For the last 25 years or so of 'popular' film-photo, 100ASA was the common 'standard' film speed.... that is where I would start.
Typical plastic-lens, 'toy' camera of the late film-era; (I probably have a couple or more still knocking about in the 'doofer' boxes with lens pouches that dont fit any lens I own and things like that!).BUT.... f16-Sunny.. suggests a shutter one-over the film ASA at f16 on a good sunny day.. open up a stop if its a bit cloudy, two if it's over cast, three if its twilight or sky's full of black-clouds and or rain... anything darker, inside, or in shaddow use the flash!
A probably a 35mm-ish focal length for wide-angle lens compact, would then invoke the old rule-of-thumb for hand-holding, keep shutter speed higher than one over focal length.... and if making a fixed setting 'toy' camera, you would PROBABLY set the shutter speed at something around 1/30th, and the aperture around f8, expecting film speed 'around 100 or 200ASA to most likely be used.
At 100ASA... on an f16-sunny day, outdoors, that would probably give around three, to four stops 'over' exposed... high-lights would blow, B-U-T you'd get a picture.... meanwhile, as ambient light fell, those settings would get closer and be good enough to get you some light and a half reasonable exposure when it got cloudy, and likely only be a 'bit' dark if you were shooting in the twilight, and only completely black, if shooting inside, without flash.
Tru-Print and Co, who developed the photo's from these cameras were then trusted to make the best of the job, and tweek the exposure in printing, to brighten up dimmer shots and dim down the brighter ones.....relying on the "Exposure Latitude" of the film to be able to even things up a bit..... and you threw away the ones that were no good at all! Hey, at least they were 'cheap'!
NOW.....800ASA, is one stop faster than 400ASA, two stops faster than 200ASA, three stops faster than 100ASA..... In a fixed setting toy camera, that pushes exposure levels up, from a cloudy twilight to a good sunny day.... and IF the settings are optimized around f16-sunny, means that you are just going to start blowing highlights sooner. Going t'other way.... three stops wont get you day-light like exposures in a dark pub interior... Either way, you wont be so far off, but, high-lights like to blow, shadows still wanna murk....
Back to the printers... How much compensation are they dialing in on the enlarger settings? I am presuming here that you are doing that bit of the job digital-wise with a scanner.... but you and/or scanner should still be doing the same, pushing it up a bit or pulling it down a bit in repro, to suit.
The Canal wharf, on a bright sunny day; the sky is blue, there's a few clouds in it, it looks not far off.... probably not quite an f-16 Sunny day, it's managed not to blow any high-lights.....
Your aeroplane shots on dull day.. bit dim, yes. But the tarmac under the planes looks pretty dark, the hanger behind well shaddowed; the sky is obviously quite grey, BUT, to my eye it looks reasonably faithful, and probably only a stops or so below what might have been a more pleasant exposure... and you can probably dial in a couple of extra stops of exposure in post, and not obviously white out the sky, just loose some cloud detail....
Its actually not far from what I'd expect if I metered by eye with the meter-less Zenit or similar, and went by f-16 sunny to suggest an exposure based on a guesstimate of 'incident' light on the scene, rather than a reflected light reading taken made by electrikery in the camera, which would likely try and up the exposure expecting an average 18% grey for the whole scene, it didn't get, because of the dark tarmac foreground and dark shadowed hanger back-ground.
There's no such thing as the 'wrong' exposure, just a more or less pleasing one.... and this gives illustration.
BUT more revealing, is that in both sets, far focus isn't 'so' crisp, which hints that either it's a very Lomo plastic lens toy camera, OR its a zone focus compact, and focus zone set to something in the close to middle distance, chucking the far subjects into the fuzz....
IF its a rather dire plastic-lens curved film-trap toy-camera.... then what film to stick in it would not be much of an issue... it's gonna be hit and miss whatever, and faster film will just blow sooner!
IF its a more sophisticated zone-focus camera... and more, its actually got some coupling adjusting the aperture and possibly shutter-speed with the set focus zone..... the game would be that using faster film, you could push the focus further away from the camera, let it pull the aperture down and maximize the DoF some-what; OR using slower film, you would have to be a bit cuter about the focus zone set, pulling the DoF closer to the camera, to make sure your subject was all 'in' that DoF zone, that you probably could only guess at, or determine by trial and error and experience.... this being the 'fun' of Lomo-esque cameras.. either trying deliberately to get more from them than they can offer, or knowing what they will do, for 'effect', discovered by serendipity.
BUT.. in such games, I'd be loading whatever film was cheapest or to hand, and I'd not really be expecting the stuff to do all that much for me; I'd be shooting to 'play' and expecting to make 'adjustment', like Tru-Print would have done in days of yore, in the scanner software and/or in post-process.... A-N-D likely just happy I GOT an exposure.... not fretting whether it was a stop over or under what a more sophisticated camera might reckon to be 'ideal'... heck... If I wanted a machine to do that all for me, I would leave the film in the fridge and take the electric-picture-maker!
Brings us back to the question 'what camera', and springing to mind is my old XA2 and its near hidden ASA selection slide under the lens, easily unfound or unset.... very sophisticated coupled metering system, calibrated from 25ASA up to possible 800ASA.. and I err wonder.... clam-shell lens cover that slides the zone-focus back to center 'group shot', when the clam-shut.
The XA's three zones, are alledgedly, 'about' 3-6 feet for close up, 4 feet to 'near' hyper focal for group shot, and 20feet to infinity for landscape.... and 'most' zone focus compacts have focus zones in that sort of order....
Fact that in your shots, the back-ground is tending to oof... sort of suggests that the focus is set or optimised for a closer focus distance and shorter DoF, which is NOT something I would expect of a fixed focus compact, I would expect to be optimized to a further focus distance and deeper DoF for focus lattitude on middle and fat subjects, and to heck with hit and miss close-ups....
On the old XA2.... that closing the clam 'reset' was and still is occasionally critasised for the ease you can forget to re-set focus if you close cap twixt shots... BUT defaulting to the 'group' middle distance setting, with almost hyper-focal focus in its range.. even there, most landscapes can still turn out acceptably sharp... its a pretty perverse mistake to get far subjects oof, and near ones crisp, using the closer focus 'head and shoulders' icon instead of the 'mountain'!
My Konica C35, is a bit easier to cock-up... it has an aperture priority mode, to manually select wider apertures, and the zone-focus lever don't default when you turn the meter on or off by covering the sensor with the rubber lens-cap! But even there, with a manually selectable and reasonably 'fast' aperture, zone focus tends towards hyperfocal, and its actually incredibly hard to get middle and far subject OoF with it!
So how the heck did an allegedly fixed focus camera get the far distance Oof?
Begs suggestion its either NOT a fixed focus camera, its a more sophisticated zone focus camera, OR its a REALLY dire fixed focus lomo-toy!!! And/or possibly damaged along the way!
Either which wayz about... what film speed is NOT the first question I would be asking, IF I asked at all.... the three stops difference between 100ASA and 800ASA re NOT going to make an awfully huge odds in the greater scheme of things, I think that there are much bigger fish to be fried here, and, looking at the legacy of old fixed exposure, fixed focus 'toy' cameras and tru-print correction in printing, that is probably as much or a bigger difference to look at using....
As said, for lomo-serendipity-photo-fun, I would chuck in whatever crud was cheap and to hand, and takes my chances... If I wanted to get a bit more deliberate about the job, where picking film to suit the subject might matter a bit, and stood some chance to make a bit of difference... I'd not be using a 'lomo-esque' camera, I'd probably be picking up my Grandad's old Kodak Retinette, or my old Zenit, or the Sigma Mk1, and a light-meter, and pontificating the difference between incident readings and reflected readings, and wondering whether to crack out the surveyors tape to get my focus range a bit closer, or if "Err, how many Ford Granadas could I park between me and that lamp post?" was good enough.....
