I've noticed that the bright reds in my photos are quite often over over saturated.
I've managed to desaturate the reds by selection small areas with the polygonal lasso and select Hue/Saturation > Reds, but sometimes the reds get very dull that way, and I'm also wondering how I can avoid this problem when shooting. I also have the same problem with Magentas when shooting in bright light, but the other colours do no seem affected in the same way.
In my opinion, there may be one of two causes regarding the red saturation, or both: your monitor calibration and/or the in-camera color preset.
Anyway, you must calibrate your monitor and also try to view your images on a different monitor, as for the camera settings, try to set the color profile and saturation at default position, and, of-course, shoot raw. Shooting raw lets you adjust any color related issues when you convert the image to jpg or tiff.
Regarding the cyan problem in highlight, it's a common lens issue, especially at large apertures, both as a general tint as well as fringing in contrasty areas (such as branches on sky background). Here, again, shooting raw is the best solution, as it allows you to compensate both fringing problem and the cyan tint.
580EX,Mamiya Universal, Intel Q6600 ws, Thinkpad T61 mobile ...
I actually typed wrongly Cyan in my first message, and meant Magenta - sorry - which I corrected almost immediately - but you were too quick :-)). In any case, I do have fringing issues now and then, especially with my zoom, but I have found some good solutions there, thanks.
Regarding the Reds and Magenta, I do shoot in RAW and process the files with Aperture before converting them to TIFF to polish them with Photoshop. I am not entirely comfortable to adjust my files on Aperture, as I find a lot of variations with Photoshop in the levels and exposure. Basically I have a much better acceptance ratio when I process my photos with Photoshop so I just do the basics on Aperture and move on to Photoshop.
I'm not sure about monitor calibration. I had some files rejected because of poor light... and once I discovered that when looking really closely my reds were over saturated and worked on that with Photoshop, my acceptance ratio increased. In any case I'll check on another monitor as you are suggesting and I'll definitely have a look at my camera settings.
Quoted Message: If your monitor seems to be ok, be sure you are viewing the correct colors when using Photoshop: go to View - Proof setup - and choose Monitor RGB (or Windows RGB, whatever works best for you).
Very interesting. I just did what you suggested and get quite a big difference indeed. Thanks for that advice.