PHOTOGRAPHY TIPS
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The Goal
Now generally understood to mean digital photography - in "shade-matching" is to provide the dental lab with additional visual information for them to use in the making of high-quality prosthetics. On the surface, this sounds simple enough, but in practice it is the source of some confusion and frustration. The Problem
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The Solution
B. Achieves a much higher level of color quality due to the larger and more sophisticated sensors.
C. Allows for greater image sharpness and when used with a macro-lense, creates superb "depth of field".
2. Use a twin light (or "point source") flash - instead of a traditional "ring flash".
A. Ringflash - Is where the light source is directly on the lens axis, produces an obvious reflection on the central anteriors, which not only wipes out a lot of color information, but also minimizes the capture of surface texture and subtle opalescence.
B. Traditional Flash - When the light sources are removed off-axis a few inches, greatly reduce these problems and can still be used for the full course of intraoral photography. Good cameras to use:
- Canon MT24 Twilight
- Nikon R1 Speedlight
- Use a true macro lense - the higher the quality, the better.
- Stay away from using "close-focus" zoom lenses, and although there are some excellent after-market lenses, generally sticking to the Cannon or Nikon macro lenses (100MM & 105MM) is a safe bet and good investment.
- Use a digital SLR camera - The most common misperception is that an inexpensive"point-and-shoot" camera will be easier to use, and therefore less prone to error.
B. Achieves a much higher level of color quality due to the larger and more sophisticated sensors.
C. Allows for greater image sharpness and when used with a macro-lense, creates superb "depth of field".
2. Use a twin light (or "point source") flash - instead of a traditional "ring flash".
A. Ringflash - Is where the light source is directly on the lens axis, produces an obvious reflection on the central anteriors, which not only wipes out a lot of color information, but also minimizes the capture of surface texture and subtle opalescence.
B. Traditional Flash - When the light sources are removed off-axis a few inches, greatly reduce these problems and can still be used for the full course of intraoral photography. Good cameras to use:
- Canon MT24 Twilight
- Nikon R1 Speedlight
- Use a true macro lense - the higher the quality, the better.
- Stay away from using "close-focus" zoom lenses, and although there are some excellent after-market lenses, generally sticking to the Cannon or Nikon macro lenses (100MM & 105MM) is a safe bet and good investment.
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Camera Settings
1. Set the camera on manual (which will allow you to) 2. Set the camera to a fast shutter speed (1/200th of a sec.) 3. Set the aperture to f/32 (some macro lenses may only go to f/22) - This is where you will obtain consistently maximum depth of field. 4. Set ISO to 100 A. The lowest ISO will give you the best color. B. Higher ISO will increase the exposure sensitivity, but do so at the expense of color quality and "noise". 5. Set the white balance to automatic (AWB on most cameras) A. Most other color pre-sets usually add color to compensate for the variations from "daylight balance in the shooting environment. B. Flashes vary, and cameras can vary, so you lab will generally have an easier time color-correcting from the more neutral value of the AWB setting. C. Trying to set a "custom-balance" can be tricky and create errors. Doing it incorrectly causes more problems than not doing it at all. |
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6. Set the flash on it's TTL setting.
7. Make the flash do all the work. It will automatically and accurately adjust its output as you move closer or further away to frame your shot.
8. Making micro-adjustments in the flash's output is easily done on the flash control unit; slight exposure adjustments can just as easily be made on most cameras too, without changing the overall settings.
9. Auto-focus or manual-focus: it is up to you. I personally find it easier to set the lens to manually focus when I'm making intraoral photos, but others find it just as easy to use auto-focus
10. Communicate closely with your lab! They may want you to place a gray-black-white tab in the shot along with the dental shade tab. They may prefer working with raw files.
7. Make the flash do all the work. It will automatically and accurately adjust its output as you move closer or further away to frame your shot.
8. Making micro-adjustments in the flash's output is easily done on the flash control unit; slight exposure adjustments can just as easily be made on most cameras too, without changing the overall settings.
9. Auto-focus or manual-focus: it is up to you. I personally find it easier to set the lens to manually focus when I'm making intraoral photos, but others find it just as easy to use auto-focus
10. Communicate closely with your lab! They may want you to place a gray-black-white tab in the shot along with the dental shade tab. They may prefer working with raw files.
The Bottom Line
The best shade-matching technique is a close working relationship with your dental lab. These thumb-nail guidelines should get you started in the right direction. We provide digital photography training to dentists all across the country, and we get more requests for help with shade-matching than anything else. Our goal, and it should be yours too, is to make this process simple and repeatable. Your lab will thank you.
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Dave Hutt
Founding partner, DMD, Digital Dental Photography Training / Workshops Coordinator dhutt@dmddigitalphoto.com 503-449-0662 www.dmddigitalphoto.com |
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