The photo below is of an (as yet) unidentified (English) family member and is from the London studio of Hermann Ernst. There is nothing printed on the back. The photo is part of a collection, the dates of which range from the mid 1860s to about 1916 or 1918.
At the moment, this lady could be any one of about 10 to 12 relatives. As we know her age in this photo, having even an approximate date ( + / - 5 years) could narrow down the number of possibles to as few as 2 or 3.
Information on Hermann Ernst's London studio, unlike many others of the period, is hard to find. Pages such as RCS Photographers Index and Victorian and Edwardian Photographs make no mention of Hermann Ernst. The only information I've found is that Hermann Ernst was a photographer and / or photographic studio owner from Hannover. The English translation of his German Wikipedia page offers very little. A date, 1865, is mentioned but the translation as to its significance is a little unclear. Also, there is no mention of his London studio.
Following the link to the page of Ludwig Hoerner, a researcher and source of the above information hasn't helped as I can't access any of his works which might have the information I'm looking for.
The best clue so far is this circa 1885 photo but it's from Hannover and the card style is quite different. I've only found one other photo online from the same studio as our photo (Waverly Place, St. Johns Wood NW); the design is closer to ours but no date is given. For the moment, I'm assuming that our family photo was taken later than 1885 as the design seems more modern (but this is really just a guess).
Can anyone put an approximate date on this photo? It seems that a big step in the right direction would be establishing when Hermann Ernst's studio in St. Johns Wood was in business. Also, the hairstyle and dress may provide further clues.