I don't have any excuse for not using a tripod. I knew I should use a tripod. I intended to use a tripod. I could have sworn that I would use a tripod. I have a good tripod. I didn't use a tripod and my photos still turned out sharp. As a result, I'm even less likely to use the tripod the next time.
On the internet, anyone can claim to be a genius. I came across a guy who swears that there are certain shutter speeds that decrease image sharpness even when the camera is mounted on a tripod. Apparently harmonic vibration varies from camera to camera. I've observed blurry images taken with a tripod mounted camera. I took the same photo 60 times yesterday in an attempt to see what shutter speed would blur my tripod mounted images.
I wasn't sure how to induce harmonic vibrations, so I tested 5 different methods. I put the camera on aperture priority and tested each method with shutter speeds that varied from 1/4 second to 4 seconds. My aperture varied from f2.8 to f11. With the camera mounted on a tripod, I took the first series using my index finger on the shutter button. I followed this with a five shot series that had a 2 second delay and another series with a 10 second delay. I took a series of 5 using a cable release and anther series using a cable release while in LiveView mode.
My 5D Mark II was mounted on a level tripod. I focused once while in Live View and turned the autofocus off. I shot at ISO 100 to keep the noise down. I wanted the only variables in the test to be the shutter speed and aperture. I normally shoot raw but I did this test in the highest quality JPEG .
I compared the 5 shots taken at each aperture and ranked them one to five. I loaded five images as stacks in a single aligned image in Photoshop. I set my view at 300% and compared the images by clicking layers on and off. I moved the sharpest images to the top of the stack. There were images that had nearly identical sharpness but each group had a shot that was clearly the best and the worst of the group.
When I had completed analysis of each group, I added the numbers for each image by shooting method. I found that pressing the shutter of a tripod mounted camera with my was clearly a bad idea. (#5) The best method was using a cable release and Live View (#1), followed by the cable release alone (#2). The 10 second delay(#3) was followed by the two second delay (#4)
I followed up this test with a second test that used the same methods with IS on. The results were exactly the same. I did notice that the longer shutter speeds were somewhat sharper than the slower shutter speeds. The cable release and Live View were clearly the best.
My best results with and without IS were so good that I nearly failed to compare them. To my surprise, the five best non-IS images were clearly superior to the best five IS images.
My tests did not find any evidence of harmonic vibrations at certain shutter speeds. They did show me that I could achieve better results using a tripod than not. The biggest change that I will make will be to start using Live View coupled with a cable release when practical.
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