1. Focal Length (The Viewing Angle and Compression):
* 35mm:
* Pros: Versatile, good for environmental portraits showing the subject in their surroundings, works well in tight spaces.
* Cons: Can distort facial features slightly, not the most flattering for close-up portraits.
* Best For: Photojournalistic portraits, lifestyle portraits, when context and environment are important.
* 50mm:
* Pros: Close to the natural human perspective, good for both full-body and head-and-shoulder shots, often relatively inexpensive.
* Cons: May need to move around to get the desired composition, not always ideal for tight headshots.
* Best For: General-purpose portraits, beginners, a good starting point to understand portraiture.
* 85mm:
* Pros: Classic portrait focal length, excellent for isolating the subject and creating background blur (bokeh), minimizes distortion. Very flattering for most faces.
* Cons: Requires more distance from the subject, less versatile for tight spaces, can sometimes feel restrictive.
* Best For: Close-up portraits, headshots, when background blur is desired, emphasizing facial features.
* 100mm - 135mm:
* Pros: Strong compression effect, beautiful bokeh, allows for comfortable working distance, minimizes distortion even further.
* Cons: Requires even more space, can make communication with the subject slightly more challenging.
* Best For: Formal portraits, outdoor portraits, weddings, situations where you need distance from the subject.
* 70-200mm (Zoom):
* Pros: Flexible focal length, can adapt to different situations without changing lenses, good for events and candid portraits. Often has great image quality.
* Cons: Can be heavy and expensive, may not be as sharp as prime lenses, can be intimidating to subjects.
* Best For: Events, weddings, sports portraits, situations where flexibility is paramount.
Key Takeaways about Focal Length:
* Shorter Focal Lengths (35mm-50mm): Wider view, more context, potential distortion.
* Longer Focal Lengths (85mm+): Narrower view, more compression, more background blur, less distortion.
2. Aperture (The Amount of Light and Depth of Field):
* Wide Aperture (e.g., f/1.2, f/1.4, f/1.8, f/2.8):
* Pros: Allows more light in (better for low light), creates shallow depth of field for beautiful background blur (bokeh), isolates the subject.
* Cons: Requires more precise focusing, very shallow depth of field can be challenging to work with (especially with movement), more expensive lenses.
* Best For: Isolating the subject, creating a dreamy look, low-light portraits.
* Narrower Aperture (e.g., f/4, f/5.6, f/8):
* Pros: More depth of field (more of the image in focus), easier to nail focus, can be useful for group portraits or environmental portraits where you want more of the scene sharp.
* Cons: Less background blur, requires more light, can make the subject blend more with the background.
* Best For: Group portraits, environmental portraits, situations where you want more of the scene in focus.
Key Takeaways about Aperture:
* Wider Aperture (smaller f-number): More light, shallower depth of field.
* Narrower Aperture (larger f-number): Less light, greater depth of field.
3. Lens Quality (Sharpness, Contrast, Distortion, Aberrations):
* Sharpness: How well the lens resolves fine details. Look for reviews that discuss sharpness, especially at different apertures.
* Contrast: The difference between the brightest and darkest parts of the image. Good contrast adds to the overall clarity and punch.
* Distortion: Curvature of straight lines in the image. Can be barrel distortion (lines bulge outwards) or pincushion distortion (lines are pulled inwards). Longer lenses are less prone to distortion.
* Chromatic Aberration (CA): Color fringing, usually seen as purple or green edges around high-contrast areas. Better lenses minimize CA.
* Vignetting: Darkening of the corners of the image. Often correctable in post-processing.
* Bokeh: The aesthetic quality of the blur. Some lenses have smoother, creamier bokeh than others.
4. Autofocus Performance:
* Speed: How quickly the lens focuses. Important for portraits of children, pets, or subjects in motion.
* Accuracy: How reliably the lens focuses on the intended target.
* Quietness: How noisy the autofocus motor is. Important for video work.
5. Your Budget:
* Portrait lenses range from a few hundred dollars to several thousand. Consider your budget and how much you're willing to invest. Often, used lenses are a great value.
6. Camera System (Mount):
* Ensure the lens is compatible with your camera's mount (e.g., Canon EF, Nikon F, Sony E, Fujifilm X).
7. Image Stabilization (IS/VR):
* Not essential for portraiture (especially with faster lenses), but can be helpful in low light when shooting handheld. More important for longer focal lengths.
8. Weather Sealing:
* Consider weather sealing if you plan to shoot outdoors in challenging conditions.
Recommendations based on budget and common needs:
* Budget-Friendly:
* 50mm f/1.8: An excellent starting point for beginners on any system.
* 85mm f/1.8: Great value for a dedicated portrait lens.
* Mid-Range:
* 35mm f/1.4: Versatile for environmental portraits.
* 85mm f/1.4: A step up in quality and bokeh from the f/1.8 version.
* 70-200mm f/2.8: A workhorse zoom lens for various situations, including portraits.
* High-End:
* 85mm f/1.2 (or equivalent): The ultimate portrait lens for maximum bokeh and sharpness. Expensive but worth it if you're serious about portraiture.
How to Decide:
1. Identify your style: Do you prefer environmental portraits, close-ups, or something in between?
2. Consider your shooting environment: Do you shoot mostly indoors or outdoors? Do you have a lot of space or work in tight quarters?
3. Rent lenses: If possible, rent a few different focal lengths and apertures to try them out before you buy. This is the best way to determine what works best for you.
4. Read reviews: Research lenses online and read reviews from other photographers. Pay attention to sharpness, bokeh, autofocus performance, and any other features that are important to you.
5. Test the lenses you are considering: Try the lenses in the store and see how they feel. Make sure they are a good fit for your hands and your shooting style.
6. Don't overspend: A great photographer can take stunning portraits with relatively inexpensive equipment. Focus on improving your skills and understanding of light and composition.
Ultimately, the best portrait lens is the one that helps you create the images you envision. Experiment, learn, and have fun!