Suggestions on the best way to compare 50mm Primes

Ok, as you can see from my gear list I have a lot of glass but always like to have 50mm prime with me. On the FF it is a lighter catch all than an L standard zoom and on the 1D IV it's just a little wider than a standard portrait which is usefull some times.

So I've had my 50L for a little over a year now and my inability to get out of it what I want which is tack sharpness from 1.4 to 2.8 has me testing others. Just picked up a mint condition Sigma 50mm f/1.4 EX DG with the new finish to try out. Had one for about a month before I got the 50L. It had the old finish which I didn't like and the 50L became a available at a killer price so I sold it, got the 50L and never looked back but never gave it a fair chance either. Also by chance just picked up a 50mm f/1.8 Mk I with metal mount for my son so I have the three 50mm and want to do both a AF and manual focus comparison but trying to determine the best way to compare them.

Casually in the last day or two I've just been shooting anything to compare them. Right now I think I'm seeing the Sigma sharper from 1.6 to 2.8. At 1.2 on the 50L I can't get it as sharp as the Sigma at 1.4. Haven't done any micro adjust on either one yet (one my 5D III) but probably should to get the best of both.

So can somebody suggest a good way to compare lenses? I know this comparisons been done before but I need to do it to help me choose which way to go here. Thanks in advance.

swldstn wrote in post #14975892
Ok, as you can see from my gear list I have a lot of glass but always like to have 50mm prime with me. On the FF it is a lighter catch all than an L standard zoom and on the 1D IV it's just a little wider than a standard portrait which is usefull some times.

So I've had my 50L for a little over a year now and my inability to get out of it what I want which is tack sharpness from 1.4 to 2.8 has me testing others. Just picked up a mint condition Sigma 50mm f/1.4 EX DG with the new finish to try out. Had one for about a month before I got the 50L. It had the old finish which I didn't like and the 50L became a available at a killer price so I sold it, got the 50L and never looked back but never gave it a fair chance either. Also by chance just picked up a 50mm f/1.8 Mk I with metal mount for my son so I have the three 50mm and want to do both a AF and manual focus comparison but trying to determine the best way to compare them.

Casually in the last day or two I've just been shooting anything to compare them. Right now I think I'm seeing the Sigma sharper from 1.6 to 2.8. At 1.2 on the 50L I can't get it as sharp as the Sigma at 1.4. Haven't done any micro adjust on either one yet (one my 5D III) but probably should to get the best of both.

So can somebody suggest a good way to compare lenses? I know this comparisons been done before but I need to do it to help me choose which way to go here. Thanks in advance.

Take pictures. Many of them. Dozens and hundreds, if necessary. Pictures of three-dimensional subjects such as people, maybe landscapes, if nothing is moving. It typically takes a few weeks of experience with any type of photo equipment to determine how well it actually works.

Unfortunately, test charts and images of staggered trios of batteries often test no more than the camera's autofocus system and the photographer's ability to align the camera with the test gadgets.

Also, of course, you're aware that "tack sharpness" becomes more difficult to achieve with faster lenses because of the increasingly shallow depth of field those lenses provide.

DC Fan speaks the truth.

Steve, it sounds like your 50L might not be in tune. Most owners of the 50L (myself included) find that by f/2 (sometimes lower) the lens is wicked sharp. If you're not seeing sharpness equal to or surpassing the Sigma by f/2.8, I'd suspect an out of whack lens. As for not getting as sharp an image at f/1.2 as the Sigma's f/1.4 image, that doesn't surprise me, but what about f/1.4 vs f/1.4?

So at 1.4 to 1.4 specifically using AF on both lenses the Sigma appears to focus on what I wanted better. I will try on a tripod but for me personally I'm counting on AF for this lens.

I also want to know how DC fan knew about my trio of battery test I did just yesterday?