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

jvc1 wrote:

streetsnyc wrote:

AlephNull wrote:

I use autofocus on the center point, and I do believe that I use settings that are generally supposed to come out with sharp photos, such as an appropriate aperture + 1/FL, etc.

It's the shutter speed, not aperture, that's supposed to be 1/FL. It would be rather difficult to set an aperture of f/100 on a 100mm lens, for example, but it's easy enough to set a shutter speed of 1/100th of a second.

Autofocus doesn't work well on smooth surfaces, because it works on edges. A striped shirt, for example, makes a good focus target. Also, try to fill the AF target box with the thing you want to focus on - it can easily get confused if you are focusing on something small. If your subject isn't wearing stripes, then place the focus box on an edge between your subject and a contrasting brightness background - like a light coloured subject on a dark background, or a dark coloured subject on a light coloured background - that will give your AF the best chance of nailing focus.

The 55-200mm zoom is not a high quality professional lens, so don't expect perfect results. You can get good images from it, but there's a reason people spend a lot more on lenses like the 70-200mm f/2.8L IS (as someone facetiously suggested ). Bear in mind, though, that the L series lenses are most needed when trying to get the shot under difficult conditions. If you stick to relatively easy shooting (lots of light, good contrast), you should be fine.

Oh, yeah, I mistyped. I know shutter speed is 1/FL. I meant setting the aperture 1-2 stops from wide open (or whatever review sites say is sharpest like f/7 or f/8, etc.).

And yeah, I'm starting to see that you get what you pay for. My obsession with sharpness really only began when I got the ShutterStock rejection for focus, and I suppose that's the reason that pro photographers use pro equipment: they can afford/justify spending big bucks on better gear since it pays for itself. For the amateur who doesn't derive income from photos, however, I suppose I'll have to be happy with whatever such a cheap lens can give me I suppose I was mistakenly expecting National Geographic level of detail from a budget lens.

Here's one of the latest shots I took with said lens, with Lightroom processing:

Sharpening: 121
Radius: 2.1
Detail: 16
Masking: 0

I'll have to settle for these being good enough for social media pics and private use, as opposed to trying to make commercial-level photos.

I agree with Ed, you can do better. the high ISO is costing you some sharpness due to noise. You're better off opening the aperture and lowering the ISO. This is an old one taken with the original 55-250. Forgive the blown highlights.

That's a very nice shot but the OP hasn't yet shown that he can take a satisfactory image of a stationary object withi good contrast in good light to satisfy himself and others that hs PDAF is working properly.  The example of birds in trees is about the most difficult to get right and any hope of seeing sharpness is destroyed by the necessary high noise due to the settings (well they could be better chosen but still difficult).