Originally posted by SamuelDixon The first thing that strikes me is how much brighter iso 1600 is on the canon than it is on the K1. Anyone know why this is?
Using the same settings and profiles in Lightroom does not mean that two RAW files from different cameras will get the same treatment.
A brightness setting of "0" for one camera may correspond to a brightness setting of "+6" for another camera. An Adobe "0" does not mean "neutral". It just means the "default" for that particular camera (and profile).
Don't be fooled by a linear curve either. When LR (Adobe) shows you a linear curve that just means "
you haven't done any adjustments yourself yet. Under the hood, the camera profile already contains a pretty strong "S"-curve. If it did not, all RAW files would look very flat.
So even if you choose "Adobe Standard" and all controls look identical, you'll get different processing. It is not secret that Adobe puts more effort into some brands over others in terms of making results look "good" out of the box.
To get a real comparison, either use a converter that does not apply different defaults under the hood (such as dcraw, or perhaps RawTherapee), or just tweak the files so that they look similar and then check which one suffered more (e.g., has more noise).
Also note what others have pointed out already: A manufacturer's ISO rating means almost nothing. Manufacturers consistently overrate the ISO value, e.g., state "ISO 1600" whereas it really is just "ISO 1150". Fuji is a particularly well-known offender. Sometimes this is rather obvious in camera comparisons when the same scene is shot with various cameras, all using the same ISO setting and f-stop, but some have to use slower shutter speeds to get a similar exposure. Oops.
I would have pointed you to a comparison page showing the real vs measured ISO values of the Canon 5D Mk II and the Nikon D800 (the K-1 has a very similar sensor; it does not have the same sensor as the D810, no matter what TN or others think), but DxOMark.com isn't working at the moment. The main effect you are seeing, however, most likely comes from different "under the hood" tone curves.
If you want to investigate this, you could use Adobe's DNG profile editor and make a clones of the "Adobe Standard" profiles with entirely linear tone curves. That would level the playing field to some extent, but I'm sure there are more "under the hood" differences when it comes to ACR and different camera brands.
Originally posted by SamuelDixon But honestly, to me, the canon files look better.
See above and I hope you are not making the mistake of comparing 100% views. A lower MP sensor will always look better in such comparisons as the higher MP sensor provides more magnification, with the latter making lens imperfections more obvious and increasing noise as well. If you want to compare noise levels, either look at both images at the same size, or -- if you want to pixel peep -- rescale one so that it has the same number of pixels as the other one.