f-stop question...

[railman44]

Can someone please clarify an f-stop question I have? When I read a certain filter needs (let’s say) down or up 1 f-stop what does that mean? Down or up from what? Down or up from where your meter tells you when you have a correct setting without the filter? I’m assuming this is what it means?? Thanks for your help!

 

[Digital Matt]

It means that the filter lets 1 stop less light through. You need to open your aperture by 1 stop, or lower your shutter speed by 1 stop to compensate for the loss of light.

If your camera has ttl metering, it will meter correctly with the filter on. If you were using a handheld meter, you would have to make the change yourself.

 

[ksmattfish]

Read up on stops and f/stops in the stickie post at the top of this forum "Vocabulary for newbies".