RGB channels in CMYK file?

Something I don't understand, maybe you guys can help.

When I convert a RGB file to CMYK I see only CMYK channels in the channels palette. So far so good. But when I want to adjust the hue and/or saturation (ctrl + u) I still have Red Green and Blue channels in de pull down. If I alter one of these channels it has major influence on the image I see on screen. But which CMYK channel am I editing at that moment? And does it have effect on the final image when printed? Or is it just a on screen effect and does it not alter any of the CMYK channels and thus the print result?

Can someone shed some light? Thanks!

You're not actually looking at Channels in the Hue/Sat dialog box. You're looking at colors or ranges of colors, which can be made from multiple channels. Any adjustment you make in Hue/Sat will indeed be reflected in the final image output, as it will make changes to the underlying channels according to your adjustments.

So if I change the Red 'channel' it will change multiple 'real' channels, e.g. Magenta and Yellow?

But still what you see is what you get. (if your monitor is calibrated right, etc. etc ...)

Depending on what you do, it could also change the Cyan or Black channel as well.

I still think it's a bit odd to have a R, G and B 'channel' and not a Black channel. Things that alter by editing e.g. the Red 'channel' I am not able to change via one of the CMYK 'channels'.

It probably works fine, but it all seems a bit odd to me.

Once again, it's not working strictly on channels but rather on ranges of colors. Images contain a full range of colors, and using Hue/Saturation, you can affect most any of them you want, without regard to channels.