I'm very new to photography. I am doing objects in studio light conditions.

I have an Olympus OM-D E-M1.

I was given a Sekonic 478DR light meter.

Trying to play around with it, and I can't figure out the shutter speed. On the meter its numbers like 8-8 the second 8 being subscript but my camera shutter speeds are like 1.3, 1.6, ... 10,20,30...500, 510..

Shutter speeds at 20 is completely white and 80 is at least visible.

How do I convert the 8-8 to something I can put into the camera?

Just trying to figure it out, not trying to discuss pro and cons and/or using a meter or not using a meter.

Image for reference


  • \$\begingroup\$ Just to clarify, are you talking about the Olympus E-M1 and the Sekonic L-478D? \$\endgroup\$
    – inkista
    Commented Jan 11, 2015 at 19:43
  • \$\begingroup\$ yup. Sorry for the mistype. \$\endgroup\$
    – William
    Commented Jan 11, 2015 at 20:36

2 Answers 2


The "T" indicator means shutter speed, so it is telling you "8" which is a shutter speed of 1/8 of a second (not 8 seconds)

For an explanation of the subscript, see scottbb's answer below.

  • \$\begingroup\$ It shows ISO, (F) for F-stop and (T) for Shutter speed? for every reading. The F was 16, ISO was 200 and the 8-8 was (T) shutter speed. \$\endgroup\$
    – William
    Commented Jan 11, 2015 at 20:44
  • 1
    \$\begingroup\$ I believe the arrows above and below f/16 and ISO 200 indicate that you may change the value to whatever you wish; f/5.6 for example. As you will therefore be admitting much more light, expect the shutter speed to be shorter, 1/30th, perhaps. \$\endgroup\$
    – chili555
    Commented Jan 12, 2015 at 1:05
  • 1
    \$\begingroup\$ FYI T is for Time \$\endgroup\$
    – cmason
    Commented Jan 12, 2015 at 1:36
  • 2
    \$\begingroup\$ ISO 200, f/16, 1/8 second is equivalent to EV 10, not EV 8. \$\endgroup\$
    – Michael C
    Commented Mar 25, 2017 at 12:34
  • \$\begingroup\$ Yes, not sure where I got that from, but the subscript is, like scottbb says, a tenth (in the case 8/10) increment from the displayed f/stop. \$\endgroup\$
    – MikeW
    Commented Mar 26, 2017 at 1:16

The subscripted "8" indicates that the measured exposure is ⁸⁄₁₀ stop higher shutter speed (that is, faster, or shorter duration) beyond ⅛ second.

⁸⁄₁₀ stop equates to a multiplier of approximately 1.74, so 8 * 1.74 ≈ 14, so the actual metered shutter speed should be just under ¹⁄₁₄ seconds.

You can visually see this on the scale at the bottom of the meter's screen: the white arrow points to a mark a bit below 15, meaning the shutter should be just a bit slower than ¹⁄₁₅ second.

Page 15 of the Sekonic L-478D manual explains the subscript is fractions of the measuring value. If you set the the time and F-number display values in whole-stop increments (Custom Settings #1), the fractional (¹⁄₁₀ stop) portion is always displayed. However, if you set the time and F-number display values in ½ or ⅓ stop increments, you can optionally disable the ¹⁄₁₀ stop subscripts using Custom Settings #2.


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