Finings and head retention

Thinking I would lose power durning hurricane Isaac I rushed a rye pale ale into a keg. I added some gelatin to the keg in hopes the yeast would settle faster and clear the beer. I really don’t have any experience with finings but can they affect head retention? Because, while this beer is crisp and clear the little head it forms dissipates pretty damn quick leaving no lacing. If this is normal for gelatin I’ll stick to cold crashing and time to clear my brew.

How much gelatin? From what I understand 1/2 of a packet from the grocery will help/work but more may create head retention problems. I have only used it one time and it was clearer but not perfect.

I used a couple teaspoons and after about a week the beer started pouring pretty clear.