[glend (Glen)]

I am sure there is a simple answer to this question but I can't find it:

When setup to image a fairly faint DSO that I can't actually see through my Canon 450D Liveview screen, how do you tell if your actually on target?

I use a ASI130MM guide camera on a 60mm ZWO guidescope mounted on the top rail of my 8" imaging newt (with Baader Coma Corrector attached to the Canon).

Guiding works fine - using Metaguide with this guide camera.

My approach has been to go to my target object with the scope setup for visual and check the seeing and that it is visable in the scope and centre it. (Obviously the scope has been carefully polar aligned in advance and in some cases is 0 0 on the SCP - using the Syncscan polar alignment routine).

Then I go to a nearby star and setup the camera and use the mask to focus it. Punch in my target and slew back to its location - but of course I can't actually see it. So I take a few test subs and sometimes it's there but sometimes its not and I can't really tell how far out of field of view it actually is. My finder scope can't see it as it's too faint, nor will it appear in my guide camera field.

So what's the practice for centering a DSO in the DSLR field of view?