Guides · Clinical photography
Shade photography for the lab
A shade written as "A2" is a guess the technician has to trust. A shade photo shows them the tooth. Here is how to take one they can match.
1. Take it first, before anything dries the tooth
Teeth lighten as they dehydrate. Rubber dam, cotton rolls, air and even a long open-mouth appointment make enamel look whiter and more opaque within minutes, and it takes a long time to recover. So take the shade and the shade photo at the start of the appointment, before preparation or isolation.
2. Prepare the mouth and the light
- Ask the patient to remove lipstick, and cover bright clothing with a neutral bib.
- Turn the dental light away. Use daylight-balanced light (around 5,500 K): a dental photography LED, or indirect daylight from a window. Avoid the phone flash.
- Put a neutral grey or black background (a contraster) behind the teeth if you have one. It stops the lips and tongue from colouring how the shade reads.
- Keep the teeth moist, not dry and not dripping.
3. Hold the tab the right way
- Pick two or three candidate tabs, not one. The lab needs to see which way the tooth differs from each.
- Hold each tab edge to edge with the tooth (incisal edge to incisal edge), in the same plane, so both get the same light.
- Keep the tab's label in the frame, so the photo says which tab it is.
- Shoot square to the tooth, at the tooth's level, with the 2× or 3× lens from a short distance. Up close at 1× distorts and darkens the edges.
- Lock focus and exposure on the tooth, then lower exposure slightly so the incisal translucency isn't washed out.
4. The photos to send
| Shot | Why the lab wants it |
|---|---|
| Tooth with 2–3 tabs | The main comparison, with the labels readable. |
| Same shot in black and white | Shows value alone. Convert a copy with the phone's mono filter; don't take a new photo. |
| Cross-polarised (if you have the filter) | Removes the shine from wet enamel so the internal colours, translucency and white spots show. |
| With a grey card | An 18% grey reference lets the technician correct the white balance of your phone's photo. |
| Neighbouring teeth, retracted | The crown has to match the teeth next to it, not just the tab. |
5. Look the way a technician looks
- Compare in short looks of a few seconds. The eye adapts and stops seeing differences if you stare.
- Rest your eyes on a neutral grey or blue surface between looks.
- Check at the patient's eye level, not from above.
- Write down what the photo can't show: characterisation, cracks, white spots, translucent incisal edge.
6. Send it without losing the colour
WhatsApp and most chat apps compress photos and shift their colour. Send shade photos as a document or file, or from your case app, together with the written shade, the tooth number and the lab order.
How OnlyTeeth helps
OnlyTeeth puts the shade tab beside the tooth in the camera guide, and files the shade photos under the case with everything else. When you make a lab order in OnlyTeeth, the shade and the shade photo go with it as a PDF, in English or Arabic. The camera and shade guides are part of the free plan; lab orders are part of Premium.
Questions
Can a phone photo replace a shade guide?
No. The photo goes with the shade you chose by eye, it doesn't replace it. Phone cameras adjust colour on their own, which is why the tab, the grey card and the black-and-white copy matter.
Why did my crown come back too white?
Usually because the shade was taken after the tooth dried out, under the dental light, or from a photo the chat app compressed. Take it first, in daylight-balanced light, and send it as a file.
Do I need a polarising filter?
It helps for anterior crowns and veneers, where translucency matters. For most posterior work, tab photos plus a black-and-white copy are enough.
More guides: Intraoral photography with a phone · Keeping a dental case log · Tracking your requirements