Just a thought, I tried to send a raw file to Fred/Mike last week and two transfer sites including WeSendIt would not have it, my upload just hung at 20%.

I used send space and it uploaded no problem. Note I have a slow connection.

 https://www.sendspace.com/

Jeff

Bruce did you ever solve your problem? If not here is a test you may want to try.

1. Display your problem image in Qimage Soft Proof, and measure the width of the image on the screen in inches.
2. Obtain the resolution of your monitor from the specifications in pixels/inch. Most monitors are around 100, but it is best to get the exact number.
3. Calculate the width of the displayed image on the screen in pixels. For example if it is 15 inches then the displayed image on the monitor would be 1500 pixels if your monitor is 100 pixels per inch.
4. Take your high resolution image that is problematic and then down sample it to 1500 pixels in width using the Bicubic method, or if you do it in Qimage use Lanczos.
5. Now take that down sampled image and display it in Qimage Soft Proof.

If that solves your quality problem, it suggests there is a down sampling method problem, potentially in Qimage itself. The testing I have done suggests that may be the case, and in certain high resolution images artifacts appear that resemble oversharpening.

"You can't be serious" as John McEnroe used to say to the umpire. 
Terry

That's fine. You only say what you see, but your conclusion as to where the artifacts originate is drawn from conjecture.
Set the setting for Antialias to HIGH and Qimage is now locked to disallow any artifacts. You might see a slightly softer looking image due to that settings, but you can rest assured, the artifacts you see were not created in Qimage.

See attached screen snap.

You asked for another theory?
How about a noisy sensor and other software, is masking, and Qimage is showing accurately.

No debating from me. I have done my best. Any further need for explanation will have to come from someone smarter than I.

Fred

Again, erroneous conjecture.
That routine is used for all downsampling; to make web copies, email copies... anything!

I'm done! You can believe the sky is falling tomorrow at noon and no one can change your mind.

Stay well.
Fred

Yep! What you see is already in the image.

We need to see examples of these "artifacts".  Screen shots or crops of screen shots would be fine.  When Bruce sent samples, I discovered that his images were defective and had a 2x2 checkerboard pattern (see previous page).  You do NOT always want to antialias when downsampling on screen because it can affect perceived sharpness and it slows down display speed.  And you generally only need to antialias when either: (a) your image is damaged and has a repeating "noise" pattern, or (b) you shoot something with a repeating pattern like bricks, etc. that repeat every other pixel or every 3rd/4th pixel, etc.

If you start out with defective images that have (for example) a 2x2 repeating defect, you don't expect software (like QU) to "fix" that problem when it downsamples because the defect becomes more noticeable at different zooms.  That's like Town A having a dam that just sprung a leak and is now flooding basements in Town B.  So Town B residents with the flooded basements send a complaint letter to their own mayor complaining that the town didn't budget for bailing buckets.  Let's see if we can fix the problem at it's source since that's what we did in Bruce's case, so let's see an example.

Regards,
Mike