Lightroom (cloud) smart preview size discrepancy

[David Meneses]

Hi all!

I'm wondering if someone can help me solve a mystery regarding smart previews.

Recently I migrated my modest (about 400 gigs) personal photo library, switching from Lightroom Classic to Lightroom (CC). The main motivator for this move was the allure of being able to essentially access the same catalog of photos from a Mac desktop (which stores all originals locally), a macbook pro, an Iphone and an Ipad. Having the ability to add originals to the Lightroom ecosystem from any of these devices and being able to cull, develop and organize photos from all devices has been a dream so far but there is one bit that confounds me. 

I'd like to store smart previews of my photos on my macbook pro which currently has about 80 gigs of free space. From what been able to find in manuals, in this community and online, my 34,000items/400 gig library (made up of RAW files, jpegs, tifs and PSDs of old film scans) should yield smart previews well under the 80 gig limit of free space on this laptop. The problem is that when I click on "store a copy of all smart previews on "xyz Drive", Lightroom tells me that I needs 265 gigs of free space.

Am I crazy or is it odd that 400 gigs of photos will yield 265 gig of smart previews? Or am I underestimating the amount of space needed for 34000 photos worth of smart previews?

Any and all help would be greatly appreciated. 

[David Meneses]

I need to ammend one part of my above post. My library also includes 500 or so videos of varying formats and resolutions. Still, from what I've read the proxies that Lightroom creates for video previews should not come close to the original files. 

Thank you

[David Meneses]

Some additional crumbs to expand the conversation about how Lightoom handles video files (assuming that this could be the issue).

I have a 4 minute 23 second Quicktime in lightroom.

If I log into Lightroom on Chrome I can access this file and have two options for downloading. 

1. Original: 3840x2160 h.264 .MOV = 2.62 gigs

2. Optimized: 1280x720 h.264 .mp4 = 68.2 megs

I could assume that Lightroom should consider the "Optimized" version as a Smart Preview and that this much smaller file should be downloaded when I select "store a copy of all smart previews on xyz Drive" on my desktop.  I unfortunately do not have enough space on any of my computers internal drives to test this theory. Any thoughts?

[Jim Wilde]

Can you post a screenshot of the Local Storage tab of your Lightroom Preferences on the Macbook Pro? I would expect smart previews of 34k images to occupy between 40 and 70GB (my 24K images produce 48GB of smart previews), but I don't know how videos fit into this scenario.

[David Meneses]

Hi Jim. Thanks for replying. 

Below you'll find screen shots of the local storage tab on the macbook. 

One note. I had to move some meadia onto the internal drive since my earlier post and my available storage is down from 80 to 34gigs but for the purposes of this conversation, I don't think it matters.

I've attached two screen shots. 

One is with "store a copy of all smart previews on "xyz Drive" unchecked.

The second has "store a copy of all smart previews on "xyz Drive" selected. 

As you'll see Lightroom is telling me that I need 255.9 gigs in order to store all the smart previews. 

[Jim Wilde]

I'm just wondering if the issue is the videos. I have no idea if a smart preview of a video is even possible, but hopefully someone who does know will be able to answer the question soon. Certainly smart previews for 34k images should occupy way less than 100GB on disk.

[Rikk Flohr: Photography]

I find 1 GB per 1000 images is a pretty good estimate for "normal".

[David Meneses]

Thank you for giving it some thought. I appreciate it.