Quote:
Originally Posted by ln1977
Deep Breath!!
 Just wondering, as I am looking at buying a true 1:1 macro lens and I use a D70 is there any difference with regards to the 1:1 reproduction? I understand that the 1:1 means the image you take will be the equivelent to the size of the object in comparison to the sensor size (ie a 16mm Bug would Appear 16mm Long on a full frame sensor) but does this mean that because I dont have a full frame sensor I will not get true 1:1 from a macro lens, will I still get the 16mm bug so to speak. 
I hope i've made myself clear  |
True 1:1 macro means that you should be able to focus close enough to get an image of an object on the focus plane (film/sensor) the same size as the actual physical object. The size of the sensor is irrelevant to the macro ratio, but may be significant to the coverage, and the size of the object that will fill the frame.
I don't know the actual size of the D70 sensor, or the specific lens you're talking about, but if the sensor is 24mm wide, you could take a picture of a 24mm long bug that would completely fill the frame (OK, the nearer bits might be slightly out of focus, you don't get much DoF that close). If you use the lens on a 35mm film camera, you could take a picture of a 36mm long bug that would fill the frame, assuming the lens isn't a reduced coverage circle digital only type.
So effectively, you get more magnification, in the loose sense, with a smaller sensor - smaller subjects will fill the frame.
Hope this clarifies things.