I've been reading a lot about macro photography and keep seeing this ratio of 1:1 mentioned.
My question is if shooting with a macro lens how can you tell when you have achieved this 1:1 ratio before taking the shot?
is it displayed somewhere on the camera? Apologies, i haven't been able to find the answer despite multiple searches, probably due to my lack of terminology.
Thanks for the help!
Most macro lenses have markings that indicate the magnification ratio. As you turn the focus ring these numbers will be exposed, at least on lenses that focus by extending the tube. If the lens is internally focusing there are normally marks above the distance marks on the lens. Mostly you do not worry about the exact magnification ratio. If you do, put the camera in manual focus, turn the focus ring to the indicated level of magnification then move the camera to focus. To get 1:1 focus if the lens supports it, turn the focus to minimum focus distance then move the camera until it is in focus.
I think you will note I mention moving the camera to focus not the focus ring, you can do both but at higher magnifications moving the camera works better. They build special focus rail systems for tripods to make this easier. If you are using autofocus, take the picture then look at the lens to see what number turns up. Make sure you are not in continuous focus mode.
If you need an exact magnification place a object of known size in the frame to scale from.
1:1 is the magnification on the sensor, the magnification when printed or viewed on a computer screen will of course be different.