Best I can do

[calmwater]

No matter how hard I try, I just can't seem to get flying birds in absolute perfect focus. I find it so hard to keep focus while trying to shoot. These hawks were hunting for fish along the shore. Here are a few of the best.
1/2000, f 5.6, iso 800, hand held Canon t6i.

 

[zombiesniper]

What lens are you using?

Part of the issue with the first two is that the birds head is in shadow which will make it look a little soft.

 

[Winona]

Not sure about that camera, but my Canon 80D has a lot of settings to help with tracking. Look for videos settings for BIF with your particular camera. And knowing the lens would be helpful. I used a lens for over a year thinking the issue was me. It wasn’t. Different lens made all the difference.

 

[weepete]

Probably a few factors coming into play. They look like they are focused ok to me, how much are you cropping?

 

[K9Kirk]

I get the same kind of pics all the time doing handheld, there's nothing guaranteed. As weepete mentioned, there are a number of factors to consider. Are you turning from the waist to follow birds? If not, you should, it's the smoothest way. Try this ... go from f/5.6 to f/8, (I do f/10 sometimes if the light allows) to increase your dof so everything is in better focus in case your camera say, focuses on a wing tip closest to you. See if that helps a little. Then increase your shutter speed to 1/2500 - 1/3200. I like shooting at those shutter speeds, I get the best results. Try mixed combinations to see what the differences are, you'll learn fast all on your own doing that.

Of course increasing your s.s. and using smaller apertures will increase your ISO and possibly introduce some noise to your pics but you can work with a little noise. The way I see it, it's better to have a little noise in a sharp pic than no noise in one with fuzzy detail. Try it and see how you like it. Post your results if they come out good, I'm curious to see what happens. GL.

 

[calmwater]

OK. I'll try some of the suggestions. I wasn't sure about how high up on shutter I should go but I'll try it. Lens is just the kit lens at 250 mm. Looking for a better one but have budget concerns. As for the shadow on the head, that seems to depend on which way they fly and never seem to cooperate for me. These images were cropped about a third. Thanks for the input.

 

[Destin]

Probably a few factors coming into play. They look like they are focused ok to me, how much are you cropping?

This. They look pixelated to me, not out of focus. This indicates that they're overcropped to make up for a lack of zoom range in your lens.

 

[weepete]

OK. I'll try some of the suggestions. I wasn't sure about how high up on shutter I should go but I'll try it. Lens is just the kit lens at 250 mm. Looking for a better one but have budget concerns. As for the shadow on the head, that seems to depend on which way they fly and never seem to cooperate for me. These images were cropped about a third. Thanks for the input.

ok, 1/2000th sec is quite fast. I'd be looking to hit that speed or up to 1/2500th sec if the action was fast, like shaking or grabbing a fish out of the water. You could probably drop it a little if they are not in a dive, but at ISO 800 you are well within the parameters I'd consider accepable for good shots. Indeed I'd be happy to push it to ISO 1600 on your camera before I'd be starting to think about trading a little shutter speed. So I think your settings look good to me.

From the exif data you seem to be using an EF-S 55-250mm f4-5.6 IS STM. It looks like an ok lens to me, not the sharpest but not totally terrible. Most of the super sharp shots you'll see will be shot using the big primes, which are generally very sharp but costly. A lot of Canon shooters look towards the 100-400mm f4.5-5.6 L as good quality versitle lens. A few of us go for the 150-600mm superzooms from tamron and sigma, they tend to be slightly softer and the AF not as fast but the reach is great. So I'd probably place a little blame on your lens, being a little short and slightly soft but I would expect your shots to be a bit sharper.

Lenses are often not the sharpest wide open, so I'd stop down to f8 and see if that makes a difference.

Cropping by 1/3rd is getting towards the limit IME, but I'd expect that still to yeild acceptable shots.

How are you post processing? Noise reduction can destroy fine detail so I'm wondering if you are underexposing a bit, bringing the exposure up in post then reducing the noise too much? I've seen that before a few times.

The only other things I can thing of right now is if you are not getting the birds in the centre of the frame (lenses are at their worst at the edges) or if your AF settings are missing focus. I'd check your AF point(s) are actually on the bird and test your lens for back/front focusing.

 

[zombiesniper]

Great advice above.

The only other things I would add is to use the least number of focus points you can maintain on the subject. I almost exclusively use a single focus point. This allows me to place it on the bird and not the wings. Also make sure your drive mode is AI Servo. This is Canons dumb name for continuous auto focus.

I can tell you that your camera is able to get great detail. It's 2 generations newer than the image below. I don't have experience with your lens but it should be able to create acceptable detail. The 1/3 crop will certainly be a large factor in detail loss.
I think if you take the suggestions here and practice you should easily be able to create images that you're happy with.

If you do ever think about getting a new lens and don't mind not having image stabilization. Find a good used Canon 400mm F5.6. It is the best bang for your buck wildlife lens on the planet.
This was also shot at 1/2000 f5.6 on a Canon T5I and Canon 400mm f5.6. I had better light but faster subjects.

Swallow Feeding by Trevor Baldwin, on Flickr

 

[K9Kirk]

OK. I'll try some of the suggestions. I wasn't sure about how high up on shutter I should go but I'll try it. Lens is just the kit lens at 250 mm. Looking for a better one but have budget concerns. As for the shadow on the head, that seems to depend on which way they fly and never seem to cooperate for me. These images were cropped about a third. Thanks for the input.

Using a kit lens may very well be the problem, they usually don't have the best glass so it will never be as sharp as a lens with more quality. Edit: I just read the review above and noticed he said your lens is actually a decent lens. I think the #1 thing to consider is tracking a moving subject well, even if you move a little with a subject sitting still it can cause some fuzziness. Give it time, practice, you'll get there.