Some of the Minolta lenses with 49-mm filter threads are great, with the same optical formulas as their earlier 55-mm counterparts but with better coatings. It depends on the lens. And even the less good lenses with 49-mm filter lenses are still quite good.

It's only some of the later Minolta zoom lenses that were likely manufactured by third parties and are not so great.

Sure, I admit I simplified, some of the 49mm are the same optical formula and have (slightly) better coatings. But they also use more plastic in construction, the older MC/MD are built like tanks.

If you can read some German, have a look at this Swiss site with very detailed information: http://www.artaphot.ch/sr-system-lenses

Here you can see why I meant in my last postage that it is better to void many old wide primes: I uploaded crops from one test footage where CA problem is well visible. I took as example here only Canon FD wide primes.

The coating of those lenses was optimized for film. None of those old lenses you will see here had visible problems with purple fringing on (film) SLR cameras they were made for. On my T90 those lenses perform still like king.

But on modern digital sensors it gets very different: many old lenses (not all, but many) produce big amount of CA. This is worlds better under control on native µ4/3 lenses. It is pity I can't upload those crops with the Pancake 20mm f/1.7 or Nokton 25mm 0.95

This test footage was originally done with intention to compare color performance of those lenses on the APS-C sensor, but CA in the corners was so much higher than expected that I shot only test photos from one lens after another, keeping the car which was half in sunshine and half in shadow in right low corner of the pictures.

Of course, one can eliminate lateral CA's without problem in the Photoshop with additional time investment. And of course, this is less visible on µ4/3 sensor especially in the centre, but it's still there at all times, reducing contrasts and color performance by any high dynamic scene in your videos.

Old Canon FD primes are nowadays very popular and quite expensive. Those FDs used here cost together around $1,5K. Maybe it wasn't best example, but look how Jupiter-8, old russian $20 lens outperforms them, although its coating was done for black and white film:

Photo 1: Canon FD 17/4 at f5.6, FD 35/2 (radioactive) at f4, FD 20/2.8 at f4, FD 24/2 at f4

Photo 2: Jupiter-8 50/2 at f4, Canon FD 24/2.8 at f4, FD 28/2 at f4, Whole pic without cropping (17mm)