Author Topic: Improvement for focus ramping during timelapse  (Read 5557 times)

KeeganBaird

  • New to the forum
  • *
  • Posts: 8
Improvement for focus ramping during timelapse
« on: June 17, 2012, 04:29:37 PM »
I have been playing around with the focus ramping feature which has just been recently added to magic lantern.  I really like it, but I had some ideas that could possibly improve it.

So, right now to only option (that i know of...) is to set how many steps the focus will change per shot, which i find somewhat limiting.  The focus will just keep going until I get the "focus limit reached" error.  I was wondering if it is possible to tell the camera to do something like this:

-Set timelapse duration to 2 hours
-Take a shot every 5 seconds
-Set my initial focus point
-Set my final focus point
-I want the focus to start ramping 15 minutes into the timelapse
-I want the focus ramping to reach its end point at the 1hr45min mark
-Automatically end time lapse at 2hr mark

I assume this would be possible if magic lantern is able to automatically determine the amount of focus steps required to rack between 2 specified points.  Maybe this would depend on the lens?  If it not possible to determine the amount of steps, I guess the timing start and end point could probably be added with little trouble, no?


a1ex

  • Administrator
  • Hero Member
  • *****
  • Posts: 12564
Re: Improvement for focus ramping during timelapse
« Reply #1 on: June 17, 2012, 08:49:47 PM »
The problem is how do you put all these on the user interface?

To set initial and final focus point, you would have to use something like rack focus (and everybody says it's very difficult to setup). You can already use it to see how many focus steps you need, but you have to stop it manually.

As it's now, you have full manual control over the process (when to start focusing, when to stop, when to go faster/slower...) but you risk moving the camera when you change some parameters. But it shouldn't be difficult to fix camera movement in post.

Probably the best way to do advanced timelapse shots like this would be to use Lua scripting.

scrax

  • Contributor
  • Hero Member
  • *****
  • Posts: 1543
  • Code monkey
Re: Improvement for focus ramping during timelapse
« Reply #2 on: June 17, 2012, 09:39:16 PM »
I think that setting the start and end points is just a bit difficult to learn at first. And when recording is not difficult at all now, once memorized the right buttons.
But maybe follow focus can be merged in the shortcuts feat so to have SET also available and using it for setting start and end points.

My idea is that when FF is active on the arrow keys we press SET for the first thing in focus (start, but better see it like point A that at first boot is null) the point is saved, then we focus with FF+ or FF- to the second thing and since point A is already set we   save this like point B (end point). Now that we have pont A and B set each press of SET button can start the focus ramp, to erase A and B we can use some other button like DOF or trash button (why not? overriding the ML menu only if we have FF shortcuts onscreen and A and B points are set).
The only bad thing I can see here is if we want to open MLmenu without resetting A and B points, and that could be done pressing the shortcuts button to change from FF to the next shortcut and so trash will not delete the focus points saved.
I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-