Different Operating Systems might trip you up. I mentioned in this post, or another similar question, that I both remote into a primary desktop, as well as having "shared" the connected HD. This gives me two options from a networked laptop. My laptop has a local copy of the primary LRCAT and "sees" the images on the shared drive. I can work locally on the laptop against a master copy of the image files on the shared drive. I can also work remotely as if seated at the primary desktop. Everything is running Windows10, the laptop Win10Pro.

Steve,

I've read your post several times. I know nothing about Apple systems so I'm guessing a lot.

I read nothing about Adobe promoting or supporting using Lightroom Classic to share the "single user" catalog. On the other hand, they promote and support using Lightroom CC (cloudy) on as many devices as you might have.

In your case, you are stuck using two versions of Classic due to operating system choices. Even if you get a collection "synced" today, it might not work with next week's update.

For a "conservative" workflow, I would take the 5% of images you want on both machines and manage them in Lightroom CC (cloudy). When they are "finished", export a copy. One of the export choices in Lightroom CC is "Original+Settings". I tried it and when I Imported in Lightroom CC, the masks and sliders were all in the right places.

On the other hand (!) if you are having fun "tricking" Lightroom Classic into multiuser work on computers with two operating system versions and Lightroom Classic versions, do it! You will be a pioneer!

Good luck!

PPI and colorspace are the only considerations for printing a JPEG, a pixel-based digital image.

PPI - pixels per inch - is a calculated value. Start with the finished image, how many pixels 'wide' and 'tall' is the current file? Will it print as-is to a 300ppi 'gold standard'? The math is simple: 36 x 300 is 10,800 pixels, probably larger than your typical 24MP camera. What if you achieved 200ppi, as in 36x200 = 7200?

With the math analysis performed, do you need to up-size the pixels to a minimum of 200ppi or higher? You can generate the up-sized file and inspect the "created" pixels at the 1:1 pixel level. How does that candidate up-size file look on your monitor? That's the level of detail (or fuzzyness) you'll get in the printed file too.

You should be using sRGB colorspace JPEGs as the output print file, unless you've found a printer who can accept other file formats or colorspace. Even then, you'll likely not find a tangible difference in the more complicated workflow of not using sRGB JPEGs.

Steve, personally, what I do here at the Digital Bear Cave is the following:

1, My Win10 desktop is my primary image editor, in an office with a large UHD monitor (color calibrated).

2, All my images reside on a USB-connected 4TB WB external harddrive.

3, The LRCAT resides on the local C: drive of the desktop.

4, Periodically, I copy (back-up) the LRCAT onto the primary 4TB drive and onto a second clone 4TB drive, along with new & updated images.

5, From a Win10 Laptop, I've both "shared" the connected primary 4TB drive and set-up remote desktop access to the primary Desktop.

So, my configuration differs from the OP's request to have two concurrent and active machines sharing images and current edits inside two unique installations of LR Classic. For me, I treat the Desktop as primary and I just remote into that machine if I want work in another room via the laptop. When I travel, I bring the 'cloned' HD as a connected device to the laptop and then just merge any updates from the road into the primary desktop when I return to Chicago. LR Classic is installed on the laptop, and configured to access the LRCAT and image files on the connected USB device.

Regarding Mac's sharing abilities of drives / computers over a 'home network', I'd expect the same options as described above. But, I'm a windows-only shop, so I defer to others about 'how' such a home-network can / should be constructed. And, I have the added wrinkle of running older LR6 software.

Clearly, I'm more cutting-edge and future-forward than these Luddites I'm dealing with on another thread ...

Alas, although I have the 2 computers, I don't have the software needed to show that not only should this collection-sync work, but that it's how Adobe intends it to work.

Our OP could also use a single connected portable drive and place the LRCAT folder and all the image files onto the drive, and just connect the drive onto the 'active' computer as needed. The LR software would reside on both computers. That's what, five (5) options so far?

Peripheral to this exact post. I have a Nikkor 28 - 300 lens I just bought an adapter to test the lens on my Sony ar7 IV. There is no vignetting and I never have noticed .I don't use lens hood but I almost always heavily crop. But I did notice that despite the adapter working well I now don't like this lens. Maybe spoiled by my new Sony 200 - 600 lens. Am not sure. The pictures are not razor sharp although the auto focus and tracking seem to be working. Still testing adapter and lens but right now it looks like I will send back the adapter and save up for a Sony 28 - 105 f2.8 lens . Any comments on this lens. I will use it for flowers and bugs and landscapes and my Sony 200 600 for birds.