Objektivskolan - Ordlista - RF (Sigma)

Förkortningen betyder

RF = Rear Focus

Förklaring från Sigma

This lens is equipped with a system that moves the rear lens group for highspeed, silent focusing.

Conventional focusing has normallybeen performed by moving either all lens groups as a fixed unit or onlythe first lens group. AF cameras are now widely used, even for close-upphotography. Consequently, demand has arisen for a focusing system thatwill keep the length of the lens unchanged while showing little fluctuationof aberration. In response to this demand, SIGMA has developed a newinner focus system that moves two lens groups inside the telephoto andtelephoto MACRO lenses. This system has floating elements thatsubstantially improve the close-upcapability of the lens. The superwide angle lens having a large front-lens uses a rear focusing system tomove the rear-lens apparatus andenhance the floating effect, and the18-200mm F3.5-6.3 DC features aninner focusing system to move thesecondary lens group duringfocusing. This lens has a minimumfocusing distance of 45 cm / 17.7inch throughout entire zoom range.The rear focus system ensures high-speed focusing with the wide lens20mm F1.8 EX DG ASPHERICALRF.

Se exempel på berörda produkter

Sigma EX 20mm f/1,8 DG ASP RF

Se länkar

	sigmaphoto.com
	sigma-photo.co.jp

Objektiv för Canon
Nedan visas några populära alternativ (se alla)
	Canon EF 600mm f/4 L IS II USM
	Canon EF 800mm f/5,6 L IS USM
	Sigma 70-300mm f/4-5,6 DG OS
	Canon EF 50mm f/1,4 USM

Objektiv för Nikon
Nedan visas några populära alternativ (se alla)
	Tamron SP AF 28-75mm f/2,8 XR Di
	Tamron AF 18-270mm f/3,5-6,3 Di II VC LD IF Macro
	Sigma EX 800mm f/5,6 HSM APO DG
	Sigma 70-300mm f/4-5,6 DG APO Macro

Objektivskolan
Våra artiklar utbildar dig (se alla)
Kameran kan påverka brännvidd
Se bilder tagna med ett visst bländartal
Se bilder tagna med en viss brännvidd
Vilken betydelse har autofokusmotor?