Backfocusing question

How can you tell if a lens has backfocusing issues or if it's just me?
Reason I ask is because I have been getting so many OOF shots where the subject is OOF and the background is focused. It seems to be happening to at least 50% of my shots. I have had OOF shots before with other lenses, but not like this. If there is something wrong with the lens, does anyone know how much it costs to get it fixed? It really very well could be me, maybe I have some settings wrong. I just recently started shooting in high speed continuous, do you think this is my problem? Should I go back to low speed continuous?
Here are just 2 examples.

Sorry, I just realized I probably put this in the wrong place. I don't know how to delete it?

do the focus test chart and check. www.focustestchart.com

What lens, what camera, where are you focusing, what is the aperture, what is the shutter speed, what AF mode are you using?

We need this information to try and help you. I'll try to give it a go, however.

If you use high speed continuous, you will likely need to set AF mode to Ai Servo, and follow the subject. It is very likely the camera focused on the background with your first shot, and by the time the players got into the picture the camera was still focused on the background as a result. In order to get thsi right, you need to track a sporter, and that is what Ai Servo is for.

Another way of shooting the shown pictures, is prefocusing, with the aid of the *- or AF-ON button. The base plate is a place where a lot of action occurs, so you could prefocus there and wait for the action to arrive, with the option to use high speed continuous to have a bigger chance of a keeper for a specific action. Similarly, the guy catching the ball is jumping straight up, and therefore you could have prefocused on him.

HTH, kind regards, Wim

Back or front focusing refers to slightly not accurate focusing. In the pics above the focused area is way beyond your subject. Taking into consideration that you shot sports, fast moving subjects, someone could easily suspect you missed the subject when auto focusing... It happens very often.
Are you facing the same issue with still subjects...???
Are you using center AF point, or automatic..?

Cheers,
G.

Canon 40D 70-200mm F/2.8L
AI Servo
Center focus
Evaluative metering
F/2.8 for both

First sample:
ISO 100, SS 1250
This shot was the 1st shot, here is the second...which is OOF as well.
(All of these shots are SOOC, just resized...no corrections or web sharpening at all)

wimg wrote in post #7894593
What lens, what camera, where are you focusing, what is the aperture, what is the shutter speed, what AF mode are you using?

We need this information to try and help you. I'll try to give it a go, however.

If you use high speed continuous, you will likely need to set AF mode to Ai Servo, and follow the subject. It is very likely the camera focused on the background with your first shot, and by the time the players got into the picture the camera was still focused on the background as a result. In order to get thsi right, you need to track a sporter, and that is what Ai Servo is for.

Another way of shooting the shown pictures, is prefocusing, with the aid of the *- or AF-ON button. The base plate is a place where a lot of action occurs, so you could prefocus there and wait for the action to arrive, with the option to use high speed continuous to have a bigger chance of a keeper for a specific action. Similarly, the guy catching the ball is jumping straight up, and therefore you could have prefocused on him.

HTH, kind regards, Wim

Thanks for the link, I will check it out!

jeromego wrote in post #7894544
do the focus test chart and check. www.focustestchart.com

I seriously do hope it is me! I got the lens a few months ago but just recently been able to use it. I never had this problem with the 70-200mm F/4L I had. Of course I had some OOF shots, but not the backfocusing like this.

The only thing I have used the lens on is baseball. I'm going to give it a test on some stills and see. I don't have great lighting in my house so tomorrow I am going to take it outside and see what I can attempt.

I'm using AF point.

Deus Ex Machina wrote in post #7894649
Back or front focusing refers to slightly not accurate focusing. In the pics above the focused area is way beyond your subject. Taking into consideration that you shot sports, fast moving subjects, someone could easily suspect you missed the subject when auto focusing... It happens very often.
Are you facing the same issue with still subjects...???
Are you using center AF point, or automatic..?

Cheers,
G.

I also noticed that this happens on brighter sunnier days... could just be coinsidence as I don't see how that could have anything to do with it?

caroleigh wrote in post #7894672
Canon 40D 70-200mm F/2.8L
AI Servo
Center focus
Evaluative metering
F/2.8 for both

First sample:
ISO 100, SS 1250
This shot was the 1st shot, here is the second...which is OOF as well.
(All of these shots are SOOC, just resized...no corrections or web sharpening at all)

2nd sample
ISO 100, SS 1600
Only shot taken, I focused on my player (or at least I thought I did)

Thanks for helping.

Thank you for the additional info.

In this shot the DoF-zone seems to extend from just before the knee of the sliding player to about a meter further, so it is hard to say if his face is in focus or not. Maybe one of the sports shooters here can jump in. I don't think this is a back or frontfocusing problem, but likely more how to handle situations like these best.

Personally, I never use continuous mode, so I don't really know how well the camera handles AF with slides like these. You may have to use more focusing points, so the camera's logic can deal better with the movement wiithin the frame, but that is only a surmise; I don't normally shoot sports, and even when I do, I only shoot in single shot mode anyway - a leftover from years of MF shooting without a motor winder .

Kind regards, Wim

wimg wrote in post #7894724
Thank you for the additional info.

In this shot the DoF-zone seems to extend from just before the knee of the sliding player to about a meter further, so it is hard to say if his face is in focus or not. Maybe one of the sports shooters here can jump in. I don't think this is a back or frontfocusing problem, but likely more how to handle situations like these best.

Personally, I never use continuous mode, so I don't really know how well the camera handles AF with slides like these. You may have to use more focusing points, so the camera's logic can deal better with the movement wiithin the frame, but that is only a surmise; I don't normally shoot sports, and even when I do, I only shoot in single shot mode anyway - a leftover from years of MF shooting without a motor winder .

Kind regards, Wim

Your settings seem ok...now set it to 6fps and shoot away