Quicklook contrast bug when zooming

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Level 1

35 points

Quicklook contrast bug when zooming

Hey everybody,

Everything started when I got home from a trip to San Andres. i shot a lot of pictures with a Canon 6D (RAW+JPG)

The images look very vibrant, with nice contrast on the cameras LCD.

After transfering everything to my macbook pro 15" retina display mid 2014, I started noticing this strange behaviour on the cameras JPG pictures. Everytime i hit space bar to quicklook a single photo it looked very vibrant, with nice contrast, but when I start to zooming a picture, right after I release the track pad, the photo looses contrast and never recover it, until I close it and reopen again. It is interisting to notice that this happens only in .JPG that came right out of the camera, If I zoom a a .jpg exported by lightroom this doesn't happen.

It is interesting to notice that all the other softwares (mac preview, canon DPP and lightroom) look exactly like the quick look after loosing contrast, but to me it seems that the correct image should be the one with more contrast, the one before I start to zooming, because it is closer to what I see in the camera LCD.

Above there is a video showing the issue.

MacOS Quicklook - Contrast Bug - YouTube

So , what is going on? Does anyone ever had this problem? What is the right apeareance of the photo and how to I fix this strange contrast switching in quicklook?

MacBook Pro with Retina display, macOS Sierra (10.12)

Posted on Aug 1, 2018 2:10 PM

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Answer 1

Sep 7, 2018 2:47 AM in response to PauloROP

Yesterday I discovered the same thing on my MBP 2018. I also own a Canon DSLR (5D IV) and after taking some photos I wanted to preview them in Quick Look. At first the image appeared vibrant and with quite some contrast. After zooming in it got desaturated, lost some of the contrast and looked somewhat dull (at least in comparison to the appearence before zooming).

Opening the image in the preview app or in photoshop directly shows the less saturated image.

Since I calibrate and profile my display I thought that this would cause the issue (although this never happened on my old MBPr 2012). There are a few posts online which stated that it could really be an issue with the macOS color management.

So I recalibrated my display with today. This time with another application (DisplayCal instead of the Spyder App) but the issue still exists.

After playing around a bit I figured that the standard display profile causes the same problems as well.

You especially see it in darker areas. Honestly the dull image after zooming shows more gradation in this regions so I guess it is in fact right this way. But it remains very confusing to me.

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Answer 2

Aug 2, 2018 6:47 AM in response to PauloROP

Is there a chance you might post one or two of the jpeg images that exhibit the problem to a place like dropbox so we can experiment?

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Answer 3

Aug 2, 2018 8:58 AM in response to Luis Sequeira1

Ok, I see what you mean, and I see it on my mac too.

I opened one of these files in Pixelmator and saved a copy (without any changes).

The copy looks darker always, i.e., it looks like the original in Preview, and not like it appears at first in Quicklook.

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Answer 4

PauloROP Author

Level 1

35 points

Aug 2, 2018 9:08 AM in response to Luis Sequeira1

Ok.

Good to know you can reproduce it. Yeah it is like I said, in all other software the image looks darker (preview, lightroom and Canon DPP, even DropBox), the only one that shows a brighter image is quicklook before zooming. But the thing is that this brighter image looks better to me, and closer to what I was seeing on the camera LCD. If there is a way to make that brighter image the default in all other software it would be great. I wouldn't even have to retouch the images because they look awesome

Seem to me that this is not a problem on MY mac. I have been searching for some information and it looks like isrelated to Display Color Profile. Are you using any custom color profile or the standard "Color LCD" that comes with tha Mac?

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Answer 5

Aug 2, 2018 9:24 AM in response to PauloROP

I am using the default "Color LCD" of my rMBP (same as yours, 15" 2014), but I don't think that is it.

The same darker redrawing on zooming - it looks like it is putting a veil over the image - also appears in an external display, with a different color profile.

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Answer 6

Sep 8, 2018 5:10 AM in response to Blizzart22

I have looked through some of my photos and it seems the issue only occurs when using Quick Look for .JPG pictures straight out of the camera. Edited and exported raw files don't show the same behavior.

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