harathedog wrote:
First, I am so pleased with the candid comments from UH friends. Thanks, everyone.
Does anyone think a full frame Canon (or Nikon) would have produced a sharper image with a longer exposure to blur the props?
The B-17 was flying low and about, oh I don't know, 150 MPH? No time for a tripod. Shot with Canon 70D (APS-C), Tamron 150-600mm lens at 500mm, 1/640, f6.3.
I frequently shoot on-the-fly..whenever things happen. Usually on an Auto mode. Appreciate any subjective comments.
First, I am so pleased with the candid comments fr... (
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The prop blur is a factor of shutter speed, with no relationship to sensor format what-so-ever. You could set and use slower shutter speeds to produce more prop blur effect (motion blur) on your 70D, with the same results.
If, in fact, you'd have used a full frame Canon or Nikon to take that shot, you would also have needed a longer telephoto lens to frame the subject the same way. Instead of 500mm on Nikon you would need 750mm... or 800mm on a Canon camera. Figure about $13,000 for the Canon 800mm lens ( the Nikon costs $16,300).... and probably another $1500 for a good solid tripod to put it on (because it's too big and heavy to handhold for anything more than a few minutes).
Another way of looking at it, your 70D gives you a "free" 1.6X teleconverter effect. By "free" I mean it's built into the APS-C crop and here's no loss of light to an actual teleconverter. Your f6.3 lens remains f6.3... instead of dropping to f9 as it would with an actual 1.4X or 1.5X teleconverter attached (or more like f10 with a 1.7X... or f13 with a 2X.)
Previous responses are correct... using a slower shutter speed to increase prop blur will also make other movement of the airplane more likely to blur. All you can do about that is use as fast shutter speed possible... that will blur the props enough, but maximize chance of keeping the rest of the airplane sharp... practice panning techniques, and take extra shots (assuming some will be blurred an unusable). It also might help to use a tripod with a gimbal head or gimbal adapter... or a monopod. I recommend you do some experimentation, take some notes, learn what works.... and what doesn't.
Here's an example of a pan-blurred shot I took....
In this case I wanted to try to capture the speed of the car with motion blur (including the faster moving blur of the car's wheels) as well as blur down an unattractive, busy background, and reduce other distracting elements by blurring them. The shutter speed I used for the above was 1/50 (and 200mm lens at f16)... however the effect varies and faster or slower shutter speeds can be necessary depending upon speed of the subject, direction of travel, distance between you and the subject and the focal length you're using. You might need to try a few different speeds to find what works. This is much, much easier with a DSLR than it ever was with film... with DSLRs you can immediately check your images to see if you're getting satisfactory results. Back in the days of film, we had to wait a few hours or days for the film to be processed, to find out if our settings were successful or not! I also can assure you that some of the shots won't be successful. That happens to anyone trying pan-blurred shots. You are walking a thin line between getting part of the image sharp while blurring other parts. Some shots work. Others fail. So plan on trashing some... and take extra shots!
Compare the above to another shot taken moments later using a different camera and lens, but using a higher shutter speed (1/800) as well as the car coming toward me instead. Both these factors helped to freeze the action (also used a longer focal length, although that would usually make for more motion blur, not less)...
I was still looking for the same things in my image... speed and action. But this time utilized the longer focal length and a larger lens aperture to blur down the background (300mm lens, f5.6 aperture), hoping to capture the speed aspect with the strong lean of the car negotiating a tight turn as well as dirt and rubber flying off the pavement around the tires (probably not visible at Internet sizes and resolutions).