Should I return/replace my lens? EF-S 55-250mm sharpness/focus

streetsnyc wrote:

Thanks everyone for the suggestions and help!

By using live view and taking a photo of an analog wrist watch, I think that I've determined that the lens can definitely create sharp images. What do you think? I know it's not ideal as my space is not well-lit and I had to shine a flashlight to even see anything...

Manual focus

Auto focus

So, given that, I believe that it is not my equipment that is defective, and that it's just me that needs improvement

Any general tips for capturing sharp images when it comes to shooting street portraits of people or animals in motion? For instance, I'm never sure if I should use AI Servo or One Shot. It's hard to do a controlled test of this, for obvious reasons

Speaking of which, would the autofocus system of my camera be another issue? Because I believe that I achieved the sharpest image (using the watch as a test) by manually focusing. The difference is barely noticeable except when viewed at 100%, but it made me wonder if there's anything I can do to optimize AF accuracy? For instance, I use an AmazonBasics UV filter.

You're making life difficult with your varied tests.

Go outside on a nice day with some clearly defined object that fills most of the frame, ISO 100, f/8 and with the camera on a tripod or resting on something and the timer set take photos using live view and then with centre focus only, One Shot.  Compare the images.

Ditch the filter, what do you want a UV filter for anyway?  Get a hood, It will protect the lens from damage and it will protect the lens from unwanted light.  I've got a Canon hood on my 55-250 but a Maxsima petal on my 18-55 which fits quite nicely.  They (nearly) never come off.

Once you've got that sorted you can try your hand at AI Servo - you are right about AI Focus, it generally is neither here nor there.  Read up on AI Servo, it takes a second or two for the tracking algorithm to get going, after all it has to see what motion there is before it can predict where the subject is going to be, and that assumes a good contrast area and a consistent motion.

This was One shot, centre focus point only, handheld: