________________________________________________________________________________________     Minolta AF 70-210mm F/4 (Beercan) and Minolta AF 70-210mm F/3.5-4.5     Comparison at 70mm and 210mm with center, mid-level and corner crops.  The Sony A900 was used for this review. In a nut-shell, the Minolta 70-210mm F/4 is a better lens overall, (including build and image quality), but the smaller and slightly newer variable aperture model is quite good when zoomed out.  Distortion is about the same overall, and so is the background highlight blur or bokeh.    For this comparison, I've used a stamp test chart, the same as the 200mm zoom comp review, but at a different distance, so don't try and compare those with the new crops below.   The distance from lens barrel to stamp for the 70mm crops is about 11' (3.35m) and the 210mm crops about 26' (7.9m) away.  Also, the right side crops below are the same used in the Minolta AF 70-210mm F/3.5-4.5 review.   Left, Minolta AF 70-210mm F/3.5-4.5, right, Minolta AF 70-210mm F/4   This product shot above is crappy because I didn't have much time to do it, and probably nobody really cares anyways.  You can see the older beercan is much larger than the newer variable aperture lens, mostly due to the zoom being internal in the beercan.  The newer lens has a focus hold button which would've been nice on the beercan, but oh well.  I like the rubber grip and finish of the newer lens much better than Minolta first generation AF lenses, like the beercan.   Distortion.   Minolta AF 70-210mm F/3.5-4.5   70mm, nearly flat. 210mm, strong pincushion distortion.   Minolta AF 70-210mm F/4 below 70mm, mild to moderate barrel distortion 210mm, mild to moderate pincushion distortion.   Distortion is nearly the same overall between the lenses, but the beercan has a little more barrel distortion at 70mm.  Pincushion appears stronger on the newer model, but really isn't.  The illusion is probably due to the fact that I don't have the crops lined up exactly the same.   Check out the center crops below.   Minolta AF 70-210mm F/4 @70mm                                     Minolta AF 70-210mm F/3.5-4.5 @70mm           F/4           F/3.5           F/5.6           F/5.6           F/8           F/8           F/11           F/11   Both lenses are a little soft in the 70mm centers wide open, but sharpen up nicely at F/5.6.  The beercan looks slightly sharper around F/8.  I see moiré in the stamp product code lines on the F/8-11 beercan crops, but not the newer model, that indicates a little better sharpness for the beercan.  Contrast looks slightly better at all apertures on the beercan also.    Now for some mid-level crops.   Minolta AF 70-210mm F/4 @70mm                              Minolta AF 70-210mm F/3.5-4.5 @70mm           F/4           F/3.5           F/5.6           F/5.6           F/8           F/8           F/11           F/11   I think these crops tell all about the quality of the newer model on the short end, and away from the centers.  This is the same area as the APS-C corners would be.  The newer model is awful outside the central area at 70mm, but does get better at F/16-22, but then diffraction messes up the centers, so there's no point right?   Also, try shooting at F/22 in less than ideal light, and you'll have a blurred mess from shutter speeds that are too slow.   Corner crops next.   Minolta AF 70-210mm F/4 @70mm                               Minolta AF 70-210mm F/3.5-4.5 @70mm           F/4           F/3.5           F/5.6           F/5.6           F/8           F/8           F/11           F/11   We see the same thing here in the extreme corner crops as we do above, fortunately, things change as we zoom in!     Now for some 210mm center crops.     Minolta AF 70-210mm F/4 @210mm                              Minolta AF 70-210mm F/3.5-4.5 @210mm           F/4           F/4.5           F/5.6           F/5.6           F/8           F/8           F/11           F/11   The full zoom center crops look about the same on each lens, and contrast has noticeably picked up on the newer model at 210mm, as compared to the 70mm crops.    Mid-level crops below.   Minolta AF 70-210mm F/4 @210mm                              Minolta AF 70-210mm F/3.5-4.5 @210mm           F/4           F/4.5           F/5.6           F/5.6           F/8           F/8           F/11           F/11   The newer model looks sharper in the mid-level areas, or APS-C corners, especially at larger apertures like F/4.5-5.6.  The crops here are exposed -2/3 eV from the 70mm crops, but both crops have the same exposure values, I just ramped up the exposure on the second set (which was the 70mm crops) because the 210mm corner crops were too dark in my opinion, and also, I didn't want to redo the entire first set!!   Corner crops next.   Minolta AF 70-210mm F/4 @210mm                               Minolta AF 70-210mm F/3.5-4.5 @210mm           F/4           F/4.5           F/5.6           F/5.6           F/8           F/8           F/11           F/11   The extreme corners are dull, and look about the same on each lens, which is odd.  I'd give the edge to the newer model though.  I also see the color fringing is about the same too.     That's it for this comparison, see my final thoughts and conclusion on the Minolta AF 70-210mm F/3.5-4.5 if you're interested in either lens.