Photoshop preview posterization - a solution!

[sharkmelley]

Have you ever had that problem where you stretch your stacked image and Photoshop displays a truly horrible posterized  result:

 

You then notice that the posterization disappears if you set the scale to 66% or 100% in the Navigator tab.  The trouble is when you are looking at the image at such a large scale you see only a small part the image so it's very difficult to properly assess the overall effect of the change you are making.

Finally I've found a solution.  Do Edit->Preferences->Performance and set Cache Levels to 1.  Close and restart Photoshop for the change to take effect. This seems to be contrary to the advice that Photoshop gives you for large images.  However it does mean that it displays your image properly at smaller scales:

 

Unfortunately now when you perform operations such as curves etc you'll notice a slight delay in the image updating because setting Cache to 1 slows down the screen redraw.   But at least now what you see is what you get

Mark

 

[sharkmelley]

Unfortunately this trick doesn't appear to work with Photoshop CC 2018 although it did work in CC 2017.

With CC 2018 when I set Cache Levels to 1 and restart Photoshop (which you need to do for the setting to take effect) then Cache Levels becomes reset to 2.

It is unbelievable that in this day and age, Photoshop is unable to display a scaled down unposterized preview.

Mark