Which pic do you prefer: the left one, or the right one?

Have you ever taken a pic of inside a dark room with bright sunlight visible outside a small window? Have you ever taken a pic where there are beautiful clouds in a bright sky and your friend standing under the shade of a canopy? You would often observe that either the sky is blown off (too bright to see any details in the clouds) or the subject is too dark. If you have a DSLR, you would often find yourself asking the question “should I meter the bright sky or should I meter the dark subject in the shade, and still preserve all details”.  Interesting thing here, is that you would be able to see the details in the sky and your subject perfectly fine, but your camera just wont be able to capture them. The problem here, is not with your photography skill, but a limitation in the camera. Let me explain:

The illumination ratio between the darkest spot and brightest spot (containing detail) is called the Dynamic Range of a scene. Typically, DSLR cameras can capture contrast ratios of around 2000:1 or 11 EV (when taken to a base of 2), LCD displays can display upto 9.5 EV. The Human Eye, can perceive well beyond that range. However, there is a catch. The human eye cannot perform both operations (viewing very bright and very dark details) simultaneously, this is done by adjusting the amount of light that enters the eye and it takes a short while to adjust. A camera cannot do this, as you have just one moment to capture, just one frame of details. If you open the shutter for too long, you get too much light (and the bright areas get blown out), if you open it for too short, you get too little light (and the dark areas remain dark).

To overcome this, photographers use multiple exposure-bracketed images to create one single image with High Dynamic Range. Are you getting the hang of it now? In principle, take three images - 
Pic 1: A little darker, so that details in the bright areas are maintained (-1 EV). The darker areas in this image would be blank with no details.
Pic 2: A little brighter, so that the details in the dark regions (shadows) are clear (+1 EV). The bright areas in the image would be blown off.
Pic 3: The last pic with an average exposure of the two above  (0 EV). Taking just this pic would not help in situations of extreme contracts, such as bright exteriors and dark interiors.

I took this set of bracketed pics at the Baha’i Temple in Wilmette, Illinois (an affluent village 14 miles north of Downtown Chicago). This was the first of the seven Baha’i Houses of Worship currently surviving. The first pic is –1 EV, the second pic is +1 EV, the third is 0 EV. (Click on them to see large)

Now put the three pics on top of each other in any image editing software and use the bright portions (highlights) from the first pic, dark portions (shadows) from the second pic, and the mid-tones from the third pic! Thats about it!

It sounds straight forward, but to do that, you need a few things:
1. Take exposure bracketed images of exactly the same frame – use a tripod and the AEB feature of your camera. Turn off auto-focus!
2. Use a photo-editing software to put the three HDRs together. I am not sure if you can do it in Photoshop, but there are plugins you can install.

Alright… If you have come this far, it makes some sense to go a bit further…

Perhaps, you did not realise, the method I walked you through to create an HDR, will still not make your images look stunning. Reason: Your LCD monitor can display images only upto a certain contrast ratio. Its dynamic range is lesser than your camera’s standard dynamic range. Now you have an image with dynamic range much greater than that of your LCD monitor and even your camera. So what do you do?

You tone map the image! Basically, you reduce the contrast ratio of the image from something like 16 EV to about 8 EV, or, from 100000:1 to about 255:1. The JPEG images you see usually, are 8 bit images, that contain upto 255 levels of illumination (from darkest to the brightest). So the goal of tone mapping is to reduce the contrast ratio but to preserve the detail. This, can be done using two techniques – Global Tone Mapping, or Local Tone Mapping.

Global Tone Mapping is the most basic operation. It is similar to contrast reduction in Photoshop, or even your LCD monitor! It reduces the contrast in each and every pixel of the image, uniformly according to the most appropriate function for that image. This, does not help us in what we wish to achieve. Really.

Local Tone Mapping reduces the contrast of each pixel based on the contrast and illumination of the surrounding pixels. If you have studied Calculus/Derivatives in school, you could think of it to be something like Global Maxima / Local Maxima. Local Tone Mapping on an image having shadows and highlights would have different impact on the dark areas and the bright areas. In fact, it would bring out more details than you thought were present in the scene! HDR tone mapping using Local Tone Mapping has become extremely popular amongst photo enthusiasts for exactly this reason. These photographs have a distinct look and seem attractive to many! Often one would get comments like “This looks so much like a painting”, or “This is like a computer game scene”. Limited dynamic range is never a problem in paintings, whereas computer game manufacturers use tone mapped HDR graphics to improve the look and feel of the play. While HDR in video games make scenarios look real, HDR and local tone mapping in photography makes real scenes look a bit graphic!

 
HDR created by merging the 3 bracketed images above. Minor tone mapping applied.

Major tone mapping applied to reveal extra details. Looks more graphic than the one above.

Sorry about the long blog post :) I should keep myself in check so that I do not go overboard and do too much of local tone mapping. My name itself says adi… which means, excess!

Recommended softwares:
1. Adobe Photoshop / Lightroom
2. Oloneo Photoengine (the one I used)

For people like me, who have lived a long time in hostel, and then as bachelor working guys, having access to a television, is a door-ki-kahaani. India has come a long way from what it was at the beginning of the decade. Regardless of the fact that you don’t have sufficient water, sufficient electricity, sufficient infrastructure, sufficient sanitation and sufficient good food, you would always have a working broadband internet connection. When you move to a hostel, or into a new apartment, the first thing you would venture out to get installed is  a broadband internet connection!

Newspaper gets delivered at the door every morning. The way to open a newspaper is from the back: Sports Page first! after going though a few pages, take a look at the photographs on the first page, and then dump the main newspaper and pull out the Lifestyles supplement… Page 3 people and stars! Hot chics!

Coming back to the point, even after all this, if we want to know what is happening in and around the place we live, the best place to check that out is websites of television news channels. They are comprehensive these days with news text, videos, photographs, polls, blogs, and even sections on sports and celebs! So after opening GMail, Twitter, Facebook and my blog, the next thing I would open on Firefox would be a tab on news!

Till some days back that news tab would be CNN-IBN, a partnership between Network 18  and Turner International. Editor-in-Chief of CNN-IBN, Rajdeep Sardesai said “With nationwide news gathering capabilities, superior journalistic talent, and a passion for news, the new service will endeavour to get the news first and direct from the ground. In a fast-globalising India, access to CNN’s global news network will add immense value for our audiences”. The television channel is perhaps the best you can get in India. However, the same when seen through the lens of the internet, may not be visible as clearly.

I have used this website for the last two years more regularly than I have had breakfast. It has been extremely helpful to me to stay abreast with happenings in India during my trips abroad. However, lately my experience of reading news and browsing some time around on CNN IBN website has not been so good. Infinite advertisements and flash pop-ups have almost ruined my liking for this news channel. I encountered the following while loading the website:

1) String of flash-based advertisements line up on the right side.
2) A big square box pops up on the screen and takes up almost a fourth of the browser’s website-viewing space.
3) Clicking the [Close X] button on the flash pop-up does not always work. The hotspots are incorrectly defined a lot of times and this leads to you ending up opening the website of the advertiser.
4) Clicking on any news link will take you to a fresh page with that news, plus the same string of advertisements and the same kind of pop-up that takes the same amount of space and blocks your view of the news text.
5) On closing the flash pop-up, if you try scrolling down the page to read more text, and happen to click anywhere in the paragraph, another annoying flash box would pop-up.
6) On every news video, there would be a 30 second advertisement that would run before the video.

Considering the above factors, I wondered if it would be a wise decision to move to another news provider. I know there exist a lot of flash advertisement blockers available for Firefox and some of them are really good. But keeping in mind the fact that 65% of internet users still use Internet Explorer, and out of those a large number use old versions of IE (below IE-7), I thought it would be great to do a quick research.

I decided to calculate the percentage of a browser’s viewing space that news channel websites offer for pure news, for advertisements, for links to other sections or just keep empty as free space. I then took a quick poll amongst my colleagues and also gathered some numbers using Facebook and Twitter, asking people the following question:
”What percent of the screen would you prefer the website devote to NEWS and what percent to ADVERTISEMENTS?”

I selected five news channel websites, 2 Indian (English), 1 Indian (Hindi) and 2 International (English) and visited their websites. I then took snapshots of the browser after complete loading of the websites and printed them. I divided the printout into various sections as shown below and calculated percentage of the total area for each section, for all five websites.

Some quick calculations later, I found it easy to rank the five websites for the following parameters: Percentage of space allotted to News content, Links to other sections, Graphic ads, Text ads, and free space left. I also checked out if the websites threw pop-ups at the user. The results are in the table below: Rank 1 means maximum points to it!

* Cluttered Interface and Pop-Up Ads have negative implication on overall score / rank.

From the calculations it was evident that IBN devotes 48% space to advertisements, the next in line NDTV devotes only 28%, whereas Aajtak, surprisingly devotes only 8%! While BBC devotes the maximum space to news content (57%), it gives very little for consolidated links to other sections (10%). The reason for this is that BBC offers widgets on its websites which users can drag, drop, move, remove, add according to their needs and likings. Almost 25 % space on CNN website is blank, and that number for BBC is 21%. IBN and NDTV both have only 5% and 6% free space. IBN is the only website which has pop-ups.

Please note, if there is a pop-up, that much space goes into the calculations as space for advertisements as the news behind it is not visible.

On taking the quick poll to know people’s preferences, I found out that on an average people prefer 80% space for news and related items and 20% space for advertisements. One of my friends also added that advertisements and pop-ups help her to get rid of the monotony offered by the news websites! Below is a pie-chart showing distribution of space as preferred by the sample I chose.

The above rank is calculated for the “Best news-reading, and browsing experience” and has no weight for the content and context of the news. For the content, IBN would still remain the number ONE website / channel for me. I can just hope the browsing experience gets revamped, and soon!

Please note: The views expressed above are completely mine. I have nothing against any news agency or company. I sincerely hope, my views, thoughts and study are communicated to the right person. For any details on the method of evaluation, contact me by mail aditya[dot]ee[at]gmail[dot]com. For everything else, please feel free to comment on the blog.

So the most important thing a domain name needs, is a domain name server (DNS), or a name server (NS). A name server essentially contains address (A) records that map the domain name to an IP address. That is, a NS contains an A record which says domain.com is actually IP 192.x.x.x and so on. When you type in domain.com in your web browser, the browser tries to find the IP address via the A record, which it seeks on the NS of the domain!

If you buy a domain registration from a vendor, the NS setting would be at default, that would be pointing to the NS of the same vendor. If you decide to just buy the domain from this vendor and host your website on some other vendor’s server, then you need to change your NS records. The new NS records should now point to the vendor where you have hosted your website.

So lets say, you purchase domain.com from vendor1, the default NS entries would be ns1.vendor1.com, ns2.vendor1.com or dns1.vendor1.com, dns2.vendor2.com
If you have chosen to host your website with host1, you need to change the NS entries to ns1.host1.com, ns2.host1.com etc.

So what was my problem? I wanted my wordpress blog (hosted at www.wordpress.com) to be pointed from a sub-domain blog.aditto.info! The best ways to point a sub domain to a website are by using A record or CNAME record. While A record points to an IP address, CNAME record points to an A record which might be on some other server! So all I had to do was insert a CNAME record for blog.aditto.info to point to aditto.wordpress.com, and then pay/enable subdomain mapping in wordpress.com settings.

I did that. However, blog.aditto.info would not point to aditto.wordpress.com. I tried my luck by changing all kinds of settings for 3 days but it just wont work.

Here is the catch: Any A, CNAME, MX, etc. records for a domain name (aditto.info in this case) must be made in the settings of the name server assigned to it. If you have purchased the domain from vendor1 and hosted your website on vendor1, then your name servers would be ns1.vendor1.com as written above. However, if you have hosted with host1 and changed your name servers to ns1.host1.com, then the A, CNAME, MX settings must be changed in the settings control panel of HOST1 and not VENDOR1.

So I logged in to byethost control panel and added those CNAME entries for ns1.byet.org.

The important thing to note here is that any change in DNS entries takes considerable time (0 – 72 hours) for propagating throughout the world wide web. So lets say you make changes about 5 times in 5 hours and wish to check the domain, what you might see after the 5th change, could well be the effect of the first change. This is exactly what happened with me and I could not stabilise on any one DNS setting. The best option is to Google and find out correct ways to do what you are doing. Better way is to let some experienced person change your DNS settings for the first time. An even better way, is to make a change, and check using some web tools if your change has propagated.

Here are a few tools:
1. World wide propagation tracker: This is a very cool web tool that lets you track your DNS entries at about 10-12 locations all over the earth.

2. DIG service to lookup DNS information: This is another cool lookup tool, using which you can query any DNS entry on any DNS server around the world.

However, whatever you do, always remember to note down and archive all your working DNS settings (NS/A/CNAME/MX/SOA/TXT/etc). You may never know what you fiddled and what your previous DNS settings were. Some web companies do archives DNS settings of domains but you need to pay a lot of money to extract the same.

I hope this makes some sense to people who have faced similar issues.