View Single Post
Old 17th October 2014
Rawcoll's Avatar
Rawcoll Rawcoll is offline
Full member
Join Date: Jan 2008
Location: Oxfordshire
Posts: 370
Thanks: 22
Thanked 62 Times in 34 Posts
Likes: 24
Liked 45 Times in 27 Posts
Re: Capture One Pro 8....

Hi Ross
Let me start by saying that I am no expert in these matters, and I'm sure there are others better placed, but I like a problem to solve . So, for what it is worth, here are a few thoughts that have gone through my creaky brain.

Just to confirm, you are here comparing the input image with the perspective correction tool applied, with an sRGB jpeg output file created from the post-applied correction, rather than comparing the on-screen view of pre-and post-application of the tool?

The first thing is that C1 (or LR for that matter) works in a much larger colour space than either your monitor or sRGB, and what you observe on-screen has to have some form of colour space compression and/or clipping from the C1 space. One must assume that the image data itself hasn't changed as all you are doing is perspective correction (and I guess this is what you are really querying), so something must be different in the way it is interpreted/presented. I'm not sure exactly what is going on here because it looks as though there is only one choice for rendering intent in preferences, and it is not clear whether that just applies to output or screen as well. However, if they are different (with the process engine to screen rendering intent hidden) then I could imagine some discrepancy between the two.

Another point is how large the colour space of your monitor is. If it is larger than sRGB, then the screen output of C1 will presumably have a larger colour space than your created jpeg, which is only sRGB. Have you tried to see what happens if you create an Adobe space jpeg?

I can't fathom why the EM-1 file should behave differently to the E-520 raw. After all, you are comparing two different renditions of the same image in the same piece of software, for each source file. It is not as though you are comparing the same scene imaged by two different cameras, which could obviously be different.

I can't see any reason for the colour temperature settings to change, but have you checked to see if anything happens pre- and post-application of the tool? (Clutching at straws here!).

Not sure I've added much here to be honest. It might be worth seeing if changing the rendering intent (Preferences/Colour tab) makes any difference, and saving the jpeg in Adobe space rather than sRGB.

Edit. "and I guess this is what you are really querying". Or perhaps you aren't, if I'm correct in assuming that the screen image after you apply the tool is OK, it's just the output jpeg that seems wrong.

Edit 2 On your E-M1 comparison you are using Windows Photo Viewer. I don't think this is colour managed so it might not be the best comparison, although for sRGB it might be OK. I'd be wary of using it for comparison with an image in Adobe colour space though.

(I can never think of anything witty to say when under pressure!)

GH2, various m4/3rds lenses, Fuji X-T1 system

My website:
Reply With Quote