I don't have your Vivitar lens myself but the results remind me of some I get from an old Tamron or two of mine i.e. lovely and sharp but with purple fringing around contrast edges - I think I see this in your shots even without pixel peeping. Maybe it's just me that has become overly sensitive to the point of hate on this but I have found solutions.

If you get purple fringing in most pictures I understand the probable cause would be a lens distortion type that some of the raw processing programs can automatically correct. If, like me, you are unlucky/unlucky and it just appears with high contrast and particularly overexposed edges it's probably not a lens distortion that can be auto-corrected but I instead get huge improvements with what I call my 'purple notch filter'. Essentially I go to the colour curves in HSV mode curve, sample a purple fringe and then put a brickwall type notch at that hue. I'm using 'darktable' for this processing but I assume that if you fancy trying the same most capable editing progs are able to do the equivalent operation these days.

Rgds,
Rob.

Love the first shot, very nicely done.

As for the lenses, last one from the 18-55? It's got the nicest colour rendition I think but not as sharp.

My guess is that differences in results between the two lenses is likely to be because of their IQ not their weight.

Yes a heavier lens should be less susceptible to movement (assuming it is not so heavy your muscles are quivering with fatigue ) but the weight difference between DA and DAL 18-55 is going to be so miniscule it'll have no measurable, let alone noticeable, effect. Remember the lenses are attached to a camera so it is the combined weights of lens and camera you need to compare.

Perhaps it's time for me to dispel some myths then Darktable was once pretty much a raw processing engine but that was way, way back. I think it aims to be a complete DAM product in its own right and all image information is stored in a high speed SQL database with image tagging and sorting and flexible queries. There are some users (not me) managing huge image collections with it.

That all said if your need is primarily cataloguing and batch throughput rather than extracting the absolute maximum from select images there probably are better suited alternatives for you ( or at least this isn't how I use darktable so I can't recommend it there from my own experience). Darktable progress in this area is fast however and some of the devs seem to be working to provide quite extreme capabilities for customising workflow, as far as I can see essentially exposing processing and storage internals to a scripting language rather than just the usual user actions and macros although most of us won't want to go that far I suspect.

Exciting times for dt as well other programs at the moment.

Rgds,
Rob.

I used to have the M/1.7, in fact it was bought new on a MX with my first ever pay check

I was quite happy with it until I got a secondhand Pentax M200/4 as my second lens and found results from that were far sharper and more contrasty. That sort of doesn't make sense as the 200/4 doesn't have a particularly good rep and the 1.7 is well regarded. Maybe mine wasn't a particularly good example, it eventually succumbed to fungus and carelessness after a wet weekend in the mountains and was retired in favour of an A/1.4.

I'm not particularly keen on manual focus standard/wide lenses on the new bodies and with them badly miss split image focusing. Strangely I'm happy with manual focus teles though - maybe its my eyes that aren't so good now ...

Actually darktable is now getting SO good that it is worth considering a Linux desktop just to use it. Those already using Linux are more than fortunate.

I was lucky enough to get the Tamron 17-50 in my stocking this Christmas and love it. Mine focuses really fast and precisely and IQ is excellent.

I used to have the 16-45 f4 Pentax a few years ago (until it was stolen) and I don't think that is in the same league at all, IQ was good but its not as fast, nor anywhere near as nice to use mechanically being a bit long, somewhat unbalanced in feel and a bit 'loose' - at least mine was. Took some good piccies though

PM sent in case its still available.