Image quality lost through editing with Photoshop?

Question

I find a number of professionals using Lightroom as their primary photo editor. 
I did a search on Lightroom vs Photoshop.  I found the following listed as the first reason for choosing Lightroom: 1.  Nondestructive Editing.  Nothing is actually changed (by Lightroom) in an image until it is exported.  This means you can make an adjustment, change it again and again, but no quality is lost as it would be with Photoshp.  This is reported in Outdoor Photographer.
My impression is there is no lost of image quality in Photoshop if you are working on a layer copy of the Background.  Photoshop tries to prevent degradation of the original image by requiring it be copied  or otherwise freed before the background can be changed.
Image quality can be lost in downstream layers through processes such as changing image size. 
Is my statement correct about loss of image quality and the 'analyst' from Outdoor Photographer misstating things?

Answer 1

Hi Vince.
I am just learning my way around Photoshp.  I have spent 18 months learning how to start and to stop it.
Good point. But if we peg the learning curve of Ps at 10, Lr comes in around 2 or 3. Like learning to drive a car as opposed to learning to fly a jet.
Smart Objects would make PS more re-editable.
True, but still no match for Lr or Ps RAW.
I have never before seens a comment that extensive work on an image in PS would deteriorate the quality of the image.
Extensive work will do what the user asks it to do. In the first 18 months I had Ps, I asked it to do lots of things that I now realize deteriorated my images. Forever.
Regarding LR, I have created for me a workflow that requires PS.
So did everyone before Lr came out. And yet, Ps users by the thousands, if not millions, have adopted Lr. Many if not most with a greater time investment in Ps than 18 months. I dropped my Ps centric flo the moment I realized what Lr could do. I had been using Ps pretty heavily for about 5 years by that time.
I feel LR works best for experienced photographers who are shoooting a lot of pictures.
While it's true that experienced photographers might realize more benifit, maybe not. It works great for everyone.
That person has good images, images that need little editing, to start the output process.
This is not true in the sense that the majority of Lr users are mediocre photographers at best. For the simple fact that most photographers (even "pros") are mediocre at best. And Lr was conceived with these folks in mind. It has the true "pro" stuff, but in an amateur friendly environment. Judging by the images and questions posted on photo and Lr forums, there are many, many, low level photographers using it.
I am an inexperienced photographer shooting just a few pictures.  So I put a lot of effort into getting a good print from my mediocre shots.
You obviously care about your images. Care more when you are shooting them. This is boiler plate advice. Time spent mastering your camera will pay off better dividends than learning to fix bad photos. This was true before the digital age, and it's just as true now. Ultimately, no matter how hard you massage it in Ps, Lr, or any other app, the quality of your final image will be a function of the quality of the original pixels you captured with you camera.
So far as masks and all the rest, Lr has an Local Area Adjustment Brush which does just that. You paint the mask, complete with any number or combination of adjustments, with a brush. The mask and the adjustments to it can be easily changed later. A good spot removal tool. A great red eye tool.
File size isn't a huge factor these days, but it still counts. Instead of layers and the pixel data for each of them as in Ps, Lr has the pixel data once, and a sidecar file with the adjustments settings in a much smaller file. Not a big deal for storage, but when rendering, maybe a bigger deal. Lr also pre-renders previews at various sizes (you can program this, plus how long it keeps them). I could go on and on (and I have).
Bottom line, it's a great tool for anyone who takes photos. For the price, it's a no brainer for $150. If you have the $150. Not true for many of us these days.
Anyway, Vince,  I hope you don't think I'm picking on you. I answered you in detail because you made such good points. And the answers might be of general interest.
Peace,
Lee