http___drkrishi.com_hyperfocal-distance_.xml
http___fotografija.hr_ostra-pejzazna-fotografija-hiperfokalna-udaljenost-i-odabir-otvora-blende__1.xml
1.1 1.2 1.3 1.4 1.5 2.1 2.2 2.3 2.4 2.5 2.6 3.1 3.2 3.3 3.4 3.5 3.6 3.7 4.1 4.2 4.3 5.1 5.2 5.3 5.4 5.5 6.1 7.1 8.1 9.1 10.1 10.2 10.3 10.4 10.5 11.1 12.1 13.1 14.1 15.1 16.1 17.1 18.1
Varanga is a small sleepy village located in the Udupi district of Karnataka at a distance of 25 Kms from Karkala and 43 Kms from Moodabidri on the way from Karkala to Agumbe. I reached Varanga just before sunset to capture the nice evening light. I had visited Varanga many a times and each time the experience is unique and exhilarating. The Kere Basadi of Varanga is unique Jain temple situated in the midst of a gentle green lake. Serene lake contrasts well with the sharp quadrilateral architecture of the temple and gentle swaying hills at the distance. I used Canon EOS 5D mark II fitted with Canon EF 16-35mm f/2.8 L USM Lens and Hoya circular polarizing filter to get these pictures. I used various focal lengths from 16mm to 35 mm take these photos. What you can notice is use of hyperfocal distance to get both foreground as well as background in sharp focus. I had mentioned in the earlier blog about use of hyperfocal distance to catch flying kite as well as moon in sharp focus. Unfortunately hyperfocal distance will not work effectively for a 600mm focal length I was planning. It really is effective in normal to wide angle lenses. So what is the definition of this term Hyper focal distance? The hyperfocal distance is the closest distance at which a lens can be focused while keeping objects at infinity acceptably sharp; that is, the focus distance with the maximum depth of field. Digital cameras with tiny sensors have almost eliminated need to get the calculator to get this hyperfocal distance. Tiny sensors which you find on most point and shoot cameras will give you a universal focus right from close up to infinity. Many manufacturers have eliminated the scale displaying a zone of focus on their digital lenses all together in recent years. So is it just meant for film cameras and not relevant to digital? As more people start venturing into larger sensors (35mm or larger) they will come to face with the hyperfocal distance. When you focus your lens there will be a zone that is in focus and areas that are out of focus. The area that is in focus is called the focal plane of acceptable sharpness. The interesting thing about this focal plane is that, when you focus on a subject, one third of the distance closest between subject and camera is in focus; secondly, two thirds of the zone that stretches out from and behind the subject is also in focus. In a landscape photography you want maximum area in focus (foreground to background), so if you keep your lens focus to infinity your focal plane stretches 1/3 in front of infinity and 2/3 beyond infinity. What is is the use of the focus infinity? it is a waste as it is supposed to be focus anyway. So trick is to focus little in front of the infinity mark so as to stretch the focal plane just into infinity. That will give you a sharply focus foreground and sharply focused background too. There are 3 rules to get best out of this trick. - Use wide angle lens which inherently has greater depth of field. - Use smaller aperture like f/8-f/16 which give you a great depth of field. - If you don’t have depth of field calculator handy, focus on a point about a third the distance between you and the subject and use depth of field preview button to check the focal plane. If you want to be accurate and mathematically inclined there is a formula to calculate this hyperfocal distance. It is dependednt on several factors. The focal length of the lens, aperture, sensor size etc. I don’t want to confuse you with all that jargon. If you are interested to know the calculation check links below. Learn more about hyperfocal distance at these links. - Digital Photography school has a nice article Hyperfocal Distance – Photographer’s Friend - Cambridge In Color also has a calculator and shows an excellent example of it in use http://www.cambridgeincolour.com/tutorials/hyperfocal-distance.htm - You can calculate exact hyperfocal charts with http://www.dofmaster.com/charts.html. - Martin Bailey has the following podcast on hyperfocal distance – Understanding Hyperfocal distance , DOF Explainedand the pdf-file to the DOF Explained - Apple iTouch/iPhone/iPad has a free hyperfocal distance calculator called Field Tools - Android phones have a similar app called Photo Tools If you need more info on Varanga check this nice article on Deccan Herald – Basadis are testimony to rich Jain culture.
1.1 2.1 2.2 3.1 3.2 4.1 4.2 4.3 4.4 4.5 5.1 5.2 5.3 5.4 6.1 6.2 6.3 7.1 8.1 9.1 9.2 10.1 11.1 12.1 13.1 13.2 14.1 14.2 15.1 15.2 15.3
Oštra pejzažna fotografija: Hiperfokalna udaljenost i odabir otvora blende Bitan element pejzažne fotografije je oštrina kroz cijeli kadar, dakle svi elementi te fotografije morali bi biti u oštrini – i element koji se nalazi svega nekoliko metara ispred fotoaparata te element koji se nalazi možda i kilometar udaljenosti od fotoaparata mora biti u dozvoljenih granicama oštrine. To se postiže odabirom, odnosno definiranjem dovoljno velikog polja dubinske oštrine (DOF). Polje dubinske oštrine je udaljenosti između početne i završne točke dubine našeg kadra unutar kojeg dobivamo elemente u oštrini. To polje oštrine, ravnina je paralelna sa ravninom senzora, definira se pomoću tri osnovna fotografska faktora: - Žarišna udaljenost: Ona se definira prvenstveno kompozicijom fotografije – dakle ovisna je o onome što želimo snimiti. Žarišnom udaljenošću se ne definira direktno polje oštrine već je oštrina polja posljedica odabira žarišne udaljenosti. Direktno je ovisna o vrsti objektiva. Ako koristite širokokutne objekive, 24mm ili manje, onda je žarišna udaljenost manja te je polje oštrine dublje. U slučaju korištenja velikih žarišnih udaljenosti, odnosno objektiva u tele području dubina polja oštrine je manja. - Otvor blende (zaslona): Otvor0m blende direktno utječemo ma dubinu polja oštrine. Odabirom velikog broja f, odnosno malog otvora blende, produbljujemo polje oštrine, odnosno obrnuto, otvaranje blende smanjujemo polje oštrine. No, pritom moramo znati da odabirom malog otvora blende recimo f/18 ili f/22 objektiv pokazuje znakove difrakcije što naposljetku rezultira smanjenom oštrinom fotografije. U većini slučajeva odabir otvora blende između f/8 i f/11 rezultira najoštrijom fotografijom. - Udaljenost ravnine fokusa: U kombinaciji žarišne udaljenosti i otvora blende na kraju odlučujemo gdje ćemo smjestiti ravninu fokusa. Udaljenost od ravnine fokusa do fotoaparata je hiperfokalna udaljenosti. Ta udaljenost direktno utječe na dubinu polja fokusa, dakle što je udaljenost već, dubina polja fokusa je također veća, te obrnuto. Hiperfokalna udaljenost Da bi naša pejzažna fotografija bila u granicama oštrine onda se moramo pobrinuti da se polje oštrine (DOF) proteže od početne točke kadra (elementa u prvom planu) pa sve do beskonačnosti. To postižemo fokusiranjem, odnosno postavljanjem polja fokusa, na određenoj hiperfokalnoj udaljenosti koje je definirana nakon odabira žarišne duljine i otvora blende. Postoji ta određena udaljenost koja će rezultirati cijelim kadrom u fokusu – hiperfokalna udaljenost – udaljenost ravnine fokusa od senzora fotoaparata. Pri odabiru hiperfokalne udaljenosti imajmo na umu da je najbliža točka ispred ravnine fokusa negdje oko 50% ukupne hiperfokalne udaljenosti Znači ako je ravnina fokusa od nas udaljena 10 metara, što znači da je hiperfokalna udaljenost 10 metara, onda nam je prva prihvatljiva točka unutra polja fokusa na udaljenosti 5 metara od fotoaparata. Odabir otvora blende Kod ravnine fokuse, e vezano uz otvor blende postoji pravilo da je u oštrini 1/3 ispred ravnina fokusa te 2/3 iza ravnine fokusa. Stoga je najjednostavniji način odabira hipefokalne udaljenosti, odnosno dobivanja zadovoljavajuće dubine polja fokusa je upotrebom malih otvora blende f/22 ili f/18 te fokusiranjem na 1/3 unutar ukupne dubine polja fokusa. Time osiguravamo oštrinu 1/3 ispred ravnine fokusa te 2/3 iza ravnine fokusa, dok će sve iza, u dubini kadra, rezultirati zadovoljavajućim oštrinama (iako neoštro). No, kako smo i naveli na početku velike vrijednosti broja f mogu rezultirati smanjenom oštrinom fotografije zbog optičkih mogućnosti objektiva. Stoga se preporuča korištenje vrijednosti broja f u granicama između f/8 i f/11. Uglavnom, izračuni hiperfokalne udaljenosti mogu biti prilično kompleksni, no postoje aplikacije za mobitele ili web stranice koja vam mogu pomoći oko toga. Svakako preporučamo odlazak na teren te što više fotografiranja i vježbanja. Nakon određenog vremena provedenoga na terenu najbolje će te znati uskladiti ova tri elementa za dobivanje zadovoljavajuće pejzažne fotografije.