Blurred image when using mask

[Dolp]

I am trying to use a mask on a models face to lighten one side.

So, creating a mask, selecting 'person' then persons skin and brush, zooming in to 100% the image become blurred and uneditable. Why?

I am running a iMac, 5k 27" retina monitor, 3.4GHz intel i5 processer with 64Gb memory. Radeon Pro 570 4Gb graphics card.

The version of Lightroom details are below.

Lightroom Classic version: 13.1 [ 202312111226-41a494e8 ]
License: Creative Cloud
Language setting: en-GB
Operating system: Mac OS 13
Version: 13.6.4 [22G513]
Application architecture: x64
Logical processor count: 4
Processor speed: 3.4GHz
SqLite Version: 3.36.0
Built-in memory: 65,536.0 MB
Real memory available to Lightroom: 65,536.0 MB
Real memory used by Lightroom: 4,886.5 MB (7.4%)
Virtual memory used by Lightroom: 50,384.7 MB
Memory cache size: 160.1MB
Internal Camera Raw version: 16.1 [ 1728 ]
Maximum thread count used by Camera Raw: 3
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 1083MB / 32767MB (3%)
Camera Raw real memory: 1163MB / 65536MB (1%)
Standard Preview Size: 5120 pixels
Displays: 1) 5120x2880, 2) 1920x1080

Graphics Processor Info:
Metal: AMD Radeon Pro 570
Init State: GPU for Image Processing supported by default
User Preference: Auto

Installed Plugins:
1) AdobeStock
2) Aperture/iPhoto Importer Plug-in
3) Canon Print Studio Pro
4) DxO PhotoLab 2
5) DxO PhotoLab 2 Importer
6) DxO PhotoLab 4
7) DxO PhotoLab 4 Importer
8) Flickr
9) Helicon Focus Export
10) Nik 6 HDR Efex
11) Nikon Tether Plugin
12) Plugin Parameters
13) Plugin Parameters

Config.lua flags: None

I have to say I do not encounter this problem using other editing software (Capture One)

[C.Cella]

Can yous share a screenshot of the Correction + its settings?

[Dolp]

I have attached two files, one showing the setting as 'fit' and the other at zooming in to 100% showing the face only. as you can see the image at 10% is rubbish and unworkable.

[C.Cella]

It looks like when you zoom-in LrC is not rendering the whole image, all is pixelated.

It's not the mask in itself.

What GPU Acceleration is set in your performance preferences ?

[Dolp]

Is that on the iMac preferences or Lightroom? I see in me initial notice the current GPU settings are noted and states that it is auto.

[C.Cella]

Please actually check the preferences and set them to custom.

Try to see if disabling full Acceleration helps.

If it doesn't help then reset preferences, usually that fixes anomalies (make a backup before resetting so you can revert to them in case)

.

Set GPU to custom and enable the 

[Dolp]

I cannot see a way to check the settings on the GPU. There is lots of information on accessing it on a MacBook but nothing on an iMac.

Looking at the activity monitor

Lightroom CC uses -  memory (184%), %GPU (27.6%) and hi energy and thats with it just on screen and not when editing images.

By comparison Capture One uses a negligble amount of memory, GPU and energy when on screen and even when editing uses far less that Lightroom.

It looks to me that lightroom is carrying out activities in the background which chews up resource on this iMac as opposed to Capture One.

My thoughts are I should consign Lightroom to the bin as editing software and just use Capture One, its more expensive but far better for editing images in particular portraits where skin tone and texture is important.

Thanks for your help anyway.

[C.Cella · Accepted solution]

@Dolp 

Here screenshot of the preferences...and where to find them.

If you set to Custom can you change them or not?

[Dolp · Accepted solution]

Thanks for that. I accessed preferences by using the settings shown it appears to have cured the problem!

I am grateful for the help you have given me. Thank you.

[C.Cella · Accepted solution]

Glad to hear that.

If you enable the second option does it work?

.

[Dolp · Accepted solution]

No, I tried that. I worked back from 'use GPU for export' only 'use GPU for display' worked