wwjd38 Loc: Wyoming

Photo help needed...Ok, I shot this in RAW, with a Canon 60D, using a Canon 24-70 F2.8 L lens. Very low light in this indoor arena no flash allowed. Shot in: Manual, Shutter 1/640, F 3.5, Iso 3200. It is a panning shot, using the center focal point aimed at the center of the horse. Every photo I took is back focusing and not where I aimed my focal point, making very soft photos.

Any any helpful advice?

(Download)

oldtigger Loc: Roanoke Virginia-USA

Any chance noise reduction softened the image?
I see focus half way between knee and saddle.

ebbote Loc: Hockley, Texas

This shot I would have used autofocus, to much movement,
let the camera do the work, it focused on the back fence.

GTinSoCal Loc: Palmdale, CA

It appears that the camera focused on the billboards, which is very common.
The billboards have much more contrast which fools the autofocus.

The only thing I've found helpful (but doesn't eliminate) is to focus on something with more contrast. In this case the riders waist.

Good luck with your rodeo photography!

GT

Meganephron Loc: Fort Worth, TX

That's fairly significant back focus at f3.5. I'm a Nikon guru and don't know much about Canon focusing. Assuming you are correct in choosing center focus only and no matrix then I would have a pro check your autofocus. It could be that panning may not have allowed your camera to refocus fast enough. One other thought, are you set to AF-C or AF-S

My suspicion is that panning and AF delay is the culprit especially with f3.5 being too shallow.

Kuzano

The solution to front/back focus is simple and not found in action shots, or testing in the field.

Download a kit to do the proper focus test. It's available on the internet, or instructions on how to test for lens calibration to the body (which is the fault causing back or front focus, not your actions, nor your manual focus accuracy).

The test involves a tripod, a remote shutter actuator, and an inclined measuring tool with a clearly marked "Focus Point".

It's a static test, measuring the accuracy of your Auto Focus or your Viewfinder correctness.

If you have set the micro adjustment for lenses (if available on your camera) and then you run the test, you will find how far in front or back or the focus target your camera is shooting.

You set the test up (static test) and you focus on the focus point on the inclined measuring tool.

It's pretty simple. If the image comes out focused (using a small aperture) exactly at the target, the camera is fine. If you do this a number of times at varied distances and the camera ALWAYS focuses right on on the subject, the problem is not the camera, or the lens. It's you!

Prepare emotionally for it to be you.

If the camera consistently focuses in front of the target point on the inclined measure stick, then you have a front focus problem.

If the camera consistently focuses in back of the target point, your camera is back focusing.

PS... You can't run this test at a Rodeo, or at a football or soccer game. It's a routine, well defined test. Don't drive out to the demolition derby to try it.

No one on this forum will be able to tell you with clear accuracy whether you have a problem, unless you feed us the pictures of the images taken of the measuring stick (I use a yardstick).

But you can avoid the test and never really know the answer.

There are only two answers to back/front focus.

1) calibration of lens to camera can be isolated as the problem by doing a proper "hands off" test

2) the only other cause would be you and your shooting/focusing technique.

I see varying back focus, which should not occur if the camera tests out properly. More time at the camera shooting range may be in order. :mrgreen:

wwjd38 Loc: Wyoming

No, it was worse before I worked on it in Photoshop.

wwjd38 Loc: Wyoming

Thank you. I did have my F-stop at 2.8 (due to very low light) the bill boards were even sharper, so I changed to F3.5 and bumped up the ISO, thinking it would help.
It was set on AI Servo AF.

Didereaux Loc: Swamps of E TX

well, I'd give two to one its the following. I use similar settings for wildlife, and birds. What is happening is that if you still have half shutter focusing that you are not giving it time to focus properly. You are AI servo so it will try and grab the biggest moving object and set on it. You were panning therefor the biggest moving object was the background billboard.

First is re-assign your focus to back button I use the * button. When you are on your moving target press and hold(using thumb), following the target. When it is in focus(keep pressing the back button) then use your index finger to press and hold the shutter. This works well for me even on small flying birds...even R/C planes.

wwjd38 Loc: Wyoming

Thank you, Kuzano.

As far as I can see, my camera (Canon 60D) does not have a "micro adjustment" I would have to send the lens and camera to Canon, which I will do if need be.

I do have a Canon 50D, that is suppose to have this function, I will look and try the lens on it and see what happens. If it is a back-focusing problem with the lens, wouldn't still have the problem using a different camera body?
I was hoping it was something I was doing wrong and might be able to find help with it.

It very well could be me that is not focusing right. I start out with the reining horse about 15 ft, back before the slide, at which point they are going about 10 mph, building up to about 30 mph, then they hit the brakes to get the sliding, dirt throwing, stop. I was there three days (not the hired official photographer) just on my own, photographing my daughter (in the photo). At the point the horse's speed slows so quickly and the horse's haunches goes downward, is a great possibility its me. But over three days, I thought I might improve slightly...lol.

I have a 70-200mm F2.8 L, lens (I forgot at home), which on the same camera body will focus properly "outdoors" ( I have not tried it indoors yet). I have a panning shot of a young 3 month old colt posted here on My Page that I took with the 70-200mm F/2.8 L.

wwjd38 Loc: Wyoming

Thanks, Didereaux.

I did re-assign my focus to the back button awhile back after reading an article on it. But...I did not know you could hold it while following the subject. I'll give it a try.

:D :-D

Kuzano

Every piece of equipment... ie. lens and body has it's own potential for a plus/minus tolerance, so each pairing has the potential for improper lens registration from the back element to the sensor (or film plane).

With the micro adjust system, you can adjust each lens to one body. The same set of lenses fitted to another body may require a different set of micro adjustments. That's the benefit of the system to adjust the lens registration to the camera.

In days of yore... to put this in a more age effective discussion mode, it was not uncommon to have to send the lens (or all the set used for a body) and the body to a qualified repair person or factory and actually have each component shimmed at the mount to assure proper registration.

This thanks to assembly line production, quality control, and no individual testing off the end of the line for a kit, for instance.

Quality control is generally the weakest component of third party lenses which is often the BEST argument for avoiding third party, although lower price causes us to simply take our chances. back/front focusing is often the result of the price savings.

The micro adjust feature is evidence of the fail point of matching tolerances correctly, particularly when you see how many people actually find benefit in the feature. Proof of the existence of front/back focus.

Now, we like to think that quality manufacturers hone the tolerance down to very fine quality. It appears that is not the case. My last camera that went in for calibration was my FF Canon 5D, with the kit lens 28-135. Marked improvement on it's return. Canon repair in Irvine CA did the calibration and had the camera back to me in one week.

It was obvious by the test I set up as mentioned in my last post, that my 5D was back focusing the lens by about two feet at normal shooting distance. Not so after the camera returned.

Again, calibration changes for every SET of pairings, because the range of where the lens sit's in it's own range of tolerance, when placed on a camera body holding the lens anywhere withing it's own range of tolerance.

This gets complicated at this point when you start throwing other pieces into the equation. There are no specific points at where a lens sits on a body within the range allowed for poor fit, causing the front/back focus situation.

Even my going to this extreme on the explanation is not often well received by many... it simply exists. Calibration or Fixed Lens camera's... take your pick.

Otherwise if the camera/lens clears the test, continuing problems can only occur in user problems with focus, aperture and movement or shake. That's why the static test is done with good light, tripod/remote shutter, combo of fast shutter/small aperture, to remove the variables. HANDS OFF.

Didereaux Loc: Swamps of E TX

that's the trick and nobody tells us! ;)

wwjd38 Loc: Wyoming

Thank you, Kuzano, for such great explanations. I appreciate the time and effort you took to explain everything to me. I found it interesting and helpful. I am going to try and calibrate a kit lens to my 50D, for the experience.

wwjd38 Loc: Wyoming

Let me back up a little...at the beginning of the day I had my focal point set on the center focal range/One shot. Half way through the day, and when I took the above photo, I changed the setting to, AI Servio AF.