Focussing a Canon lens
I've spent the afternoon trying to find the best way to focus a Canon lens. After fiddling with Indi focus tab buttons, the camera's live view etc. I figured the easiest way to do it is this:
1. Switch on the camera, leave it in autofocus mode, disable mirror lock, manually focus it roughly to infinity.
2. Connect the cam to Ekos
3. In the Capture/CCD tab activate Live Video [Edit: Can now be done in the focus tab]
4. In the focus tab click at "focus in" or "focus out" while observing the result in the Live Video window. Once you're happy with the result, close the Live Video window and you're ready to take pictures.
A few remarks:
a) I'd like to have a live video button in the focus tab. [Edit: Has been done. Thanks, Jasem!] With that, the user would be enabled to do it all in one place.
b) Unfortunately I don't know how to increase/decrease the focuser's step size (focus ring movement). Changing the value in the "step" field as far as I can tell doesn't have any effect. The values entered in the Indi control panel focus tab also don't alter the step size unless the Indi control panel itself is used to focus the lens.
c) The Live Video has an "Exposure" field that is set to 0.1s. Increasing the value does not have any effect on video brightness.
I also tried alternative ways to focus, for example by activating the camera's Live View at the camera body first, then opening the live video window in Ekos/capture tab and then focusing from the Indi panel's focus tab. The latter provides the luxury of 3 focusing speeds and a focus timer, something I'd like to have in Ekos' focus tab. The downside with this method is: After focusing, the ISO field in the capture/CCD tab has changed to "AUTO" instead of the usual ISO number. To get rid of "AUTO", the camera has to be disconnected and re-connected from the Indi panel's "Main control" tab. Once this has been done, you have to exit the Ekos capture/CCD tab and re-enter it. Now AUTO can be changed to a proper value again.
In order to improve the user experience / ease of use, it would be nice to have a Live Video button in the focus tab and some means to inrease/decrease the step size for focusing.
knro wrote: Since the Canon focuser is not an absolute type of focuser, it doesn't have "step size" per se. It depends on direction/speed rather than a fixed number of steps.
That's right, there is no absolute position that could be set. The Indi Panel, however, provides two options to control focus movement, "focus speed" and "focus timer". That's what you mean when you say "It depends on direction/speed" I suppose.
It would be very helpful to have control over speed in the ekos fokus window. Otherwise, in case the focus isn't set close to perfect when you start, you'd have to press the "focus in" / "focus out" buttons several hundred times since the default movement is tiny, really.
knro wrote: I'm aware of the Live Video exposure field issue.. it actually changes the value but does not restart the stream. At any rate, on Canon, this cannot be controlled.
Pity. There is another problem with the video stream. When I "draw a box" using the mouse, the driver crashes. Log and video attached.
In the focus tab one has to open the Live Video window before clicking at any of the focus in / focus out buttons. If a user happens to press one of these with no Live Video window open, they don't work and also won't work later when the Live Video window has been opened (unless the cam is disconnected and reconnected to Indi).
Therefore we should make sure the focus in / out buttons are inactive/non-functional whenever
1. Canon DSLR is selected as active Focuser AND
2. no Live Video window is open.
I'd be happy to hear from other Canon DSLR users if this is the same with their cams.