# Use of Sekonic L-308S



## Commonman (Jan 31, 2008)

I recently acquired a Sekonic flashmate L-308S.  Im not unfamiliar with light meters and how they work but I feel a little uncertainly about the instructions and use of this light meter.

These days I am most commonly using the meter to measure the reflected light, especially in situations where I cannot get close to the subject so I am usually pointing the meter towards the subject from the camera position.  The manual indicates that, if you measure from the camera position, the  entire object is measured in average.  However, the manual (to me) is not clear on whether or not the Lumisphere should be used for this type of application. (as opposed to the Lumidisc. It does indicate that the Lumisphere is appropriate for INCIDENT light measurement.  But, as I am usually not able to get close to my subjects, I usually cannot use the meter in this fashion.

The manual appears to indicated that the Lumidisc is used to meaure manuscripts, painting  or other flat copy, or otherwise for measuring light contrast.  So, this leaves the Lumisphere or the naked lens for a reflected light measurement.  

My question is, is it correct to use the lumiSPHERE for both incident and reflective light measurements (using this meter)?

I realize that I have to use my brain as well as the meter in evaluating light and setting the camera to give me the type of exposure I want.


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## Helen B (Jan 31, 2008)

You use the Lumisphere or Lumidisk for incident light measurements only. You don't always have to be able to get to the subject - all you need to do is to measure in the same (or similar) lighting as the subject.

Best,
Helen


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## Big Mike (Jan 31, 2008)

I don't have a Sekonic meter...but I've always used the naked lens for reflected readings (although, I don't use it for reflected reading when I have my camera) and used the dome for incident readings.


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## Commonman (Feb 3, 2008)

O.K., I will use the Lumisphere or Lumidisk for incident light measurements only. 

Using the Lumisphere, I now understand that I need only measure in the same (or similar) lighting as the subject.  

But let me give an example of a recent condition and see what you recommend.  I'm inside a house, on the second floor looking out of an open window.   I want to photograph various objects that are about 40 -50 yards from the window.  It is very bright outside at the location of the objects and pretty shady where I am standing.  I would think that it is only possible to take a reflected light reading, and therefore the Lumisphere or Lumidisk would NOT be appropriate.  Will I be able to get a useful reflected light reading from the naked lens of the meter?


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## Christie Photo (Feb 3, 2008)

Commonman said:


> Will I be able to get a useful reflected light reading from the naked lens of the meter?



Sure...  BUT remember, the meter is telling you how to achieve GRAY.  You'll have to consider this when selecting your exposure settings.  The reading will give you an pretty good idea of what your exposure should be in order to retain detail in the shadow AND highlight areas of the scene.  Of course, for more critical work, bracket the exposure.

Good luck!

-Pete


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## jstuedle (Feb 3, 2008)

You would need to go to the subject and meter for incident measurements. I have the same meter, and the dome can be removed and replaced with a reflected light attachment supplied with the meter. They also make spot attachments for this meter.


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## Commonman (Feb 3, 2008)

You state that the dome can be removed and replaced with a reflected light attachment supplied with the meter.  I'm pretty sure I only got the dome and a thing called a lumidisc.  Are you referring to the lumidisc or something else?  What  does this attachment look like?


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## Commonman (Feb 6, 2008)

Yes, I think in a recent discussion I had someone said "expose for the shadows" or something like that.  I just got a gray card and when I get time, I'm going to fool around with using that.  And, yes - I will bracket if it is critical.


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## Christie Photo (Feb 6, 2008)

Commonman said:


> ... someone said "expose for the shadows" or something like that.




Expose for the shadows, print for the highlights....  when shooting NEGATIVE FILM.

I wouldn't recommend this for reversal film or digital.

-Pete


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## Helen B (Feb 6, 2008)

To use the L308 for reflected light just slide the Lumisphere out of the way of the cell.

A grey card reading should give similar results to the Lumidisc - ie it is like an incident reading using a flat receptor. The actual value should be slightly different because of the way the L308 is calibrated. Grey cards are a way of using a reflected light meter for incident readings.

Best,
Helen


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## Commonman (Jun 2, 2008)

Helen, O.K. good.  I was just beginning to think that the L-308 was useless for reflected light measuring.  I've been getting mixed messages on this matter.  Some say it's only good for incident readings and that if I really want to do the reflected light thing, that I should get a spot meter.


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## Commonman (Jun 2, 2008)

I also find Helen B's comments about the use of the grey card very interesting and informative.  Thanks Helen!


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## usayit (Jun 2, 2008)

http://www.sekonic.com/support/support_21.asp

I have the 308 and it has served me well for the past several years.  I'm in the process of replacing it with a used (and discontinued) 408.  The primary reason is that I need aperture priority metering which the 308 only has shutter.  Other than that... it is a wonderfully and compact meter.


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## usayit (Jun 2, 2008)

Is there any technique when using the ambient meter in bright daylight?  It seems the 308 with the lumidisc tends to meter mostly bright sky during ambient metering.  This results in underexposure.    In the past, I've been taking a reading then opening up a stop or two.  Is there a better way?

On the street, I am generally taking a reading over my shoulder as a good guess of the exposure for most other potential subjects that come my way.


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## Helen B (Jun 2, 2008)

When you use an incident meter in full illumination (ie full sun in this case) at the box speed (for film) or camera ISO setting (for digital) you are effectively metering for the highlights. The meter measures the amount of incident light from many angles* (if the dome is used) and places the exposure at a level that puts the brightest objects a little below being blown out. This works well for reversal film, and can work well for digital, though some compensation, by increasing the exposure a little, may be required for the best results (as you have discovered).** If you do this with negative film the compensation will be around one stop or so &#8211; which can be applied by setting the meter to half the box speed of the film, give or take a little. 

  If the meter is placed in the shade (not deep shade, but open shade) you will be metering more for the shadows. With negative film this works very well. You can use the nominal speed (box speed) and meter in the shade.

  Minor White&#8217;s _Zone System Manual_ includes a brief section on using incident readings to estimate the subject brightness range &#8211; in simple terms you take one reading in full illumination and one in the shade. You add five stops to the difference in those readings &#8211; eg if there is a difference of three stops between the full and the shade readings, the brightness range is about eight stops. This technique was later used in the &#8216;BTZS&#8217; &#8211; Beyond The Zone System.

  This works because there are limits to the reflectance range of practical, common objects &#8211; about a five-stop range. A bright white has a reflectance of about 96%. One stop down is 48%; two down is 24%; two and a half down is 17% (close enough to 18%); three down is 12%, four down is 6% and five down is 3%. A 3% reflectance object is quite black-looking. These are all rough figures, to give the general idea.

  *The whole idea of the dome is to read all the light falling on the subject except that coming from directly behind. The dome, pointed towards the camera, should receive the same light that is falling on a three-dimensional subject. If you feel that the dome needs to be shaded from light coming from a particular direction to fully mimic the light falling on the subject, then shade the dome from that light with your hand.

  **The speed/metering standards for digital are generally designed to allow some  headroom for the highlights &#8211; one effect of which is to permit exposure errors without oversaturating the sensor. This headroom can be used if you have good metering technique - the same as getting the histogram over to the right.

  That&#8217;s a bit condensed, but I hope that it makes some sense.

  Best,
  Helen


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## usayit (Jun 2, 2008)

As always thanks for the indepth explaination Helen... I've actually copied your post into a journal for later reference.

I did a google on BTZS and found this link.. seems to be an interesting read:
http://www.viewcamera.com/pdf/2007/btzs.pdf


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## Commonman (Jun 3, 2008)

Yes, I agree.  A most excellent response, Helen.  I think I'm beginning to "get it."


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