Major differences between ACR and Aperture in red channel

Question

Hi!
I did some printing a couple of days ago and the result was really not acceptable. At first we thought it was the printer and then the process of saving the files from tiff mac to tiff pc. After that we hade a look at the channels and the findings explained exactly why we got the result. After that I decided to compare ACR with Aperture and here are the differences in the Red channel. Camera is Canon EOS 350D, ISO 200. The image is 25% zoom. I don't know if it is possible to post images but a link is perhaps good enough.
http://www.d.kth.se/~vendelin/ap-acr.jpg
Do you have any ideas why Aperture gives me this result? If this is what I can expect from Aperture I'm afraid I'll have to use another raw converter for printing and that is a shame. The Image look fine in RGB but Red is destroyed and the printer in this case uses the red channel I'm told.
kind regards,
Edvard

Answer 1

Obviously that would be one way of doing it but
digging after every file in the aperture lib, opening
them in ACR, saving as tiff 16, importing to aperture
is a to painful process.
If you have to do it for every image it would be annoying, but if you don't often have blown out color channels it would not be too bad...
I actually use Aperture myself by importing TIFFs because my camera is not supported in Aperture directly.
As you pointed out the dark
area is in fact not dark grey but black. No
information there what so ever. Is this a common
problem with aperture? Has anyone else experienced
this or is this image an extreme example?
I'm not sure why that would be, that's a different issue. I have not seen anything like that as Aperture seems to recover as much detail as any other converter.
Are you sure there is no detail there, if you raise exposure some? ACR is set by default to automatically change adjustments, you may want to try auto-level or something like it.
<...>
Is this really a problem with Core Images or is it an
Aperture problem? Correct me if I'm wrong but
aperture uses the same RAW converter as iPhoto does,
in other words Core Images framework? I see why Apple
want Aperture, iPhoto and other to use their raw
converter that's built into the operating system but
when the performance is lacking perhaps the Aperture
team should consider to build one for them selves?
<..>
You are thinking about it backwards. What Apple is doing is to spend resources producing a pro level converter, which then every part of the system (including iPhoto) can use. If Aperture were going to build thier own RAW processor then why would you not want iPhoto to be able to use it as well?
And in fact that's pretty much what happened, before Aperture came out OS X RAW conversion was pretty mediocre. But after Aperture Apple spent a lot of resources improving RAW conversion and it's far better now - whcih also benefits iPhoto.
Is there any form of modified RAW converter for OS X
I could use to replace the one shipping default? I
would do anything in order to keep using aperture for
prints also.
Sorry, there's no way to swap out the OS decoder.