How many products using "roadster_black_small.gif" as the thumbnail photo?
products using roadster_black_small.gif as the thumbnail photo refers to ThumbnailPhotoFileName = 'roadster_black_small.gif';
SELECT COUNT(DISTINCT T2.ProductID) FROM ProductPhoto AS T1 INNER JOIN ProductProductPhoto AS T2 ON T1.ProductPhotoID = T2.ProductPhotoID WHERE T1.LargePhotoFileName = 'roadster_black_large.gif'