View Full Version : Hyperfocal distance and depth of field display


Tramm Hudson
August 1st, 2009, 03:38 PM
I've just posted a demo video of some of the new features in the upcoming 0.1.6 Magic Lantern (http://magiclantern.wikia.com) release: hyperfocal distance, depth of field readout and focus stacking: Magic Lantern - DOF and Focus stacking demo (http://vimeo.com/5879032)

I'll film another demo to show off the HDR capabilities with programmable bracketing. It's not really cinema related, but believe it or not, I get more requests for 5-11 exposure bracketing than 24p.

If the early beta testers don't come up with any show-stopping bugs (list them here (http://bitbucket.org/hudson/magic-lantern/issues/?sort=milestone)), Monday should be the release date.

Robert Esmonde
August 1st, 2009, 04:38 PM
Thanks Tramm - looks interesting.

But can someone explain what 'Stacked Focus' is useful for?

Will 0.1.6 include the option to set a 'Focus Pull' between A and B at variable speeds?

Al Bogdan
August 1st, 2009, 05:14 PM
Thanks, Tramm! So many great features for 0.1.6! Having DOF and Hyperfocal values on screen will make life much easier. And that automated focus pull will certainly get used. I understand there are some good changes to the GUI as well.

That HDR feature's going to be a hit. I've certainly wished it was available in the past.

I'm going to have to watch for a project to experiment with the recorded camera information you mentioned. I'll be interested to see if it can be imported into virtual camera timelines for some applications.

Many thanks to the you and your team!

Tramm Hudson
August 1st, 2009, 05:36 PM
But can someone explain what 'Stacked Focus' is useful for?
The macro photographers do focus stacking (http://en.wikipedia.org/wiki/Focus_stacking) to increase the depth of field. They have the opposite needs of most cinematographers -- they want the infinite depth of field, but their subjects are much, much closer than the hyperfocal distance.

Will 0.1.6 include the option to set a 'Focus Pull' between A and B at variable speeds?
Yes, but the exact interface hasn't been decided on. I can't depend on the values reported by the lens, so it might be a menu that lets you select the number of steps, the size and the direction, then you hit the rack-focus button and it racks. Hit it again and maybe it racks back the other way to the initial position.

This is a feature that is begging for a remote follow focus controller of some sort. Trying to do it through the GUI is just painful.

Tom Daigon
August 1st, 2009, 05:53 PM
Tramm...so is it the general consensus that 29.97 is not viable on the 5D?
And what is the status of HD output on HDMI during recording?

Tramm Hudson
August 1st, 2009, 06:15 PM
Tramm...so is it the general consensus that 29.97 is not viable on the 5D?
I haven't seen anything to convince me that it isn't. I don't believe Chuck Westerfall's "non-announcement" (http://prolost.com/blog/2009/7/22/canon-speaks-up-special-third-hand-unconfirmed-rumor-edition.html) that it is not possible due to 30fps being "baked in"; clearly the DIGIC4 has variable frame rates since the same chip in the 500D can do 20p without any problems. He wasn't in the loop on the 1.1.0 firmware before it was released (or was so NDA'ed that he might as well have been out of it), so I don't see any reason to listen to him on the 24p issue.

It is something that I hack on occasionally to see if I can find the register in the DIGIC that the system writes into to set the frame rate. It might be useful to poke in the T1i/500D firmware to find what it writes to set the 20p frame rate and how the 1.0.9 firmware . Anyone have a sacrificial 500D?

And what is the status of HD output on HDMI during recording?
Still not working. It has been bumped from 0.1.6 milestones (http://bitbucket.org/hudson/magic-lantern/issues/?milestone=0.1.6&sort=component), but I'll get back on it once we have the new release out the door. I love setting up shots with my DP1 (http://smallhd.com), but dislike recording with it. I had to crank the overscan settings to get everything on screen in 1080p mode, which causes the 480p mode to have awful bright green borders.

Tom Daigon
August 1st, 2009, 06:19 PM
Thanks so much for the update. You are keeping up a very impressive campaign
on the Magic Lantern development.


I love setting up shots with my DP1 (http://smallhd.com), but dislike recording with it. I had to crank the overscan settings to get everything on screen in 1080p mode, which causes the 480p mode to have awful bright green borders.[/QUOTE]

I know what you mean. My daily Glidecam exercise sessions are done with the preview
on th DP1 which looks stellar. Im dreading a real record for just the reasons you mentioned.

Robert Esmonde
August 2nd, 2009, 03:31 AM
The macro photographers do focus stacking (http://en.wikipedia.org/wiki/Focus_stacking) to increase the depth of field. They have the opposite needs of most cinematographers -- they want the infinite depth of field, but their subjects are much, much closer than the hyperfocal distance.

Thanks Tramm - I don't do macro so this is the first time I've come across this ... live and learn.


Yes, but the exact interface hasn't been decided on. I can't depend on the values reported by the lens, so it might be a menu that lets you select the number of steps, the size and the direction, then you hit the rack-focus button and it racks. Hit it again and maybe it racks back the other way to the initial position.

Maybe I'm misunderstanding here, but I would ideally like to have the option to:

1. 'Select Start Focus'
2. 'Select End Focus'
3. 'Select Focus Pull Duration in ms'

Are you saying that the Canon lenses are too unpredictable to allow these focus points to be consistently set? I'm also not sure if your plans include some kind of selectable 'ease in' and 'ease out' to the focus movement.

This is a feature that is begging for a remote follow focus controller of some sort. Trying to do it through the GUI is just painful.

Thanks again for all the great work. I'm continually amazed by the new 'bells and whistles' you're managing to wring out of the firmware. But in case it's all been lost in these developments, please remember those of us in PAL land who badly need 25 fps. That would be the greatest prize.

Jon Fairhurst
August 2nd, 2009, 02:36 PM
...I would ideally like to have the option to:

1. 'Select Start Focus'
2. 'Select End Focus'
3. 'Select Focus Pull Duration in ms'

Are you saying that the Canon lenses are too unpredictable to allow these focus points to be consistently set? I'm also not sure if your plans include some kind of selectable 'ease in' and 'ease out' to the focus movement.

I also think this would be fantastic - especially if it can be triggered by an IR shutter release. It would allow rack focus on a gimbal rig without introducing any torque. If a sequence of triggers would go back and forth between points A and B, it could be used for exchanging dialog.

Even if the start and end points aren't absolutely correct, as long as they are somewhat close, one could adjust the staging and/or camera position to compensate for the errors.

Aside from spending $$$ on a wireless follow focus, there is no workaround for focus control on a gimbal rig today.