Good lens quality is of vital importance, but for the best possible sharpness in your final print you have to take care at every key stage on the way. The following checklist contains all the main influences on image detail:

Lens quality. Use the highest-quality modern lens you can afford. Its covering power must match or exceed your camera’s picture format. The correction of aberrations must suit your typical subject distance. The lens should be multicoated to minimize scattered light.

Lens condition. Do not use a lens with scratches, grease, dust, condensation or misalignment of elements (e.g., due to physical mishandling). Avoid inferior filters, converters or close-up lenses.

Camera. Focusing must be completely accurate on the film – beware of non- registration of focusing screen, and also autofocus errors. Do not overuse movements (especially view camera shift movements which can position the picture format excessively off-axis). Sometimes the focus or zoom control slips when the camera is pointed vertically. Mechanical faults include SLR mirror movement vibration, shutter bounce or film starting to wind-on before the shutter has fully reclosed, etc.

Shooting conditions. The atmosphere may contain dust, ripples of warm air,  pollution and moisture particles. Avoid shooting through glass windows, however clear looking, especially with a long focal length lens. Prevent vibration or movement of camera or subject during exposure.

 The light-recording material. Its ability to resolve fine detail. With silver halide material this means film speed,

grain and emulsion thickness; degree of exposure and development; also the type of developer. With digital capture it means the number and pitch of elements in the CCD; also whether it is a static one- or three-shot matrix or scanning array 

Enlarging. With film image magnification, type of light source, quality and condition of enlarging lens; the flatness of the film in the carrier and accuracy of focusing; movement during exposure; and the contrast and surface texture of your printing paper.

Finally, there are the conditions under which you view your result, especially the brightness of the lighting and your viewing distance.

No one can control all these factors all the time, of course, but at least try to use equipment and routines which minimize the pitfalls if optimum sharpness is important in your work.