My title explain it all really. When i zoom into a picture in order to remove dust or spots i tend to get a massive lag. Only when using the alt-key ( the 'infrared" option ) it tends to go away.
Any advice would be lovely.
Joris van Gennip
[link removed by moderator]
Is this a photo where you have already removed lots of spots? If so, this is a known issue with Lightroom, using lots of spot removal or lots of brushing will cause the CPU to work hard and that results in slowness.
If you really need to remove lots of spots, Photoshop will offer better performance.