What lens should I use for extraoral photography

I’m a dental student and I’m starting to get more serious about documenting my cases. I want to take really good extraoral photos – you know, portraits and profile shots of patients, smiling and resting face, etc. – that are clear, well-lit, and show detail without being too distorted. I need them for case presentations, publications, and maybe even eventually for my own website.

I’m using a Canon EOS Rebel T7, which I got a decent deal on when I started school. Right now I’m mostly just using the kit lens (18-55mm) and the quality is… okay. It definitely feels limiting, especially for portraits. I’m having trouble getting the background blurred nicely (bokeh) and the images feel a little soft overall. I’m also finding I need to stand really far back sometimes, which is awkward in our clinic setup.

Budget-wise, I’d prefer to stay under $500 if possible. Used lenses are totally fine. I’m also not really sure what focal length is best. I’ve heard 50mm is good for portraits, but I’ve also seen people recommend longer lenses like 85mm or even 100mm. Which would be best for dental extraoral photography specifically? Are there any specific lenses for Canon that you’d recommend, considering my camera and budget? I also need to consider working distance, because I’m often in a small operatory and need to be able to move around the patient somewhat easily. So, what lenses are best, considering these constraints?

Answer

The best lens for extraoral photography depends on the specific goals of the images, the type of camera you have, and the environment you’re shooting in. However, some lenses are generally more suitable than others for achieving optimal results in dental extraoral photography. Here’s a detailed breakdown of lens considerations:

Focal Length:

• Mid-range Telephoto (85mm to 135mm): This range is often considered ideal for portrait-style extraoral photography. It offers a good balance between working distance and subject magnification.

  • Advantages:
    • Provides a flattering perspective by compressing facial features, minimizing distortion, and creating a more natural look.
    • Allows you to maintain a comfortable distance from the patient, which is crucial for both patient comfort and capturing natural expressions.
    • Can produce a shallow depth of field when used with a wide aperture, effectively blurring the background and isolating the subject.
  • Considerations:
    • May require more space to work in, especially at the longer end of the range (135mm).
    • Image stabilization can be beneficial, particularly at longer focal lengths, to prevent camera shake.

• Standard Zoom Lenses (e.g., 24-70mm, 24-105mm): These can be versatile options, particularly if you need to capture a range of shots from full-face portraits to slightly wider views.

  • Advantages:
    • Offer flexibility in framing and composition.
    • Can be a good "all-in-one" solution if you don’t want to switch lenses frequently.
  • Considerations:
    • May not provide the same flattering perspective as a dedicated mid-range telephoto lens for close-up portraits.
    • Image quality may be slightly lower than prime lenses (lenses with a fixed focal length).

• Macro Lenses (e.g., 100mm, 105mm): While primarily designed for close-up and macro photography, some macro lenses can also function well for portraiture.

  • Advantages:
    • Exceptional sharpness and detail rendition.
    • Can be used for both extraoral and intraoral photography, making them a versatile investment.
  • Considerations:
    • Can be more expensive than other lenses.
    • May be too sharp for some portrait applications, potentially emphasizing skin imperfections.
• Wider Angle Lenses (e.g., 35mm, 50mm): These are generally not recommended for close-up extraoral portraits as they can distort facial features. They are more suitable for environmental portraits where you want to show the patient in their surroundings.

Aperture:

• Wide Aperture (e.g., f/1.4, f/1.8, f/2.8): A wide aperture is crucial for creating a shallow depth of field, which blurs the background and isolates the subject. It also allows more light to enter the lens, which can be helpful in low-light situations.

  • Advantages:
    • Creates a pleasing bokeh (background blur).
    • Allows for faster shutter speeds, reducing the risk of motion blur.
  • Considerations:
    • The depth of field can be very shallow at wide apertures, so careful focusing is essential.

Other Considerations:

• Image Stabilization (IS) or Vibration Reduction (VR): This technology helps to reduce camera shake, resulting in sharper images, especially when shooting handheld or in low-light conditions. It’s highly recommended for longer focal lengths.
• Lens Quality: Invest in a high-quality lens from a reputable manufacturer. Better quality lenses generally produce sharper, more detailed images with less distortion.
• Autofocus Performance: A fast and accurate autofocus system is essential for capturing sharp images of moving subjects.
• Budget: Lens prices can vary significantly. Determine your budget and look for the best lens that fits within your price range.
• Sensor Size (Crop Factor): If you’re using a camera with a cropped sensor (APS-C), the effective focal length of your lens will be different than on a full-frame camera. For example, an 85mm lens on an APS-C camera with a 1.5x crop factor will have an effective focal length of 127.5mm. This needs to be taken into account when choosing a lens.

Recommendations:

• For general extraoral portraiture: An 85mm f/1.8 lens is a popular and affordable choice for full frame cameras. If you have a cropped sensor camera, consider a 50mm f/1.8 lens.
• For versatility: A 24-70mm f/2.8 or 24-105mm f/4 lens can be a good option, but be mindful of potential distortion at the wider end.
• For high-quality images and potential intraoral use: A 100mm or 105mm macro lens can be an excellent choice.

It’s best to try out a few different lenses before making a final decision to see which one works best for your individual needs and preferences. Renting lenses can be a good way to test them out without making a large investment.