লেন্স টার্মিনোলজি

ক্যামেরার জন্য লেন্স পছন্দ করতে গেলে প্রথমেই একটু হয়তো খটকা লাগে এর গায়ে লেখা বিভিন্ন অক্ষর আর সংখ্যা দেখে। কিছু হয়তো এমনিতেই বোঝা যায়, আবার কিছু হয়তো অবোধ্যই থেকে যায়। এই সমস্যা বেশী হয় একদম নতুনদের বেলায়। আমারও হয়েছিলো যখন প্রথম ডিএসএলআর কিনি। সাথে একটা কিট লেন্স ছিলো, গোল বাঁধলো পরবর্তী লেন্স কেনার সময়। নাইকন লেন্সে আবার ফোকাস মোটর নিয়ে একটা ঝামেলা আছে। সব লেন্সে আবার এই ফোকাস মোটর নেই। ফলে কম দামী ক্যামেরা বডিতে (ডি৩xxx এবং ডি৫xxx সিরিজ) ফোকাস মোটর না থাকায় সব লেন্সে থেকে অটো ফোকাস সূবিধা পাওয়া যায় না। আমি তাই ইয়াহু গ্রুপে এ ব্যাপারে একটা প্রশ্ন রেখেছিলাম। অনেকেই উত্তর দিয়েছিলেন, তবে আমি বেশ অবাক হয়েছিলাম Ken Rockwell উত্তর দিয়েছেন দেখে। তিনি বেশ ভালো করেই বুঝিয়ে বলেছিলেন বিষয়টি, সেই সাথে কিছু লিংকও দিয়েছিলেন। আজ আপনাদের জন্য মোটামুটি পরিচিত ব্র্যান্ড এর যেসব লেন্স প্রচলিত আছে, তাদের সেই সব অবোধ্য সংখ্যা আর অক্ষরের মানে কি সেগুলোই তুলে ধরছি। সাথে কিছু লিংকও দেয়ার চেষ্টা করছি। আশা করি আপনাদের কাজে লাগবে।

Canon Lenses

Canon lenses use the following terms to indicate features of each lens:

  • Common
    • XYZmm: Focal length
    • f/x.y: Maximum aperture (or f/a.b-c.d for variable aperture zooms)
  • Focus/Mount Type
    • EF: Electronic Focus
    • EF-S: Short-Back Electronic Focus
    • EF-M: Mirrorless Electronic Focus
    • TS: Tilt-Shift
      • TS-E: Tilt-Shift, Electronic aperture control
    • MP-E: Macro-Photography, Electronic aperture control
  • Features
    • IS: Image Stabilization
    • USM: Auto Focus Type: Ultrasonic Motor
    • STM: Auto Focus Type: Stepping Motor
    • (Mark) N: Version of lens (Mark II = v2, Mark III = v3, etc., word Mark may not be present)
    • DO: Diffractive Optics
    • L: Luxury series
    • Macro: close focusing, but not necessarily 1:1 magnification
    • Softfocus ability to use soft focusing for smooth dreamy look
    • PF Power Focus

Examples

  • Canon EF 16-35mm f/2.8 L II USM Lens
  • Canon EF 70-200mm f/2.8 L IS II USM Lens
  • Canon TS-E 17mm f/4 L
  • Canon EF 50mm f/1.2 L USM
  • Canon EF-S 10-22mm f/3.5-4.5 USM

Leica Rangefinder and SLR Lenses

Leica RF and SLR lenses use the following terms to indicate features of each lens:

  • Common
    • XYZmm: Focal length
    • f/x.y: Maximum aperture
  • Lens Mount
    • xxx-R: Lens for the R (35mm SLR) system
    • xxx-M: Lens for the M (rangefinder) system
    • xxx-S: Lens for the S (MF DSLR) system
  • Lens Speed
    • Noctilux: Fastest lenses with max aperture around 1.0
    • Summilux: f/1.4 lens
    • Summicron: f/2 lens
    • Summarit: f/2.4 or f/2.5 lens
    • Elmarit: f/2.8 lens
    • Super Elmar, Elmar, Tele-Elmar: f/3.4+ lens
    • Telyt: f/3.4 telephoto lens
    • Vario-Elmar: Zoom version of Elmar (see above)
  • Features
    • ASPH: Lens with aspherical elements
    • APO: Lens with apochromatic correction

Note: There are sometimes small numbers engraved next to the infinity symbol on the focusing scale. These numbers indicate a difference of the actual focal length of the lens compared to the nominal value in tenths of millimeter. For example, if the number is 14 and the lens is 50mm, the actual focal length is 51.4.


Nikon F-Mount Lenses

Nikon SLR/DSLR lenses use the following terms to indicate features of each lens:

  • Common
    • XYZmm: Focal length
    • f/x.y: Maximum aperture (or f/a.b-c.d for variable aperture zooms)
  • Lens System
    • DX: Digital, Short Back, for 23.6mm x 15.6mm sensor.
    • FX: Full Frame (film or digital), for 36mm x 24mm sensor.
  • Lens Mount
    • AI: Automatic Indexing mount (includes metering sensor)
    • AI-S: Improved Automatic Indexing mount
    • IX: Lenses designed specially for APS film SLR-s; their rear end protrudes too much to allow using them on a 35mm film camera or a dSLR
    • Series E A cheaper series of AI-S where plastic replaced some metal parts. Not designated as Nikkor but “Nikon Lens Series E”
  • Focusing System
    • AF: Auto Focus, built into camera
    • AF-S: Auto-Focus Silent (Silent Wave Motor, required for bodies without focus motor)
    • AF-I: Auto-Focus Internal
    • AF-N: Auto-Focus (improved version, rare)
  • Features
    • Reflex: Catadioptric (mirror) lense.
    • D: Distance, communicates focus distance for 3D Matrix metering mode and also for flash autoexposure. All AF-I, AF-S, and G-type lenses are also D-type. (Indicated after the f-number in the name, sometimes designated as AF-D).
    • SWM: Silent Wave Motor
    • N: Nano-Crystal Coating
    • NIC: Nikon Integrated Coating (multicoated lenses)
    • SIC: Super Integrated Coating (multicoated lenses)
    • VR: Vibration Reduction
    • ED: Extra-low Dispersion Glass
    • FL: Fluorite. Designated a lens with some element in fluorite instead glass.
    • ASP: Aspherical Lens Element
    • IF: Internal Focusing
    • RF: Rear Focusing
    • RD: Rounded diaphragm
    • Micro: Enable high reproduction ratio. Typically at 1:1 or 1:2.
    • G: No aperture ring (automatic aperture only)
    • DC: Defocus Control
    • PC: Perspective Control. Lenses with shift feature (older) and newer with tilt as well.
    • PF: Phase Fresnel Lens Elements. Lenses which provides superior chromatic aberration compensation performance when combined with a normal glass lens.
    • E: Electronic diaphragm. Some lenses with an electronic diaphragm. Only supported by bodies from D3 and after.
    • P: CPU enabled version of AI-S lenses (Sometimes designated as AI-P)

Examples

  • Nikon AF 85mm f/1.8
  • Nikon AF 85mm f/1.8D
  • Nikon AI 500mm f/4.0 P
  • Nikon AF-S DX 16-85mm VR f/3.5-5.6G IF-ED
  • Nikon AF-I 600mm f/4D IF-ED
  • Nikon AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED

Nikon 1 NIKKOR lenses

These lenses are used on Nikon 1-series compact systems cameras. The lenses are marked “Nikon 1 NIKKOR”. Terms used in names are mostly the same as for F-mount.

  • Common
    • XYZmm: Focal length
    • f/x.y: Maximum aperture (or f/a.b-c.d for variable aperture zooms)
  • Lens System
    • CX: For use with 1″ sensor (13.2mm x 18.8mm).
  • Features
    • AW: Water-proof to 15m or 20m.
    • PD-Zoom: Power drive zoom (primarily for movies, no zoom ring, sometimes designated PD)
    • VR: Vibration Reduction.
    • IF: Internal Focus.
    • RF: Rear Focus (or Rapid Focus? Marked on 18.5mm f/1.8 lens which has lightweight/fast AF.)
    • ED: Extra-low Dispersion glass.

The last three terms (IF, RF, ED) are marked on lenses but may not appear in Nikons description of the lens. Many of these lenses incorporate aspherical elements and will be marked “Aspherical”

Examples

  • 1 NIKKOR VR 10-30MM F/3.5-5.6 PD-ZOOM
  • 1 NIKKOR VR 70-300MM F/4.5-5.6
  • 1 NIKKOR AW 10MM F/2.8
  • 1 NIKKOR AW 11-27.5MM F/3.5-5.6
  • 1 NIKKOR VR 10-100MM F/4.0-5.6
  • 1 NIKKOR VR 6.7-13MM F/3.5-5.6
  • 1 NIKKOR 32MM F/1.2
  • 1 NIKKOR 18.5MM F/1.8

Olympus 4/3 lenses

  • Common
    • XYZmm: Focal length
    • 1:x.y: Maximum aperture (or 1:a.b-c.d for variable aperture zooms)
  • Features
    • ED: Extra-low dispersion glass elements
    • SWD: Auto Focus Type: Supersonic Wave Drive Motor
    • N: Version of lens (II = v2, III = v3, etc.)

Panasonic lenses

  • Common
    • XYZmm: Focal length
    • Fx.y: Maximum aperture
  • Mount and Design Type
    • Lumix: Panasonic design
    • Leica: Leica design
    • Lumix G, Leica DG: micro four-thirds mount
    • Leica D: four-thirds mount
  • Leica Nomenclature
    • Vario: Zoom lens
    • Lens Speed (see also Leica Rangefinder and SLR, above)
      • Nocticron: f/1.2
      • Summilux: f/1.4 or f/1.7
  • Features
    • O.I.S: Optical Image Stabilization
    • X: “Pro grade” high-end line
    • ASPH.: Aspherical elements
    • PZ: Power zoom
    • HD: HD video features: tracking silent AF
    • 3D: 3D lens

Examples

  • Panasonic Leica D Vario-Elmar 14-150mm F3.5-5.6 ASPH. MEGA O.I.S.
  • Panasonic Leica D 25mm F1.4
  • Panasonic Leica DG 25mm F1.4
  • Panasonic Lumix G Vario 45-200mm F4-5.6 MEGA O.I.S.
  • Panasonic Lumix G X Vario PZ 14-42mm F3.5-5.6 ASPH O.I.S.

Pentax lenses

  • Common
    • XYZmm: Focal length
    • 1:x.y: Maximum aperture
  • Focus/Mount Type
    • K, M: Manual Focus, Manual/Aperture priority metering
    • 645: Medium Format mount
    • AF: Early AF system with AF motor and electronics in lens that works only with ME-F body.
    • A: Manual Focus, supports Shutter priority and Program exposure metering
    • F: Adds Auto Focus to capabilities of A lenses
    • FA: Adds ability to communicate MTF to body to capabilities of F lenses
    • FAJ: Removes aperture ring from capabilities of FA lenses
    • DA: Same capabilities as FAJ, but with reduced imaging circle for digital cameras with APS-C sized sensor
    • DA L: Same capabilities as DA lenses, Lighter construction
    • D FA: Same capabilities as FA lenses, usable on both film and digital cameras
  • Features
    • AL: Aspherical elements
    • ED: Extra-low dispersion glass elements
    • SMC: Super multi coating lens coating
    • HD: Newer “high grade” multi-layer lens coating
    • PZ: Power Zoom
    • SDM: Auto Focus Type: Supersonic Drive Motor
    • DC: Auto Focus Type: direct current motor
    • IF: Internal focussing
    • WR: Weather Resistant (when matched with weather resistant body)
    • AW: All Weather (again when matched with WR body; it’s unclear how if at all this differs from the above)
    • ★: High performance, including weather and dust sealing
    • Limited: High quality, compact design (primes)
    • Macro: 1:1 magnification
    • XS: Extra slim, even more compact than Limited
    • RE: retractable (compact size in standby mode)
    • SR: Shake Reduction (image stabilization)

Sony/Minolta Lenses

Sony lenses, previously Minolta lenses, have similar features to Nikon and Canon. Their notation is as follows:

  • Common
    • XYZ/x.y: Focal length/Maximum Aperture (or XYZ/a.b-c.d for variable aperture zooms)
  • Lens Mount Type
    • Alpha: α Type Mount
    • E: E Type Mount
  • Focusing System
    • SSM: In-Lens Super-sonic Motor
    • SAM: In-Lens Micro Motor
  • Features
    • G: Gold Series (highest quality)
    • (D): Distance Encoding (supports ADI feature of some Sony bodies)
    • DT: Digital Technology (optimized for digital cameras)
    • APO: Apochromatic correction using AD elements
      • HS-APO: High-Speed APO
    • AD: Anomalous Dispersion
    • OSS: Optical Steady Shot (E-mount only)
    • T*: High-performance Coating
    • M: 1:1 magnification
    • Z: optical engineering by Carl Zeiss
    • STF: smooth transmission focus (apodisation element)

Examples

  • Sony Alpha 70-200/2.8 G
  • Sony Alpha 28-75/2.8 SAM
  • Sony Alpha DT 18-250/3.5-6.3
  • Sony E 18-200/3.5-6.3 OSS
  • Sony Alpha 100/2.8 Macro

Off-Brand Lenses

Many off-brand lens manufacturers make lenses that fit many types of bodies, including Canon, Nikon, etc.

Sigma Lenses

Sigma lenses use the following terms to indicate features of each lens. They differ slightly in how they denote aperture:

  • Common
    • XYZmm: Focal length
    • Fx.y: Maximum aperture (or Fa.b-c.d for variable aperture zooms)
  • Compatible Body Brands
    • Sigma
    • Nikon
    • Canon
    • Minolta/Sony
    • Pentax
    • Kodak (extremely limited)
    • Fujifilm
    • Olympus (limited)
    • Panasonic (very limited)
    • Leica (very limited)
  • Features
    • HSM: Hyper-Sonic Motor
    • ASP: Aspherical lens element
    • APO: Aphochromatic (low-dispersion) lens element
    • A: Art Series
    • OS: Optical Stabilizer
    • RF: Rear focusing
    • IF: Inner focusing
    • CONV: Teleconverter compatible (APO Teleconverter EX), not usually part of the lens name but mentioned in the product description
    • EX: Professional lens body finishing and construction
    • DG: Supports full-frame cameras (newer lenses only, implicit on older models)
    • DC: Supports cropped-frame cameras (lightweight construction, smaller image circle)
    • DN: For mirrorless cameras
    • Macro: close focusing, but not necessarily 1:1 magnification

Examples

  • Sigma 18-250mm f/3.5-6.3 DC OS HSM
  • Sigma 150-500mm f/5-6.3 DG OS HSM
  • Sigma 50mm f/1.4 EX DG HSM
  • Sigma 105mm f/2.8 EX DG Macro

Tamron Lenses

Tamron lenses use the following terms to indicate features of each lens. Tamron offers a considerable degree of functional features and lens types, particularly lens types that affect chromatic aberration:

  • Common
    • XYZmm: Focal length
    • F/x.y: Maximum aperture (or F/a.b-c.d for variable aperture zooms)
    • AF: Auto-Focus
  • Compatible Body Brands
    • Nikon
    • Canon
    • Minolta/Sony
    • Pentax
  • Features
    • Lens Elements
      • XR: Extra Refractive Index Glass (lighter, smaller lenses)
      • LD: Low Dispersion (chromatic aberration reduction)
      • XLD: Extra Low Dispersion (advanced chromatic aberration reduction)
      • ASL: Aspherical (improved focal plane convergence)
      • LAH: LD + ASL hybrid lens element
      • AD: Anomalous Dispersion (improved control over chromatic aberration)
      • ADH: AD + ASL hybrid lens element
      • HID: High Index, High Dispersion Glass (minimizes lateral chromatic aberration)
    • Functional Features
      • VC: Vibration Compensation
      • USD: Ultrasonic Silent Drive
      • SP: Super Performance (professional line)
      • IF: Internal Focusing System
      • Di: Digitally Integrated (optimized for use with full-frame digital cameras)
      • Di-II: Digitally Integrated (optimized for use with APS-C digital cameras)
      • ZL: Zoom Lock (prevents undesired zoom lens barrel extension)
      • A/M: Auto-focus/Manual-focus Switch Mechanism
      • FEC: Filter Effect Control (controls filter direction when lens hood attached, i.e. for Polarizing filters)
      • 1:1 Macro: 1:1 Magnification

Examples

  • Tamron SP AF17-35MM F/2.8-4 Di LD Aspherical (IF)
  • Tamron AF18-200mm F/3.5-6.3 XR Di II LD Aspherical (IF)
  • Tamron SP AF180mm F/3.5 Di LD (IF) 1:1 Macro

Tokina Lenses

Tokina lenses use the following terms to indicate features of each lens:

  • Common
    • VW~XYZmm: Focal length
    • f/x.y: Maximum aperture (or f/a.b-c.d for variable aperture zooms)
    • AF: Auto-Focus
  • Compatible Body Brands
    • Nikon
    • Canon
    • Minolta/Sony
    • Pentax
  • Features
    • AT-X Pro professional line (primes and constant aperture zooms)
    • AT-X consumer line (variable aperture zooms)
    • AS: Aspherical Optics
    • F&R: Advanced Aspherical Optics
    • SD: Super Low Dispersion
    • HLD: High-Refraction, Low Dispersion
    • MC: Multi-Coating
    • FE: Floating Element System
    • IF: Internal Focus System
    • IRF: Internal Rear Focus System
    • FC: Focus Clutch Mechanism (allows switching between auto & manual focus)
    • One Touch FC: One-Touch Focus Clutch Mechanism
    • FX: Full frame
    • DX: Digital (cropped frame)

Samyang Lenses

Samyang (also sold as Pro-Optic, Rokinon, Bower) lenses use the following terms to indicate features of each lens:

  • Common
    • XYZ mm: Focal length
    • f/x.y: Maximum aperture
    • Tx.y: maximum light transmittance
  • Compatible Body Brands
    • Nikon
    • Canon
    • Minolta/Sony
    • Pentax/Samsung
    • Olympus
    • Panasonic
  • Features
    • AE: contains electronic chip to allow Automatic Exposure and iTTL flash metering on a Nikon body
    • AS: contains Aspherical element(s)
    • Aspherical: contains Aspherical element(s)
    • ED: contains extra-low dispersion element(s)
    • IF: Internal Focusing
    • VDSLR: designed for video use (smooth aperture selection with T-number scale, toothed aperture and focus rings); can be used for still photography, too
    • DH: detachable hood (indicated only if a similar focal length model with fixed hood exists)
    • T-S: tilt-shift
    • MC: Multi Coating
    • UMC: Ultra Multi Coating
    • NCS: nano crystal anti-reflection coating
    • CS: crop sensor coverage
    • MFT: designed for Micro Four Thirds systems
    • VG10 – custom design for Sony Nex-VG10
    • Preset: Aperture preset (so you can quickly flick aperture ring between maximum aperture for focusing and desired aperture for shooting; there’s no aperture linkage on a preset lens)
    • Mirror: a mirror lens

Examples

  • Samyang AE 14 mm f/2.8 ED AS IF UMC
  • Samyang 35 mm f/1.4 AS UMC
  • Pro-Optic AE 85 mm f/1.4 Aspherical IF

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রিফাত জামিল ইউসুফজাই

জাতিতে বাঙ্গালী, তবে পূর্ব পূরুষরা নাকি এসেছিলো আফগানিস্তান থেকে - পাঠান ওসমান খানের নেতৃত্বে মোঘলদের বিরুদ্ধে লড়াই করতে। লড়াই এ ওসমান খান নিহত এবং তার বাহিনী পরাজিত ও পর্যূদস্ত হয়ে ছড়িয়ে পড়ে টাঙ্গাইলের ২২ গ্রামে। একসময় কালিহাতি উপজেলার চারাণ গ্রামে থিতু হয় তাদেরই কোন একজন। এখন আমি থাকি বাংলাদেশের রাজধানী ঢাকায়। কোন এককালে শখ ছিলো শর্টওয়েভ রেডিও শোনা। প্রথম বিদেশ ভ্রমণে একমাত্র কাজ ছিলো একটি ডিজিটাল রেডিও কেনা। ১৯৯০ সালে ষ্টকহোমে কেনা সেই ফিলিপস ডি ২৯৩৫ রেডিও এখনও আছে। দিন-রাত রেডিও শুনে রিসেপশন রিপোর্ট পাঠানো আর QSL কার্ড সংগ্রহ করা - নেশার মতো ছিলো সেসময়। আস্তে আস্তে সেই শখ থিতু হয়ে আসে। জায়গা নেয় ছবি তোলা। এখনও শিখছি এবং তুলছি নানা রকম ছবি। কয়েক মাস ধরে শখ হয়েছে ক্র্যাফটিং এর। মূলত গয়না এবং নানা রকম কার্ড তৈরী, সাথে এক-আধটু স্ক্র্যাপবুকিং। সাথে মাঝে মধ্যে ব্লগ লেখা আর জাবর কাটা। এই নিয়েই চলছে জীবন বেশ।