[ln1977]

Hello all and thankyou for your help and replies, so to settle this am i correct to suggest that with 1:1 to make it simple if somthing goes in to the lens at 15mm long it will in effect come out of the other end 15mm long and if your sensor is 15mm long that object will fill the length of the sensor.
Would I be correct in thinking that if its a 36mm sensor the the object would fill 15mm of that 36mm frame?

I hope i'm seeing the light at the end of the lens now, once again thanks to all
Lee