It is the lens which makes the photos razor sharp. There are many blog articles on how to take sharp photos with DSLR cameras but without a proper lens, you can not test them. For an average camera with standard zoom lens, like Sony A68 with 18-135mm kit lens, you will not get sharp close-up photos of flowers. There will be a deficiency in sharpness. Sony 18-135mm kit lens is enough great but it is not a prime lens or normal lens. Achieving a tack sharp photo is one of the keys to creating an eye-catching photograph. It is not the fact that you need more costly lens than the Sony 18-135mm kit lens to achieve sharp photos. Picking up the correct kind of lens suitable to a situation makes a big difference.
A wider aperture technically will permit more light. Camera lenses can only achieve their sharpest point at one particular aperture. That is one reason why the macro lens is a separate category for the close-ups. Sony SAL 30mm f2.8 macro will produce sharper photos for a big reason – perception. As the background gets smoothly blurred and focus is sharper for the closer objects, it produces an effect of more sharp photos. On the other hand, Sony DT 35mm F/1.8 SAM lens will be perfect for low light situations for the landscape and portrait. Sony DT 35mm F/1.8 SAM lens will fail to produce “sharp effect” when we will use for a close-up of flowers. These two lenses have a point of overlap. A lens is a factor, we have an article to choose some perfect lens for Sony A68. Costlier lenses of the same aperture and focal length will produce a more sharp photo. DxO measures the pairing of specific lenses mounted on a camera body to report this difference in perceivable sharpness they describe.
The camera takes the photograph in case of digital photography (manufacturers can do a lot of tweaks to keep low performing). Sony A68 has a crop sensor. A full frame sensor may produce more details (as noise will be lower). As we are talking about “digital photography”, the statement “a full frame sensor may produce more details” is not always the truth.
The higher is the ISO speed, the more will be noise. To use the camera’s lowest ISO setting around ISO 100 to 200, we need a lens with a wider aperture.
Faster shutter speed is less susceptible to movement. You should stick to use a shutter speed of at least 1/focal length. So for a 50mm lens, you should use a speed of 1/50th of a second or faster.