Umerjanje objektiva "ribje oko" za fotografijo hemisfere

Diaci, Jurij (author), Kolar, Uroš (author)

Fotografija hemisfere je v gozdoslovnih raziskavah ena najprimernejših metod za ocenjevanje poprečij sončnega sevanja skozi daljša obdobja. Metoda temelji na uporabi skrajno širokokotnih objektivov ribje oko, ki so znani po velikih popačitvah preslikav. Prvi pogoj za uporabo metode je poznavanje preslikave za kombinacijo fotoaparata in objektiva. Značilnosti preslikave pridobimo s postopkom umerjanja. V prvem delu prispevka opisujemo postopek umerjanja objektiva ribje oko za ocenjevanje sončnega sevanja v gozdoslovnih raziskavah.V drugem delu predstavljamo rezultate umerjanja objektiva ribje oko proizvajalca Sigma 8 mm, f/4 (MF, N), ki ga uporabljamo v kombinaciji s fotoaparatom Nikon F50.

• Language: Slovenian
• Keywords: sončno sevanje, meritve sevanja, gojenje gozda, ocenjevanje sevanja, objektiv ribje oko, umerjanje objektiva, fotografija hemisfere, pretok energije, gozd, fotografija, hemisfera
• Work type: Not categorized
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publisher: Inštitut za gozdno in lesno gospodarstvo
• Year: 2000
• Number of pages: Str. 5-25
• Numbering: Št. 61
• PID: 20.500.12556/RUL-63727
• UDC: 630
• ISSN on article: 0351-3114
• COBISS.SI-ID: 677542
• Publication date in RUL: 10.07.2015

Record is a part of a journal

• Title: Zbornik gozdarstva in lesarstva. forest and wood science & technology
• Shortened title: Zb. gozd. lesar.
• Publisher: Gozdarski inštitut Slovenije, Biotehniška fakulteta, Oddelek za gozdarstvo in obnovljive gozdne vire, Biotehniška fakulteta, Oddelek za lesarstvo
• ISSN: 0351-3114
• COBISS.SI-ID: 6206978

Secondary language

• Language: English
• Title: Calibration of fisheye lenses for hemispherical photography

Abstract

Hemispherical photography represents one of the most appropriate methods of estimating averages of solar radiation over extended periods of time. This method is based upon the use of extremely wide-angle fisheye lenses, which produce large projection distortion. To correctly interpret hemispherical photography we have to know the projection characteristics of the fisheye lensin combination with a camera body. This can be achieved through lens calibration. The first part of the article explains in detail the calibration method for fisheye lenses which are used to assess the solar radiation in forest ecology research. In the second part the results of calibration for fisheye lens Sigma8 mm, f/4 (MF, N) are presented. The lens was used on a Nikon F50 camera body.

• Keywords: solar radiation, radiation measurement, silviculture, photosynthesis, photosynthetically active radiation, photosynthetically usable radiation, fisheye lens, calibration of lens, assessment of radiation