Panning focus/blur question

I'm trying to take pan shots at motorsport events, using a slower shutter speed and panning the camera to blur the background. In many cases this works quite nicely:

[IMG]http://i10.photobucket.com/albums/a149/hpfirenza/Donington%20March%2022nd%202014/IMGP0706a.jpg[/IMG]

But by far the majority of the time, I get this:

[IMG]http://i10.photobucket.com/albums/a149/hpfirenza/Donington%20March%2022nd%202014/IMGP0692c.jpg[/IMG]

Literally the majority of shots I took last weekend are like the above, and I'm looking for advice on what the issue might be. I'm trying to decide between:

Expecting too much from a Kx and Tamron 70-300 lens
Focus position is wrong
General technique is wrong
Shutter speed too slow, just good luck that some work
Or anything else.

As I recall I started out at 1/100, increased to 1/125, and then to 1/160. Much faster than that and the background starts to get sharper and the effect is lost. I didn't get noticeably better shots on 1/160 than I did on 1/100.

Any suggestions greatly appreciated.

I do a lot of motorsport photography and I can say that it took me several months to get to grips with the panning technique and basically, it takes a lot of practice to get it right more often than not. Even now I occasionally screw up after 2 years of doing it every other Saturday.

I think your gear is fine for daylight shooting. I use a K-5 II + Sigma 70-200mm 1:2.8 + AF540FGZ (when needed).

For daylight shooting I use TAv mode, setting the shutter speed to 1/160th or 1 stop either side. The aperture I tend to use is f8 and sometimes f4 depending on the available light (I shoot during the evening, 7 - 9PM, March to December). In TAv mode the camera adjusts the ISO for correct exposure. In the following example, Shutter 1/160th, aperture f4, ISO 800, no flash.




One trick I learned very early on is to not try and fill the frame with the car(s), you'll be able to follow the action more precisely and more smoothly by using a wider focal length lens and cropping later.

Another tip, keep panning before, during, and for 2 seconds after you've pressed the shutter button. It's the same technique as clay pigeon shooting, you keep following the target's trajectory even after you've squeezed the trigger.

Vary your panning speed to match that of the target vehicle. In your two photos, the grid markings seem to have the same amount of blur indicating that the panning speed was more or less the same for the two shots. Could it be that car two was traveling much faster/slower than car 1, and you weren't panning fast enough/too fast?

It looks to me like shake rather than focus.
Not having witnessed your technique I can't rule it out but I suspect its mainly a matter of practice & the high failure rate normally expected with panning.
I've been practicing panning for years and still get quite a high proprtion of failures.
Checking the EXIF on the panned images I have in the gallery here & on Flickr I've managed some sharp ones at 1/90s (150mm and 340mm focal length), and in some places got good background blur at 1/180s (270mm). My record is probably https://www.pentaxuser.com/photo/take-off-21525/large 1/20s at 170mm.

I do remember other shots where one end of the car is sharp but the other shows considerable vertical movement. I think this was down to a bumpy section of track as the worst ones were all from the same area.

Generally I find the inside of a bend works best to shoot from, as this keeps the cars nearer to the same distance throughout, and catch fencing is often less of an issue too.

Mannesty's technique tips are all good, I'd just add twist at the hips to follow the cars (unless you're using a monopod).

I don't think it has anything to do with gear, just technique.

For slow shutter speed panning to work you have to have the target stationary with reference to the camera. Looking at the image, say at the 'T' in 'BRUT', it seems that you have managed to track the car pretty well in the vertical plane but there are multiple images blurring it in the left/right plane. From this I think the technique fault is probably going to be not maintaining a smooth panning action throughout the shot.

Mannesty (who clearly has a lot more panning experience than me) suggests smoothly panning for a longer distance than the actual shot time and that suggestion seems spot on the money for fixing the apparent problem with that second image.

Good luck,
Rob.

I should add that my Sigma lens is an OS version which I have set to mode 2 OS, this mode maintains image stability only in the vertical plane and locks the horizontal plane rigid otherwise the lens keeps trying to stabilize the panning lens. I'd like to see this choice for the Pentax SR system because it's incredibly useful for panning shots such as these.

For the above reason I'd suggest turning SR off when trying to make panning shots. It could be that your camera is simply trying to correct for what it thinks is camera shake, but isn't.

My point about continuing to pan after pressing the shutter is especially true when you have a decent racing scenario and cars are close together. Don't try and snap them all on the same lap because you'll be tempted to jab at the shutter and quickly reposition yourself for the next car whilst the shutter is still partially open.

Thanks for those thoughts - if nothing else it's good to know that it isn't just me that (should be) binning a fair number of shots.

Peter, that shot is what I was trying to achieve - pin sharp vehicle and blurred background. Even my good shots are good when cropped, dropped to 800 pixels and run through the unsharp mask in PS, I'm not sure they'd stand up to scrutiny if posted full-size. Though there will be some improvement on that score with your higher-resolution camera.

There is a chance that the cars are at different speeds, what I really should have done was post a second shot of the same car - again, no telling whether it was going slower for one lap than the other, but of six or seven shots of the Firenza, one worked and the rest are just like the Capri shot below. I was trying to pan with the car, a short distance before, then take the shot, then carry on. Trouble is, take 200-odd shots across two races and it all starts to get a bit hazy as to what I tried.

They are both quite cropped, though could have been more so - I was using the 70-300 to get some distance freeze-frame shots as they came around the bend, but then at other times using the shortest focal length to get the pan shots, and 70mm is a little too close. I was having the same trouble at Oulton last year using the 50-500 from a bit further away. I don't do this very often (mostly static car show shots) so perhaps it is practice.

There will be some shake Mike - this was Donington last weekend, and although it was blue sky a lot of the time, it did go very cold at one point and I was having shake trouble for the later race due to freezing cold rain. I've got a couple where one car is overtaking another and I've managed to get the one in the background pin-sharp but the one you can see all of is blurred, not what I intended at all.

Good to know it's not really the equipment though - at least that means it's worth carrying on trying to get the technique right.

I wondered about the lens because it's a cheapo zoom really, but then the Sigma isn't cheap (to me at least) and I still had similar trouble. It's the old Sigma, though, without built-in stability control.

I always used to try to get the fastest possible shutter speed to freeze the action, but frozen shots don't look as good (IMO) as these panned ones unless you catch a roll or something special, and I'm always looking the wrong way for those. I will practice some more in the summer.

I was editing my post above when you posted yours Mike. Read the amended version. If you are using SR turned on, that might be the cause of your blurry images.

I was getting a lot of poor quality/blurry images when panning and eventually realised that this was often due to the camera shake reduction not having stabilised. This can take up to a second, and it is unlikely to stabilise whilst panning. Nowadays I turn off SR for this kind of picture, and get much better results. Still plenty of poor shots, but certainly more and better keepers.

When I said shake I meant movement relative to the car. Gwing's reply explains it much better than I did.

I love the first photo, Mike. I was at Donington yesterday and suspect I don't have any Firenza shots of even remotely parallel quality.

There's some good advice above about deactivating in-body shake reduction - and panning is a hit-and-miss technique (mostly miss, in my case, but the hits sometimes make it worthwhile) that requires practice and patience.

As for the lens, I would counsel using manual focus with a Tamron 70-300 - they are great value for money, but not nearly quick enough to track moving racing cars. I no longer have one, but found it worked much better if I pre-focused on the racing line with AF disabled. Below is a 1/100 shot taken with K-5 and Tamron 70-300 at the 2011 Italian GP. Almost every AF shot I took had to be deleted, but switching to MF brought a significant improvement.

Thanks Peter - I saw your second post, edited mine to add about the Sigma lens, but didn't see your edit. I had never thought of turning off shake reduction, but will try that next time.

Simon, thanks for the note about AF - I think that's probably what I meant about the equipment not being up to it. I'm not sure my eyesight is up to the idea of using manual focus, but maybe the catch-in-focus feature will help me out.

In any case it seems that dispense with shake reduction and do a lot more practising is the way forward, along with accepting that I'll have a lot of deleting to do.

Cheers all.

MIke, the catch in focus system only works with manual focus lenses, or lenses that have an MF/AF setting set to MF. It won't work with AF lenses even if the body is set to MF.

Yes, I think I remember that - I used it with my Tamron 500mm mirror but I'd never looked at the zoom, now I look it doesn't seem to support that. Looks like there was a good reason for keeping all my old manual PK lenses after all!