I am an amateur photography and although i have taken long exposure photos before, this is the first time for a while and with my new camera Canon EOS1300D.
I am surprised at the blurry result. The photo was taken on a sturdy tripod with 2 sec timer delay. Aperture 29 and 30 sec exposure. Iso 100. I was in our house and there was no wind.
Lens 18-200mm tamron.
Am I missing something or forgotten some basic photography skills?
Although I call myself an amateur, there were some basics that I was sure I had got right. For the record, the initial photo in question was taken in clear view. There were no windows or any sort of obstruction. Also, the tripod was sturdy and I was surprised that the second-floor flooring might make such a difference. Saying that, these are all possible options.
After some testing, I have come to a solid conclusion that the issue only occurs when the 'VC' function on my Tamron 18-200 mm DiII VC Zoom Lens for Canon is turned on. Below are two pictures taken. The blurred one is with VC on and the good one is with VC turned off. Both on a tripod 2 sec delay; 30 sec exposure and 29 aperture. 100 ISO.
Looking at the website I purchased the lens through, the VC function is "Three-coil electromagnetic VC image stabilization system provides a 4-stop handling advantage for significantly sharper images"
So my question now is; Is my lens VC function working? Perhaps the VC function is not meant to be used for long exposure shots. This is beyond my expertise.
Answer
It looks like movement (primarily vertical) during the exposure. I understand you think the tripod was steady, but I think the parallel doubled mountain range and background seems to indicate that during the exposure the camera moved.
EDIT: Given the updated question and example, since right now this is the upvoted, wanted to clarify since it appears to have a specific cause not just vibration.
It appears the VC is not maintaining control during the entire exposure. My GUESS is that it's timing out in some fashion and re-centering; it might also be defective. Lens based optical vibration reduction works by shifting one or more lens elements to track (or more precisely track opposite) of vibration. The effect means the field of view is shifted during exposure, ideally to keep it in one place. It is possible that it is timing out, and re-centering back to some neutral position. It is possible it is defective and "flops" in some fashion after a given time. Testing a different VC lens might tell you if this is a "feature". All that said, most vendors recommend vibration control be turned off when locked down on a tripod; a few lenses may have a "tripod mode". If it is working at more typical stabilization shutter speeds (say 1/30th), it is likely not worth pursuing.
An interesting way to tell how image stabilization interacts with long exposure is to get a dark night and lock down on a tripod and shoot a bright star for a long exposure (adjust ISO as needed to get a dark sky and thin line). Ideally you get a perfectly straight line. Rotate the camera 90 degrees and shoot again; still should be a straight line. Both regular vibration (e.g. wind) and any optical stabilization impacts can be seen in that, effectively graphed over time, and the 90 degree flip will tell you if the stabilization is different in different orientations (note some lenses have a "mode" for active or normal or similar that can affect this also). This will let you see, for example, if it times out at 10 seconds or something consistent, with a sudden movement (my guess), or if it is just jittery. Reading the manual (lens or camera) to see if there's any comment on timeout may help also.
No comments:
Post a Comment