Objective: Determine the focal length of a lens using the Bessel method
On an optical bench it is possible to set up a light source, a lens, a screen and an object to be imaged in such a way that a well focussed image appears on the screen. Using the geometric relationships between the ray paths for a thin lens, it is possible to determine its focal length.
![Kísérlet: Lencse törvények, (230 V, 50/60 Hz), 8000678 [UE4010100-230], Geometriai optika](/imagelibrary/UE4010100-230/UE4010100-230_01_Kiserlet-Lencse-toervenyek-230-V-5060-Hz.jpg)
![Kísérlet: Lencse törvények, (230 V, 50/60 Hz), 8000678 [UE4010100-230], Geometriai optika](/thumblibrary/UE4010100-230/UE4010100-230_01_1200_1200_Kiserlet-Lencse-toervenyek-230-V-5060-Hz.jpg)
![Optical Bench K, 1000 mm, 1009696 [U8475240], Kröncke - féle optika](/thumblibrary/U8475240/U8475240_01_140_140_Optical-Bench-K-1000-mm.jpg)
![Optikai lovas K, 1000862 [U8475350], Kröncke - féle optika](/thumblibrary/U8475350/U8475350_01_140_140_Optikai-lovas-K.jpg)
![Clamp K, 1008518 [U84755401], Kröncke - féle optika](/thumblibrary/U84755401/U84755401_01_140_140_Clamp-K.jpg)
![Optikai lámpa K, 1000863 [U8475400], Kröncke - féle optika](/thumblibrary/U8475400/U8475400_01_140_140_Optikai-lampa-K.jpg)
![Transformer 12 V, 25 VA (230 V, 50/60 Hz), 1000866 [U8475470-230], Tápegységek](/thumblibrary/U8475470-230/U8475470-230_01_140_140_Transformer-12-V-25-VA-230-V-5060-Hz.jpg)
![Convex Lens K, f = 50 mm, 1000869 [U8475901], Kröncke - féle optika](/thumblibrary/U8475901/U8475901_01_140_140_Convex-Lens-K-f-50-mm.jpg)
![Convex Lens K, f = 100 mm, 1010300 [U8475911], Kröncke - féle optika](/thumblibrary/U8475911/U8475911_01_140_140_Convex-Lens-K-f-100-mm.jpg)
![Fehér ernyő K, 1000879 [U8476320], Kröncke - féle optika](/thumblibrary/U8476320/U8476320_01_140_140_Feher-ernyo-K.jpg)
![Kép diakeretben készlet, 1000886 [U8476605], Blendék, elhajlási elemek, szűrők](/thumblibrary/U8476605/U8476605_01_140_140_Kep-diakeretben-keszlet.jpg)
![Precíziós dinamométer 5N, 1003106 [U20034], Dinamométer](/thumblibrary/U20034/U20034_01_140_140_Precizios-dinamometer-5N.jpg)
![Háromágú talp 150 mm, 1002835 [U13270], Talpak](/thumblibrary/U13270/U13270_01_140_140_Haromagu-talp-150-mm.jpg)
![DC Tápegység 0 - 20 V, 0 - 5 A
(230 V, 50/60 Hz), 1003312 [U33020-230], Tápegységek](/thumblibrary/U33020-230/U33020-230_01_140_140_DC-Tapegyseg-0-20-V-0-5-A-230-V-5060-Hz.jpg)
![Tartókampó, 1002828 [U13252], Fogók](/thumblibrary/U13252/U13252_01_140_140_Tartokampo.jpg)
![Biztonsági kísérleti kábel, 15, 1002843 [U138021], Elektromos áramkörök](/thumblibrary/U138021/U138021_01_140_140_Biztonsagi-kiserleti-kabel-15.jpg)
![Főzőpohár, magas, 1002873 [U14211], Üveg](/thumblibrary/U14211/U14211_01_140_140_Fozopohar-magas.jpg)
![Rozsdamentes acélrúd 750 mm, 1002935 [U15003], Állványrudak Rozsdamentes](/thumblibrary/U15003/U15003_01_140_140_Rozsdamentes-acelrud-750-mm.jpg)
![Laboratóriumi emelő asztal II, 1002941 [U15020], Dugaljak](/thumblibrary/U15020/U15020_01_140_140_Laboratoriumi-emelo-asztal-II.jpg)
![Alumínium test 100 cm3, 1002953 [U15037], Felhajtó erő](/thumblibrary/U15037/U15037_01_140_140_Aluminium-test-100-cm3.jpg)
![Set of Weights 1 g to 500 g, 1010189 [U29576], Ellensúlyok](/thumblibrary/U29576/U29576_01_140_140_Set-of-Weights-1-g-to-500-g.jpg)
![Kísérlet: Lejtő, 8000524 [UE1020400], Erők](/thumblibrary/UE1020400/UE1020400_01_140_140_Kiserlet-Lejto.jpg)