Using the Paul C. Buff Einstein with a Light Meter

In con­tin­u­ing to learn the ins and outs of my recently acquired Paul C. Buff “Einstein” (model E640) stu­dio strobe, I’m teach­ing myself to meter flash. My Sekonic L-308S Flashmate expo­sure meter has 3 mea­sur­ing modes:

• Ambient
• Auto Reset Cordless Flash
• Cord Flash

For this light­ing test, I used the Auto Reset mode, since the sub­ject was too far from the strobe to con­nect a sync cable. To meter the light, I attached a Yongnuo receiver to the strobe’s trig­ger port via a short sync cable, then fired it with an inex­pen­sive Yongnuo trans­mit­ter. I later installed the trans­mit­ter in the cam­era hot shoe to light the por­trait. To cal­cu­late the expo­sure, I:

1. Set the meter to match the cam­era ISO & shut­ter speed (160 and ¹⁄₁₈₀ sec­ond, respectively)
2. Set the mea­sur­ing mode to Auto Reset — for the next 90 sec­onds, the meter will mea­sure only when flash is activated
3. Ensured that the plas­tic “Lumidisc” was posi­tioned over the meter’s lens
4. Moved to where I would be stand­ing for the self portrait
5. Pointed the meter at the cam­era & depressed the “mea­sure” button
6. With my free hand, used the trans­mit­ter to trig­ger the strobe
7. Adjusted the cam­era aper­ture to match the meter reading

Here’s the setup:

Subject dis­tance from strobe

≈ 10′ 6″

Strobe posi­tion & modifier

to sub­ject front & right, ~7′ up, with a 43″ sil­ver “bounce” umbrella angled at subject

Strobe tem­per­a­ture

5600K

Light level

ƒ/-4.0

Camera dis­tance from subject

≈ 2.5 meters (8′ 2″)

Lens

Zeiss 50mm C Sonnar T* ƒ/1.5

ISO

160

Shutter speed

¹⁄₁₈₀ second

Aperture

ƒ/​4

Ambient light

Negligible cloudy late after­noon ambi­ent light from win­dow to sub­ject left