[Karrot_Kream]

Do you let guests shoot the 90mm in full auto mode? Personally I've found that the general population has a really hard time operating a camera. My partner and I can both do photography though I'm more serious about it and we frequently travel with cameras. When we want someone else to take pictures, even on Auto mode I find others have a hard time. If we're in a hurry and want a picture taken by someone else we just hand them a phone.

[PaulHoule]

Usually it would be aperture priority (f/2.8) in a situation where I know what the light is so I can set the ISO and leave it there. I develop with DxO so I am not worried about noise or the shutter speed too long but I do worry about hitting 1/8000 sec -- so usually it would be a situation where the lighting is predictable.

The autofocus can be set in a mode where it will reliably lock on the subject's eye. I would demo how you have to be a certain distance to get a headshot, since it is a prime lens, if they are too far away I don't worry too much because modern cameras have a lot of pixels.

[ezst]

For me it's the AF. Every. Single. Time. People on smartphone, used to near-infinite depth of field, just forgot/never learned about focusing, and handing them a camera just too often results with the background being in focus and the subject blurry.

[Karrot_Kream]

Yeah that's been my experience too, or if the lens is open wide enough they don't watch the AF and have it focus on a belt or something weird and then blur out faces and eyes.

The other big one is HDR. HDR on phones makes lighting a lot less of a factor but a lot of times if I'm asking a friend to take an indoor picture they underexpose the shot because they don't have good lighting.