MGrayson
Subscriber and Workshop Member
Will,Not to encourage you (and so far you have been doing this without any encouragement from anyone here ), but how does mounting the camera based on its center of gravity effect vibration? Would having the mass off center act as a dampener or a tuning fork?
I don't know, although I suspect balanced is best.
And speaking of unsolicited experiments ... everything in the last post was focal plane shutter (the leaf will only work with THIS lens and no teleconverter) BUT, I had to see how much it improved things. First, the raw data:
As before, huge shock when the human presses the shutter button. Two seconds later, an interesting set of clicks. I suspect that it starts with the aperture blades and is then followed by the leaf shutter. I'm going to stick with my (unjustified?) rule that the exposure starts at the last vibration peak. In that event, the vibration induced blur from a leaf shutter exposure is FAR below any of the focal plane examples:
I removed the bit of raw displacement data as it only applied to one curve, and the plot was getting too busy.
The top gray line is the head with no support and a focal plane shutter. Adding the bar *with or without the head* makes a large improvement. Adding a leaf shutter makes *another* and much larger improvement. Look at the 0.005 vibration level. The leaf curve passes that at about 1/45 second. The bar supported focal plane curves cross it at around 1/5 second, and the Acratech by itself at 1/2 second. The leaf shutter added 3 stops. The bar added 1.5 stops.
The moral? With long lenses, use a support bar and leaf shutter when you can. This is a rare (but no doubt temporary) setback for Dante.
Matt
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