drj3
Forum Pro
The last time (02/07/24I went to my local wildlife refuge to photograph Short-eared Owls, I noticed a higher percentage of images with target blur than in the past. I was shooting in SH2 (25 fps) mode with the MC20+300mm f4 at 1/1600. Previously I had used the normal burst mode at 20 fps (IS Priority – actual fps rate 7-10 fps). While I always shoot with S-IS Auto, the camera cannot typically stabilize each image at more than approximately 10 fps, so I do expect a higher shutter speed to be required for SH2 mode than with the normal burst mode with IS Priority.
As a test, I planned on starting with a shutter speed of 1/2000 and then successively increasing it during the visit. Unfortunately, the owls did not get the Memo. They stayed at 1000+ feet distance and mostly flew so the setting sun was the background. (Image #1)
Shortly before sunset an eagle appeared and I shot a long burst at 1/2000, but unfortunately the eagle remained at a distance of 980 feet or more, making any determination of motion blur by comparing fine feather detail of the images impossible. (Image #2).
Finally, as the sun was setting, a Northern Harrier flew by, close enough to see some feather detail (220 feet). I could only run a single test at 1/2000, to see if that shutter speed was sufficient to eliminate motion blur for the moderate size hawk. It was flying fairly fast as it was leaving the refuge for the day.
I chose a set of three consecutive images from this burse as an example to show that a shutter speed of 1/2000 in SH2 (25 fps) mode is not sufficient to prevent motion blur for this bird. There will be some blurred images and loss of fine detail on some of the images.
The bird was flying parallel to the camera, so the image distance changed very little for the three images in 3/25 of a second. The EXIF image distances were 221, 219.7, and 219.7 feet for the three images with a total depth of field of 215 to 226 feet. All three images were close enough to the center of the DOF to provide good detail if there was no motion blur.
The third image is the first of the three image set to show the image size in the frame.
The fourth image shows the crop of the bird for the three images and finally the fifth image shows the crop of the head of the bird for each of the three images in the set.
The first bird in image #4 is what I would generally consider an Okay image, but not a maximally sharp image. You can see the fine feathers around the beak, but that detail is somewhat blurred.
The middle bird image has significant motion blur. Since there is no detailed background for comparison, I can not determine if this was caused by camera/lens movement or bird movement. However, a faster shutter speed would reduce the blur caused by either camera/lens or bird motion.
The final image of the bird’s head in the set is what I would consider a sharp image for the MC20+300mm at a distance beyond 200 feet. You can see the fine feather detail around the bird’s beak even though the head was in the shadow of the body/wings.
This finding of blur at approximately three times the focal length does not surprise me. Several years ago, I ran tests with the E-M1.2 with the MC14+300mm f4 and found that some of the images of a GBH shot at 18 fps and 1/1250 with fps Priority were blurred due to camera/lens movement. I do sometimes use very slow shutter speeds for moving targets in CAF mode (as low as 1/100 for flying hummingbirds), but I typically use IS Priority when the shutter speed is less than 1/3 x FL.
The next time I go to the refuge I will try to run bursts at 1/2500 and 1/3200 with SH2 (25 fps) to see how much these reduce the percentage of images showing motion blur.
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drj3
As a test, I planned on starting with a shutter speed of 1/2000 and then successively increasing it during the visit. Unfortunately, the owls did not get the Memo. They stayed at 1000+ feet distance and mostly flew so the setting sun was the background. (Image #1)
Shortly before sunset an eagle appeared and I shot a long burst at 1/2000, but unfortunately the eagle remained at a distance of 980 feet or more, making any determination of motion blur by comparing fine feather detail of the images impossible. (Image #2).
Finally, as the sun was setting, a Northern Harrier flew by, close enough to see some feather detail (220 feet). I could only run a single test at 1/2000, to see if that shutter speed was sufficient to eliminate motion blur for the moderate size hawk. It was flying fairly fast as it was leaving the refuge for the day.
I chose a set of three consecutive images from this burse as an example to show that a shutter speed of 1/2000 in SH2 (25 fps) mode is not sufficient to prevent motion blur for this bird. There will be some blurred images and loss of fine detail on some of the images.
The bird was flying parallel to the camera, so the image distance changed very little for the three images in 3/25 of a second. The EXIF image distances were 221, 219.7, and 219.7 feet for the three images with a total depth of field of 215 to 226 feet. All three images were close enough to the center of the DOF to provide good detail if there was no motion blur.
The third image is the first of the three image set to show the image size in the frame.
The fourth image shows the crop of the bird for the three images and finally the fifth image shows the crop of the head of the bird for each of the three images in the set.
The first bird in image #4 is what I would generally consider an Okay image, but not a maximally sharp image. You can see the fine feathers around the beak, but that detail is somewhat blurred.
The middle bird image has significant motion blur. Since there is no detailed background for comparison, I can not determine if this was caused by camera/lens movement or bird movement. However, a faster shutter speed would reduce the blur caused by either camera/lens or bird motion.
The final image of the bird’s head in the set is what I would consider a sharp image for the MC20+300mm at a distance beyond 200 feet. You can see the fine feather detail around the bird’s beak even though the head was in the shadow of the body/wings.
This finding of blur at approximately three times the focal length does not surprise me. Several years ago, I ran tests with the E-M1.2 with the MC14+300mm f4 and found that some of the images of a GBH shot at 18 fps and 1/1250 with fps Priority were blurred due to camera/lens movement. I do sometimes use very slow shutter speeds for moving targets in CAF mode (as low as 1/100 for flying hummingbirds), but I typically use IS Priority when the shutter speed is less than 1/3 x FL.
The next time I go to the refuge I will try to run bursts at 1/2500 and 1/3200 with SH2 (25 fps) to see how much these reduce the percentage of images showing motion blur.
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drj3
