It’s great that you have a background in photography; that’s a big advantage when it come to Reality/Lux I’ve trained and worked as a cinematographer, back when celluloid was still being used
The camera film settings are done in Reality, not Daz; you’ll still need Daz to set the focus if you want a shallow dof, though
RL camera settings aren’t always the equivalent in Reality/Lux; it took me some time to wrap my head around that
From what I see, the first and second scenes have good key/fill ratio although they are rather grainy. Graininess is caused by “light starvation” as Paolo would put it. A quick and easy fix (and this may seem counter-intuitive) is to tweak the settings while rendering. That’s one of the advantages of LuxRender: you can do that without ruining the render. When the image seems overexposed as you open up the ISO, don’t panic; you can tweak down again when you get rid of the graininess.
I just checked a previous render which is also a daylight exterior scene, it’s eff is 107%; daylight exteriors tend to have low efficiency because the light travels a long distance before bouncing back to the lens. Low efficiency is not always a bad thing just as high efficiency is not always good (like when a scene is overlight and the RAM usage goes through the roof )
My suggestion, like JimmyC’s is to create as safety file (and don’t forget to change the file name and output in Reality!) , render in Lux and tweak the settings as it renders. By way of comparison my daylight exterior settings are:
Film Response: Agfacolor Vista 800 (doesn’t over saturate the colors; kodak favors reds and yellows and fuji blues and greens, like in rl )
In the safety render, I suggest tweaking the ISO up while bringing the Shutter and f-stop down. While rendering you can have it a bit overexposed and bring it down later by stopping down and/or tweaking the gain (both of which can be done during rendering as well).
I think bringing up the ISO and bringing down the shutter/f-stop should help with the exposure/graininess.