In the run-up to the Wagner bicentenary in 2013, Plamen Kartaloff, director of the Sofia Opera, began to nurture a native Wagner culture with a staging of The Ring – the first in Bulgaria, apparently – which has since received near-annual revivals and enthusiastic notices on tours to Germany. These films were made – Das Rheingold in 2010, Die Walküre in 2011 – at the start of the company’s Wagnerian adventures and not some years down the line, when workshopping would likely have ironed out the worst of the technical wrinkles.

As it is, the tetralogy gets off to a less than dignified start with a trio of trampolining Rhinemaidens (uncredited members of the Sofia Ballet?), supplanted at the last crotchet by their less athletic vocal counterparts, and no wonder their singing comes and goes as they bounce around. Accompanying the Prelude to Die Walküre, there is a staging of sorts of the battle between the Wälsungs and Hunding’s kinsmen: another idea probably more convincing on paper – and in the house – than under the camera’s dispassionate gaze.

The stylised naturalism of the acting corresponds well to some sympathetic individual performances – the late German dramaturg Richard Trimborn deserves credit here – but not at all to the creakily executed, vaguely space-age Konzept for the staging. We’ve had the centenary Ring (Patrice Chéreau) and the time-tunnel Ring (Götz Friedrich): welcome to the Red Dwarf Ring, where Rimmer and Lister will surely turn up as extras lunking about in the Gibichung scenes of Götterdämmerung.

I jest, but not about the bathetic dissonance between the sound of the Ride and the sight of eight Valkyries wheeled on atop warheads; a method of locomotion even less well suited to any intimacy of rapport between their sister Brünnhilde and Siegmund in the previous act’s Todesverkündigung. What’s important is not how subjectively hideous or unintentionally comic it looks from scene to scene (though surely Fasolt’s death by golf club is meant to be funny) so much as how ill it fits the music’s continual movement and how far it falls short of bringing the world of The Ring to new life.

A reduced orchestration is the work of one (not the) Gotthold Lessing, dating from the 1940s and cutting back the six harps of the Rhine and the Magic Fire to one. Lessing slimmed down the band, not the score, but the curtain-raising octave E flat in the basses lasts for three seconds rather than the full four bars specified in the score: again, not a propitious start.

The recorded sound is more of a crease than a wrinkle, resembling the kind of in-house feed generally used to ‘archive’ a staging, though its deficiencies are more obvious on headphones than on a standard domestic TV set-up. Voices wander across the stage while the bodies they belong to remain motionless; the Rossinian cello solo to accompany Sieglinde’s refreshment of her brother struggles against the amplified rustling and scraping of Siegmund’s costume.

The blurred aural focus of Das Rheingold in particular affords no more than a hazily positive impression of brightly sung Rhinemaidens and the sepulchral Wotan of Nikolay Petrov. In this regard the miking of Die Walküre counts as an improvement, albeit one not flattering to the thinned-out instrumental textures or the beat in Mariana Tzvetkova’s soprano at close quarters. Once halfway up the stage for the third act, she and Petrov draw the best from each other – for once, a believable father and daughter in voice as well as appearance – in as strong a final scene as the setting will permit. More consistently pleasing is the Italianate radiance of the Wälsung twins as sung in distinctly Bulgarian German by Tsvetana Bandalovska and Martin Iliev: her ecstatic cry as he pulls a loosely installed Nothung from a conical tree is quite something. Otherwise, approach with caution.