P: Reduce magnification in Enhance Preview window

Added my upvote to the OP, it's difficult to tell what's luminance noise or just pixellation at that magnification.

With a bit of maturity, I can see this easily replacing my current workflow of starting with DxO PhotoLab for denoising and lens correction before finishing my edits in LR. Especially once the requirement to make a DNG is no longer necessary as is planned. Definitely looking forward to all these simplifications coming to fruition!

But why 250? Why not 200, or even 300?

Engineering told me that the preview in the Enhance dialog is zoomed in to highlight the difference b/w Enhanced and Not-Enhanced previews. This difference may not be generally seen at 100%; Adobe decided to zoom in on the preview a few years back. The zoom level was set to 250% in Lightroom Classic to show the same focus area in Enhance dialog as other apps ( LrD/ACR ).

They are aware that other zoom ratios are desired, though the best way to get this more attention is to upvote the feature request here. There is, as of now, ONE upvote (mine).

No idea why 250 but I'll ask. 

But why 250? Why not 200, or even 300?

And more to the point - how is this resampling actually done?

Resampling zooming past 1:1? I'm not certain there is any. Zooming out from 1:1 yes but that's not an option. 

As to the minus zoom, it is a "fill screen" so to speak, so one can click on an area to get the actual zoom which yes, is well past 1:1. It's not super discoverable I'll give you that. 

This entire dialog needs a bit of love but for an initial release, it seems fine to get the job done. 

The magnifying glass just goes to full image. You can see in the first screenshot that it's around 250%. Main image is at 100:

How can I trust 250% zoom?

Not at a computer to check, but looking at images in:

https://blog.adobe.com/en/publish/2023/04/18/denoise-demystified

In the preview window, bottom right corner, a minus magnifying glass, what does that do? And does it stick?

You're right, and it does seem strange. It's not even a hard ratio, but somewhere around 250%.

What could possibly be the justification for this? And more to the point - how is this resampling actually done?