Thanks everyone for your interest
Last night I got a shot of the second nova discovered by Japanese amateurs in the past month - this one a little higher in the sky but still low in the SW after dusk as shown in chart below.
The spectrum, as before, uses a 'grating' in front of the camera to split the nova's light into as streak or spectrum with brightish hygrogen line in 'emission' as marked - characteristic of a 'new' star or nova.
Below it is a reference star eg Altair with the its 'lines' marked. The separation of the H-alpha line from each star's image [to right] is identical
