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I bought a lens reversal ring to try macro photography on my 50mm f/1.8 prime lens. But when I tried it, I couldn't control the aperture as my lens doesn't have manual aperture control. I attached the lens normally and changed the aperture and again detached it to use it reversed. But still, the aperture hole was the smallest. How can I overcome this problem? And if not possible, what equipment should I buy to make this work?