Incident macro light metering

Hello, how do you meter when photographing macros?

Is there anybody using an external incident light meter such as the Sekonic L-398?

What are the (dis-)advantages of TTL metering? What is faster?

I use my Nikon F2 Photomic with such a Sekonic because I find the Photomics not reliable any more.

I don't like to spend hundreds of dollars to get the prism repaired. The named Sekonics are available for 50 USD.

I was surprised how easy you can do macro photography with the F2, a Micro Nikkor 3.5/55 and this incident light meter!

The newer Nikon F5 with 3D color matrix metering is much more complicated.

An incident meter is going to be more accurate than any TTL meter since it cannot be fooled by subject matter that isn't middle gray in brightness. For macro, a handheld meter has the downside of needing you to calculate exposure compensation for lens extension. A TTL meter automatically deals with that.

chriscrawfordphoto said:

An incident meter is going to be more accurate than any TTL meter since it cannot be fooled by subject matter that isn't middle gray in brightness. For macro, a handheld meter has the downside of needing you to calculate exposure compensation for lens extension. A TTL meter automatically deals with that.

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Back in the day my Father used an AsahiFlex IIa with tubes for macro work. The exposure compensation isn't difficult, he used a 5 inch pocket slide rule, but you have to remember to do it! He used various reflection selenium cell meters, metering off an 18% card to avoid background bias. He also had bellows for the work, but IIRC he found the tubes with the fixed extension easier to deal with than bellows, even with the bellows extension scales, etc.

Some years back, I had a need to do quite a lot of product photography (many of which were quite small). The old Kodak Photo Guides had a scale for adjusting for magnification factors that I grew to trust with use. I like the incident metering routine in general and this, in combination with adjustment factors was quick and easy, especially when doing large numbers and settling into the routine with continuous feedback from so many images.

While TTL metering automatically compensates for macro shooting need for increase in exposure (from the f/stop selected on the lens), TTL metering will always be subject to being fooled by a scene/subject which deviates from the assumption of '18% tonality' that all reflected meters assume.

Average TTL will always be fooled, but a well designed TTL matrix meter will expose correctly for the low values when the conditions are as predicted.

The TTL functionality removes the need to adjust the exposure for the bellows extension and other close-focus related factors.
Once you take those factors out of the equation, using the reflected light meter becomes just the same as when photographing normal scenes - just adjust for the perceived reflectance of the subject.

The problem with using an incident light meter for macro work is that the camera blocks to incident light thus throwing off the light reading.

Bracket exposures.

I've had excellent results shooting near macro and macro with my Pentax LX using a Vivitar 100 mm macro lens, which focuses from infinity to 1:2, and from 1:2 to 1:1 with its matched achromatic closeup lens. The LX meter is strongly center weighted and meters off the film during the exposure; using mirror lockup poses no problem. Pentax's implementation of TTL with off the film metering during exposure is also excellent for flash work with their ring light, and more general purpose flashes. I'm sure that contemporary (c. 1980) Nikon and Canon cameras also had TTL off the film metering, Olympus may have been the originator of this technology.

The OP might look into a Nikon F3 or later if my conjecture about their TTL off film metering is correct. F3s can be had for reasonable money, and the F3s interchangeable finders would make life easier shooting on the ground, as do the finders on my LX.

If you use incident metering, you can adjust your exposure reading based upon the magnification of the object being photographed. For example, if the subject is sized at lifesize at the focal plane of your camera, immediately you know you need to add +2EV to the exposure indicated by the incident meter. If subject is at 0.5X, immediately you know you need to add +1.5EV to the exposure indicated by the incident meter