ISO invarijantnost

Tandara, Matej (2022) ISO invarijantnost. Master's thesis - Graduate Programme. Grafički fakultet. [Mentor: Strgar Kurečić, Maja].

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Abstract

U analognoj fotografiji je ISO vrijednost označavala fizičko svojstvo fotografskog filma te je ovisila o veličini zrnaca srebrovog halida. Dolaskom digitalne fotografije se uloga ISO vrijednosti u potpunosti promijenila jer više nije bila nikakvo fizičko svojstvo digitalnog CMOS senzora već je ovisila o analognim i digitalnim amplifikatorima unutar fotoaparata. Polako se počelo pojavljivati pitanje o tome je li uopće bitno ako se ISO vrijednost namjesti prilikom snimanja fotografija ili prilikom uređivanja RAW fotografija u programu za obradu slika - odnosno, je li ISO vrijednost invarijantna? U eksperimentalnom dijelu su uspoređene fotografije kojima je ISO vrijednost bila namještena u fotoaparatu tako da je ekspozicija bila ispravna te fotografije koje su uslikane s potpuno istim postavkama - osim ISO vrijednosti koja je bila snižena tako da se dobiju postepeno podeksponirane fotografije. RAW formati podeksponiranih fotografija su nakon toga bili uvezeni u Adobe Lightroom gdje im je ekspozicija izjednačena s fotografijom čija je ISO vrijednost ispočetka bila ispravno postavljena. Rezultati eksperimenta su pokazali kako postoje rasponi unutar ISO vrijednosti fotoaparata gdje ISO invarijantnost odlično funkcionira te najviše ovisi o backend read noise-u fotoaparata te da toliko raznih faktora utječe na istu da je nužno poznavati arhitekturu fotoaparata, izvore šuma u digitalnoj fotografiji i vrste amplifikacije signala kako bi se mogao iskoristiti puni potencijal ISO invarijantnosti.

Item Type:	Master's thesis - Graduate Programme
Mentor name:	Strgar Kurečić, Maja
Thesis Committee:	Mandić, Lidija and Strgar Kurečić, Maja and Pibernik, Jesenka
Defence date:	29 September 2022
Abstract in english:	In analog photography, the ISO value indicated the physical property of the photographic film and depended on the size of the silver halide grains. With the rise of digital photography, the role of the ISO value changed completely because it was no longer a physical property of the digital CMOS sensor, but depended on analog and digital amplifiers inside the camera. Slowly, the question began to arise as to whether it even matters if the ISO value is adjusted when taking photos or when editing RAW photos in an image editing program - that is, is the ISO value invariant? In the experimental part, photos where the ISO value was set in the camera so that the exposure was correct were compared with photos that were taken with exactly the same settings - except for the ISO value, which was lowered so that gradually underexposed photos were created. The RAW formats of the underexposed photos were then imported into Adobe Lightroom, where their exposure was equalised with the photo whose ISO value was set correctly from the beginning. The results of the experiment showed that there are ranges within the ISO value of the camera where ISO invariance works great and depends mostly on the back-end read noise of the camera and that so many different factors influence it that it is necessary to know the architecture of the camera, sources of noise in digital photography and types of amplification signal so that its full potential can be used.
Uncontrolled Keywords:	ISO invarijantnost, digitalni CMOS senzor, analogni i digitalni amplifikatori, back-end read noise
Keywords in english:	ISO invariance, digital CMOS sensor, analog and digital amplificators, back-end read noise
Subjects:	TECHNICAL SCIENCES > Graphic Technology
Institution:	Grafički fakultet
City:	Zagreb
Number of Pages:	55
Callnumber:	STR 2022 TAN
Inventory number:	DB969
Depositing User:	Nina Jelača
Status:	Unpublished
Date Deposited:	23 Mar 2023 10:03
Last Modified:	24 Mar 2023 08:30
URI:	http://eprints.grf.unizg.hr/id/eprint/3433

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