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Messages - pulsar124

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76
Another solution for the same problem - perhaps it is easier to implement? Instead of remapping any buttons, a new feature 'delayed LiveView AF' would achieve the same thing. Specifically, if there were a ML option which would introduce a delay between the moment the AF-ON button is pressed and LiveView AF action then one could achieve very accurate contrast detect AF even with telephoto lenses (no camera shaking). For this to work, the AF would have to run on its own (not as long as AF-ON is pressed, as it is now), until perfect focus is achieved, or until it times out.

77
Feature Requests / Map AF-ON button to Shutter-half-press (50D etc)
« on: May 04, 2013, 04:37:54 PM »
I always found it very annoying that the most accurate (albeit slow) way to focus on my 50D  - using LiveView AF - can only be engaged by pressing the AF-ON button at the back of the camera. This pretty much fails when you try to do it with either long telephoto lenses (>100mm) or using macro lenses - even with a sturdy tripod, the camera shakes so much when you are pressing the AF-ON button that the focus is often not accurate. E.g., when using the new feature of Magic Lantern - dot-tune lens calibration - the very crucial first step (putting lens in exact focus) - fails for me with my 135mm and 200mm lenses, because of too much shaking.

Ideally, I'd like to be able to trigger LiveView AF using my remote shutter control, but it only works with the phase-detect AF, not with Live View AF. Apparently, many Canon cameras suffer from this deficiency: http://www.dpreview.com/forums/thread/3093770 . For 50D at least there is one option - to tether camera to a laptop with Canon remote shooting software (but that defeats the purpose for using ML), but apparently even this option is not available for other cameras (Rebels).

Is it possible for ML to map AF-ON button to the half-press shutter button? That would make it possible to do LiveView AF using remote shutter control.

78
Modules Development / Re: [DONE] DotTune AFMA
« on: May 03, 2013, 08:50:30 PM »
Thanks - I am also experimenting with this right now.

Actually, one simple ML modification would accomplish most of what I'm asking for: if at the end of calibration ML would print on the screen not just the median value, but the good interval as well. Then one can do any kind of calculations with these numbers.

I know the good interval is a function of the distance - but so is the median MA value as well, for many lenses. As a result, MA calibration is normally done at the typical distances the lens is used, hence the good interval information should still be valid.

The essence of my original point is that not just the median, but the whole MA interval information is valuable, and should not be discarded. The whole interval corresponds to MA values deemed "as good as it gets" by the AF system of the camera (or at the very least as "sufficiently good"). I'd expect this interval being wider at shortest FL of zoom lens (because of deeper DoF), and more narrow at the longer end (more shallow DoF). Using my approach to find the optimal MA value would take this DoF behaviour into account, and allow you to find the MA value where AF deviation from the perfect focus is comparable (in DoF units) at any focal length.

Here is actually another possibility - even more accurate way to find the optimal MA for a zoom which has different MA and different interval widths at the opposite FL ends perhaps would be to assume the interval width (or rather half-width) as a std (standard deviation), and the compute the optimal MA as a weighted average, using the standard formula:

<MA> = [MA1/(del1**2) + MA2/(del2**2)] / [1/del1**2 + 1/del2**2].

All these different approaches can be tested, if only ML could print the good MA range at the end of calibration.

79
Modules Development / Re: [DONE] DotTune AFMA
« on: April 26, 2013, 05:47:56 PM »
No, I am not talking about means, I am talking about overlapping intervals, these are different things. In the case of say [-16...0] at one FL end and [-2...+2] at the other, the cumulative approach would yield MA=-1. The mean of means would yield MA=-4 - definitely bad number, as it is outside of the good MA values for the second FL.

80
Modules Development / Re: [DONE] DotTune AFMA
« on: April 26, 2013, 04:08:05 PM »
So, no comments about my "cumulative mode" suggestion (see two posts above)? It wouldn't be too hard to implement (I think), and zoom lens owners would really appreciate it.

81
Modules Development / Re: [DONE] DotTune AFMA
« on: April 21, 2013, 07:41:52 PM »
I have another suggestion for dot-tune improvement. How about an optional 'cumulative' mode? Specifically, when testing zoom lenses or/and lenses at different distances from the target, one often gets different good dot-tune intervals for MA. E.g, my Sigma 17-50  has MA say -15...-2 at 17mm, and -5...+5 at 50mm. The current dot-tune implementation is not very useful for finding a single compromise value for MA which would be acceptable at any FL. All I get is either one FL or the other FL values; the important interval width information is discarded. But if ML had a cumulative mode, and let me run dot-tune a few times at different FL, and then computed a single compromise value taking into account interval widths, that would be very helpful. In my example, the common MA interval for both FL is -5...-2; the compromise value would be either -4 or -3. At the very least, you could make ML print out the intreval at the end of every calibration; the compromise value would be computed manually.

82
Modules Development / Re: DotTune AFMA
« on: March 04, 2013, 07:46:36 PM »
Either way, that would be an improvement. More power to users is always a good thing!

83
Modules Development / Re: DotTune AFMA
« on: March 04, 2013, 06:28:31 PM »
Thanks for the detailed response! But this begs a suggestion - would it be possible to let the user choose both the number of passes and the duration of one measurement, from the ML menu?

84
Modules Development / Re: DotTune AFMA
« on: March 04, 2013, 06:05:09 PM »
Thanks - but wouldn't lower weight be reflected in shorter bars in the MFA progress diagram? When I get less-than-good AF confirmation, I can still see the bar having the same height as for good MFA values.

85
Modules Development / Re: DotTune AFMA
« on: March 04, 2013, 05:57:23 PM »
I just did fairly comprehensive testing of dot-tune/ML on my 50D, using  magiclantern-v2.3.NEXT.2013Mar02.60D.550D.600D.50D.500D.5D2.1100D.zip. The results are reported here:

http://photography-on-the.net/forum/showthread.php?t=1280584

In particular,

Quote
- ML implementation of dot-tune is not perfect yet - at the edges of the good interval, I could see the delay in AF confirm light, sometimes double beep (all these should be discarded according to the Dot-tune author, but ML would apparently still consider them okay, and count them in). Meaning - you can do slightly better if instead of using ML, just do dot-tune manually. But I am sure this will be addressed quickly in the future releases of ML.

86
Modules Development / Re: DotTune AFMA
« on: March 02, 2013, 09:30:16 PM »
Thanks for the efforts - fantastic project! I just wish one day you will figure out how to make MFA values FL and/or distance dependent.

I gave a try to the nightly built on my 50D, and happy to report that it seems to be working fine. I will do more thorough testing with good light and target, comparing ML/dot-tune results to FoCal results, on my fast lenses (135mm f2.0, 17-50mm f2.8, 70-200mm f4).

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