Help with panning shot problems

[smcclelland]

Hi everyone,

I'm new to the canon boards so pardon the rather generic thread title. I recently switched to a Rebel 400D coming from a Pentax DSLR and have been trying to wrap my head around some anomalies with my panning shots. I picked up a 75-300 EF f4-f5.6 III USM lens to use for motorsports until I sell the rest of my pentax gear and have been noticing some strange out of focus issues. Below is an example and here is a link to the full resolution example shot (http://www.creaturetd.net/pictures/IMG_1669.JPG)

I'm curious if it may be my panning technique that is causing the edges of the shot to become soft, either because of vertical camera shake or not fluid enough motion. The lighting was horrid this weekend at Mosport with consistent clouds and very poor conditions which made me wonder if the AF wasn't getting a good enough lock. The example shot was taken at 1/80, ISO 400, 95mm @ f9 and some of my better pans were only sharp when using a shutter speed of 1/200 and above.

Any help would be greatly appreciated.

Cheers,

Shawn

http://www.creaturetd.net/pictures/IMG_1669_web.jpg

[dann22]

Welcome.
I will be watching this thread cause I am curious to see the responses.
I am no pro, but I will take a stab at it.
From looking at your full resolution pic, it seems as though you caught the rear end with some vertical rebound movement from the suspension (or something like that). I say this because the front hub looks nice and round, and the rear hub is not. The Brembo in the front caliper is ok, but the decals on the rear of the car are blured. I don't know what is up with the right front of the car unless maybe the suspension is the problem there also.
Hopefully someone will give you there professional opinion.

[Tiesse]

It looks to me that you were panning from the outside of the bend which can be difficult as the car is turning away from the radius of your pan. It is either that, or you have captured the image slightly past the optimum panning point as the car passed you.

The high res image shows from the driver forwards is in focus, however the stickers etc to the rear of the car show a horizontal movement, not vertical. To me, this goes some way to supporting my theory above. I don't personally feel it is a focusing issue as the driver is in focus.

I wouldn't be too disappointed though, it is still a good shot & the only way to improve your panning technique is through practice.

[NickR]

1/80th, you can't expect to get your subject sharp all over with the best pan and shoot technique, I would think the vibration of the car would cause motion blur @ 1/80th, you achieved good images @ 1/200th, I would stick with that or faster.

Nice image all the same.

Cheers

[smcclelland]

Thanks for the feedback, I did some more testing today at the track and noticed it was a mix of things. Where the cars entered the Moss turn there's a repave patch, the Prototype 1 cars were shaking as they came about (the audi's would scrape and spark). Also as noted, I noticed I was extending my pans a bit far and was "reaching" to get the last few frames which was throwing things out of focus on extremes. I got some much nicer ones today as the weather improved greatly and started to learn the more focussed points of the pans, seems I was spoiled with SR in the Pentax body and it's like re-learning a whole new technique for me :) Thanks again for the help.