# Topic #2, Light Metering, White Balance, JPEG vs RAW formats



## Dominantly (Jan 6, 2010)

*Intro:
* 
This will be round number two of the basics.
References will be:
Google
Lighting by Chris Bucher
Photography Field Guide by Bryan Peterson
Digital Photography: Top 100 tips and tricks by Rob Sheppard

Just in case you want to expand on anything I type here, all my info and technical knowledge has come from them. So a couple days later and you could be all caught up

Topic #1 can be found here http://www.thephotoforum.com/forum/...9084-exposure-your-photographic-triangle.html
*

Light Metering:*

Alright, so in the last "lesson" we talked a little bit about light metering and the fact it plays a very important role in your goal of capturing a proper exposure. I'll try and expand on here a bit more here, because I feel it's pretty important to understand.

Most (if not all) modern cameras have some sort of light metering capability built in. Back in the day, in order to be successful at dialing in your exposure, you had to carry an external light meter to aide you. They could meter ambient light falling on your subject (have you seen those small hand held devices with the small white half sphere?) or reflective light by pointing it at your subject and reading it.
With your cameras meter all you have to do is point your camera at your subject and your camera will continuously meter and assist you in your exposure (or do it all for you minus hit the shutter in Auto modes).
The built in meter is called a _Through The Lens (TTL) meter._ You may have heard of i-TTL or intelligent Through The Lens Metering which uses the in camera meter and an external flash to pick the appropriate amount of light for any given scene, at any setting.

-The way this metering stuff works is it measures the amount of light reflected off your subject. Your camera is calibrated to want to see the luminance of reflected light coming off a subject of _middle/neutral gray_ (with a reflectance of 10-18% depending on your manufacturer/model), when it does this it's the happy, properly exposed, point.
So what about trying to photograph two extremes together? For example if you are photographing a black object in front of a white backdrop with strong, even lighting falling on both; you will get different metering results on both if you zoom in and focus on them, even though they are lit the very same way. The reason this occurs because dark colors absorb light while brighter colors (like white) will reflect it. Your white background will reflect approx 40% of the light, and your black object will only reflect 10%.
The important thing to do in a situation like this is meter off the subject, and use a mode that allows you to meter specifically off that (modes described below). Your camera freaks out at those extremes and will want to render them gray if you don't step in and take creative control of the metering and settings.
The Gray card Can be found here will allow you to get proper exposure when shooting dark or bright subjects.
 It's pretty simple to do, you place the card in front of the camera with the same light hitting it that is hitting your subject. Then you place your camera (should already be there ) in manual and adjust your settings until your camera tells you that you have a correct exposure. Then just remove the card and shoot away.

For daylight we have the Sunny 16 rule. This rule just gets you in the right direction, and shouldn't be taken as gospel.
So for a middle of the day exposure, set your aperture to f/16 and then match your ISO and Shutter Speed as close as possible. SO for example f/16 ISO 100 1/125, or f/16 ISO 400 shutter 1/500..... SO shutter speed = ISO for this rule of thumb.


*
Modes:*
For Nikon we have Matrix Metering (Canon calls it Evaluative
Light Metering), Center weighted, and spot modes.

-Matrix works by evaluating the entire frame and set the exposure based on the distribution of brightness, color, distance, and composition. The Cameras internal processor chip references thousands of images with greatly varying contrast and brightness (think snow to city nights) and references what you are metering and picks a "like" reference image to reference for your images exposure settings. This is the safe setting,  and will work well in a large majority of exposures, and will give you pretty consistent results.

-Center weighted still evaluates the entire scene, it just shifts its priority to a 6, 8, or 10mm circle in the center of the screen then tapers outward(user adjusted, Canon may vary)..This is a very common metering method for portraits, and the standard for cameras without an evaluative/Matrix metering mode.

-Spot metering is just as it sounds, it meters off one little tiny dot, the rest of the scene be damned. It will meter 2.5% of the frame, or 3.5mm/0.14in on average. Spot meter will probably be something you learn to use in very specific situations, and not a whole lot in between them. One example of a great time to use your spot meter would be when photographing the moon.


*

White Balance:*

What you see before you at a photo shoot with your very own eyes, and what your cameras see are  very different. Your fancy brain compensates for different color temperatures (measured in degrees Kelvin (K) ), and allows you to see various lighting conditions which may be intermixed, as normal. That's why it's sometimes hard to try and recreate that awesome lighting you may be seeing with your eyes, in your exposure. Lets see if we can break down how White Balance and Color temperature are intertwined.

So it may seem backasswards but in Kelvin, Cooler colors have a HIGHER temperature then their warmer counterparts (lower temperature). Thats confusing so I will break it down a bit more:

WARM- Candle light, Fire light, etc.....     Color Temp- 1500K to 1900K
WARM- Incandescent Bulbs.................    Color Temp- 2500K to 3000K
WARM Studio Tungsten.................       Color Temp- 3400K

Neutral- Daylight (midday).................      Color Temp- 5000K to 5500K

Cloudy day, Shade, ..........                     Color Temp- 6000K to 7500K
Various other blue lighting.......        Color  Temp- up to about 11000K

So you can see that the red/yellow/orange; warm light, has the lower Kelvin number, and the bluer cool lighting has the higher Kelvin number.

As a general theory/rule/feeling, warmer tones actually draw out better emotions from people Vs cooler, blue tones. Most people can imagine an orange, warm, beautiful sunset, and all the good feelings/awe it draws. It's just something to think about when setting up your white balance. For reference, Bryan Peterson states he sets his camera in Cloudy mode and shoots away. He spends most of his time shooting outdoors with natural lighting, and enjoys the color and warmth the Cloudy setting gives. If it doesnt work out, you can always change it in Raw (thats why you shoot in raw, right?).
What your camera does with Auto White Balance..... It just adds and mixes colors.If the blue light in your scene rises, your camera will add orange to balance. If it is shot under fluorescent (which appear greenish) it will add magenta. It will mix and match to try and get your colors correct, your whites white with no tint (doesnt always work that way, you can end up with peach colored whites, or dull gray whites).
 Auto white balance will work the majority of the time, but it can be fooled so if you want to nail the white balance and save time, you can use an 8"x10" bright white card at your shoot. Once you have your lighting set up, take your shot of the white card to set the white balance for that specific time. Your meter can be fooled with large amounts of the same color, especially blue, and will try and compensate for it, even though you want the blue as blue as you can get it.
*
Courtesy of IgsEMT when I had specific topic questions:: (THANK YOU!)*


*For MANUAL WHITE BALANCE (D90 specific instructions)*
You might also want to try and adjust your white balance using your gray card.

If you are shooting with a D90, so this is how you would do it. Grab your gray card, do the same thing mentioned above in regards to filling your field of view with the card and subjecting it to the same light source. Then hold your WB button and turn your main command dial to "PRE". Now hold the WB button down; PrE will flash on your LCD. Take a photo of your gray card. GOOD will flash if the shot was acceptable. After GOOD flashes, press the WB button again, and you are now good to go with your custom white balance.
Now if you go under your shooting menu, the 5th option down is White Balance (should say PRE), press the right arrow into, then the right arrow again at the PRE submenu. You will see your WB reference photo labeled d-0, you can store up to 5 (d-0 thru d-4). You can edit comments/labels for each reference, and you can go in and fine tune them.




			
				IgsEMT said:
			
		

> So My take on WB: ups and downs as well as personal Hx with it.
> Until few years ago, my camera was awb and results were ok. Lab did color correction and I could really care less any further. But when I began experiment at home/studio with colors I entered into wonderful world of WB. It was then I learned once again that Socrates, was a genious (paraphrasing - the more you - home boy wen to the Oracle, she told him he's the smartest, yet he felt as being the dumbest -  )
> So here's my personal settings and reasons for them.
> Camera Presets: 99% of the time I shoot with flash, so my Wb on Nikon is daylight/sunny. Daylight is a bit cooler then FLASH and I like the skin tones it produces. Also when shooting outdoors and not using flash (1%) my colors are still pretty accurate. Comparing Nikon and Canon, I find that canon's presets are more warmer then Nikon's - my opinion.
> ...


*
Raw vs JPEG*

Shoot Raw. Well, let me expand on that. If you are taking photos that you care about, want to come out perfect, and cant easily do a re-shoot (or don't care to); you want to shoot raw. If you are taking a snapshot and could care less about the results, OR you just don't care to hassle with the processing of a raw file, then by all means shoot a fine JPEG.

JPEG's are processed files that have been run through your cameras image processor, then compressed and saved to disk. The problem with these files is that when the processor is compressing the data, it will average similar colors and similar contrast. Also when you you load the JPEG to your computer, you are pretty much done with it. If you plan on editing the photo, you will be limited as to what you can do, and you can only do it once (without more loss). When you go to save that file, save it as Image Quality 12 and let it be. Every time you open it after that and edit it, you will compress it further upon saving it. One way to handle this is saving the file as .Tif right away, Tif's are loss-less files so they will not compress and lose data with each subsequent save.
RAW is just that, a RAW file of all the image information from your camera. It is quite a bit larger (3 times) then your average JPG, but that's understandable as it contains more color and contrast information, in a minimally processed file. You can change 2-3 stop Underexposures and 2-3 Over exposures into perfect examples, using a raw file. Maybe you didn't nail the exposure in the camera, but with raw you can go back and make it a perfect exposure in most cases (as long as you were in the ball park).





			
				IgsEMT said:
			
		

> RAWvsJPG - 2005 (a bit earlier) until 2009, I was 100% JPGer and nothing one can do to change my mind. Also my PP skills were directed less to processing images and more to make them into collage and album. Sept 09, I went RAW and hit a wall - PP, what/where/when/how/why. for JPGs, I used LR and no problem. Since I preset the camera to give me best optimum results, I was happy with what I was getting, but during an even where I had to be in FRONT of the camera, I gave me camera to a buddy of mine (learning to become a photog) and set it on RAW. It was only 250frames, but I spend a week, if not more, PPing them. It is when I learned about camera's profile in ACR. Finally, and this topic I discussed here with many members both privately and publically, in the last 3 months, I've tried Adobe Camera, dxo, bible lab, acdsee, capture nx2 (since I'm a nikon guy). Right now, my verdict is Capture NX2 and I would recomend manufacturer's RAW converter to anyone who is starting to shoot raw; b/c... If i set everything in camera the way I like it, and get different (RAW) results, why spend all the time metering, presetting, etc? and since my LCD results are 90% of what I'm looking for, I need the same to be on computer but better. So I made a little test (don't have the image to show) and shot RAW+JPG. I find that CaptureNX2 conversion to JPG at 70% = sharpness of camera's LgFine JPG. Therefore, I compress MOST images to 80% of original quality and they are pretty darn good.
> 
> Software: As said, I've tried various and stopped for RAW work on Capture NX2. I do not know how to set up camera profiles, if would know, - I'd be using LR b/c it is faster and allows more plugins from Nik Software.



Thanks for looking. I will try and do some photo examples and post them in this post, in the next couple days. If anyone has any good example shots covering metering or white balance, and you want to add them, PM me...

:thumbup:


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## IgsEMT (Jan 7, 2010)

In my defense, I was tired when was writing this and apologize for spelling/grammer mistakes, plus I'm ESL :lmao:


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## Dominantly (Jan 7, 2010)

Same here, except I'm EFL :meh:


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## Craig G (Jan 7, 2010)

I enjoyed your first write up (didn't care where it came from) and was looking foward to #2. Thanks:thumbup:


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## AfroKen (Jan 7, 2010)

I just wanted to say thanks for writing that.


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## keith foster (Jan 7, 2010)

Thank you for this.  Good stuff.


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## KalaMarie (Jan 7, 2010)

:thumbup: Very useful info. I gave the link to this thread to someone who just bought a dSLR and has questions re: RAW v JPEG etc.


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## TylerF (Jan 8, 2010)

thanks for taking time to write these Topics out.

maybe you could touch upon how to fix WB, exposure and other things when shooting in RAW. many people say they use a gray card and then use an eye dropper to fix the WB. i dont know what that means lol.

also, if i am shooting RAW, should i really fuss over settings and try getting them perfect, or should i just aim to get close? i usually shoot jpeg, but plan on shooting concerts where i most likely wont have correct setting all the time and cannot re-shoot.


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## Josh66 (Jan 8, 2010)

Dominantly said:


> *
> Modes:*
> For Nikon we have Matrix Metering (Canon calls it Evaluative
> Light Metering), Center weighted, and spot modes.



Not sure if Nikon has an equivalent, but on Canon bodies there is also Partial.

Partial is pretty much the same thing as spot, but the spot is bigger.

Spot metering uses a small spot, like you said - 2.5% or something like that.
Partial will do the same thing, but the spot is maybe 7% (not sure on the exact size).


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## Josh66 (Jan 8, 2010)

TylerF said:


> many people say they use a gray card and then use an eye dropper to fix the WB. i dont know what that means lol.



In many PP programs there is a dropper tool for WB.

You just select the tool and click on something that should be neutral.

If you take a reference picture of something that you know is neutral, fixing your WB in PP only takes 2 clicks.  You can then apply those settings to any other pictures that were shot under the same lighting conditions.


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## Dominantly (Jan 8, 2010)

TylerF said:


> thanks for taking time to write these Topics out.
> 
> maybe you could touch upon how to fix WB, exposure and other things when shooting in RAW. many people say they use a gray card and then use an eye dropper to fix the WB. i dont know what that means lol.
> 
> also, if i am shooting RAW, should i really fuss over settings and try getting them perfect, or should i just aim to get close? i usually shoot jpeg, but plan on shooting concerts where i most likely wont have correct setting all the time and cannot re-shoot.


Thanks for the idea on what to think about posting next.

If you shoot raw, you should still do your best to nail the exposure the first time. You can't fix everything with a Raw file, for example if you shoot and have areas that are blown out (face from spotlights), or that are black/underexposed, you can't pull detail from them. The reason for that is, there isn't any detail to pull. So picking your creative exposure, I mean deciding what in the photo is important to you, and setting your camera up to record this the first time, is very important. I mean maybe you want dramatic lighting, half the face to fade to shadow, or maybe you want the opposite with hot lighting and skin tones- just decide and set the camera up as close to it for the first few shots and let her go.


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## Dominantly (Jan 8, 2010)

O|||||||O said:


> Dominantly said:
> 
> 
> > *
> ...


I just went through the User manual to check for a partial comparison for Nikon, and came up with nothing.
From the way you describe it, it sounds an awfully like our Center Weighted, which is adjustable from 6,8,10mm. I mean spot is just that, narrow, spot specific, where the center weighted seems more partial with it's highest priority the center, yet still taking into account a little outside as it feathers to the edges.


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## Josh66 (Jan 8, 2010)

Dominantly said:


> O|||||||O said:
> 
> 
> > Dominantly said:
> ...



No, we have Center Weighted too.  

Partial is exactly the same as Spot, just with a bigger spot.

Entry level (Canon) bodies usually _only_ have Partial - there is no Spot.

The higher end bodies have either Partial _and_ Spot, or just Spot.



I don't really know why they felt the need to make the spot bigger and call it Partial, but they did...


EDIT

So take that!  We have more metering modes than you!

:lmao:




j/k...


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## Dominantly (Jan 8, 2010)

Damn...

WELL, one of our modes has the word MATRIX in it, so it's +50 extra cool points.


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## Josh66 (Jan 8, 2010)

...OK.  MATRIX does get you a few extra cool points.  50 might be a little optimistic though.


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## IgsEMT (Jan 8, 2010)

> maybe you could touch upon how to fix WB, exposure and other things when shooting in RAW. many people say they use a gray card and then use an eye dropper to fix the WB. i dont know what that means lol.


Ideally, it's better to *get it right* in camera. 
WB and Exposure, in programs like Adobe PS/LR Camera Raw, bible pro, dxo, acdsee, capture nx2, can be set using sliders and eye dropper/marque tool. However, if your monitor isn't calibrated, you are prone to have some errors.
Eye dropper: - you point to an area that is supposed to be neutral in color.
Marque - you select a general area of neutral colors where software will take an average of the scene and bring appropriate adjustments as it sees fit.



> also, if i am shooting RAW, should i really fuss over settings and try getting them perfect, or should i just aim to get close? i usually shoot jpeg, but plan on shooting concerts where i most likely wont have correct setting all the time and cannot re-shoot.


Should you _fuss_ depends on you. I found that b/n Nikons D300 and D90 LCD screens and prints I get (not from corner 1hr places) there is no variation of skin tones. Since, what I see on LCD is what I get in the print, I try to get the _most accuracy_ (color, exposure) on lcd.
Plus, I prefer to spend time shooting rather then editing so again, I try to get my lcd look the way I need it to look in print. Later in PP I spend less time in front of a monitor and only add minor enhancements here/there if feel the need.


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## TylerF (Jan 8, 2010)

Lol at the matrix thing

 Thanks for replying to my post, I think its going to be trial and error for me lol. The concerts I go to are very fast paced and a lot of moving lighting. 

Another question, how would I go about metering if I intend to use flashes? Thanks


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## Dominantly (Jan 8, 2010)

TylerF said:


> Lol at the matrix thing
> 
> Thanks for replying to my post, I think its going to be trial and error for me lol. The concerts I go to are very fast paced and a lot of moving lighting.
> 
> Another question, how would I go about metering if I intend to use flashes? Thanks


Will you be allowed to use flash? What glass are you taking (70-200 is ideal, 50mm will do)
I would knock Matrix/Evaluative off the list. If you zoom in with matrix selected, you will have stage lighting on the subjects face, then black surrounding the head. Matrix will try and balance to (middle gray) and cause the black to fade, and the face to overexpose.

Center weighted- Better then Matrix, but still not as good as spot. It will also take into consideration more of the scene, IE clothing (is the subject sparkling or wearing all black?!?)... You'll want a meter that takes into consideration about 4% of the scene.

Spot-... It puts the spot on the face, or it gets the hose again..........:blushing:


Using flash/
But let me step back and say, if you own a SB-600 you can give the i-TTL balanced fill flash a shot, which will be served in Matrix mode. Take a shot, you like? Keep it there.

Auto FP High Speed Sync......Gives you the ability to use a fast shutter with crap lighting, to stop action and give you good light.


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## igloopants (Jan 13, 2010)

Thanks for this thread


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## Craig G (Jan 13, 2010)

Dominantly said:


> Damn...
> 
> WELL, one of our modes has the word MATRIX in it, so it's +50 extra cool points.


 Yea.......We have Neo..:thumbup: 

Neo will defeat the machines.


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## Dominantly (Jan 23, 2010)

Example from yesterday.

Conditions: Overcast, dark afternoon.

I was setting up my camera to take some shots, so I first adjusted my meter until it said good, while pointing it at the grass (I was going to be photographing alot of green), then I took a shot to see how it was going to look. I was not impressed, so I then spot metered off the concrete I was standing on (the path you see in the background), then took a shot and found what I was looking for.

straight out of camera.
1. Metering off scene/grass






2.Metering off concrete


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## johnnyg (Feb 4, 2010)

great info.--will be comin' back for more--would like you to comment on my ? about 8mp vs. 10mp--thanx


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## AliasPros (Feb 4, 2010)

thanks for all the info guys very helpful, think I'm gonna buy some bigger cards...


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## NikonD80Shooter (Feb 6, 2010)

How do you meter on a gray card when your camera can't even focus on the card?


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## IgsEMT (Feb 6, 2010)

> How do you meter on a gray card when your camera can't even focus on the card?


metering is light intensity, focusing is sharpness. you could be blurred and out of focus yet well exposed; opposite is true...
so, you place your focus point on corner of the gray card (contrast tones), luck the focus and recompose on the card...
good luck


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## Dominantly (Feb 6, 2010)

NikonD80Shooter said:


> How do you meter on a gray card when your camera can't even focus on the card?


Like mentioned you do not have to be in focus to set your WB. In fact, there are devices that fit overs your lens like a shower cap, designed to give you an accurate WB measurement (Lally cap). A cheap but effective way to measure your WB is to place a coffee filter (like a Melitta), over your lens, then measuring your WB.
They are CHEAP CHEAP CHEAP, and weigh next to nothing, so why not take one along!


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## IgsEMT (Feb 6, 2010)

*coffe filter?*
REALLY?! - how about color cast on it?


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## Dominantly (Feb 6, 2010)

Just don't get the brown ones and you are good 
They actually work BETTER then most $30-$60 WB devices.

I'll find a link to a test..

http://www.ppmag.com/web-exclusives/2008/11/product-comparison-white-balan-1.html

This DIY would LOOK less cheesy on location
http://www.diyphotography.net/worry-free-digital-white-balance-the-5-cent-expodisc

http://www.digitalimagecafe.com/learn/coffeeFilter/


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## IgsEMT (Feb 6, 2010)

> Just don't get the brown ones and you are good
> They actually work BETTER then most $30-$60 WB devices.
> 
> I'll find a link to a test..


intersting... I'd love to read it.
I went simpler cheaper way - $5 for an 8x10 card, cut in 2 (backup) and happy


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## Dominantly (Feb 6, 2010)

updated


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## IgsEMT (Feb 6, 2010)

> updated


interesting.
thanks for sharing


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## Dominantly (Feb 6, 2010)

No problem bud.

I have an urge to do topic #3. For fun, I think I am going to do something on post processing, mostly layers.


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## IgsEMT (Feb 6, 2010)

> I have an urge to do topic #3. For fun, I think I am going to do something on post processing, mostly layers.


hhhhmmmmm,
go for it, let me know what I can put in ?


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## Dominantly (May 17, 2012)

Bump


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