Rich's Tongfamily (Richtong.net add-on)

But in reading about at dpreview the camera I got to a bunch of mysterious features that I wonder whether to enable. Highlight Tone Priority and Auto Light Optimizer as well as L ISO. The short answer is that you should disable HTP and ALO and don’t go below ISO 100 and use RAW processing in general to get the best detail.
DPReview.com says they use HTP for most photos as it lifts highlights even when shooting raw. As http://shootintheshot.joshsilfen.com/2010/11/29/highlight-tone-priority-in-canons-dslrs/ explains what it is doing is exposing at one stop lower and then bringing up the highlights so if u think ur shooting at ISO 200, the camera shoots at ISO 100 and then brings up the darker areas. In effect this is like doing a DXO-like adjust. I normally leave this off since I’m shooting raw and DXO does such a great job.
Dpreview does compare raw processing with native canon dpp, adobe camera raw and DXO and says the dpp is very close to the in camera jpg, adobe is more natural than dpp and DXO is similar to adobe with slightly more saturation and sharpening with the default neutral tonality. Normally I actually use neutral but have lately been switching to the camera default which is more saturated overall.
Another site says http://photo.stackexchange.com/questions/12171/what-is-highlight-tone-priority that what ALO does only affects jpegs while HTP affects both. ALO essentially reduces the dynamic range to make sure u don’t lose shadows. In essence it applies a different tone curve that brings up shadows mainly. So kind of useless for us raw only people.
HTP however affects both raw and jpg so I’m still probably going to leave it off as I can do the same in raw.
The other setting thing is overexposure in the 5d2. I sometimes feel like it overexposed and normally end up shoot 1/3 EV less but lately I’ve been experimenting with leaving it up and then doing exposure compensation in DXO under the theory that I’m getting most of the photo in the dynamic range and then can adjust. I notice that most of the time the exposure compensation in DXO turns down exposure about 1/3 so maybe that was a good hack when I was doing lots of direct jpg
As another note the ISO range of both the 5d2 and 5d3 goes down to ISO 100 but they have an artificial ISO 50 which you shouldn’t use. It is synthetic and actually takes an ISO 100 and then darkens it. Use ISO 100 and if it is too much light then use a neutral density filter. I have a nice one that does six stops worth. I had thought ISO 50 would have more detail but dont be fooled