Have you checked accuracy of focus for both lenses?
Maybe a static focus-check (and adjustment) might help.

However, that's just a thought... I can't find much evidence of OOF in the 300mm shot, perhaps a combination of slight motion blur + slight OOF.

I'd also need to go off and check DoF at 300mm, f/4 vs 100mm, f/2.8 ....

Matt

Did you set the profile type to LUT?
If you didn't - that's your problem
(My Toshiba laptop has a very poor black point, and only by using LUT does everything fall into place.)
HTH
Matt

Sigh... use dispcalGUI It really isn't hard.
My iMac is set to:
Whitepoint: Native
White Level: Maximal
Black Level: Minimal
Tone Curve: 2.4
Calibration Quality: High

Profile Quality: Medium; Profile Type: LUT

With those settings you should get a "correct" display. You can then go from there... but be warned! Your eyes may take some time getting used to a calibrated screen

Obviously you can set your whitepoint to something representative of the medium you are targetting (e.g. print). Do some Googling

Have fun!
Matt

Mr Argyll is definitely the way to go

You could try ringing Asahi Photo. Not sure whether you'll get just the K-mount ring, or whether a complete disassemble and recalibration will be needed
Matt

Nearly, but not quite
The address bar contains the main thread topic (or the page number).
If you use the "Link" URL then that will contain a shortcut to that exact comment in the thread
Matt

I almost always use centre focus point anyway. That way I know where the camera is going to focus and can help it along in low-light situations (by pointing the centre at something with decent contrast)

Matt

Oh, nearly didn't notice, the 1D IV is actually 1.3x crop, not FF anyway
It's the 1Ds that's FF.

As the title suggests, "Who needs FF?"
Matt

I'd rather have the £4500
Matt

Yes, that's the dispcalGUI. You also need to install ArgyllCMS first: http://www.argyllcms.com/

Argyll is command line based. Works on Mac, Linux and Windows. dispcalGUI provides a much easier way of calibrating, rather than fumbling around with loads of command line stuff.

At the bottom on the options, choose "Profile Type: LUT" for a better calibration (especially if the display hasn't got a very good black point). Be aware of the following points:
* It's a good idea to have the screen on for an hour before calibration
* LUT calibration can take an age (30 - 60 minutes on Medium quality)

Hope that helps!
Matt