I have this lookup field which is coupled to a customlist of artists. I use this lookup field as a column for another list. So when someone creates a listitem in this second list he or she can choose one item of the previousely mentioned artistlist in the form of a lookup. Well, after a while this artist list will get bigger and bigger. So when there are 500 artists our customer has to scroll through an anoyingly hugh list. Is it possible to add a search function to the newitem page to search in this lookup list?
If you are using SharePoint Server, the best way to handle this feature is to move away from lookup fields and use a managed meta-data field with an associated termset. The termset will provide a type-ahead feature, but also a lot more capabilities around managing the list long term versus a linked list and lookup field.
You can likely pre-populate all of the existing values using a PowerShell script helping with the transition from the old to the new field so that it doesn't have to be manual if you have thousands of records.