AF Consistency Test via FoCal Software: Tamron vs Canon 24-70

I think one thing everyone can agree upon is that both of these lens are sharp. However, what good is a sharp lens if it is only hitting focus 60% of the time? I thought it might be helpful to employ FoCal to compare the focus consistency of the Tamron 24-70 f/2.8 VC and the Canon 24-70 f/2.8 II. This would be a good way to provide objective data rather than another anecdotal comparison.

While I do have the pro version of the FoCal software, I don't own either of these lens. Is there anybody out there with one or both of these lens that could post up some numbers and/or graphs for focus consistency?

Worse I've seen is around 93% with a cheapo 50mm 1.8 and my 85mm 1.8 has a 99.2% af consistency. Sigma 30mm was 97.8% and the sigma 70-200 was 98.8%. The tamron 17-50 I had was around 98% also

One thing about that test with the two lenses you talked about is both will give 98.5% or better results so there will not be any difference. Your focusing on a chart which is the best case scenario. Go focus on solid colored shirts or anything real world. That would be the only real test you can do.

The focal pro software is nice but take it with a grain of salt.

You're going to have a very difficult time finding someone who owns both, honestly.

Wouldn't necessarily have to find somebody who owns both. Posting up numbers for each lens independently could let us get an idea if there is or isn't a difference. As far as using a chart for best case scenario, I don't see how that is any different than the way TheDigitalPicture site uses ISO charts for sharpness tests. I'd rather see AF performance in a somewhat controlled best-case scenario rather than test the lens in the dark. The best lens still isn't going to lock focus in a dark and extremely low-contrast scene, so why purposely cripple the equipment?

mannetti21 wrote in post #15033924
Wouldn't necessarily have to find somebody who owns both. Posting up numbers for each lens independently could let us get an idea if there is or isn't a difference.

It will give you an idea if there is a difference between the lens AF consistency; and variation in the type of target, distance to target, light source colour, light source intensity, tripod stability and camera AF consistency between the independant testers.

In science you soon learn to change just one variable at a time.