macro frame size

[hacknet]

hey guys,

i'm venturing into macro photography i have a little question about the ratio that they use.

i alway see this 1:1 ratio poping up everywhere when they talk about macro lenses. from what i know, it means that 1cm of the picture will co-relate to 1cm on the film.

so if i were to take a picture of a ruler, i would be able to see from 0mm to 35mm correct?

 

[ortega]

if you were using film yes

 

[hacknet]

what about my 1.5x crop nikon digital?

should i end up with 22mm or would 35mm be still considered macro?

thanks!

 

[OlyFlyer]

Magnification 1:1 is regardless of media or sensor size. It means that a 1mm life size object takes up 1mm on your film or CCD, regardless of the size of your film or CCD. It is relatively easy to calculate the actual magnification by taking an image of a ruler. Divide the with of your sensor with the number of millimeters you see in the image and you get the magnification ratio. Remember, you MUST use the same units for both the film width and the ruler image.

An example:

I have an Olympus E-500 and the sensor size is 17.3x13mm. The image above represents about 4.5mm of an aluminum ruler. 17.3/4.5=3.8 so the image above is a 3.8:1 image. In a 1:1 image you would see 17.3mm long part of the ruler in my camera or a 35mm part in a 35mm film camera.

 

[hacknet]

ahh.. thanks for the confirmation!

looks like i now have an objective way to compare lenses!