You may be able to find the location and dates of operation of the studios.
If these photos are from your great-grandmother, researching her family will be your best bet. I belong to a surname society where we have at least three separate groups of inherited photos. Working together we have found many of the same photos and some had names attached. So we have been able to identify some of the people and groups and places of the photos. It is slow going but getting multiple family members involved will help in the process.
Over the decades I have received old photos from distant relatives, especially once the WWW was established. They didn't know who they were but I did.
In fact my research was so far along prior to the WWW, 1994, that I have had little help with genealogical research. The boon I have had is old photos from distant family members.
If you can, scan the front and backs of the photos (tif or binary file, do not use jpeg) and make a CD of the photos. Then when you contact family members during your genealogical research you can easily send them the photos. This also assures that the photos will not be 'lost' forever.