[INVALID] MLU Auto -- When Shutter Speed its under the Focal Length (Lens)

Started by Nhilson, October 05, 2014, 07:17:27 PM

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Nhilson

Hello Magic Lantern People

First let me give a biggest thanks for the majestic works that you are make it.

I have a feature request for a 6D.113 firmware if its possible.

The photographer well know that to avoid a blur effect of the Camera Shake you need activated the MLU when the Shutter Speed (SS) is under the Focal Length of the Lens (FLL) (or effective focal length, if you're using a crop sensor camera).

The empirical formula for a FullFrame camera is SS=1/FFL or for and for  a crop sensor SS=1/(crop factor x FFL). Of course, many Canon Lenses have built-in  Image Stabilization (IS) features that reduce the effects of shake and allow you to use shutter speeds two to four steps slower than normal.

The question is if it possible write an algorithm that detect the Shutter Speed and relation whit the Focal Length of the Lens (FLL) when te IS its no actived or when we don't have a IS Lens for example:

For a FullFrame Camera like a Canon EOS 6D (6D.113), If I have a Canon EF 70-300 ƒ/3.5-5.6 or wathever EF Lens and I need a Shutter Speed of 1/125sec if the Focal Length of the lens is 70mm I don't need a MLU but if I need a 300mm the MLU need activated. the MLU Auto algorithm  must be detect this situation and activated the MLU; this  program must be independent for ƒ/number  and ISO that we need.

For a APS-C Canon Crop Sensor  (and maybe this is another feature request) the algorithm must be multiply the  Focal Length of the Lens by the crop factor to obtain the effective focal length if the Lens is a Canon EF but directly if the lens is a Canon EF-S or Canon EF-M.


In general this must be different feature request one for the fullframe sensor and another for the crop sensor but this is the idea

here some internet links documentations about this:

1. http://www.cambridgeincolour.com/tutorials/night-photography.htm
2. http://www.luminous-landscape.com/tutorials/understanding-series/mirror-lock.shtml
3. http://en.wikipedia.org/wiki/Canon_EF_lens_mount
4. http://en.wikipedia.org/wiki/Canon_EF-S_lens_mount
5. http://en.wikipedia.org/wiki/Canon_EF-M_lens_mount


Thanks a lot Majestic People ;)

Best regards!!!

Nhilson V.

eduperez

Do you really want ML to switch MLU on and off automatically? Personally, I would find that really annoying.

Nhilson

Thank you eduperez for your comments...

The actual  ML for the 6D.113 Mirror LockUp (MLU) configuration only set up for hanheld shutters between 1/2...1/125 option, for me is interesting activated the mirror lockup only when the shutter speed was under the equivalent focal lens to avoid blur for camera shake.

Audionut

From what I recall, the shutter speeds were chosen based on their usefulness.

That is, at shutter speeds slower then 1/2, the mirror vibration effect on the image was negligible, since the vibration time was a small percentage of the total exposure time.
And at shutter speeds faster then 1/125, the exposure time (I think) was faster then the vibration time.

The mirror lockup effect, is different to the focal length/shutter time ratio.  The FL/ST ratio is for handheld motion, MLU is for mirror motion.