Ideal technique of shade matching, recording, processing and communicating in dentistry and dental photography

Ideal technique of shade matching, recording, processing and communicating in dentistry and dental photography

No matter how hard we try it is extremely difficult to capture the true colors of teeth as we see them ( as per the technology available today – NO CAMERA of the world is capable of recording true colors and that to consistently)

■Even the best cameras can go wrong
■Despite using fully manual settings colors might show some alterations in pictures taken at different times'

The way out? 

18% GREY CARDS

■The only way to record colors consistently or at least reduce the errors in recording colors is by
■USING A GREY CARD
■DOING COLOR CORRECTION (in a software) to remove any faulty color casts that occur due to flash light, angle, exposure settings, white balance settings etc.

What is a Grey Card?

■Its is a simple card which is grey in color but manufactured using a very high Quality Control protocols and printed using the best technology available
■It is used by some of the best professional photographers of the world during commercial shoots where colors hold prime importance
■It is essentially 18 % GREY
■Dental Photography grey cards are usually credit card size and autoclaveable
■They last for a life time
■The almost never loose color if maintained and preserved cautiously

Logic behind a grey Card

■All cameras meter in a manner to achieve MID TONES
■This mid tone is essentially neither too white nor to black
■This is the aim of metering for every camera – to achieve a balance between not too white and not too black
■Now neither too white or neither too black is essentially GREY
■This means every camera sees in GREY during metering or aims at achieving a neutral 18 % grey 

How does a grey card fit in for shade match in dentistry?

■When we do shade matching we keep an 18 % grey card within the confines of the image we are composing
■Essentially what we are doing by this is that … we are ready to tell our image processing software that in the image we have an area which is 18 % grey

When we import this in image processing software like Adobe Camera RAW

This is how it works and removes any color cast

■As you can appreciate in the after image … there is a HUGE difference in the tooth color after color correction
■This technique can be applied during lab communication by dentist or by lab as well
■During Composite buildups
■And other aesthetic procedures as well
■Note that the images which were opened in ACR (Adobe camera RAW) were RAW files which are way more accurate than a JGEG/ JPG file hence color corrections are more accurate
■Software like Picasa must be avoided

Can this technique be used for mobile phone images? mobile dental photography?

■Yes although mobile phone images are least accurate this technique still works …. All you need is an authentic 18% grey card (available with www.dentalphotographyschool.in, dentalphotographyschool@gmail.com )
■Jpeg/ jpg images can be corrected with this technique
■It is a very simple technique and can be done by labs , ceramists and assistants as well. 

CARE HAS TO BE TAKEN that light does not get reflected from the grey card back onto the camera … if this happens the card will appear silver and not grey. Keeping the card at an angle to the lens would be a good technique to avoid this mistake

Equipment used for this write up

■Canon 6 D DSLR

■100 mm 2.8 macro IS lens

■67 – 58 step down adapter

■MT 24 EX Twin Flash

■Standard diffusers for flash

■18 % Grey Card

HOPE THIS ARTICLE HELPS THE DENTISTS AND ALL DENTAL PROFESSIONALS ACROSS THE GLOBE TO DO BETTER DENTAL PHOTOGRAPHY AND DOCUMENTATION. FOR MORE SUCH ARTICLES YOU MAY VISIT WWW.DENTALPHOTOGRAPHYSCHOOL.IN OR WRITE TO US ON THE ABOVE ADDRESS OR CALL US ON  +91 99204 20317


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