What is Wrong Here?

Hey all,
I have a question about some of my shots that I figured you would be able to answer. I shoot with a Rebel XSi and a Tamron 70-300 f/4-5.6 Di VC lens. I went spotting at JFK yesterday, using Tv mode with a mix of Spot and Evaluative metering (which is correct?) and AI SERVO (is this correct?). I shot from North Woodmere Park, so the planes were a bit far away, however, this is how photos would come out (unedited):
http://farm8.staticflickr.com/7018/6...fb9e5886_b.jpg
A lot of my pictures come out with this blur, and I feel the pictures just aren't crisp and clean. Do you all have any tips here?

Can you post the EXIF data for this photo? Shutter speed, aperture, ISO? I usually use spot metering and always use AI Servo mode when shooting aircraft.

http://www.flickr.com/photos/7085653...n/photostream/

You can see some editied ones on the Flickr photostream as well.

I'm no pro, but when I encountered this, I was usually not following my typical procedure and being careless; but if you're shooting at shutter priority, I'd aim for 1/500, and then adjust your exposure compensation to get your apertures at about 8.0. Use your histogram after each shot (or each plane) to see that the primary peak is down the middle. If not, that's when you adjust your exposure compensation.

I think 5.6 is a little low and wasteful when you're extending your lens to the max. You also need to see if your lens, though it can reach 300mm, can actually shoot EFFECTIVELY at 300mm.

If you are going to let your cam pick settings I wouldn't use shutter priority. You may as well be shooting manual. Pick the Aperture and let the cam pick the shutter for best exposure. If light is decent and not harsh no need for exp comp. Put it around F8 or so and go from there. You also need to get a bit closer.

Good starting point with good to ideal light would be.

F8
ISO 200 or lower if you can hold it steady.
Aperture priority will pick shutter for best exposure
0 Exp Comp
Set WB for sunny or Auto.

If you are close enough you should see some improvement.

I do agree with Nick about using Av mode instead of Tv. Having the camera choose the shutter is a better bet than having it choose the ap.

Adam, for shooting airliners in good light, I usually start in Aperture Priority, f/7.1, ISO 100, using spot metering and AI Servo mode. I'll keep an eye on shutter speed, looking to keep it at 1/400 or faster. I'll bump the ISO a little if I start to lose the light and need to catch something. I do use shutter priority for prop aircraft, so I can slow down the shutter speed to ensure I get an acceptable amount of prop blur. I'll also use it at times when shooting fast movers (military jets, mostly) and want to ensure I have a fast shutter (1/1000 and faster).

Just to rule out other causes - have you had this problem with non-aviation photos? Try shooting a distant stationary object, with the Tamron on the camera, just to make sure it's not an issue with the camera's focus or your technique.

If you're issue is the blurryness/OOF then it most likely is your AF system being fooled by heat shimmer/haze. The distance to the flightline from North Woodmere is great, don't discount that fact. At the far end of the walkway it is far. IF you shot from the parking lot, it is even further. Take a look at my map here for distances to the flightline from our spotting locations.

http://g.co/maps/5s63k

Zoom in and click on the thin green lines for distances...

300mm at North Woodmere does not magnify the subject enough (especially a white body aircraft against gray sky) for some AF sensors to properly lock on solid. So if the subject does not present a sharp contrast to the a/f sensor, your camera will either guess or hunt or both.

You could try to test by setting infinity MANUALLY using Live View against a static object like one of the homes near the flightline and then manually setting it and see if that gets you good results. You MUST make sure you do not bump the Focus Ring so it is not a suggested mode of normal ops :wink:

i always shoot in evaluative metering, F8-11 (unless it's really low light or i'm panning), and AV mode...I used to shoot with a 0EV but recently i've been shooting at ISO 200 to help cut through heat haze and keep things crisp...I've also started shooting entirely in .RAW (should have done that looooooong ago rather than shoot 800 shots I'm not going to use) and push the histogram as far to the right as possible without blowing any major highlights (landing/taxi lights, sun flare exempt). When I edit in .RAW, I can tone back the image a bit which retains much more detail in the shadows and highlights without producing an excess of noise.

Also check to see that you're actually shooting in AI Servo for your focusing...I've forgotten to change it from one shot for statics to servo and missed several shots because of it.

Thank you all for your responses. I will try to use f/ 7.1 or 8 next time I'm out at CLT, and switching between spot and evaluative to see which one works better for me. I talked to one of my friends who is also into photography, and he says that f/8 or f/11 is the lens's sharpest point.
I've never shot in SERVO up until last time I went out, so I'll do that from no on. I'll make sure to post results.
Manny, we were all the way at the end of the park--and if I could go back tomorrow, I would, but I'm in Charlotte, so it's hard to teleport up there lol. But the traffic at JFK is unbeatable...wish we had it here in CLT.