I recently upgraded from a prime 400 5.6 to the 100-400 4.5-5.6. Many of my shots have a bokeh with parallel lines in it. Trying to figure out why. I have a UV filter on, not a polarizer, which was my first thought. I have not tried without a filter yet, but will. Thought maybe someone here might have an idea why I'm getting this. The other thing I have noticed is that the autofocus is not as fast as with the prime and sometimes struggles to get to focus. I'm a bird photographer, so sometimes my subject is quite small and in a bunch of branches, but my prime was faster. I still like the final photo result of the new lens better, so I'm sticking with it. I attached an example of the bokeh problem
"Some of the softness there is likely atmospheric haze / humidity."
Bingo! Anytime you shoot that far away the atmosphere is not your friend. Especially over water.
The lens is not the 'holy grail' of zooms. It is right dab in the same IQ range as most of the better zooms like this.
The Tamron 150-600 and Sigma twins 150-600 all do about the exact same quality.
You are too far away. Of that there is no doubt. Always use the hood, never take it off. The bottom picture is fine for the distance. The top one is enlarged too much for the conditions. Plus you probably downsized it for the web.
Here is a Blue Heron I shot from around 40 to 50 feet. It was done with my 1D Mk IV and the Sigma S at 600mm.
I softened the exposure of the background in PS and applied lens correction. This guy was truck'in, I mean!
You can do extreme enlargments. But you must select the right ones. Cropping or enlarging costs you in sharpness.
I don't remember exactly how much this one was but it was a lot. I was again pretty close so it was a good candidate.
My trusty 1D Mk IV and the big Siggy at 600mm.
BTW, I use filters on all my lenses that they don't impact. I always have a I always will most likely. The SIgma doesn't have one because it has a special coating on the front element which is huge. A filter would coat a boat load of money.
@mfostervt wrote:I recently upgraded from a prime 400 5.6 to the 100-400 4.5-5.6. Many of my shots have a bokeh with parallel lines in it. Trying to figure out why. I have a UV filter on, not a polarizer, which was my first thought. I have not tried without a filter yet, but will. Thought maybe someone here might have an idea why I'm getting this. The other thing I have noticed is that the autofocus is not as fast as with the prime and sometimes struggles to get to focus. I'm a bird photographer, so sometimes my subject is quite small and in a bunch of branches, but my prime was faster. I still like the final photo result of the new lens better, so I'm sticking with it. I attached an example of the bokeh problem
I'm not sure if this issue has been fully diagnosed, but I can reproduce it at will.
Too much crop. Too much sharpening, at too large a radius brings out the distortion, which is already present in the photograph. I shot this photo in AI Servo mode. In One Shot mode, it seems to go away.
It is not always visible in AI Servo mode. It seems to show up at certain shutter speeds. I'm placing my bet on the shutter speed being a harmonic of the update frequency of AI Servo, or possibly combined with IS.
[EDIT] I haven't been clear. In One Shot mode, it is less apparent, although it still seems to be apparent. I shot this in IS Mode 1, and focusing mode 3m to infinity. Distance was roughly 20 meters.
Also, what I meant when I said the shutter could be a harmonic of the update frequency of the AI Servo, I was referring to the frequency of the pulses being sent to the motor, not how often it updates the tracking.
I seldom use more than 10 Clarity, but, will often use 100 Sharpening in conjunction with very heavy Masking typically 75.
Apply a heavy sharpening mask in Lightroom so you don't sharpen even areas.
By pressing and holding the 'ALT' key, while moving the Masking slider you can see what is being masked. Black areas will not be sharpened.
Sharpening Amount set at 100 and Masking set at 70
Smooth unsharpened bokeh.
"By pressing and holding the 'ALT' key, while moving the Masking slider you can see what is being masked. Black areas will not be sharpened."
Slick trick!
YOU cleaned up the shot of the robin.
