What is ISO?

ISO is one of the three pillars of the photography exposure triangle, along with shutter speed and aperture that you can adjust when capturing a photo.Β It is a measurement of the sensitivity of a film stock or digital camera sensor to light. The more sensitive a film stock is, (or the more a camera sensor is made to amplify available light) – the more grain (or noise) is introduced into a photo. This is a trade-off between being able to take a photo in low light as opposed to using a finer, less sensitive film stock (or camera setting) in well illuminated conditions.

Originally, ISO numbers were set by the International Organisation for Standardisation (where the name ISO comes from). ISO standards in digital photography today still have the same numbering system to indicate the sensitivity of a digital camera sensor to light.

Please also see: ISO invariance.

[ more to follow ]

Powered by BetterDocs

Competition - Conditions of entry

This contest is only open to fully paid-up members of Bollington Photographic group.

Images should be submitted with the theme/title as specified on our contest page and elsewhere on social media – all photographs to be taken in the local vicinity unless otherwise agreed with the organisers in advance. Images not complying with these conditions will be disqualified from the contest.

Submissions must be your own work and by entering the contest, you are agreeing that they may be subsequently used for promotional purposes by the group. Credits to the individual photographer will be given, and copyright of the image(s) remain(s) with the photographer.

Winning entries will be professionally printed for display in the exhibition and the winners agree to contribute to the production costs at Β£5 per image chosen by the voting process. 

Voting is only open to paid-up members of Bollington Photographic group and members of the Bollington Photographic Facebook Group. 

Voting will only be allowed following the closure of the submission period. No cheating, mind. You can only vote once for your TWELVE  favourites, – so make your votes count!

Please note: You WILL be disqualified if you vote for your own Photographs!

  • Image format should be JPG, either colour or mono and of a quality to allow printing up to A3 in size.
  • All submissions will be validated following the closure of the submission period and voting will thenΒ  commence.Β 
  • The voting period will be as specified on the contest pages. Votes outside these dates will be disqualified.
  • The twelve images with the most votes will be declared the winners and will be selected and printed for exhibition.
  • Winning entries will be announced within the website and on social media following the closure of the voting period and the winning photographers will be also be notified by e-mail.
  • The winners’ images will be posted on the groups’ Facebook Page and will be printed and displayed in the Turners’ Arms as part of the Bollington Photographic GroupΒ  exhibition. At the end of the exhibition period, the prints will be archived for future exhibition or returned to the photographer upon request.Β  Β  The decision of the organisers will be final. E&OE