OK, this is not an accessory but for me "Release Shutter Without Card" is a useless feature, which I never use but can get into trouble real easy ... Film days, 1975 - I had my beloved Nikon F2 (cost me 1.5 months pay) and was hiking on the south end of Guam. A trail runs along the crest of the hills providing great views of two postcard perfect bays, a lake in the interior and in general just gorgeous scenery while the ceaseless tradewinds temper the heat and humidity. I followed a trail that went across to the east side of the island, met a group of boys enjoying the day at a shallow stream with a couple of carabao. Rode with them through a bamboo forest until we reached the outskirts of the village where they lived. Realizing I had miles to go to return to my car still on the east side, I resigned myself to a very long trek back. About that time a pair of Navy Seabees tooling around the boonies in a jeep came by and gave me a lift around the south end of the island back towards where my car was. We stopped at the ruins of an old Spanish fort overlooking Umatac Bay around sunset, all of us happily snapping away. 'twas just about then I discovered my film had slipped off the takeup spool, not a single shot exposed.........
That's too bad. Fortunately however (at least in my experience), photography opens our eyes to the world around us and amplifies the visual experience. I bet your memories of that day would have been less vivid had you not observed your surroundings with the photographer's eye. At least the 'film' in your mind was properly exposed that day
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