Real-world Case Study: Taking Photo at Zoo with Lumia 535

On “How I Chose My Smartphone, Lumia 535“, I gave my account on my understanding of smartphone and personal computing in general; based upon such understanding, I eventually reached a decision to buy Lumia 535. In this article, we would have a chance to explore a real-world case study of using Lumia 535’s camera. While the higher-end or even mid-end Lumia Smartphone cameras are often praised for having decent smartphone camera; the low-end models are often ignored or being dismissed completely by some of the reviewers. My early tests closely match what are being said by Rich W Woods in regard to the smartphone camera; granted, he too prefers higher-end models and did not think Lumia 535 was a great choice without trade-off. My overall judgment does differ somewhat from him and many others. It’s not meant to be main computing device regardless; that is going to be my desktop PC’s role.

Who, where, and how? When the weather is right, I thought that zoo might be the right place to be; animals are going to be shown to public anyway. I am not sure how much optical zoom would help; but I did as best as possible to capture the images of the animals with Lumia 535 as we were not allowed to get close to animal for safety concerns; I was not a professional photographer. While some of the images admittedly show a very small “size” of animals due to the distance; the environment in the zoo is simply amazing compared with where I am used to be: a noisy, crowded big metropolitan area. One of the reasons why animals are chosen is to test the video-recording functionality of Lumia 535. It did not capture video in 720p by default but only in 480p in either 4:3 or 16:9 format. This photo-taking experience might have given some possible answers to the limitation of video-recording. The videos were later re-encoded into 720p. Before I wrote further, let me show you the result of this trip.

Click on the above image to view or download the still photos I took with Lumia 535. I also made available a slideshow created with those photos; encoded with x264 in H.264 lossless format. You may need to install K-Lite Codec Pack Mega or VLC Player to play that video. I separated one MKV file into two parts using 7-zip; make sure that you download all parts before extracting using 7-zip. To extract files from multi-part 7-zip, open the file with the filename extension of .001 using 7-zip. Alternatively, you watch the three-part slideshow on YouTube

I offered three versions of photos for the visitors. JPG is lossy image format natively being used by Lumia 535. In OneDrive, all the still photos in JPG are unedited. You can scale up and down yourself to figure out the best viewing experience; I remind you that full resolution does not represent highest quality. The slideshow in MKV of H.264 lossless format is created using the unedited JPG images; downscaled to 720p; it showcases the fairly decent viewing experience of the downscaled photos instead of full-res. The last one, the YouTube version, was created by uploading the MKV of H.264 lossless. Google re-encoded them to lossy H.264 format; due to lossy compression, they might look decent but did not fully match the original quality. The only reason I uploaded to YouTube was compatibility; the popularity of YouTube coupled with lower requirement of computing resources of lossy video allows the viewing on slideshow on a variety of devices; YouTube might also be an option for those who weren’t technical enough to handle installation of programs, 7-zip, etc.

Click here to download the videos captured using Lumia 535.

Lumia 535 captured videos and encoded them into H.264 Baseline Profile; those videos are of the resolution of 848 × 480 pixels; their nominal frame rate is 30 FPS; audio codec being used is lossy mono AAC. With the aspect ratio of 16:9, the videos use non-square pixel rather than square pixel being used by photos. You may have wondered why such discrepancy of resolution between still photos and videos exist. In the process to re-encode them into 720p or 1280 × 720 pixels; I found that some artifacts that were not seen in the original footage appeared; the culprit of such artifacts was due to varying frame rate of the video-recording process. The lack of processing power results in the slight drop of frame rate from time to time when the videos are recorded; this only poses problems during re-encoding process on a PC because the encoder assumes the constant frame rate of 30 FPS as being reported by the MP4 Container; those artifacts were not seen in the original footage of 480p videos. The drop of frame rate explains why Lumia 535 software does not allow video-recording at a higher resolution. Even while recording at 480p, the battery drains much faster than usual as expected.

Even though the videos captured are not exactly of 30 FPS; the frame rate is generally pretty closed to the reported nominal frame rate. To re-encode them into 720p while avoiding visual artifacts; I convert the video into individual frames of PNG format; FFmpeg would automatically duplicate frame whenever it noticed a drop of frame rate; I encode those frames of PNG back into 720p video. The profile I chose was H.264 High 4:4:4 Predictive; it was highly computing-intensive in both video-encoding and decoding (playback). The use of lossy compression may be inevitable for video encoding; but I at least want to reduce quality loss by choosing the most complex profile. I did not keep the original footage as I did not plan for further production other than re-encode them into 720p videos. Lossless encoding does exist but they are for production purpose; due to high usage of computing resources, video of lossless encoding is unsuitable for local playback. H.264 High 4:4:4 Predictive is generally incompatible with mobile devices or standalone media player; it can be played on a PC when the right codec is installed; which I recommend K-Lite Codec Pack Mega or VLC Player. H.264 Baseline provides greatest compatibility due to least complexity but less compression-to-quality ratio.

Just as the slideshow, the highest quality you can get is from the link I provided, which leads you to my OneDrive. That allows you to assess the video quality more accurately. However, for convenient access, I also uploaded them to YouTube; which unfortunately do suffer from further lossy compression. I have no control whatsoever over how Google encode the videos I uploaded.

Maybe it is not professional camera by any means; but for a consumer’s casual camera, it’s pretty good for photo-taking and video-recording.

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