Does Sigma deceive us with the ISO rating?

Started Apr 14, 2012 | Discussions thread
Shop cameras & lenses ▾
Halldor Eiriksson Senior Member • Posts: 1,983
Re: Does Sigma deceive us with the ISO rating?

Chunsum J Choi wrote:

you should explain sunny 16 as well.

On a clear and sunny day, aperture is f16 and speed is 1/ISO. If ISO is set at 100, it's 1/100th of a second.

If you want to use f11 instead, you raise the speed to 1/200s.
f8 gives the speed of 1/400s

If it's not sunny, but bright, you lower the aperture one stop.

If it's overcast, not raining, you lower the aperture one stop again and so on.

It's easy to get really good at this, it takes practice.

If this rule gives constantly wrong exposure, I would draw the conclusion that the ISO rating is not correct.

-- hide signature --

"There is nothing worse than a sharp image of a fuzzy concept." -Ansel Adams

http://www.pbase.com/sigmadslr (Sigma Users Gallery)

http://www.flickr.com/photos/chunsum
http://500px.com/chunsum
http://www.pbase.com/chunsum

-- hide signature --
 Halldor Eiriksson's gear list:Halldor Eiriksson's gear list
Nikon D7200 Nikon AF-S Nikkor 70-200mm f/4G ED VR Sigma 18-35mm F1.8 DC HSM Art Nikon AF-S DX Nikkor 18-140mm f/3.5-5.6G ED VR
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow