Understanding the Exposure Compensation Scale and the Light Balance

[Dektol]

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REGARDING: Leica Q2

 

I’m confused as to understanding how the Light Balance (LB) works in conjunction with the Exposure Compensation Scale (ECS).

 

For Example, Q2 is set to Manual:

• Aperture - f/1.7
• Manual ISO at - 100
• Shutter Speed - 1/125
• Room is dark and the only light is emanating from the monitor on my 27” iMac
• I’m pointing the Q2 directly at my monitor

 

When I look through the EVF

• ECS reads 0
• LBS reads 0 (sometimes + ⅓)
• When I turn the Thumbwheel Left 3 clicks the ECS reads -1 stop ( I get that!) and the LB reads +1 stop (I DON’T GET THAT!!)
• The histogram never changes (I DON’T GET THAT)
• ISO and Shutter Speed remain unchanged (I would expect that).
• QUESTIONS:
  • Why didn’t the histogram move to the Left when I decreased exposure 1 stop?
  • How am I to interpret the ECS & LBS moving in opposite directions? (Clearly, I don’t understand their relationship IF there is one).
  • Can you recommend a source (or provide a link) that would clearly explain how the Light Balance Scale works and it’s function?
  • If I shoot in AF and Aperture Priority (for Street photography) will it change how ECS and LBS interact with one another?
  • On page 69 of the Instruction Manual under EXPOSURE METERING METHODS there is the sentence “The line on the left of the light balance will flash in the display if the measuring range is undercut/overshot”. I don’t see any flashing line on the left of the light balance.

 

I apologize for all the questions, however, I’m very confused. I gone through the Q2 Instruction Manual and page 69 lists the only mention of the Light Balance I could find. Perhaps you may know where the LB is clearly explained in it.

Edited December 19, 2019 by Dektol

[jaapv]

What do you mean by Light Balance? The term is unknown to me. If you mean White Balance, that has nothing to do with light intensity, but with light colour. In fact, I am as confused by your question as you are.

[Dektol]

japan thanks for your reply.

Light Balance ... good question. To the best of my knowledge I've never seen the term either. I'm even more confused that it interacts with the Exposure Compensation Scale as outlined in my initial post.

LHSA.org could not answer my questions either. I've contacted Customer Service in Wetzlar, Germany for an answer. If I receive one that makes sense, I'll post it to this forum.

 

[JonPB]

I'm just guessing here since I don't have a Q, but:

If you're in manual mode, the thumbwheel/exposure compensation will set the target exposure level but not any actual exposure variables (aperture or shutter speed). Since your desired exposure is nominally one stop darker than the current exposure settings, the light balance indicates that you're currently one stop over-exposed. To test if this is correct, set the camera to center-weighted metering, manual, and an exposure that is "correct" while pointed at your screen; then set EC to -1, which should show -1 EC and +1 LB; then tilt the camera so it is pointing only partially at the light source. The expected result is for the LB to shift downward as there is less light entering the frame while neither the EC nor the exposure settings change.

If that's how it works, then EC indicates how much you want to vary an automatic exposure from the metered "correct" value, and LB tells you how far you are away from what exposure the camera would set it if had the choice to do so. Which is to say: "light balance" is the meter's needle.

(If I'm wrong, please say so!)

[sfphoto]

On 12/19/2019 at 2:11 PM, Dektol said:

 

• • Why didn’t the histogram move to the Left when I decreased exposure 1 stop?
  • How am I to interpret the ECS & LBS moving in opposite directions? (Clearly, I don’t understand their relationship IF there is one).
  • Can you recommend a source (or provide a link) that would clearly explain how the Light Balance Scale works and it’s function?
  • If I shoot in AF and Aperture Priority (for Street photography) will it change how ECS and LBS interact with one another?
  • On page 69 of the Instruction Manual under EXPOSURE METERING METHODS there is the sentence “The line on the left of the light balance will flash in the display if the measuring range is undercut/overshot”. I don’t see any flashing line on the left of the light balance.

Dear Dektol

1. You are in manual mode. The image in the viewfinder (and the histogram) are not changing as you are not changing any parameters relevant for the photo: shutter, aperture, ISO. 

2. If your thumbwheel is set to "exposure compensation" you are trying to change the exposure in manual mode (see manual page 47), in your case you are telling the camera that you would like to make the photo 1 stop darker (as indicated by the ECS). The light balance indicates how you need to adjust the exposure to get the desired result. In your case it indicates that your photo is overexposed by one stop as you have not yet changed any of your settings (shutter, aperture, ISO). If you now, e.g. close the aperture one stop, the light balance will go to 0 and you get the desired result (1 stop dark).

3. The light balance is a standard feature on any camera. It indicates how to set the camera exposure settings to get a well exposed photo. On my Nikon FM2 it is simply three lights with  "+ o -".

4. In aperture priority the camera will make sure that the light balance is always at 0. Only if it reaches the limits of the shutter speeds will it indicate how much you ware off.

5. They flash when you are outside of the measurable range of the exposure meter.

Hope this helps.

[jaapv]

Ah, now I understand what was meant by "light balance" .😎

[Leica Guy]

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54 minutes ago, jaapv said:

Ah, now I understand what was meant by "light balance" .😎

Me 2! 

[Dektol]

Thank you JonPB and sfphoto.I appreciate your input!

You have me pointed in the right direction now.