Well after many try's i finally got the focus right on the X5... with help from DJI Tahoe Ed Windham.... its all in calibrating the lens properly... i had spent many hours trying to get it to focus... calibrated the lens many times in video mode.... it was sharp in 1920x1080 and everything under.. but not sharp in 4K ???..  
So if you are haviing trouble with focus try this.... select photo mode... bring up lens calibration... select focus point .. (must be HIGH CONTRAST at least 50met away)... set focus to infinity... use focus assistant ... if you dont get the result you want the first time keep doing it until you do... hope this helps...

For those having lens calibration / soft focus issues with your X5... It was happening to me also.  I have been messing with my X5 for the past 3 hours and believe I have this lens calibration figured out... sort of.  I wish DJI would make a video on lens calibration, but after what I just went through I see why they are not making that video after many requests from Inspire Pro and X5 owners.

1.  As it states, make sure you have a high contrast object to focus on at least 50 meters out.  I live on a dead end street, so just centered the calibration on a home front about 60 meters out that was high contract.  I set my aircraft on my case so the camera was above the grass.

2.  I made sure that my aperture was at 1.7 so I could quickly check the results against manual focus infinity setting.  At  F1.7 if you hit the infinity button, everything should be in focus on the targeted high contrast object 50 plus meters out.  If you are in f 8 you might be in focus if you hit the infinity button... this does not mean it is calibrated because of the long depth of field associated with F8.

3.  Go to "tool", then "calibration".  I made sure that the object I was going to focus on was in center of screen (not sure if this makes a difference).  Click calibration.

4.  Click OK, it will tell you to tap on the area you want to calibrate on.  I found I had to tap on it twice some times.  If it beeped and calibration went back to OK it was complete.  Click OK again... it will exits calibration mode.

5.  I immediately went to Manual Focus mode to see if in F1.7, when I touched the infinity button, things were in focus.   They were not.  I had read a comment to try repeating the process.  I did repeat the process approximately 20 times before... OMF'nG... the focus in manual focus mode was perfect at F1.7 when I hit the infinity symbol.

6.  Because I am hard headed I tried for another couple of hours more to see if there was a way to make lens calibration consistently successful.  It seems to me to be a purely hit or miss process.

*** Important Note *** from what I can tell the lens calibration resides within the mobile device your aircraft is connected to,   so if you use another mobile device from time to time you will need to calibrate the lens for that mobile device also.

Have to say that I'm confused about the whole focus calibration thing with the X5.
There is no other digital camera out there, fixed lens or removable that needs its focus calibrated.

Some DSLRs offer a micro adjustment feature, but that is just about fine tuning.

For this price, surely it's a reasonable expectation that the camera can manage to focus?

Farnk666 Posted at 2015-11-15 13:14
Have to say that I'm confused about the whole focus calibration thing with the X5.
There is no other ...

Hey Farnk,

Actually this is not uncommon amongst micro 4/3.  The following is from an article about the cameras in general -

The light beam is split by the partially transparent mirror, and directed towards the AF sensors. Algorithms compare the images at the different AF sensors, and when they match, the image is considered to be in focus. This is similar to how focusing in rangefinders work, which is why phase detection works well when tracking moving objects. The problem with phase detection as implemented using separate sensors is that lenses often need to be calibrated to achieve perfect focus, since the AF sensors are separate from the main camera sensor.

http://www.tested.com/tech/photography/459395-everything-you-should-know-about-micro-four-thirds-mirrorless-cameras/

There seems to be an important step people are missing that worked for me. When you select Calibrate, it asks you to tap on the high contrast, +50m etc point. When you do this the app will attempt to focus on that point and  beep when complete. However, that's not the end of the calibration. If you do it in photo mode, not video and use the focus assistant, you can then fine tune the focus to what you want using the C1 button and focus wheel. Only then select OK on the Calibration menu. Press the infinity button now and it should be spot on.

Hope this helps guys.

jimhare Posted at 2015-11-15 22:52
Hey Farnk,

Actually this is not uncommon amongst micro 4/3.  The following is from an article abou ...

Is there a mirror in the x5?
Didn't see too clearly in the photos of it so far.

Farnk666 Posted at 2015-11-16 08:25
Is there a mirror in the x5?
Didn't see too clearly in the photos of it so far.

No, the only need for a mirror is for an optical viewfinder, so you can look through the actual lens before shooting.

SkyOptics Posted at 2015-11-16 03:35
There seems to be an important step people are missing that worked for me. When you select Calibrate ...

The instructions says nothing like what you are telling - strange .

So you
1 enter camera mode
2 goes to setting in camera menu
3 choose calibration
4 enter calibrate now
5 tap on a high contrast object + 50 m away
6 hear the beeeeep
7 tap on the infinity button
8 tap on ok

is this what you are saying ?

I think I will try this

Almsot, select calibrate first, as it always returns you to video mode. So calibrate now, then camera mode etc. Yup there's nothing in the instructions about that, but it works!

SkyOptics Posted at 2015-11-15 11:35
There seems to be an important step people are missing that worked for me. When you select Calibrate ...

Interesting additional step you mentioned. I'll try holding the C1 button and fine focusing on the pre selected + 50m away subject that the calibration procedure shows as being set at infinity. Then I will hit OK.