|
Re: Field curvature is irrelevant...
In reply to TOF guy,
3 months ago
|
TOF guy wrote:
Robin wrote:
I've seen amateur telescopes take as long as five seconds to settle.
Well, telescopes are big ! So they carry more momentum even for the same weight.
One could test settling time by simply attaching a laser pointer to the camera and watching the do jump around. Aim the laser pointer at a piece of grid paper 20-30 ft. away. Trigger the camera with a wireless remote, or watch the grid paper with binoculars.
For the record I do it differently. I use a fixed laser pointer (not attached to the camera) and take an image of the laser dot. The dot will appears as a random line in the picture, which provides a recording of the camera motion. The time it takes to see how long it takes to settle is measured by taking several pictures at different shutter value (the time it takes for the dot to just barely returned to its original position). It also gives an extent of the vibration.
Are you taking a photo of the laser dot reflected off a piece of paper? How far are you from the paper? What focal length lens?
Or, are you aiming the laser at the camera?
This can be awfully sensitive. I use a wireless a few feet away from the camera.
But there is no need to discuss our differences in the approach: we've had this discussion already
We did? Oh well, my memory isn't what it used to be, or at least what I remember about what my memory used to be.
--
Robin Casady
http://www.robincasady.com/Photo/index.html
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts."
— Bertrand Russell
| Post (hide subjects) | Posted by | When | |
|---|---|---|---|
| 3 months ago | |||
| 3 months ago | 2 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 6 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | 2 | ||
| 3 months ago | 1 | ||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago |