Everything about Clinical Photography: Exercises structured to make you Photo-Pro in documentation and publication. Two live case photography sessions. One beachside photography session. #FRAMES#PHOTOPRO#DENTALPHOTOGRAPHY
A well strustured dental photography workshop to polish your documentation skills.
2 days of learning and fun along the beachside views of the most happening tourist destinations of India #Goa
In this blog post we shall discuss about HOW to select the best lens for dental photography
BEFORE WE BEGIN WITH LENSES IT IS IMPORTANT TO NOTE THE BEST CAMERA FOR DENTAL PHOTOGRAPHY
In our earlier blog post we had already discussed about the kinds of cameras available in the market and which is the ideal camera for dental photography. We reached a unanimous conclusion that DSLR cameras are the ideal choice and that buying an entry level (start-up DSLR) gives us satisfactory results with ease of operation rather than going for a high end DSLR which is very bulky and expensive. MOVING ON TO LENSES An ideal lens for dental photography would be the one which satisfies the following conditions:
OTHER THINGS TO LOOK FOR IN AN IDEAL LENS: Internally Focusing Lens, Minimum Aberrations (Spherical and Chromatic) and diffraction errors, Lens diameter should be ideal, Third party lenses? Good choice or bad? COST EFFECTIVE: Probably the first thing we look at while buying lenses is how cost effective it is but to be honest you get what you pay for. This is because premium lenses are made up of premium materials and the glass quality is extremely good and refined. When glass quality is good we can expect maximum quality and minimum aberration and errors from the lens and its glass elements. CONCLUSION: Buy the best possible lens for your camera because ultimately the camera will be capturing what the lens is seeing. If the lens is not seeing properly don’t expect the camera to give you great results.
MINIMUM DISTORTION Have you ever wondered why your nose looks bigger in some images that you took with your mobile phone camera? Well the answer to that is Phone cams are made up of wide angle lenses which give a high degree of distortion when the subject is kept very close to them. No wonder the nose which is closest to the cameras lens looks bigger and the eyes and ears appear smaller.
This is also called “FISH EYE EFFECT” This effect is more pronounced in ultra wide angle and wide angle lenses hence they are best avoided! So how to avoid fish eye effect and barrel distortion? Simple switch to the telephoto lenses. Lenses can be placed on a focal length line as follows
It important to note that telephoto lenses can be available in huge focal lengths like 1000 mm and more. It is however impractical to use a lens which has a focal length more than 180 mm for dental photography because more the focal length of a lens greater is the “Minimum Focusing Distance “of the lens which means that we have to stand quiet far away from the subject to shoot. In fact using a 180 mm lens for dental photography is quiet difficult because it is a very bulky lens. The problem continues even in the manufacturing process of the lens. Since it is understood that while shooting macro we need a very short minimum focusing distance; macro lenses face a lot of difficulty in manufacturing because they are special lenses with a shorter focusing distance compared to normal lenses. A huge challenge in arranging the glass elements. An ideal lens for dental photography would therefore be between the focal lengths of 50 mm – 180 mm. The lenses available in this range are: 65 mm macro 85 mm macro 90 mm macro 100 mm macro 105 mm macro Out of all of these 65 mm macro gives a noticeable distortion when used carelessly. It is therefore wise to stick to a focal length of 85 mm – 105 mm. Personally I feel 100 m is the “SWEET SPOT” between achieving minimum distortion and usability in dentistry. (A thing that might interest people who are already deeper into photography is DoF or depth of field, It is important to note that an 85 mm lens will give give greater DoF as compared to a 105 mm lens … this might be an advantage to dentists who require full arch images on a routine basis as compared to single tooth images. CONCLUSION: A 100 mm lens is a good lens for dental photography.
MINIMUM FOCUSING DISTANCE The minimum focus distance is the shortest distance at which a lens can focus. In the case of digital SLR cameras, the distance to the subject is measured from the focal plane mark on the camera body, not from the front of the lens. If you try to go closer than this distance the lens will NOT FOCUS. VERY IMPORTANT PROPERTY FOR A MACRO LENS (Has to have LOW focus distance)
Conclusion: We need a lens which has a short focusing distance as compared to a normal 100 mm lens … this is possible only by a 100 mm MACRO LENS (NOTE: It makes more sense to have shorter focusing distance even for our flash systems because shorter the distance more effective is our flash)
TRUE MAGNIFICATION VALUES Probably the most important use of a macro lens in dental photography is that it provides us with magnification values. These values can be set even before we start making images of our cases and are extremely important in maintaining standardization in dental photography, especially before and after comparisons where we do not want that before image looks radically different as compared to after image with respect to composition. Above: A 100 mm macro lens set at 1:1 magnification
CONCLUSION: ONLY and ONLY a macro lens can give you magnification values. We have no other choice for dental photography. OTHER FACTORS: 1. It is important that the lens is internally focusing and not externally focusing because in externally focusing the lens will protrude outside when you rotate the focusing ring. This causes the external flash (like ring or twin flash system) to move along with it which is not a recommended situation. In internally focusing lenses the lens remains static from outside even during the rotation of the focusing ring (auto / manual focusing) and hence the attached flash system like the ring or the dual point flash also remains static.
Externally focusing lenses look like the image on top. The dimensions of theses lenses change as we change the magnification / focusing and hence a flash attached to the lens also moves inward or outward along with the lens which causes a lot of discomfort to the dentist and the patient also feels scared
2. Usually premium lenses are the lenses that have extremely good materials in the glass elements and hence they cause minimum distortion/ aberration / errors. It is always wise to go for the best available lens for your camera.
3. It is always wise to go for a lens which has a suitable diameter for ones flash system (external macro like ring or dual point flash) rather than be worried about premium or non-premium because one cannot compromise on using an adapter which is extremely easy to loose. For example if the (external macro) flash fits on a lens of diameter 58 mm and one has a lens of 67 mm diameter then one MUST use a step down adapter if they would like to use flash. It is impossible to use a flash on this lens otherwise. In other words without the adapter it is impossible to use the flash system on the lens of a wrong diameter. Now the flash systems have a FIXED diameter to be mounted on. Lenses with different diameters are available. Hence always select the lens based on the flash dimensions and not vice versa.
(The above flash system clearly states that it is meant for a lens having a diameter of 58 mm. It is always best to have a lens of the same diameter to avoid disappointment. In case of canon there are 2 100 mm macro lenses. One is the premium L series lens with a diameter of 67 mm One without IS which is of a diameter of 58 mm It is best to stick to 58 mm diameter lens so that we do not have to purchase a separate step down adapter for the flash because using a step down adapter is highly inconvenient.)
4. Lastly NEVER invest on a third party lens (Lens make of some other company rather than the same company as my camera) This is because when one shifts from the camera company to other company many features of the lens and the camera are not available for use, meaning that we are not using the lens or the camera to its full capacity!
We have been lecturing since more than 2 years in various parts of the globe.
We found out that most of the dentists do not know how to decide on which camera to buy for dental photography and hence we have come up with this free PDF called WHICH IS THE BEST CAMERA FOR DENTAL PHOTOGRAPHY?
The article was really appreciated by most of our colleagues in various parts of the world.
If you have any suggestions or additions kindly mail us on firstname.lastname@example.org
We hope that you will like this PDF. Your feedback is invaluable to us.
FREE DOWNLOAD: PDF of best camera for dental photography
This question has been there since a long time and we have decided to
bust a couple of myths and misconceptions.
There is NO doubt that DSLR cameras will always remain the GOLD standard in Dental Photography
for many more years to come… The following FREE article will tell you why. You can download the article for FREE and you may also share it with your friends. Please feel free to write to use on email@example.com if you have some suggestions/ comments for us.
All efforts made in photographic documentation of cases in dentistry loose their value if the images captured don’t match the ones taken at prior appointments.
This is where standardization comes to the rescue. Standardization is the art of MAKING images for a case. Its involoves standardizing everything right from equipment, to patient position, posture, appearance, composition of the image and finally the camera and flash setings.
In this part I will work u through the standardization of equipments.
Standardization of Equipment includes:
1. CAMERA- any entry level camera (dslr) is good. It is a wise decision to invest more on a great flash system as compared to the camera because light is the most important aspect of dental photography.
2. LENS – a 100mm macro lens is IDEAL for dental photography. These lenses allow the dentist to maintain a respectable distance from the patient even at a magnification of 1:1.
Other options are 85mm, 90mm and 105mm.
P.S. : 18-105mm, 75-300mm etc. Also have a 100mm focal length within their range but these are NOT macro lenses and hold NO usage in dentistry.
3. FLASH SYSTEM- a dual point flash system “MT24EX” by Canon is the most ideal for dental photography. This system standardizes not just the movement of both the flashes in all 3 axes but also the power output. The most important feature however is the presence of an external contant source of light.
4. TRIPOD for extra oral photography- it ensures that the camera is exactly at the eye level making verification very easy and minimizes subtle angular changes made by the dentist will he holds the camera.
5.BACKGROUND- always use a white background for extra oral photography. A Slave flash kept behind the patient ensures that the final image has NO SHADOWS on the white background because of the master flash on the camera.
A white background easily sets off the patient and makes important anatomical landmarks stand out making it the best choice for backgrounds.
6. RETRACTION AND CONTRASTORS –
Always use transparent retractors for retraction also use of half retractors may be better for certain shots. Retraction should always be laterally and forward and not backward. Finally use of black contractors where ever possible provides an excellent background.
More insights into standardization coming up in the following sections… Till then HAPPY CLICKING!
When a dentist is sharing his cases with his colleagues / students or patients the series of images of a particular case need to look identical and uniform in composition.
The advantages of well composed images are far more greater than poorly composed images.
Furthermore if images of a single subject, when taken at different times, look different and are shot from different angles and at different settings the impact is much lesser and the audience finds it very confusing, difficult to relate to and uninteresting. There is loss of detail and co relating between the before and after images becomes a nightmare.
When the images are uniformly composed, well lit in similar (or same) settings, relating to the images and the situation becomes much more authentic and understandable.
The audience finds it very easy to understand and accept the changes or whatever the dentist is trying to show.
It is however not a child’s play to get the composition uniformly correct all the times because the dentist / dental assistant (anyone who is taking images) has to face long intervals in between the shots.
These intervals can be in hours/ days, weeks, months or even years!!!
So it is always best that before starting the shoot the dentist takes a look at the earlier images first and goes through the METADATA (EXIF) (file information after right clicking on the image)
What is more important is that the images need to be shot with the same equipment that were used at the start of the case and use the same settings as far as possible.
The dentist needs to maintain the patient position and camera position constant for all the shoots (be it intra or extra oral)
The following details might help every dentist / dental ceramist to achieve uniformly composed image:
1) Constant background(E.g. appropriate use of contrastors)
2) Angle of shooting
3) Good uniform retraction (Retraction has to be outward and laterally)
4) Avoiding saliva/blood/ GCF at all times. (Use a good high vac suction)
5) MAGNIFICATION(biggest factor) (In our course we teach 4 magnifications which a dentist typically uses to do all the dental photography. it is a major topic and has to be discussed separately)
6) Uniform cropping (cropping done in the camera maker software is the best because it helps you with a GRID which will guide a dentist to crop accurately)
7) Preferably keep the main tooth/area in the center(This is because this allows for maximum cropping in case there is a mistake with respect to composition)
8) Always notice the other teeth / landmarks
(For instance if its a midline anterior shot at 1:1 magnification then how many teeth are seen?
If the before image shows 2 centrals and half laterals on both sides then this frame has to be accurately repeated and the post-operative image should also show 2 centrals and half laterals on the sides.
It can also happen that 2 centrals ARE visible and the dentist might think that the purpose is solved because the work was only in the centrals like diastema closure, but the post-operative picture instead of showing 2 half laterals is showing 1 full lateral of one side!!!
In the latter case the composition is unacceptable and a lot of data with respect to the work is lost and not recorded.)
9) Another important and hugely neglected part about composition is that a dentist should never lose a sense of orientation which frequently happens and is evident in the shots.
Parallelism has to be maintained between the guiding lines and the viewfinder.
If this is lost then we will be able to see a “CANT” in the images which is visually very disturbing.
Always keep your frame in such a way that the ridge or the teeth are parallel to the viewfinder (either lengthwise or breadth wise)
10) Lastly whenever a Shade guide is to be used the incisal edge of the guide tooth has to align with the incisal edge of the natural tooth. Always wet the surface of the teeth slightly before shade matching.
Insist on taking 2 shots for shade matching (one at picture style NEUTRAL and the other at picture style MONOCHROMATIC which is for appreciating the VALUE of the tooth)
(I always use Microsoft PowerPoint to make composite images like the one on top because i have made pre-set templates for use by adding shapes and keeping it ready mostly of course as you can see i insert a rectangle and i place my images on the pre-set rectangles.
I find Microsoft PowerPoint extremely easy to use as compared to more sophisticated software’s like photoshop)
Back to Basics: which is the best camera for dental photography?
Which is the best camera for dental photography is a question that still remains unanswered for millions of dentists world-wide. This particular blog aims to reduce the confusion amongst the minds of the dentists and help them choose a camera for dental photography.
Let’s begin with what we should expect from an Ideal camera for dental photography…
Listed below are the expectations from an ideal camera for dental photography and on the right hand side a few popular camera types. For every point on the left marks have been given under each camera type on a scale of 1 to 5 depending upon how much they hold true to that particular point.
It is extremely clear from the figures above that a DSLR camera has no real competition when it comes to serious dental photography.
A bridge camera is not for serious photographers while sub-compact (point and shoot) and mobile phone camera come under least preferred category of usage.
Let me share a note from Wikipedia over here…
“A point-and-shoot camera is a still camera designed primarily for simple operation. They are popular with people who do not consider themselves photographers but want an easy to use camera for snapshots of vacations, parties, reunions and other events. Point-and-shoot camera sales declined after about 2010 as smartphones overtook them in such uses.”
About DSLR (Digital Single lens reflex) Camera:
DSLR Cameras are increasingly becoming a type of camera that is in the reach of the average photographer as prices fall and as manufacturers develop more user friendly models.
DSLR stands for “Digital Single Lens Reflex”. In simple language, DSLR is a digital camera that uses mirrors to direct light from the lens to the viewfinder, which is a hole on the back of the camera that you look through to see what you are taking a picture of.
When you look through the viewfinder on the back of the camera, whatever you see is exactly what you are going to get in the photograph. The scene that you are taking a picture of passes through the lens in a form of light into a reflex mirror (#2) that sits at a 45 degree angle inside the camera chamber, which then forwards the light vertically to an optical element called a “pentaprism” (#7). The pentaprism then converts the vertical light to horizontal by redirecting the light through two separate mirrors, right into the viewfinder (#8).
When you take a picture, the reflex mirror (#2) swings upwards, blocking the vertical pathway and letting the light directly through. Then, the shutter (#3) opens up and the light reaches the image sensor (#4). The shutter (#3) remains open for as long as needed for the image sensor (#4) to record the image, then the shutter (#3) closes and the reflex mirror (#2) drops back to the 45 degree angle to continue redirecting the light into the viewfinder.
Conclusion: If you require a true distortion free image for your dental practise with wide variety of settings and good flash and lens attachment options always insist on a DSLR.
Pioneers of Dental Photography Training and Research In India