inside the porch area and the doorways to the left and right. I also want to bring out more of the lovely colours and texture in the walls and that front gate so now I will move onto more advanced post-processing to maximise the detail and information from this image.

Advanced Post-Processing - Stylisation

I have been increasingly using the wonderful Perfect Photo Suite from onOne Software and have recently been testing the latest Version 8. Using the Perfect Effects module we can extract more detail from this image and stylise it to the way we want it as detailed below. This module has a extensive library one-click presets, filters and other powerful tools to bring out the most from your image.

The first filter I usually go straight for is the wonderful new Dynamic Contrast which has a number of options, as seen in the left column of the software interface, and these help tremendously to bring out contrast and texture from your image.

You can then sequentially add in filters to work the image to your desired finish point - the stacked filters are listed on the right hand panel so you can adjust each of these individually and the way they are applied to the image. Highly flexible and very easy to adjust and see what you need for your particular image.

I now add in a Bleach ByPass filter at around 50% layer opacity to lighten the image.

I want now to bring out just a little more colour from the walls so I use the Colour Adjustment filter and the Increase Colour option to do this.

I then use the Adjustment Brush (lighten and detail) to bring out information in the dark porch areas, the doorways left and right and of course that wonderful old green gate. This allows you to brush in the adjustments to specific areas of the image and the new Perfect Brush is wonderful at recognising the areas you are working on and not going "outside the lines" as you apply or remove adjustments.

Final Image

All of these changes are subtle and hard to see in a small web image - you really need to see this fullscreen. Of course the post-processing stylisation is really a personal thing and each person will have their own style or requirement for an image. This post briefly outlines the philosophy of the process and describes some of the software tools that allows the user to extract the "data" and then customise it or stylise it to reach the final vision that the user has. I feel the finished image as below and at the top of this post really brings out everything I imagined or saw in the scene and has successfully managed to extract a vast amount of image information or data from the original raw files recorded by the camera.

Authors Note: The author bears no responsibility for anyone calling the iMassage telephone number which is stencilled on the building wall of this image!!

Tin Dredge TT5

Tin mining is one of Malaysia’s oldest and most successful industries. In the 1600s, this industry started to thrive in Kedah, Perak and Selangor. Over the centuries, tin was extracted in huge quantities from both open cast and deeper mines. Dredges were commonly used to extract the tin. Today, there are only about three old dredges left in the country, and this one at Chenderoh, near Tanjong Tualang, Perak, has been preserved. In Feb 2008, it was opened to the public for tours.

The first tin dredge was introduced in Malaysia in 1913 by Malayan Tin Dredging Ltd and started operations in Batu Gajah, Perak. It was steam-powered, using 280-litre buckets that could dig to a depth of 15 metres. The company acquired four dredges and by 1924 was the largest tin dredging company in the world. In 1926, a sister company, Southern Malayan Tin Dredging Ltd was formed, and operated a further five tin dredges between Batu Gajah and Tanjong Tualang.

This fifth dredge, the Tanjung Tualang Dredge No.5 (TT5) was designed and built by F.W. Payne in 1938 in England. It is located approximately 9 kilometres south of Batu Gajah on the Tanjong Tualang road. The dredge was in operation for 44 years, until August 1982, when a drop in tin prices made the dredge uneconomicaly viable.

The pontoon of the dredge is 75m long, 20m wide, and is three storeys high. The total weight of the dredge is 4,500 tonnes. It is essentially a floating factory where buckets on a chain scoop earth deep from the pond. These buckets were then transported up to an area high in the body of the dredge. It was moved by means of a 1.5km long cable, worked from the control area.

The dredge would run on diesel generated electricity 24 hours a day, in two shifts with approximately 20 workers per shift. The conveyor buckets would dig the tin-bearing soil and transport it upwards, emptying the contents into an oscillating drum. The tin would then be extracted through a system of jigs and screens, leaving the excess material to be disposed of via a system of chutes at the back of the dredge.

During the heyday of the tin mining industry, 40 dredges were operated in Perak, with a record of 105 working in 1929 in the whole of the peninsula. This particular dredge stopped work around 1983 after more than 40 years of service.

The TT5 tin dredge is currently owned by the Perak State Government. It is of enormous heritage value as the last remaining tin dredge of its kind in Malaysia. A committee was formed at the end of 2010 to save, preserve and enhance TT5 tin dredge so that it could showcase Malaysia's tin mining past through tourism and education. This has resulted in a "Save the Dredge" campaign in order to raise funds for restoration of the dredge. The TT5 tin dredge is open from 8:30am to 7pm daily, including weekends and public holidays with an entrance fee of RM10.

Bukit Nanas Heritage Mansions - a panoramic perspective.

This row of heritage style mansions in Bukit Nanas, Kuala Lumpur have been slowly crumbling and decaying over the last many years and will no doubt at some point disappear for good. I wanted to capture this historic architecture and try to create a panoramic image to fully image the fine details of these classic buildings. To do this I used a 17mm tilt-shift lens and captured a total of 106 individual images (16 framed shots each with 7 bracketed images to fully capture the dynamic range of the scene). The images were post-processed in Apple Aperture then tone-mapped in PhotoMatixPro plugin. 

The final images were then converted to black and white and selective colour brushed in using Aperture to highlight some specific parts of the image. 

The individual resulting 16 images were then stitched using AutoPanoPro. The stitching result is not ideal given the geometry of the buildings and the location of my camera setup but it certainly gives you a real sense of the geometry and design of the structure. 

The final panorama was imported into FotoMagico to create the short slideshow sequence as shown in this video.

Camera: Canon 5D MkIII

Lens: Canon EF17mm f/4.0 TS-E

ISO: 100

Focal Length: 17mm

Aperture: f/8

No of Brackets: 7 (-3 to +3)

Old Volvos Never Die.

I discovered this old Volvo left to rot in a small village, Kampung Sungai Penchala, last week at the end of a jungle walk in Bukit Kiara and made a mental note to return to grab some HDR brackets. Old decaying buildings and cars just seem to scream out HDR to bring out the very best detail in the decay.

Abandoned & Decayed - An HDR/URBEX Paradise

Decaying and abandoned old buildings are a treasure trove for the photographer or the urban explorer (URBEX) and these types of environments just shout out for the use of HDR and other post-processing styleization techniques to produce a moody and atmospheric image. The inside of these buildings are normally very dark and where there is bright light spilling in from the outside you can get large changes in dynamic range which can be limiting for most camera sensors. Hence the need for taking multiple bracketed images over a range of exposures to bring out the details in the shadows and properly expose the washed out highlights.

The above image, taken inside an old abandoned colonial house in Georgetown, Penang, Malaysia, was created by tone-mapping 3 bracketed images as shown below.

0 EV

-2 EV

+2 EV

For dynamic ranges like this where there is a large difference between the dark shadows and the bright highlights of the open doors and windows I would normally have taken more brackets; 5 or even 7 to cover the dynamic range of the scene. However in this case I was taking hand held as I was sans tripod so shot off 3 quick brackets to try and miminise any camera movement.

The images were imported into Aperture and then tone mapped using PhotoMatixPro. I subsequently did some additional post-processing in  Viveza 2 from Nik Software to enhance the colour and texture of some areas such as the wall on the left hand side and the wonderful eroded ceiling beams.

Looking at the final image compared with the "normal" 0 EV photo it really highlights the benefits of HDR techniques to bring out the full dynamic range of the scene.

A Perspective of Shih Chung School, Penang

This imposing old tumbledown, heritage building in Georgetown, Penang used to be the Shih Chung School but actually has a much longer and interesting history.  The once glorious mansion was called Goh Chan Lau (literally meant five-storey bungalow) by the local Chinese and was built by millionaire Cheah Tek Soon, founder and partner of Penang Khean Guan Insurance Company (the first Chinese insurance company in the Straits Settlement in year 1885). The Cheahs are one of the big five Hokkien families in the state. In 1908, the building was sold off to Tye Kee Yoon, another eminent personality at that period. and the mansion then housed the Chinese Residency for a point of time before it became a hotel, the Raffles-by-the-Sea. The hotel was a failure and had to be shut down. 

Later on, Kee Yoon, who was a Hakka, collaborated with another millionaire Leong Fee to set up the Shih Chung School within Goh Chan Lau in the same year. Leong Fee, whose full name is Liang P'i Joo, also set up a girl's school called P'i Joo Girls' School which occupied the upper floor of Goh Chan Lau. In 1929 Shih Chung School was moved to Love Lane. By 1938, the school became so overcrowded that a branch had to be established and Goh Chan Lau became the choice destination again. From then on, Shih Chung existed as a main school and a branch school. The periods in between had the mansion leased to the Government Branch School.  

During the Second World War,Goh Chan Lau was used as an administrative headquarters for the Japanese Military and therefore the branch school had to relocate to its main body. There the combined school co-existed until 1949, when the Shih Chung Branch School returned to occupy Goh Chan Lau. In 1961, the launch of the Uniform Salary Scale for Teachers saw the full severance of Shih Chung Main School from Shih Chung Branch School. The branch school again relocated, this time to its current premises at Sungai Nibong in year 2000, when the urbanisation of Penang Island brought forth a collapse in the population of the Inner City, hence a precipitous drop in student attendance. Goh Chan Lau was later sold by the Tye family trustee, when the restriction period in the will expired (after three generations). The building had been purchased by a new owner, Malaysia Vegetable Oil Refinery Sdn Bhd in 1993. Now an abandoned building, the new owner had initially planned to turn it into a columbarium (a place for the respectful and usually public storage of cinerary urns -  i.e. urns holding a deceased’s cremated remains) but was met with harsh protest by the people of Penang. The site is apparently now set for demolition and a condominium built on the site. 

An interesting point to note is that the Tye family trust was an early example of a Hakka family that left a will for the descendants, which provided that the family estate including the Goh Chan Laucannot be sold for at least three generations, and 10 per cent of estate revenue is to be donated for education purpose. It is Chinese belief that the estate of a family cannot be passed more than three generations or will be finished by the third generation. The will of the Tye family provides clauses to mitigate the risk on that belief and provided clauses in the will, that the family estate cannot be sold prior to three generations. It also provided for a clause that 10 per cent of estate revenue to be used for education purpose. This reflected the wisdom of the Tye family, and their trust was able to support the Chinese education in Penang for long time. 

Tilt-Shift Lens Comparison

The main image above was shot using a Canon TS-E 17mm L lens and is an HDR processed image from 7 bracketed shots. Just to show the comparison between a shifted image and a normal one, the two photos below illustrate the shot:

1) using the TS-E 17mm L lens without shift and the camera body then tilted up to capture the entire building 

2) using the shift function of the lens to properly align the vertical perspective of the architecture. 

The un-shifted photo shows the typical leaning verticals giving the viewer an impression that the building is falling backwards. This is caused by the wide angle lens and the tilt of the camera body which is needed to capture the whole building. 

The shifted photo gives better perspective control of the verticals. This tilt-shift lens is therefore very useful for properly capturing photographs of architecture where perspective control is important.

 1) Canon TS-E 17mm L - no shift

2) Canon TS-E 17mm L with vertical shift to align perspective

Blue Indigo Window

This blue coloured shuttered window was photographed in Lorong Stewart in Georgetown, Penang, Malaysia. The back streets and lanes of Georgetown are great to wander through to view old historical and heritage houses. I particularly like windows and doors and this window was a great example of that run-down, dilapidated and decaying style that I like in these Asian buildings. You can make out a blue colour in the surrounding walls as well as on the window shutters and this was a very typical colour used in the colonial period. The distinctive blue colour is made by mixing lime with the natural blue dye made from the indigo plant and this dye was imported from India during those days.

Heritage Buildings of Georgetown, Penang

Backstreets and lanes of historic towns like Georgetown, Ipoh and Malacca are a wonderful place to find some colorful old heritage style houses and shops. This corner house has had some rather unique renovation carried out as you can see with the tacked-on extra room made from corrugated iron. Of course I'm sure that proper planning permission was granted here and that these modifications adhere to good building practice and regulations!

Vietnamese Buddhist Temple

Asian temples offer some great photography opportunities as they are usually full of ornate and highly decorative walls, pillars and floors. However as these temples are usually very poorly lit, sometimes only using candles, it poses an enormous challenge to be able to capture the dynamic range of the scene. This is where HDR photography really comes into its own as shown in this shot in a dark interior of a temple in Ho Chi Minh, Vietnam.

Graveyard Greenery

This old Christian graveyard in the center of Kuala Lumpur, Malaysia lies overgrown and run down providing an atmospheric environment of tropical crumbling, decay. It's fascinating to explore these types of abandoned urban areas which provide opportunities for HDR photography. 
Urban exploration (often shortened as urbex or UE) is the examination of the normally unseen or off-limits parts of urban areas or industrial facilities. Urban exploration is also commonly referred to as infiltration, although some people consider infiltration to be more closely associated with the exploration of active or inhabited sites. It may also be referred to as "draining" (when exploring drains) "urban spelunking", "urban caving", or "building hacking". 

The nature of this activity presents various risks, including both physical danger and the possibility of arrest and punishment. Many, but not all, of the activities associated with urban exploration could be considered trespassing or other violations of local or regional laws, including—but not limited to—invasion of privacy and certain broadly-interpreted anti-terrorism laws.