Hi Gerry,

Yes, you'll need an adapter to fit that older, manual focus lens to your camera.

Focal length is focal length, regardless of format so a 50mm lens will act like a short telephoto, just like a 50mm lens made to fit your camera would.

You can use...

- Manual mode.... BUT only if the adapted lens has a means of setting the aperture on the lens itself. Most vintage, manual focus lenses have that. But a few don't. You set the ISO and shutter speed in the camera, the aperture on the lens. No, you don't set the aperture using the camera. There's no connectivity between camera and lens to allow that.

- Manual plus Auto ISO... will give you a form auto exposure. You set the shutter with the camera and the aperture on the lens. The camera will then select an ISO that will make for what it thinks is a "correct" exposure.

- Aperture Priority Auto Exposure.... Here you set the aperture on the lens and the ISO in the camera, then the camera will choose a shutter speed that it thinks will make a "correct" exposure.

You CANNOT use Shutter Priority AE.... in order for that to work, the camera must be able to adjust the lens aperture and there is no way for it to do that with an adapted lens. (Note: The only reasons some other responders have been able to do this is because they were using Auto ISO in conjunction with Shutter Priority AE. First, I don't recommend ever combining two different AE modes. It is usually not a good idea, though in this case it probably saved their shots because there is no way that Shutter Priority AE can work with a manual aperture lens. To provide AE in that mode, the camera MUST be able to adjust the aperture, which it cannot do.)

You CANNOT use Program AE... for the same reason you can't use Shutter Priority.

You CANNOT use any "full AUTO" mode or any "SCENE" modes the camera might have.

In order to use the adapted lens, most digital cameras require you to set something in the menu that "allow shutter release without lens on camera". Because there is no electronic communication between the lens and camera, the camera won't know there's a lens installed and might refuse to release the shutter unless you override it with this setting.

Hopefully your camera has "focus peaking" or other manual focus assist feature. Otherwise it can be difficult to achieve focus accurately with a fully manual lens. Check if your camera has means of magnifying the view to help with focusing, too. Many have that and it helps, although it's slower to work that way.