{"product_id":"canon-400mm-f4-0-do-is-usm-ii","title":"Canon 400mm f4.0 DO IS USM II - 1931","description":"\u003ch2\u003eCanon 400mm f4.0 DO IS USM II - 1931\u003c\/h2\u003e\n\u003ch5\u003eWhat our Experts Think\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli data-section-id=\"vzmpw3\" data-start=\"27\" data-end=\"248\"\u003e\n\u003cstrong data-start=\"29\" data-end=\"66\"\u003eLightweight super‑telephoto prime\u003c\/strong\u003e with \u003cstrong data-start=\"72\" data-end=\"99\"\u003ediffractive optics (DO)\u003c\/strong\u003e for a \u003cstrong data-start=\"106\" data-end=\"142\"\u003emuch smaller, lighter 400mm lens\u003c\/strong\u003e than conventional designs, ideal for handheld use on long shoots. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"2logcm\" data-start=\"249\" data-end=\"442\"\u003e\n\u003cstrong data-start=\"251\" data-end=\"280\"\u003eExcellent optical quality\u003c\/strong\u003e with gapless dual‑layer DO, aspherical, and UD elements for sharp images with strong contrast and controlled aberrations. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"n64y6l\" data-start=\"443\" data-end=\"618\"\u003e\n\u003cstrong data-start=\"445\" data-end=\"475\"\u003e4‑stop image stabilization\u003c\/strong\u003e helps reduce blur from camera shake—very useful for field, wildlife, and sports work without a tripod. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1uth0z4\" data-start=\"619\" data-end=\"745\"\u003e\n\u003cstrong data-start=\"621\" data-end=\"645\"\u003eWeather‑sealed build\u003c\/strong\u003e and solid construction suit challenging outdoor conditions. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"139fvld\" data-start=\"746\" data-end=\"891\"\u003e\n\u003cstrong data-start=\"748\" data-end=\"780\"\u003eFast and quiet USM autofocus\u003c\/strong\u003e with full‑time manual focus override gives reliable focus performance. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"116t51o\" data-start=\"892\" data-end=\"1059\"\u003e\n\u003cstrong data-start=\"894\" data-end=\"919\"\u003eCompact for its class\u003c\/strong\u003e yet delivers true prime‑length reach with excellent handling compared to bigger f\/2.8 counterparts. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1j6882t\" data-start=\"1060\" data-end=\"1226\"\u003e\n\u003cstrong data-start=\"1062\" data-end=\"1090\"\u003eVariable bokeh character\u003c\/strong\u003e typical of DO optics—smooth but with unique rendering that may differ from conventional primes. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"rs80dq\" data-start=\"1227\" data-end=\"1373\"\u003e\n\u003cstrong data-start=\"1229\" data-end=\"1251\"\u003eBest in good light\u003c\/strong\u003e—wide‑open f\/4 means lower light performance isn’t as strong as f\/2.8 super teles\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003e\n\u003cbr\u003eQ\u0026amp;A\u003c\/h5\u003e\n\u003cp data-start=\"73\" data-end=\"323\"\u003e\u003cstrong data-start=\"73\" data-end=\"107\"\u003eQ1: What type of lens is this?\u003c\/strong\u003e\u003cbr data-start=\"107\" data-end=\"110\"\u003eA: It’s a \u003cstrong data-start=\"120\" data-end=\"151\"\u003e400 mm telephoto prime lens\u003c\/strong\u003e with \u003cstrong data-start=\"157\" data-end=\"184\"\u003eDiffractive Optics (DO)\u003c\/strong\u003e for Canon EF‑mount full‑frame cameras — designed for sports, wildlife, and long‑distance shooting. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"325\" data-end=\"631\"\u003e\u003cstrong data-start=\"325\" data-end=\"374\"\u003eQ2: What does “DO” (Diffractive Optics) mean?\u003c\/strong\u003e\u003cbr data-start=\"374\" data-end=\"377\"\u003eA: Canon’s DO technology uses special optical elements to \u003cstrong data-start=\"435\" data-end=\"461\"\u003ereduce size and weight\u003c\/strong\u003e compared with conventional super‑telephoto designs while maintaining excellent correction of chromatic and spherical aberrations. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"633\" data-end=\"900\"\u003e\u003cstrong data-start=\"633\" data-end=\"690\"\u003eQ3: What’s the aperture and optical performance like?\u003c\/strong\u003e\u003cbr data-start=\"690\" data-end=\"693\"\u003eA: It has a \u003cstrong data-start=\"705\" data-end=\"738\"\u003econstant f\/4 maximum aperture\u003c\/strong\u003e with a 9‑blade diaphragm and includes UD and aspherical elements to deliver sharp, high‑contrast images across the frame. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"902\" data-end=\"1168\"\u003e\u003cstrong data-start=\"902\" data-end=\"957\"\u003eQ4: Does it have image stabilization and autofocus?\u003c\/strong\u003e\u003cbr data-start=\"957\" data-end=\"960\"\u003eA: Yes — built‑in \u003cstrong data-start=\"978\" data-end=\"1016\"\u003e4‑stop optical Image Stabilization\u003c\/strong\u003e reduces shake for handheld shooting, and \u003cstrong data-start=\"1058\" data-end=\"1065\"\u003eUSM\u003c\/strong\u003e ensures fast, smooth autofocus with full‑time manual override. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"1170\" data-end=\"1391\"\u003e\u003cstrong data-start=\"1170\" data-end=\"1212\"\u003eQ5: What’s its close‑focus capability?\u003c\/strong\u003e\u003cbr data-start=\"1212\" data-end=\"1215\"\u003eA: The minimum focus distance is \u003cstrong data-start=\"1248\" data-end=\"1268\"\u003e~3.3 m (10.8 ft)\u003c\/strong\u003e with a magnification of ~0.13× — suitable for distant subjects but not true macro. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"1393\" data-end=\"1625\"\u003e\u003cstrong data-start=\"1393\" data-end=\"1433\"\u003eQ6: How is the lens size and weight?\u003c\/strong\u003e\u003cbr data-start=\"1433\" data-end=\"1436\"\u003eA: It’s \u003cstrong data-start=\"1444\" data-end=\"1501\"\u003ecompact and relatively lightweight (~2.1 kg \/ 4.6 lb)\u003c\/strong\u003e for a 400 mm prime, making it more portable than many other super‑telephoto lenses. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"1627\" data-end=\"1801\"\u003e\u003cstrong data-start=\"1627\" data-end=\"1675\"\u003eQ7: Is the build quality professional‑grade?\u003c\/strong\u003e\u003cbr data-start=\"1675\" data-end=\"1678\"\u003eA: Yes — weather‑sealed and robust construction stands up to demanding outdoor use. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"1803\" data-end=\"2025\"\u003e\u003cstrong data-start=\"1803\" data-end=\"1850\"\u003eQ8: What types of photography benefit most?\u003c\/strong\u003e\u003cbr data-start=\"1850\" data-end=\"1853\"\u003eA: Ideal for \u003cstrong data-start=\"1866\" data-end=\"1926\"\u003ewildlife, birds, motorsports, action, and outdoor sports\u003c\/strong\u003e where reach, sharpness, and lighter weight are priorities. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"2027\" data-end=\"2231\"\u003e\u003cstrong data-start=\"2027\" data-end=\"2070\"\u003eQ9: Can it be used with teleconverters?\u003c\/strong\u003e\u003cbr data-start=\"2070\" data-end=\"2073\"\u003eA: It’s compatible with Canon EF teleconverters for extended reach, though performance varies with teleconverter used.\u003c\/p\u003e\n\u003ch5\u003e\n\u003cbr\u003eMaintenance Tips\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli data-section-id=\"1bde1eu\" data-start=\"57\" data-end=\"165\"\u003e\n\u003cstrong data-start=\"59\" data-end=\"86\"\u003eClean optics carefully:\u003c\/strong\u003e Use a blower and microfiber cloth; avoid direct contact with the lens glass.\u003c\/li\u003e\n\u003cli data-section-id=\"15zjtoo\" data-start=\"166\" data-end=\"282\"\u003e\n\u003cstrong data-start=\"168\" data-end=\"194\"\u003eProtect lens elements:\u003c\/strong\u003e Always use lens caps, UV\/filter, and lens hood to prevent scratches, dust, and flare.\u003c\/li\u003e\n\u003cli data-section-id=\"4e5r32\" data-start=\"283\" data-end=\"396\"\u003e\n\u003cstrong data-start=\"285\" data-end=\"304\"\u003eStore properly:\u003c\/strong\u003e Keep in a dry, padded case with silica gel to prevent moisture, fungus, and dust buildup.\u003c\/li\u003e\n\u003cli data-section-id=\"1jkmye2\" data-start=\"397\" data-end=\"484\"\u003e\n\u003cstrong data-start=\"399\" data-end=\"434\"\u003eHandle zoom, focus \u0026amp; IS gently:\u003c\/strong\u003e Operate rings smoothly; never force mechanisms.\u003c\/li\u003e\n\u003cli data-section-id=\"r1h0rq\" data-start=\"485\" data-end=\"563\"\u003e\n\u003cstrong data-start=\"487\" data-end=\"516\"\u003eAvoid extreme conditions:\u003c\/strong\u003e Protect from rain, dust, heat, and humidity.\u003c\/li\u003e\n\u003cli data-section-id=\"5spema\" data-start=\"564\" data-end=\"652\"\u003e\n\u003cstrong data-start=\"566\" data-end=\"588\"\u003eInspect regularly:\u003c\/strong\u003e Check for dust inside, mechanical wear, and IS functionality.\u003c\/li\u003e\n\u003cli data-section-id=\"1os4epi\" data-start=\"653\" data-end=\"756\" data-is-last-node=\"\"\u003e\n\u003cstrong data-start=\"655\" data-end=\"676\"\u003eTransport safely:\u003c\/strong\u003e Use a dedicated lens case or tripod collar for safe handling of the heavy lens.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Canon","offers":[{"title":"Default Title","offer_id":46395454455958,"sku":"1931","price":5174.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0680\/3128\/3350\/files\/1931-00.jpg?v=1779693594","url":"https:\/\/paw-counter.com\/products\/canon-400mm-f4-0-do-is-usm-ii","provider":"Move Better Every Day","version":"1.0","type":"link"}