1. Subject Distance:
* Closer Subject Distance: Requires a smaller dish.
* Further Subject Distance: Requires a larger dish.
2. Desired Softness/Hardness of Light:
* Softer Light: A larger dish creates a softer light with more gradual falloff and softer shadows.
* Harder Light: A smaller dish creates a harder light with more defined shadows and a more contrasty look.
3. Working Space:
* Small Studio/Limited Space: A smaller dish is easier to manage and maneuver.
* Larger Studio/Ample Space: You have more freedom to use larger dishes.
4. Subject Size:
* Headshots/Close-ups: Smaller dishes are typically preferred.
* Half-body/Full-body Portraits: Larger dishes are better suited.
General Guidelines:
* 22" (56cm) Beauty Dish:
* Good for: Headshots, close-up portraits, beauty shots.
* Pros: Portable, easier to handle, provides a slightly harder and more contrasty light, good for emphasizing skin texture.
* Cons: Can be too small for full-body portraits, requires precise placement, harsher falloff.
* 27-28" (68-71cm) Beauty Dish:
* Good for: Versatile size, suitable for headshots, half-body portraits, and even some full-body shots. A good "general purpose" size.
* Pros: Balances softness and contrast, more forgiving in placement than smaller dishes, works well for a variety of portrait types.
* Cons: Not ideal for very soft, diffused light, not as portable as smaller sizes.
* 32" (81cm) or Larger Beauty Dish:
* Good for: Half-body and full-body portraits, larger groups, fashion photography.
* Pros: Produces softer, more flattering light, larger coverage area, good for blurring imperfections.
* Cons: Less portable, requires more space, can be too soft for some tastes, may require higher power output from your strobe.
In summary:
* Smaller (22"): Ideal for adding detail and a slight edge to headshots. Think editorial, slightly harsher lighting.
* Medium (27-28"): The most versatile. A good starting point if you're unsure.
* Larger (32"+): Best for softer, more flattering light, and larger subjects.
Other Considerations:
* Grid: A grid can be added to any size beauty dish to control the light spill and create a more focused beam. This can be particularly useful with larger dishes.
* Diffusion Sock: Using a diffusion sock will soften the light even further, mimicking a softbox.
* Color of the Dish (White vs. Silver):
* White: Produces a softer, more even light.
* Silver: Produces a brighter, more specular light with higher contrast. (More commonly used.)
* Budget: Prices increase with size and brand quality.
Recommendation:
If you're just starting out, a 27-28" beauty dish is a great all-around option. It's versatile enough to handle a variety of portrait types and allows you to experiment with different lighting styles. Once you're comfortable with it, you can then decide if you need a smaller or larger dish to achieve specific looks.
Experiment! The best way to determine the right size is to experiment with different dishes and see what works best for your style and subject matter. Consider renting different sizes to try them out before making a purchase.