Can We Really Use Mobile Phones For Professional Dental Photography?

It is no secret that mobile phones are an important part of our lives. The first thing that most of us do when we wake up in the morning and the last thing we do before retiring  is usually check for any message from colleagues/family or probably google for something online. Mobile phones, internet to be precise have made a huge impact in our lives and this includes our professional lives as well. It wouldn’t be wrong to say that they have become an indispensable tool for continued dental education, with so many WhatsApp groups and Facebook groups taking part in mutual exchange of vital information including sharing of case reports. With the use of a single phone and internet one can surf innumerable videos, audio blogs, scan articles, presentations, and attend LIVE webinars / whatsappinars as well. Never before did we have so much power in our hands when it came to procuring information. The biggest reason for it to become so popular is that it is extremely handy, always available and capable of outperforming what it is actually meant to be used for. One such use is photography which it is of course capable of and has already outperformed many digital cameras of the past due to enhanced technology but we as a dentist have to understand weather it is time to restrict ourselves or go with the flow. This is because we have particular standards that we need to follow when we document our cases which do not imply to a hobbyist photographer. This problem has arisen because the protocols haven’t been openly discussed in the past.  The dentists aren’t aware about what standards are needed to be followed before making a good documentary. “There comes a time when you have to choose between turning the page and closing the book.” This article intends to open up the horizon of thought process that a dentist must be informed about before taking the next image with a mobile phone or a DSLR.

BASIC expectations from a camera that can be used for dental photography

In order that a camera can be used for dental photography it needs to satisfy some basic requirements. In order to understand these basic requirements we need to ask ourselves the following questions about our expectations and answer them truthfully.   For a camera to be used for professional dental photography …

1. Should it record distortion free images OR would you be comfortable with distortion in your images? An example of distortion for a better understanding would be as follows:

   

   IMPORTANT: ABOVE IMAGES ARE OF THE SAME TYPHODONT. Image on the left looks more like a Horse Jaw (Horse Jaw effect due to Distortion caused by wide angle lens) Unfortunately we have accepted the left image to be normal because we have never seen what ideal situation must look like. A distortion free image on the right looks exactly as it is in the patient’s mouth.  
   1. Should it record true colors or incorrect colors are acceptable?
   2. Should the images be free of so called Visual NOISE or noise and poor quality are acceptable for your documentation?
   Below is an example of Noise: They typically look granular and make images blurred when image is blown up in size (cropped). To appreciate NOISE one must view the image in 100 % view. Images with noise must never be used for publications.

   

   Compare the above mage with the image below.

   

   1. Should the images be affected by ambient (available) light (e.g.: dental chair light/ our clinic lights set up like tube light or LED) which keeps on changing every time both in color temperature and intensity when we make an image OR irrespective of ambient light we must get consistent results with our image documentation?
   2. Your camera is such that it shoots only in JPEG format and virtually removes all chances of publication OR would you prefer having a camera which also gives you a RAW file also called as digital negative which is mandatory for all international level publications?
     Our main aim as a dental professional would be to record any given situation as it is in the patient’s mouth without any digital modifications.   Hence if your answers to the above questions were:
   1. NO DISTORTION in images
   2. TRUE COLORS must be recorded
   3. NO NOISE IMAGES for the best publication quality
   4. IMAGES MUST NEVER BE AFFECTED BY AMBIENT LIGHT (Only then pre-operative and post-operative images will match for a given situation)
   5. YES, YOU WOULD WANT A RAW file
   Its time you switch to a DSLR because mobile phone cameras are worst at it.    

   GROUND REALITY and true facts hidden behind the scenario

   1. DISTORTION :
   It is of various types and known by various names most often referred to as BARREL DISTORTION which is most significant and obvious. All of us must have heard of fish eye effect distortion as well.

   

   Distortion & focal length of a lens are related to each other as follows DISTORTION is inversely proportional to focal length of a lens This means that at lesser foal lengths (like in case of wide angle lenses) distortion is maximum and at telephoto focal lengths (focal length more than 50 mm) distortion goes down. (E.g.  For an 18-55 zoom lens which comes free with every DSLR camera at 18 mm focal length distortion is maximum and 55 distortion is minimum but never the less distortion is present even at 55 mm focal length)   It has been observed that at 100 mm distortion is minimum or negligible   If you have ever seen the DETAILS or properties of ANY image clicked by your own mobile phone camera you might have realized that their focal length is between 2 to a maximum of 5 mm. (Depending on cameras of different makes) this makes it to the extremes of wide angle lenses and hence they exhibit maximum distortion. (For people who want to dig deeper into the matter the mobile company shall say that it is equivalent to approximately 35 – 40 mm focal length of a 35 mm camera, which though might be true, is still way behind the desired values to avoid distortion.)   Compare this with a 100 mm macro lens which virtually gives you ZERO distortion. Hence always insist on a 100 mm macro lens for dental photography

   

2. 1. The image processors and sensors of a mobile phone camera are far too inferior to detect and record true colors. As compared to that a DSLR has a huge dynamic range and is capable of not only detecting and recording true colors at appropriate settings but is extremely efficient with HUE, VALUE AND CHROMA.
   2. Mobile phones usually work with compromised settings of exposure pyramid with less than normal shutter speeds, high ISO and low aperture values. This is possibly the worst combination of settings and one has very little control over the same. This results in HIGH NOISE images. Most of us don’t realize this because all these settings are automatically controlled by a meter which in itself is highly inaccurate in a mobile phone camera. Moreover megapixels are just a marketing gimmick that most of us fall for.

      

   3. Mobile phone LED lights are the worst lights possible for dental photography because they aren’t color corrected, they are upfront, they aren’t flash lights but continuous source LED’s which are possibly the worst lights to work with and lastly they aren’t powerful enough to give you freedom of desired settings for dental photography. It is due to these reasons that mobile phone photography is easily affected by ambient light like dental chair light, fluorescent light or CFL/ tube light of clinic etc. This is NEVER the case with DSLR cameras because their flash is extremely efficient for all our dental photography requirements. There are always higher chances that pre and post-operative pictures will match with a DSLR.
   (NOTE: YES dental chair side light doesn’t affect DSLR photographs provided you know how to manage the settings well. Hence it doesn’t matter if the chair light is on or off during documentation.)
3. 1. Lastly DSLR gives you the ability to STORE DIGITAL NEGATIVES of every image that you click and it is called as a RAW format file. Just for comparison if a JPEG file of an image is of size is 5 Mb the RAW file is usually close to 22 Mb which means that it has way more information compared to a JPEG format file. RAW files on the other hand are privacy protected and need a special software to open them and hence considered as one of the most secure formats. They have all the METADATA in them including your copyright signatures which can NEVER be changed. In recent time’s publication make it a point to ask for a RAW file along with jpeg files to confirm if the content is actually owned by oneself or downloaded from internet/ stolen. RAW files have higher medicolegal values unmatched by LOSSY JPEG files. Jpeg files are possibly the worst files to work with. They have already lost a lot of information and can be easily stolen, downloaded and photo shopped.
     Thus it is important for every dentists to know all these finer aspects of dental photography to make an informed decision. Does mobile phone photography even stand a chance in front of a DSLR? We shall discuss more on this topic in PART 2. THINK BEFORE YOUR “CLICKS” For any queries or suggestions you can feel free to write to us on dentalphotographyschool@gmail.com. For more interesting articles on dental photography please visit our website www.dentalphotographyschool.in Dental Photography School is India