The T mount is a standard dating back to 1957 I believe, in those days it provided a convenient way of connecting a standardised lens to a variety of different manufacturers cameras by means of a suitable adaptor. As the lenses and the cameras had none of the complications of modern day equipment it provided a way of keeping costs down.
It could clearly be used to connect anything with a T mount to a camera. T2 is merely a proprietary name for a T mount and does not change its functionality.
As it provides no electrical contacts (or mechanical ones in most cases) your camera will not see anything electrical confirming the attachment of a lens and behave as you have indicated.
Many cameras of that era did have a menu entry or other method that would allow the use of simple extension tubes and older mechanical lenses and since Minolta was a major manufacturer I would have expected that facility to exist.
So summing up - preferably read your handbook, if you still have one, or look on the camera set up menus to see if there is a setting for manual lenses, trying anything that may be related.
To qoute a seller of Minolta T2 mounts (Heritage Cameras)
http://www.heritagecameras.co.uk/t2-mount-t-mount-for-minolta-af-dynax-maxxum-35mm-konica-minolta-sony-alpha-digital-slrs-dslt-3130-p.asp
'This mount fits most Minolta AF 35mm, Konica Minolta 35mm, 5D and 7D digital plus many Sony Alpha digital SLR cameras. Most film cameras work with stopped down metering in manual and aperture priority auto exposure modes, but models with program modes only are not suitable for manual lenses or accessories. The Sony Alpha A33, A35, A37, A55, A57, A65, A77, A100, A560, A580 and A700 (plus the A850 and A900 with firmware 2.0 or higher) work with stopped down metering in aperture priority auto or metered manual exposure modes. Other Alpha DSLR cameras (the A200 to A550) work in metered manual mode only. Most of these cameras require setting up for manual lens operation, either by changing an option in the menu system (digital) or pressing a combination of buttons while turning on (film).'
As it notes there are some auto only cameras that cannot be set up correctly.
Vignetting, as Mike indicates did not happen if a T2 mount was used with a T2 lens. Using T2 mount with other devices had the potential for vignetting on some occasions, this was generally not the fault of the T2 mount.
Following writing the above, I see that it may be irrelevant as you have also posted under digiscoping, I will leave it to avid digiscopers to comment further, but camera settings will usually not affect a vignetted image.
