I've simply put these 2 windows below side by side and used the windows 'snipping tool' to take a screen grab of the area I marked out and it gives a true representation of the differences in colour saturation which is most noticable in the RED tho of course if you look closely the whole colour spectrum has increased saturation... which I'd rather not have. Oh and of course I played this with a couple of different players and on a couple of different monitors with same results.
On the left is the original photo... and on the right is my rendered video paused on the same still image.
I can see a definite 'red' saturation increase in the rendered video.
Is this a common issue and is there an easy way to ensure the reproduction in the video truly represents the original still image colour saturation...?
I normally use auto correct within Irfanview on still images to bring them alive and the still image has had that applied before bringing into the project... does Vegas apply it's own adjustment on top to possibly cause this...?
Stills from a camera are full range levels and video needs levels to be in studio range, aka video levels. Use the Sony levels effect, Computer to Studio RGB, preset to adjust your stills as necessary.
Note that this happens often with video as well. Many cameras output video in full range. Commonly DSLR and digicams and GoPros.