Why 'photoshop' passport photos?

I shoot RAW files and process in Lightroom.

There is no such thing as an unprocessed image — simply automated processing. The color rendition to match the light sources, choosing the right range of values to make a good exposure, etc. are all basic things.

In the old days, prints would choose the paper grade and exposure time, and you would do “dodging and burning” while making the exposure, and then you chose the developer and timings for the process.

So when I shot my wife’s photo for example, I did it outdoors in the shade against a white reflector I just taped up to use as a background. Those are choices too! Then the first “processing” step is choosing which of 10 or so exposures to use. A burst taken over the span of one second will show different eye positions etc. especially if a blink was taking place.

Then, I used the relevant control to indicate that the background should be neutral in color. This is not changing the color, as it would be if you started with a finished jpeg file that was blue, orange, or buff when it should be grey as it was in life. This is interpreting the raw data to match the light source.

Now the background should be uniform white, not showing cloth folds or anything. That's the brightest thing in the picture, so setting the detailed exposure settings (whites and highlights, in addition to overall exposure control) can push that up while coordinating with the main slider to make the skin look exposed right.

Note that this is the opposite of what an automated system might guess — recovering blown out highlights, bringing out details of the wrinkles in the cloth.

No Photoshop (or explicit pixel manipulation) required. That's just what a good picture takes to make.

Another issue is that (in the UK at least) it can take more effort to find somewhere to get passport photos taken than to take the pictures and get them printed.

My nearest (or at least most convenient) passport photo booth is 8km from my house at the mainline railway station, because you need photocards for season tickets. It even works most of the time. In previous jobs it would have taken my entire lunch break to get to a machine and back or been completely impossible without making a special trip somewhere busy at the weekend. That sort of thing can be tricky to fit in to a busy schedule. Compare that to 5 minutes setting up the SLR on a tripod, 5 minutes cropping (etc.) and uploading, then the pictures arrive on my doorstep 3 days later. For less money.

As requested here's my passport photo solution from the comments; photo booths are most common in super stores (usually the "Big 4" supermarkets in the UK) and transport hubs (bus and train stations). In a supermarket they're usually near the checkouts, for transport most likely near ticket machines and self service systems. That removes the requiremet of Photoshop at all.

Then there's the cost issue - they are super expensive, especially back when I was a secondary school (High school in the US) student. My simple trick is sit in the booth and have someone take the photo with your smart phone, then go to Boots (that's a UK cosmetic/health/childrens store) who also have self service print machines. For £0.32 (is it worth currency converting that??) you can get 6 passport photos and, provided you have a decent camera and didn't smile, it will be suitable for a passport.

Can't find a booth? Use a well-lit while wall - worked for me one time!

Don't have a friend? Buy a selfie stick - still cheaper!