A bit more useful than I thought it would be.

Pretty simple really I set up the D90 for Auto ISO (ie pick a max ISO limit I want) set the camera to M mode. Adjusting the aperture/shutter speed the camera then sets the ISO level to the "metered" exposure. So reducing the exposure ie faster shutter speed or smaller aperture and the ISO value climbs up to the max ISO you have set in camera.

Pretty similar to the TAv mode in the K-5 (but I didn't have it on the models I had)

If you want manual ISO simply disable Auto ISO in the menu.
In a nutshell M mode with Auto ISO enabled is like having shutter and aperture priority in one mode.

The Canon 60D can do this too, but it has a restriction that should get removed in the future. The 60D restriction is that you can't use EC while using auto ISO and M mode. Some cameras do allow that and probably your D90 will allow it. I haven't used this feature on the 60D, but I have seen quite a few posts from people who like it a lot, along with the complaint that you can't use EC.

I just tried that and exp comp works by shifting the ISO and holding the aperture and shutter speeds.
Maybe try AEL on the Canon and then exp comp?

No, that doesn't work, I just tried it. I have seen discussion about this restriction several times and the people who like to use it all want it to be allowed, as it is allowed on Nikon. I have never used it, but I can certainly see how useful M + auto ISO would be in some situations, particularly if you can also use EC.

Sony doesn't allow M + auto ISO -- it doesn't on my A700 anyway. If you use M mode it does not allow you to select auto ISO.

There have been a few discussions about it at dpr. I think they need a new mode on the dial, an SA mode which allows you too set the Shutter speed and the Aperture and the camera adjusts the ISO to suit. AEL spot would work as normal and exposure compensation works as per normal as well.
It's up to the photographer to set realistic exposures though, if one ends up with a photo that looks like snow on the TV screen there is only one person too blame, but hey you can't make an omelette without breaking a few eggs....right?
It might be the considerations with system flash that is the hold up in Sonyland, or it might be they are too focussed on video and still shooting stuff like that doesn’t register on the radar
Greg

Another DPR debate, this time pretty heated with arguments from both sides

http://forums.dpreview.com/forums/read. ... e=41620311

Just to clear things up here for some folks if you want the M mode with no Auto ISO you simply don't enable Auto ISO and it acts as you expect ie you have to set the ISO speed. You lose nothing by having an Auto ISO in M mode because it's a choice, not forced on you.