Having trouble getting sharp focus on a moving subject

[ilzho]

Ok, I have been taking pictures of horse racing, some good, some not so much.

I am using Rebel Xsi, usually in a creative mode, AV or TV or just starting manual mode as well.

I am in AI servo, using center af point, continuous shooting mode.

I have not tried Back button focusing (yet).

These pictures where taken in later afternoon, early evening, (6-7 pm) so the ISO is a little higher, just trying a few different things.

One thing that is common is that I am getting more pictures out of focus than in sharp focus, so clearly I am doing something wrong.

Either I'm not getting the center af point on my subject, or camera shake, or too slow of a shutter speed. Or I need more practice 🙂

My post processing is pretty bad as well as I am only using what Iphoto has to offer.

I am panning my shots, either to freeze the motion or to try a little motion blur.

I realize it will be very hard for you all to give me any concrete advice as you are not with me, but as always, you have giving me sound advice.

This one is in focus.

This one, not so much.

Some others......

[ebiggs1]

I am not a fan of Creative Mode.  As a matter of fact none of my cameras even have it as an option. Of course I come from a time when all cameras only had manual.

But for making the subject the sharpest it can be, the SS must be faster by some degree than any moving item.  Make sense?  Camera or subject, doesn't matter. SS must be quicker.

You might try Tv.  You may need to experiment to see just how how it must be for stop action.  But 1/500 gets a lot of things pretty well stopped.  You could set the Tv to 1/500 and let the camera choose the Av.  You can also use auto ISO of which I am not a fan either but some like it.  I just can't seem to give up the control.  Funny though, I always say, a lot of the time the camera is smarter than the photographer. 

[ilzho]

It makes total sense.

I usually am in TV mode.

It was getting late so I thought the very quick shutter speed would make my pics a little darker, maybe I should have used a little Exposure compensation.

The first one that is sharp, was ISO 320, f 3.2, SS 1/1000 with a 100mm lens.

I usually have the ss on a bright day (hopefully today), about 1/1500 or higher, but these pics, being early evening, light disappearing, it was hard for me...... One day, I will figure it out, haha.....

 Some of these were in manual mode and some in av & tv mode.

I'm slowly trying to get into manual mode......

[ebiggs1]

I think your next step is to get in to post editing.  Always shoot RAW.  A good editor for the amateur is Photoshop Elements.

When you shoot RAW you have a great deal more latitude in post. If you miss exposure by a stop or even two, you can usually recover all.

If I were you I would stick with one mode, in htis case Tv.  Make sure you know how it is acting on your shots.  Try different settings in the ISO and the Av.  But keep the SS pretty high at least 1/500 and stay with Tv.  When you make big changes like switching between modes, Tv and then Av and perhaps,... etc., your ability to learn what is happening goes down. Too many variables!

Because of slightly differing conditions, what worked last weekend might not work this weekend. Some tweaking is in order.  If you have stuck with Tv for a while and know what it is doing, making small adjustments is a snap.  You will just know, feel, what to do.

[TTMartin]

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@ilzho wrote:

It makes total sense.

I usually am in TV mode.

It was getting late so I thought the very quick shutter speed would make my pics a little darker, maybe I should have used a little Exposure compensation.

The first one that is sharp, was ISO 320, f 3.2, SS 1/1000 with a 100mm lens.

I usually have the ss on a bright day (hopefully today), about 1/1500 or higher, but these pics, being early evening, light disappearing, it was hard for me...... One day, I will figure it out, haha.....

 Some of these were in manual mode and some in av & tv mode.

I'm slowly trying to get into manual mode......

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Canon calls P, Tv, Av, and M the Creative Modes and you are correct for using that.

I don't think you need to use a faster shutter speed than 1/1000 of a second. All your other settings, AIServo, continuous shooting etc. are correct. By using the center AF point you have to be sure that the AF point has sufficient contrast to focus on. So if your center AF point is on the horses brown neck there may not be enough contrast for it to focus on. You might try Auto AF point selection mode. In AIServo Auto AF point selection mode, your camera will start with the center AF point, and hand it off to the surrounding AF points if the center AF point loses enough contrast to focus on. 

Other than that, just keep practicing.

[ilzho]

Thanks!

Good advice.

I did try auto af point one time at the track and I learned not to do it when it's a group of horses together, because it grabbed focus of a subject that was in the background and the front horses were out of focus.

Now, I probably did some things to create that, but I guess if the horse is clearly by itself, auto af point would probably work better.

From that day, I just figured I better learn how to use the center af point, haha.

This rebel only has 9 points, so I try to use the center one.

[ebiggs1]

"This rebel only has 9 points, so I try to use the center one."

That is what you should be doing.

[jrhoffman75]

The primary value of AI Servo is when a subject is moving around the viewfinder and/ or moving to or from the camera. There is about a tenth of a second lag between when you actuate the shutter and when the image is captured. Depending on the speed of the subject it could move out of the focus point/DOF. 

A horse/race car etc. moving parallel to you doesn't present that issue. The distance between the subject and camera isn't changing. 

Canon on recommends that if you are in AI Servo you focus on the object and half press the shutter about a ½ second before you snap to allow the camera to "do the math". 

Different people pled have different opinions, so you should try your own experimentation, but I would suggest you try One Shot. 

I agree 1/1000 shutter speed is more than adequate. At 60 mph the subject would only move an inch. 

[ilzho]

Well, I will certainly keep trying and playing around with everything.

As the horses are coming down the track, they are coming towards me and then crosses my parallel plan and then they get further away as they head to the finish line.

Granted they aren't moving around like a basketball or football player, but I'll keep trying.

I'm going to the track in a few hours to try again........

[Waddizzle]

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@ebiggs1 wrote:

"This rebel only has 9 points, so I try to use the center one."

That is what you should be doing.

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With only 9 points, that is exactly what you should be doing.  You do not have AF assist points in AI Servo mode.  What you have is the camera frequently making undesireable decisions for you,.as it chooses an AF point to use.

I get the best success with my T5 using just the center, and pre-focusing [using back-button focus] in One Shot mode.  I have never tried to photograph horses, but I would begin by knowing my distances to the subjects so that I can know what depth of field to expect.  By knowing what my depth of field will be, I can get a handle on what to expect to be in focus when the action moves into my "focus zone."

I have gotten great results by pre-focusing on an area where I expect action to be.  I try to "focus low", by that I mean that I angle the camera downward focus at the ground, and then recompose the shot by moving the camera to a level position again.