Can anyone tell me what the difference in magnification achieved using the same lens ona dslr vs a slr are?

If any.....

 

depends on the camera.

My nikon there is about +7mm differnce.

 

On the cheaper Canons it is 1.6x

 

The difference is due to the larger optic on an SLR camera ie 35mm format, than a DSLR, you get a larger zoom but will only "see" a certain amount as the image is larger than the chip face. if you have a DSLR camera with a through the lens viewfinder you will shoot what you see. The 1.6 time is the magnification from 35mm format to the chip size

 

basically, the image you get with a 50mm lens on a 1.6 crop Canon DSLR is the center of the frame on a 35mm camera with the same lens. People often multiply the lens focal length times the crop factor (the size of the digital sensor in relation ot a 35mm frame) to arrive at the 35mm equivalent. So a 50mm lens becomes similar to a 1.6 * 50mm = 80mm. IOW a 50mm becomes an 80mm equivalent when mounted on a 1.6 crop DSLR.

So depending on your sensor size, the difference in magnification is ~1.6, ~1.3 or in the case of a full-frame sensor, no difference.