Macro lens help

[wxnut]

OK. I have searched for 10 mins and couldnt find a thread with this answer, so forgive me if its been covered, but...

I am in the market for a macro lens, and am having trouble with the numbers. I have seen MANY times here on the fourm, that 1:1 is full size on the sensor, but what does that mean? How does that translate to a 4X6 print? I will mostly be shooting wedding rings with this lens. I dont need help picking out a lens, just learning what the ratio numbers mean. i.e. how does 1:1 compare to 1:2? Is the magnification worse as the second number gets bigger? Thanks for the help.

Doug Raflik

 

[Polygon]

For 1:1, if your object is 10x10mm in size, then it will also be 10x10mm on film. A 4x6 print (I suppose that's inches) will scale the negative by about factor 4 (a little more) so your object will show as 42x42mm (for DSLRs that would be around factor 6)
For 1:2 cut the size on film and the size on print in half. So yes, if the second number gets bigger, your magnification will get worse. The same is true for digital cameras, you should only be careful with the sensor size if you are going 1:1 or even more. If your sensor is only 24x16mm then the biggest object you'll be able to photograph can't be bigger than that (seen from the camera perspective that is) if you want to use 1:1.