I had the 50L few years back first with the 5D and then 1DsII. The lens was much easier to use with the 1 series body, less hunting and more keepers. Recently I browsed through my photos with the 50L and was supriced to how many frames were OOF. I also noticed that in some shots there's quite lot of blooming so images might have underlying sharpness but still kind of soft and others might be quite contrasty and sharp with no blooming or softness to be seen. Seems like the quality of light changes the character of the lens. I'd be able to shoot concerts with bright colorful spotlights and the images look very sharp and contrasty at f/1.2 but the I'd shoot a soft window light portrait and it looks glowing. I also find the lens does not suffer this glowyness when subject is further back (like fullbody portraits). I still like the lens but am not sure if I'd buy one back. ..maybe for the beautiful bokeh, I don't know.
hauxon wrote:
I had the 50L few years back first with the 5D and then 1DsII. The lens was much easier to use with the 1 series body, less hunting and more keepers. Recently I browsed through my photos with the 50L and was supriced to how many frames were OOF. I also noticed that in some shots there's quite lot of blooming so images might have underlying sharpness but still kind of soft and others might be quite contrasty and sharp with no blooming or softness to be seen. Seems like the quality of light changes the character of the lens. I'd be able to shoot concerts with bright colorful spotlights and the images look very sharp and contrasty at f/1.2 but the I'd shoot a soft window light portrait and it looks glowing. I also find the lens does not suffer this glowyness when subject is further back (like fullbody portraits). I still like the lens but am not sure if I'd buy one back. ..maybe for the beautiful bokeh, I don't know.
With the help of VF Eg-S, Center AF light/beep confirmation and LV, I did conduct a MF test with my 5D2 & 50L. In the first test, i have MF switch position engaged to control the lens elements from moving and the focal plan results are the same in both wide open and aperture stopping down cases. I repeated exactly the same MF test with AF switch position "on" and the focal plans sometime found in and out positions from wide open default position.
From these test results. It tells me, the 1/3 dof focal plan calculation from body AF firmware is not always stable and it might be the main reason not to get the best shot sharpness. Best is not to trust your cam AF system while using any fast lenses. Get yourself a VF focusing screen to help you monitoring the final focal plane before shutter.
Using a 5D3, I find I need to use centerpoint AF and recompose to increase my success rate. If I use the outer points the results are never as good. The 5D3 focuses fine with other lenses using the outer points but the 50L seems to be unique in this regard. It really isn't that big a deal for me to recompose as long as I'm getting a sharp subject.
Gust wrote:
when I put the combo now on a tripod and using the AF by 1.2 its in focus [ but a little soft, but its in focus]
every time I close the aperture from 1.2 to 1.4 and up to 2.8, the [in] focus moves with every 1/3 stop further away from the original focus point.[ focus distance ca 1-1,5 meter
At 4.0 its gone and every thing is fine.
That's how those lenses ARE, by their design. I had one and tested it carefully (tripod, mirror lockup and all that) and it performed exactly like what you describe. Got rid of it.
D. Diggler wrote:
That's how those lenses ARE, by their design. I had one and tested it carefully (tripod, mirror lockup and all that) and it performed exactly like what you describe. Got rid of it.
You should read Gust's later response on this issue. Imo, My 50L is a fine lens and it does not behavior like described. You might either have a bad calibrated copy or bad focus system.
