DOF Question

[Hill Country Hack]

Ok gang,

I went to a local HS Freshman game to practice my action photography. I was not very successful. Even with back button focus, I can't track the action to allow the camera to focus, or my auto focus is too slow. I had better luck with subjects coming at me or away. Anything at an angle or perpendicular was OOF. I was using center focus point and was trying to keep subject in center of frame. I even changed to all focus points and focal lengths without any improvement. I was able to keep my shutter speed above 1/300 and up to 1/500 with ISO from 100-400. Below are three examples. These are SOOC as I have yet to do any PP except to convert to jpeg and resize.

My main point of this exercise was to try to soften the distracting background by shooting wide open (for me). The most open I can get with my kit zoom (75-300 Non IS) at 200-300mm focal point was f5.6. I was able to achieve some softening, but not what I wanted.

Looking through my images I have concluded:
1. The nearer my subject is to me and the further the background is from the subject the better the results I obtained.
2. I may need to shoot more from above (hard to do at field level) or closer to ground shooting up as to have opposite sideline/sky at top of frame to lessen distractions in BG.
3. Get faster glass if I was to get better results with DOF.

Any and all feedback to include tips will be appreciated. Thanks for taking the time to look.

As for the focus issues, I'll have to do a lot more practicing and concentrate on action at me or away and not at angles.

For the mods- I did not include EXIF data as I already stated my setting ranges at beginning of post and I am not asking about exposure.

[RichardTaylor]

Your three conclusions are correct.

Just one question, what's the background like when shooting from the other side of the field (if the lighting is OK)?

Re focus:
I shoot motor racing and birds in flight etc.

Miss focus is the largest reason for technical failure.
When talking with other photographers; focus accuracy is the #3 topic.
The light is #1, very closely followed by (#2) the racing itself.

You will find better (including faster focussing) lenses do help, to a point (I am usually using a Canon 100-400 F4.5-F5.6 IS L on a Canon 40D)

I use centre focus point only and AI servo. I don't use back button focussing yet.
I acquire the subject as soon as possible and start tracking it with the shutter button partially depressed to give focus time to lock on. When the subject looks good in the frame I fully depress the shutter button. The first pic usually looks good.
Depending on the speed and direction (velocity) of the subject to me, and if I am firing off a burst, the next photograph will not quite be in focus and possibly the one after will be. I don't think the ~2/10 of a second between shots in burst mode is long enough to lock on & start tracking again.

Hope this helps.

.

[Hill Country Hack]

Thank you Richard.

If I were on the opposite side I would be facing the home stands and it is a concrete structure painted blue and therefore not any help. The posted shots were taken between 5:00 and 6:00, so I had plenty of light. Plus I was exposing slightly to the right.

As for my back button focussing, I would start my focussing prior to the snap and track my subject with the button depressed and acuate the shutter ahead of what I wanted to compensate for the lag from depressing the release and the actual release of the shutter. I was getting pretty good at that.

On a side note, the local pro sports photog was there with his BIG lens and while I was chugging away with my 3-5 fps, he was bursting around 10fps. Sounded like a mini machine gun.

[mrteacherdude]

Going beyond the scope of your original question about DOF and going in the direction of your focusing woes, your lens may be a factor here. I have not read any "good" reviews about the 75-300 other than it is inexpensive. The reviews I read were about the newer versions of this lens and it looks to me like you are using an older version since you mentioned non-IS. Lenses typically do improve with new iterations. I do know some people that have this lens and like it, but they are not trying to shoot action. If you know someone with a collection of other kit-type or relatively inexpensive lenses, you might try the EF-S 55-250 f/4-5.6 IS (about $200 new) and the 70-300 f/4-5.6 IS USM (about $550 new). It looks to me like the newest version of the 75-300 includes micro USM, but the reviews of the quality of photos were not favorable for what you are trying to do.

I own the 55-250 and it does an "ok" to "pretty good" job. I've used the 70-300 IS USM and it does a better job, and focuses much quicker even though it is not ring USM. I rented a 70-200 F2.8L (non-IS) and it blew me away. When I feel I have enough money to invest in better glass for telephoto action, I am likely to go with L series like a 70-200 or with the 100-400 that RichardTaylor mentioned in his post.

But if you don't have a lot to invest, just starting out, etc., I would recommend seeing if you can try the other two lenses to see if it makes a difference for you.

RichardTaylor already addressed your three conclusions about your DOF, but I thought I would elaborate some. You will get better bokeh when the distance between your subject and the background is increased. You will get better bokeh with bigger apertures. So, if you want your background to appear as just a smooth blending of color, get down on the field with the players and shoot them with a really fast (f1.8 or better) prime lens as they run you over Hmmm... not practical. Faster glass like you suggested, and longer focal lengths, should yield improvement.

Incidentally - there is no shame in chugging away at 3-5 fps. I have lots of good action shots taken with my 3.5fps camera. After much thought about a body upgrade recently, I decided to go to a 7d so I could have the higher frame rate as well as a few other features and improved UI over the Rebel series. That decision has resulted in having about 3 times as many photos (when shooting action) I have to sort through and decide whether or not they are keepers. Sometimes I dial down the frame rate or put it into single shot mode just so I don't get so many pictures. And sometimes I just use my Rebel

[Hill Country Hack]

mrteacherdude-

Thank you for the valuable input. First off, I feel no shame at my fps. It leaves me less images to go through It is a fact and I need to work within the parameters of my equipment. I took about 170 images and actually imported about 20. I have yet to really look at them, but I feel I'll get about 10 usable images and then only 2-3 worth even fiddling with. I do not have expectations of 100% keeper rate, but I feel I should be able to get about 10% keepers with my skill level and equipment limitations. I'm sure that will increase slightly with more practice. I would be elated with 20% knowing how difficult it is to get it all right during a constantly changing situation.

I know I have entry level gear as my wife bought this stuff for her and I kinda hijacked her gear and at the time neither of us knew squat about photography and gear other than P&S.

I am still satisfied with what I have, but I am beginning to look longingly at other gear. The quality of my images are steadily improving and I have no aspirations on making photography a profession. I am just trying to become more well rounded and versitile, while being able to put some great stuff on my walls and give as gifts to family and friends.

[sk66]

You didn't mention..Were you in AI focus mode? In AI the camera will attempt to track and predict focus for a moving subject.
The Rebel XS only has seven focus points so it may be a little weak in performance here.. (or so I've read)

[sk66]

BTW, aperture and subject distance both affect DOF. The further from the subject you are the greater the DOF, and to battle this you need a wider aperture.
How close the BG is to the subject determines if it falls w/in the DOF.

People misunderstand this all the time, it's why you can't always "zoom with your feet" and get the desired results.

[Hill Country Hack]

Originally Posted by sk66

BTW, aperture and subject distance both affect DOF. The further from the subject you are the greater the DOF, and to battle this you need a wider aperture.
How close the BG is to the subject determines if it falls w/in the DOF.

People misunderstand this all the time, it's why you can't always "zoom with your feet" and get the desired results.

I was in AI serv mode to allow continual focussing on the moving subject while tracking. That mode is the only one that allows back button use, otherwise I would have to maintain a 1/2 press of the shutter release. It is easier for me to continue to press with my thumb than to maintain 1/2 press the release.

In my next session I'll concentrate on action in the middle of the field/coming to me and forget about the stuff headed to the opposite sideline. I'll also spend more time in the end zone when the offense is inside the 50 yard line.

[sk66]

Sounds like a plan..
Next step would be gear, and it's an expensive direction to go... You'll need a camera with better AF tracking AND a longer/faster lens.

[Jim Bryant]

One thing that might help you with your focus woes is to change focus functions from shutter button to the back focus button. Here a bunch of info. back focus button - Google Search.

I've been using this method since 2002 and it truly works. I get about 7/8 of my images in focus.

Also...the 70-300 is one slow focusing lens.