Using coins for scale is discouraged as it will require people unfamiliar with them to look up the dimensions or guess, both of which defeat the purpose of the object in the first place. Coins can also reinforce a geographical bias, and some coins' designs are copyrighted.
Ideally, a photograph should include a ruler with the subject (example) or an added scale marking.
SI ("metric") units are the most commonly used worldwide (see meter and centimeter).
This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: converted to JPG + minor crop. The original can be viewed here: Aluminium oxide2.png: .
Nik, lan honen egileak, argitaratzen dut ondorengo lizentzia pean:
Public domainPublic domainfalsefalse
Nik, lan honen egile eskubideen jabeak, lan hau domeinu publikoan jartzen dut. Mundu osoan du eragina honek. Estatu batzuetan beharbada hori ez da legez posible izango. Halakoetan: Edonori ematen diot lan hau edozertarako erabiltzeko eskubidea, inolako baldintzarik gabe, legeak nahitaez ezarritako baldintzak izan ezik.
Jatorrizko igoera erregistroa
This image is a derivative work of the following images:
Fitxategi honek informazio gehigarri dauka, ziurrenik kamera digital edo eskanerrak egiterako momentuan gehitutakoa. Hori dela-eta, jatorrizko fitxategi hori aldatu egin bada, baliteke xehetasun batzuek errealitatearekin bat ez egitea.