meanwhile

Put an ebay arca grip or sugru on the front of the camera and more sugru on the back where your thumb fits. Problem fixed.
Did you read about Ming Thein's problems with Leica? I think 7 out of 8 copies of the same lens de-centred or with a malfunctioning iris? Have you seen the posts from Leica owners who have to wait months for simple repairs?
Honestly, so not a problem for me...
I really hope they don't:
https://www.l-camera-forum.com/topic/264856-leica-repair-wait-times/
https://petapixel.com/2016/04/11/30-years-photography-ive-never-service-experience-like/
..Initially I believed that perhaps my eyes entering their 4th decade were responsible for these missed shots, but it turns out these missed shots were due to a badly aligned focusing mechanism along with a lens that was also focus shifting.This was a service issue that required shipping the lens and camera back to Leica to calibrate for an additional $300 and a month away, out of my hands... when it came time for the Monochrom to be serviced, I’ve not been able to get it back within anything close to a reasonable amount of time. The Leica Monochrom camera has been undergoing service with Leica for literally six months now. Say that with me… six months… SIX MONTHS! It turns out the problem is due to a defective sensor cover glass, and it is not just me that is inconvenienced by this. I understand that this may be a difficulty for Leica that is not entirely their fault as they outsource production of sensors to another company. But what Leica absolutely owns about this is their relationship with the customer. This product was clearly defective and Leica’s solution is simply to keep people’s investments for half of a year or more. No offers were made to reimburse costs, or offer of a loaner camera until I raised hell 5 months into the process. Nor, to my knowledge, were any offers made to treat Leica’s customers with respect by offering refunds or exchanges for working models.
https://blog.mingthein.com/2014/05/06/qc-and-sample-variations/
My experience with hand-assembled cameras and lenses – namely, Leica – has been less than stellar. I’ve gone through six samples of the 50/1.4 ASPH; one was mechanically defective – it threw an aperture blade on day two – one was astigmatic; two were just soft – one I suspect had a slightly too-short intermediate helicoid, the other perhaps elements that skewed slightly in all directions; only the first and last were ‘good copies’ – i.e. elements were aligned, the mechanical bits didn’t break, and the lens generally performed to expectations and in line with the theoretical MTF chart**. The thing is, short of the broken aperture – if you didn’t handle more than one sample, you wouldn’t know that the one you have was defective. 
Leica quality control levels are waaaay below those of Panacanikony as evidenced by, say, Lensrentals.com reports. So overall no, I'm not impressed by Leica once sending some filters that they bought for a fraction of the store price.
And more importantly, Contax was always the cool 35mm rangefinder company...

For anyone finding this by google in the future -
DSLR Video Shooter
Very useful on lights as I think jonpai said, also ok on basic lighting technique and some other gear
https://www.youtube.com/channel/UCMmA0XxraDP7ZVbv4eY3Omg
(Note: Apurture seem to be very good on CRI. If not spelling)
Dugdale:
I found his website completely useless. There may be useful info on basic technique there, but if so it is buried in a hotchpotch of other stuff.
Focal length reducers:
Much less useful than I hoped. They reduce FL by 0.7 before the m43 35mm equivalence factor comes in. So a 50mm takumar becomes about a 70mm lquivalent ens, and you can forget finding lenses to use as real wide angles.
Additional lens option
At least one Oly m43 lens seems to have real manual focus - the Pro 12-40mm . True of the other pro lenses as well???
 

@Gregormannschaft
That's so useful - thanks. You guys have helped a lot - jonpais saved me from a lot of frustration trying to manually focus those fly by wire lenses!
I thought the Metabones was the only tolerable focal reducer - again, that's really interesting. Especially as I love the Takumar look - that's one of the reasons I was thinking about the Tiffens, to get that from modern lenses without too much time in post.
I've got to say though "Lens Turbo II" sounds like some Shopping Channel product from the 80s. (It's *always* the 80s on the Shopping Channel...)
 
 

@Gregormannschaft
That's so useful - thanks. You guys have helped a lot - jonpais saved me from a lot of frustration trying to manually focus those fly by wire lenses!
I thought the Metabones was the only tolerable focal reducer - again, that's really interesting. Especially as I love the Takumar look - that's one of the reasons I was thinking about the Tiffens, to get that from modern lenses without too much time in post.
I've got to say though "Lens Turbo II" sounds like some Shopping Channel product from the 80s. (It's *always* the 80s on the Shopping Channel...)
 
 

meanwhile, it sounds like you'd like some sort of crash course for video work. I'd recommend delving into Dave Dugdale's earlier posts and videos as he documented his learning process pretty extensively. I'd also recommend looking at Philipp Blooms stuff, specifically when it's related to a piece of equipment or camera you're using or plan to use. He typically gives very in-depth run throughs. 

"That's a vile accuracy"...
 
C-mount lenses look confusing and problematic...
I'll dumb down my focus all the way - shoot with back button focus on the AF lens and forget about anything fancy. Is that the best thing to do with AF lenses?
And I'll maybe try follow focus with a c-mount lens or my Takumar, then get the lenses jonpais suggested - or the Voightlanders ? - if I get interested enough.

I'm going to pimp this again!
Really flexible (literally) thing that can adapt itself to numerous support functions and thanks to the mounting threads all over it can have other things like monitors and recorders attached to it as well.
Folds down small as shown with the diminutive GX80