It changes a lot across the season, and none of it can be promised. November into early December gives a lower sun with more accessible sunrise, sunset and warm low-angle light. Mid December through January brings extremely long days, with true 24 hour daylight south of the Antarctic Circle around the solstice and, on much of the Peninsula, a sun that barely sets. Late February into March brings back distinct sunrises, sunsets, shadows and golden light.
If photographic light is your priority, the shoulders of the season are the better bet. That's the same conclusion the wildlife and pricing arguments reach for late season, which makes March a strong choice for photographers specifically.
What nobody can promise you is a golden hour. Near midsummer the sun may stay above or close to the horizon most of the day, which gives prolonged soft light but not a conventional sunset. And whenever the best light appears, the ship might be repositioning, or at dinner, or the weather might have closed in entirely.
Treat dramatic light as an opportunity rather than something on the itinerary. Keep a camera or phone ready aboard, because some of the best light turns up outside landing hours.