Close-up Photography With Medium format



Pentax 67, 300mm f-4 lens, Fuji Velvia 50, Bogen tripod and ball head with Bogen Super Clamp attached to tripod leg. Average metering, 1/125 sec at f-5.6.

For close-up photography a macro lens is best. Unlike 35mm system where you have different choices in a macro lenses with different close focusing abilities, medium format macro lenses are much limited. Most of the macros offer less than 1/2 life size magnifications with only a few going to full life size. There are several ways to increase magnification with your lenses, even if they don't offer any macro capability. One way is by using bellows. Some cameras such as the Mamiya RZ and RB have rack-and-pinion system, and thus built-in bellows. This offers a good magnification without a need for any attachments. For other cameras a bellows must be purchased to get into very close range. Use a standard lens with a bellows for easier set ups, although longer or shorter lenses can also be used. Remember that you need more bellows extension for longer lenses. Another method and the easiest is the use of extension tubes. Tubes are much smaller and lighter to carry than bellows. You can purchase them in a set of three and use them one at a time or combine all three for maximum magnification. To find out different magnification rates use this formula: 

Magnification= Extension/Lens focal length. 

If you want to photograph a subject at 1/2X with an 80mm standard lens, you need 40mm of extension. If you are using a camera with TTL-metering, the meter will compensate for the light loss, but with cameras without a built-in meter, you must calculate exposure for different magnifications. The amount of light loss depends on the lens you are using. You should run a test for the lenses and Extension tubes or bellows you plan to use for close-ups. Set your lens at its closest focusing distance and photograph a middle tone subject or a gray card in even light, taking notes of the exposure setting. Add your extension tube or bellows and take a series of bracketed shots in 1/3 or 1/2 stop increments +/-2 stops without refocusing. When you get your pictures back from the lab, compare them with your original shot taken without any extension. Note the difference in stops between your bracketed shots, and pick the one which is closest to your original shot. Add the total number of stops for this extension/lens combination you will be using. Supplementary lenses can also be used for modest magnifications. These fit on your lens like a filter. Their main draw back is the loss of sharpness especially in the corners, but there is no loss of light. Use a high quality supplementary lens between +1 to +3 with a standard lens for best result.