I have noticed that, in Blender 2.8, the orthographic and perspective views are toggle automatically as a view is selected from the number pad (orthographic) or the mouse pan or rotate (perspective). In normal modelling this is very useful, but at present I am modelling a scene which contains small items, which, in the perspective view can be clipped. Is it possible to override this automatic change so that the view remains in the orthographic mode?

I don't know how to turn that off, but something that might help you until someone who does know comes along, in your sidebar (shortcut n) click on the view tab and you can adjust the clipping start distance so it doesn't cause the disappearing act.

OK yes the numb pad will change from right front bottom and top the 5 key will switch you to either Orthographic or Respective and the "." will focus you in directly on what you have selected maybe I am not understanding the question correctly or missing something

You can turn the auto-toggle for perspective/ortho off - I found it annoying to have it on myself:

Turn off auto-toggle

^Read down as the first answer is corrected by a later one

Another solution to help you when object start "clipping" when close up is to decrease the Clip Start parameter to an extremely low number, like 0.001. It all depends on what scale you're working at, and be sure you have the scale set not only in the Units but also in the Overlay > Guides > Scale properly. For example, if you are modeling very small items, then it may be beneficial to model in real-world units like millimeters. You not only need to set this scale in the System Units parameter but also in the Viewport Overlays Scale. If this still doesn't help you, then you can reduce the clipping start value in the view tab. Press N, then in the view tab, change the clip start parameter. However, if your scale is set up properly for the type of modeling you're doing, then this is not usually necessary.

Not trying to promote myself with this, but I have a process in this tutorial of exactly how to set the scale properly for modeling in a very small scale, like millimeters. This is beneficial for modeling jewelry or other small scale objects in real-world units. If you watch the first part of this tutorial, you'll see exactly how to set this up. Again, the other technique is to change the clipping value in the view tab of the side panel.

SilentWinter posted at 9:00PM Mon, 09 September 2019 - #4361558

You can turn the auto-toggle for perspective/ortho off - I found it annoying to have it on myself:

Turn off auto-toggle

Thank you sooooo much!! I have always hated having to use the 5 Key to get back to Ortho view constantly. Now I know how to fix it.

SilentWinter posted at 2:23AM Tue, 10 September 2019 - #4361558

You can turn the auto-toggle for perspective/ortho off - I found it annoying to have it on myself:

Turn off auto-toggle

^Read down as the first answer is corrected by a later one

Thank you...hitting that 5 key all the time was getting tiring. LOL

Laurie

Thanks you SilentWinter . That has sorted the problem. Thanks to others for their responses.