0

I have been using Preview for reading lecture notes and slides (compiled using Beamer and edited in Xournal). Now, whenever I go to the next slide, I see a blurred version first which seems to be a cached image of the slide (nowhere near vector graphics) and then the page renders to smooth and clear text. I am using a 2018 MacBook Pro so I am assuming that hardware is not a bottleneck here.

Is preview designed to behave in this way? Can this behaviour be changed?

Clarification: I am not referring to the transition animation when changing pages using the trackpad. I change pages using the keyboard and the blurring looks like an actual rendering delay.

Improve this question

2 Answers 2

Reset to default
2

I am facing the same issue. What follows may not be considered an "answer" by some people, but may lead to an answer I think and I've never seen it mentionned on the numerous web pages complaining about this issue : I've noticed that when you open the pdf not with Preview BUT with the built-in previewer from finder (the one you obtain when clicking on SpceBar when file highlighted in the finder) then you can scroll through the pages (using PageDown PageUpp, or Fn+Arrows) and this ugly effect does not show. This is very surprising as I've always assumed (and I'm not alone I guess) that this builtin finder preview was using the same toolkit as Preview, which is not the case apparenlty.

Improve this answer
1

In short: Preview cannot be changed. The problem is not one at the application level, but in the way that MacOS's Quartz engines renders images. For some reason, the OS 'sharpens the focus' of the image over half a second or so.

It may be possible to change the parameters of such animated effects for a given application, but it will only be possible in Preview if Apple's developers have included a mechanism to do so within the app. None is documented and it seems unlikely that Apple would go to such trouble.

If you don't like the effect, then leave Feedback for Apple. You may prefer to use another viewing app, but it will have to use different image rendering libraries from those present in MacOS.

(Apropos of nothing, I'm currently writing a replacement app to make up for Preview's shortcomings, and I haven't found any method of changing this animation. Yet.)

Improve this answer
4
  • I hope you are not referring to the transition "fade" animation when changing pages using the trackpad. I have added a clarification in the question regarding this. Also, I am not talking about rendering images but PDF files.
    – Ansh Khurana
    Commented Aug 26, 2019 at 17:31
  • 1
    @AnshKhurana No, I'm not talking about the "page swipe" effect, but the blurry fade in seen in Single Page mode, using the arrow keys. Maybe fade is the wrong word, but it's an animated effect that the image 'comes in'. PDFs and images.
    – benwiggy
    Commented Aug 26, 2019 at 17:38
  • I see. I used Adobe Acrobat Reader before switching to macOS. Will try that again. Preview does provide some niche features for free like the ability to edit PDF documents, inserting pages etc., but this effect is quite annoying.
    – Ansh Khurana
    Commented Aug 26, 2019 at 18:19
  • Preview also has some simple image editing capabilities.
    – Natsfan
    Commented Jan 31, 2020 at 18:13

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .