Daguerreotypes by Joseph Wenninger, probably a betrothal couple, 1843
The bodice of the lady reminds me a bit of this dress in my other post here.
In the summer of 1843 Wenninger visited Stockholm. The portraits might have been taken during this visit. Wenninger was one of the first foreign daguerreotypists to visit Stockholm, and thereby overpriced. One of the the first professional portrait photographers in Sweden. Joseph and his brother Heinrich arrived in Stockholm in June-July 1843. On August 25th they proceeded to Finland / Helsinki and Russia / St Petersburg. Joseph was a chemist and portrait painter, and active as a Daguerreotypist about 1840-1849. His brother Heinrich was a landscape painter and also a Daguerreotypist.
See also: Geschichte der Fotografie in Österreich. Ed. Rudolf Kirchschläger (Bad Ischl 1983); Söderberg – Rittsel: The Swedish photographic history 1840-1940 (tr.1983), p. 16.