As we get close to the subject the depth of field decrease considerably. It is therefore advise to choose a small aperture. Here below some sample of subjects and the chosen F-stop. All photos are taken with a full frame sensor camera and a 100mm lens.
distance to the subject 25cm/10 inches, shot at F16
distance to the subject 15cm/6 inches, shot at F18
distance to the subject 10cm/4 inches, shot at F22
2. Low ISO for greater quality
Macro photography is sharpness critical. Noise level has to be controlled. High ISO produce noise and this degrades the quality of the photograph. Shooting at the lowest ISO setting is advised. Being so close to the subject give us enough strobe’s power and it shouldn’t be difficult to use the lowest ISO possible.
3. Shutter speed and Flash duration consideration
Typically we shoot Macro at small apertures (F16-22 etc.) and low ISO (100-200 etc.). This result in a completely black image if we didn’t use strobe’s light. Strobes produce light pulses with a duration in the thousands of a second. Very short! This very short flash duration is what freezes your subject motion regardless of your shutter speed. Shooting at 1/200th or 1/30th of a second makes no difference, provided of course the picture would be black when shot without strobes.
4. TTL vs Manual
When shooting in TTL mode the exposure is almost always optimal and you can concentrate on the needed aperture and where the light should come from. This is very convenient and sometimes also necessary in situation when your first shot has to be the right one, for you don’t have a second chance. However, if you want to obtain a particular atmosphere, or you need to bring up some texture or separate the subject from the background, you need more control on what each strobe is doing in terms of output. Manual mode lets you do exactly this.
5. Shoot RAW
Even though with practice and experience we can produce a quality image, some adjustment is always needed to optimize our photos. A RAW file can be corrected with editing software. A jpeg file will not be suitable because it’s already been worked by the camera with little control from you. We can of course shoot both at the same time if needed with most cameras.