Motion Blur (High Speed Effect Panning)

Canon Fan

TPF Noob!
Joined
May 28, 2004
Messages
1,125
Reaction score
7
Location
Purgatory, Wisconsin
Can others edit my Photos
Photos NOT OK to edit
OK so I guess I'll take a stab at this for some of the people who have had questions on motion panning. This may be a repost topic (I know xmetal did one on auto photography in March) but this is a slightly different technique and only my take on it.

Here is an example of what we are talking about . . .

smx8077.jpg


#1. Shutter Speed
This shot was taken with a Canon EOS 10D using a 50mm lens handheld at a shutter speed of 1/40 second. The key to the background motion blur is created by using a slow shutter speed and moving the camera to keep the object in the frame while releasing the shutter during the movement.

Many different shutter speeds will create this effect. A faster shutter will keep more of the frame in focus while a slower shutter speed will make the motion effect much more dramatic. The amount of effect will depend on the speed of your subject and focal length to some extent. Practice and experiment make perfect here. You will find that probably the hardest thing to conquer here is the will to stop moving the camera when you press the shutter button! It really is like a golf swing, learn to follow through after releasing the shutter and the rest will fall into place.

Too slow?!?!? Yes there is such a thing! While going slower and slower with the shutter speeds adds to the motion effect (making the subject appear to be going faster and faster) eventually vertical camera shake becomes a real problem. The image below was shot at an amazingly slow shutter speed of only 1/13 of a second! However out of about 20 shots I attempted this was the only one even worth looking at due to the horrendous amount of vertical camera shake. This might have been avoided somewhat by the use of a monopod or even a fluid head tripod. I did have good results that were handheld at shutter speeds of 1/25 and faster. You just have to practice to see what works for you.

Same basic subject speed, much slower shutter speed = Faster looking picture . . .
smx8099b.jpg


#2. Focus Issues
Focusing a subject while panning can be a bit of a trick. First off for my shots I set the camera's AF mode to AIservo so that the camera will constantly readjust the focus setting automatically on my chosen focal point while I am tracking the subject. I usually will select the center focus point and worry about cropping to my liking later which makes it easier to concentrate on the subject and your panning speed. In the end you'll have less throw away's doing it this way I believe.

When you set up your scene and prepare to shoot an image coming past try to Pre-Focus the camera using an object that is approximately the same distance from where you are to where the subject will first enter your view for the panning. For instance when making the capture above I found a fence post that was the same distance to me as the rider would be when first entering my view. I then depressed the sutter half way to focus on the pole and hold there until the rider entered my viewfinder. As soon as the rider enters the frame I began moving with him as he proceeded towards me keeping him centered with my choosen focus point to ensure a sharp image. As soon as the rider was centered on my focus point and had reached a pre-determined position (or re-determined on the spot) I released the shutter while still moving the camera and following through with the movement until he had left my veiwfinder.

Focal length and movement axis can also reek havoc on these shots. The above pic was shot in a corner so the rider was almost always the same distance from my camera. This makes things a little easier because you are only dealing with movement on one axis. A rider going straight past my camera would be more difficult because as they pass you they are also getting closer and/or farther away which will add motion blur in the subject depending on how slow you shutter speed is. The only thing I can say to this is that your best shot will come when the subject is most perpendicular to the film plane (or sensor plane) because you will reduce the amount of axis movement at that point and hopefully only be dealing with the effects of one. Focal length is also of consideration here because the further zoomed out you are (say 200mm as opposed to 20mm) the harder it is to isolate one axis of movement. However the distance at which you are to the subject can have the same effect! :confused:

There is a mathmatical equation for figuring out how fast of a shutter speed is needed to keep a moving object X amount of distance from the camera sharp while blurring the background but I admit I have absolutely no idea what it is. My best advice is to experiment and practice to see what works well in your situation.

#3. Depth of Field, Exposure, and Filters
There are two ways of determining exposure for this situation that I have used personally. One is to meter various parts of the scene, averaging them, and then compensating by one or two 1/2 or 1/3 stops in either direction according to your subject or take a shot with a higher sutter speed first and then figure out the required exposure for a longer shutter mathmatically. I usually use the first method and have had good results. If you are shooting with digital you can also check the histograms on the spot to see if you have it right and make adjustments accordingly.

Depth of field isn't much of a problem here but it can wreck some would be good shots if it is too shallow. Just remember that DOF will appear shallow already due to the motion blur so using very high f/#'s won't be a problem if the shutter speed is slow enough. However if you do go to low (say f/2.8) you may lose much of the intened effect because there won't be any texture to the moving background to show the motion because it will be so blurred already. Also a low f/# can create focusing issues because of the shallow DOF. You really need everything on you side working to make the subject sharp here so I would almost always stay above f/8.

Filters may be necessary depending on the lighting situation. If your lenses minimum aperature (ie- f/22, f/32) still allows too much light in for your chosen shutter speed a Neutral Density filter can be used. This will block some of the incoming light allowing for a longer shutter speed while maintaining a proper exposure.

#4. Using a Flash?
Yes you can use a flash! You do need a camer and flash unit that will allow for slow sync speeds though (I would also recommend rear curtain sync for this as well). While it sounds dumb there are still issues concerning fill and low ambient light shots. Pick up almost any skateboarding or mountain biking magazine and you will most likely see some images that flash was used on while panning. I used some fill flash on a couple of my shots at the track and had varying results. This is another area I can only advise you to experiment with ;)

#5. Multiple subjects
Panning multiple subject in one frame can produce some interesting results beacuse you are dealing with so many aspects at once. Multiple movement axis, focus, DOF, panning technique are all at work at the same time. Mainly you just need to remember you can really only pic one as your main subject and forget the rest. If two are close enough that will probably work but I personally try to just pick one to focus on as my main subject. Pictured below is a not so great attempt at this.

smx8163.jpg


OK so now my brain is flustered and my fingers hurt! I can't think of anything else right now so I'll leave you with the above and will try to answer questions as they arise in the future. Hope this helped at least a little bit ;)
 
Absolutely awesome tute! If only I had a camera that could do this - I'd be out there now!

In the great words of Ali-G .... "Respect!"
 
There are way to force even disposable cameras to do this to a certain extent. What type of camera are you using?
 
i've tried this a few times and have only come up with one that i like at least a little, but next time i find something moving ill definately try ur tips because some things i havent thought to think about before

anyway thanks!!!
 

Most reactions

Back
Top