Jump to content

Recommended Posts

Is AWB calculated from the metering area or the whole image? On a sunny day I get a wide variation in colour temperature (anything from 4000 to 6000 and sometimes beyond that at either end) and I'm wondering if it's because I have a tendency to use spot metering.

 

Alan

 

Link to post
Share on other sites

I use centre-weighting and it's very consistent, so I think the answer is yes.

Assuming AWB uses the metering optics anyway I suppose it makes sense.

Link to post
Share on other sites

Is AWB calculated from the metering area or the whole image? On a sunny day I get a wide variation in colour temperature (anything from 4000 to 6000 and sometimes beyond that at either end) and I'm wondering if it's because I have a tendency to use spot metering.

 

Alan

 

This is a question I have asked more than once and so far have not had an answer. I've searched the web but to no avail.

 

From very limited experimentation myself in the last few minutes after reading this post, I think that whatever senses AWB (on a Nikon D800 at least) uses the whole area (or certainly more than the spot meter). Using a 24-70 zoom, I took 4 shots - 2 at the 24 end spot and matrix, 2 at the 70 end spot and matrix. The shots at the 70 end had little else but my bathroom window (frosted glass looking out) and the AWB from both shots were virtually the same (around 4900 +21). Zooming out to the 24 end, and with the camera centred on the window, the spot and matrix settings were identical to each other but now the AWB measurements were 5500 +20 or thereabouts.

 

A simple interpretation of this is that the AWB is not being measured by the spot meter. If it was the spot meter, then the shots at 24 and 70 using the spot meter should be very similar. The fact that the spot and matrix reading are the same at a given zoom setting support this.

 

Do post back if you find a more authoritative answer.

Edited by MDM
  • Upvote 1
Link to post
Share on other sites

Is AWB calculated from the metering area or the whole image? On a sunny day I get a wide variation in colour temperature (anything from 4000 to 6000 and sometimes beyond that at either end) and I'm wondering if it's because I have a tendency to use spot metering.

 

Alan

It's going to depend to an extent on the colour content of the scene. I believe cameras use some form of 'integration to grey' then neutralise that. So if your scene has a bias towards one colour the system is going to try to compensate - the temperature of the light falling on it becomes secondary.

So grey card and set your balance either then or at the processing stage.

  • Upvote 1
Link to post
Share on other sites

I always shoot everything hard-set to daylight. It worked in the day of film. I vastly prefer the results rather than AWB. For instance, if I'm shooting a street market at night, I WANT the bulb lights to show a warm glow and not look like pure white leds. Daylight. all one needs.

Link to post
Share on other sites

I always shoot everything hard-set to daylight. It worked in the day of film. I vastly prefer the results rather than AWB. For instance, if I'm shooting a street market at night, I WANT the bulb lights to show a warm glow and not look like pure white leds. Daylight. all one needs.

OK but (forgive my ignorance) if you shoot AWB can't you just switch to daylight in PP anyway if shoting RAW?

Link to post
Share on other sites

 

I always shoot everything hard-set to daylight. It worked in the day of film. I vastly prefer the results rather than AWB. For instance, if I'm shooting a street market at night, I WANT the bulb lights to show a warm glow and not look like pure white leds. Daylight. all one needs.

OK but (forgive my ignorance) if you shoot AWB can't you just switch to daylight in PP anyway if shoting RAW?

 

Yes it doesn't matter what WB you use for raws. I just use AWB and then As Shot in LR as a starting point when processing raws. It can be and frequently is way off so I modify this to taste in the raw conversion. This is why the question of how cameras measure it (original post) is of interest to me and still unresolved it seems, but it's only academic if shooting raw .

Edited by MDM
  • Upvote 1
Link to post
Share on other sites

 

 

I always shoot everything hard-set to daylight. It worked in the day of film. I vastly prefer the results rather than AWB. For instance, if I'm shooting a street market at night, I WANT the bulb lights to show a warm glow and not look like pure white leds. Daylight. all one needs.

OK but (forgive my ignorance) if you shoot AWB can't you just switch to daylight in PP anyway if shoting RAW?

 

Yes it doesn't matter what WB you use for raws. I just use AWB and then As Shot in LR as a starting point when processing raws. It can be and frequently is way off so I modify this to taste in the raw conversion. This is why the question of how cameras measure it (original post) is of interest to me and still unresolved it seems, but it's only academic if shooting raw .

 

Thanks for clarifying MDM, or can I call you M?

Link to post
Share on other sites

Is AWB calculated from the metering area or the whole image? On a sunny day I get a wide variation in colour temperature (anything from 4000 to 6000 and sometimes beyond that at either end) and I'm wondering if it's because I have a tendency to use spot metering.

 

Alan

 

So what's wrong with that? Isn't that one of the main reasons films shooters liked to work early or late in the day, to get a variety of hues? Surely you don't want your colors to look exactly the same all the time . . . unless you're doing studio product photography.

 

And, Mike R? Don't you shoot RAW? 

Link to post
Share on other sites

I always shoot at the same WB in RAW. This ensures consistency throughout.

 

AWB will always vary making post production work more time-consuming as it results inconsistence.

 

dov 

 

I can see the sense in that for Stock especially if putting out big numbers of images

Link to post
Share on other sites

@Dov - sorry, I just gave you a greenie and it came as a red! Apologies.

 

Anyway, as yourself I ignore AWB and set the WB per the conditions. Works for me and saves a lot of PP.

Edited by ReeRay
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.