Exposure Compensation in RAW

KED · March 5, 2008

This has been very much on my mind based on recent shoots, and just yesterday I stumbled upon a link to an "arodney" article on this topic but quite honestly, it was WAY over my head. So I will give a little detail on the specific scenario:

Shooting outdoors in RAW, aperture priority, wide open (2.8), adjusting ISO as needed to keep shutter speed at or above 500. In post, everything warranted pushing exposure up, in a wide range from .25 to almost 2.0 (and in most cases blacks down too). That's fine if that's what is to be expected under these circumstances, but is there anything to be gained from in-camera exposure compensation in this scenario? Doesn't in-camera exposure compensation just force one of the three variables?

I know this is basic and I know that I've touched on a similar topic before (I searched!), but that related to Manual mode and not RAW. Thanks in advance.

KED · March 5, 2008

Mods: I found the original thread over in Finishing School. I'm going to copy and paste this over there, feel free to cut me here. Sorry.

KED wrote:

This has been very much on my mind based on recent shoots, and just yesterday I stumbled upon a link to an "arodney" article on this topic but quite honestly, it was WAY over my head. So I will give a little detail on the specific scenario:

Shooting outdoors in RAW, aperture priority, wide open (2.8), adjusting ISO as needed to keep shutter speed at or above 500. In post, everything warranted pushing exposure up, in a wide range from .25 to almost 2.0 (and in most cases blacks down too). That's fine if that's what is to be expected under these circumstances, but is there anything to be gained from in-camera exposure compensation in this scenario? Doesn't in-camera exposure compensation just force one of the three variables?

I know this is basic and I know that I've touched on a similar topic before (I searched!), but that related to Manual mode and not RAW. Thanks in advance.

pathfinder · March 5, 2008

KED wrote:

This has been very much on my mind based on recent shoots, and just yesterday I stumbled upon a link to an "arodney" article on this topic but quite honestly, it was WAY over my head. So I will give a little detail on the specific scenario:

Shooting outdoors in RAW, aperture priority, wide open (2.8), adjusting ISO as needed to keep shutter speed at or above 500. In post, everything warranted pushing exposure up, in a wide range from .25 to almost 2.0 (and in most cases blacks down too). That's fine if that's what is to be expected under these circumstances, but is there anything to be gained from in-camera exposure compensation in this scenario? Doesn't in-camera exposure compensation just force one of the three variables?

I know this is basic and I know that I've touched on a similar topic before (I searched!), but that related to Manual mode and not RAW. Thanks in advance.

KED,

I am not sure I completely understand what you are saying. If I am not mis-taken, you are saying that you shot images out of doors, in Av mode, at f2.8, raising or lowering the ISO to keep the shutter speed above 1/500th - but when you brought these images into your RAW converter, most were under-exposed by 2 stops or so.

Is this correct? What time of day were you shooting? Or were these shot after sun down, perhaps?

Out of doors during daylight hours in sunlight, an aperture of f2.8 at ISO 100 yields a shutter speed of 1/4000th for proper exposure.

I do not understand how you images can be under exposed so badly in Av mode if used properly.

How did you meter your exposures? Exposure Compensation as a term, refers to the way the camera interprets the light meter data in the camera.

Exposure Compensation really does not refer to RAW. The Exposure slider in Adobe RAW converter does not really do exposure compensation, so much as adjustment of exposure after the fact.

KED · March 5, 2008

pathfinder wrote:

KED,

I am not sure I completely understand what you are saying. If I am not mis-taken, you are saying that you shot images out of doors, in Av mode, at f2.8, raising or lowering the ISO to keep the shutter speed above 1/500th - but when you brought these images into your RAW converter, most were under-exposed by 2 stops or so.

Is this correct? What time of day were you shooting? Or were these shot after sun down, perhaps?

Out of doors during daylight hours in sunlight, an aperture of f2.8 at ISO 100 yields a shutter speed of 1/4000th for proper exposure.

I do not understand how you images can be under exposed so badly in Av mode if used properly.

How did you meter your exposures? Exposure Compensation as a term, refers to the way the camera interprets the light meter data in the camera.

Exposure Compensation really does not refer to RAW. The Exposure slider in Adobe RAW converter does not really do exposure compensation, so much as adjustment of exposure after the fact.

These were extraordinarily variable conditions between 3 -- 5 pm EST, ranging from heavy overcast with and without snow to bright sunlight, the latter mostly at the end. I simply metered in-camera (evaluative) for "correct" exposure, with ISO as the variable as described above. How could Av mode be used other than "properly" under those circumstances? I understand that "Exposure Compensation really does not refer to RAW" as a concept. The entire point of my post is whether in-camera exposure compensation even matters when shooting in RAW. I'm sure I am the one who is missing something here, but of course I am the one asking the questions!

Richard · March 6, 2008

KED wrote:

These were extraordinarily variable conditions between 3 -- 5 pm EST, ranging from heavy overcast with and without snow to bright sunlight, the latter mostly at the end. I simply metered in-camera (evaluative) for "correct" exposure, with ISO as the variable as described above. How could Av mode be used other than "properly" under those circumstances? I understand that "Exposure Compensation really does not refer to RAW" as a concept. The entire point of my post is whether in-camera exposure compensation even matters when shooting in RAW. I'm sure I am the one who is missing something here, but of course I am the one asking the questions!

This is puzzling. One possibility is that you had negative EC dialed in without realizing it. It would be helpful if you posted a few shots with complete EXIF data.

KED · March 6, 2008

pathfinder wrote:

I am not sure I completely understand what you are saying. If I am not mis-taken, you are saying that you shot images out of doors, in Av mode, at f2.8, raising or lowering the ISO to keep the shutter speed above 1/500th - but when you brought these images into your RAW converter, most were under-exposed by 2 stops or so.

Is this correct? What time of day were you shooting? Or were these shot after sun down, perhaps?

Out of doors during daylight hours in sunlight, an aperture of f2.8 at ISO 100 yields a shutter speed of 1/4000th for proper exposure.

I do not understand how you images can be under exposed so badly in Av mode if used properly.

How did you meter your exposures? Exposure Compensation as a term, refers to the way the camera interprets the light meter data in the camera.

Exposure Compensation really does not refer to RAW. The Exposure slider in Adobe RAW converter does not really do exposure compensation, so much as adjustment of exposure after the fact.

You are understanding me exactly correctly! Metering is evaluative -- I don't mess with the default on that. I was in extraordinarily variable conditions on my last shoot, ranging from driving snow to bright (and then sinking) sun. My exposure adjustments in PP generally ranged from 1/3 to 1 2/3 -- and that seems to be exactly the point -- since I'm in RAW anyway, should I even care?

Icebear · March 6, 2008

Yes, you should care. RAW gives you more latitude than jpeg for rescuing an improperly exposed shot, but your goal should always be to properly expose the shot. While you were shooting, did you have a look at the histogram every now and again? It will give you an idea whether your exposure is "in the ball park" or completely out. Some people are real experts in histogram evaluation, but I'm not one of them. At this point, I just have a look to see if it's generally where I think it should be, given the subject. If you're having to correct a couple EVs in post, then your exposure wasn't right, and the camera's histogram would have shown that to you had you looked.

KED · March 6, 2008

Icebear wrote:

Yes, you should care. RAW gives you more latitude than jpeg for rescuing an improperly exposed shot, but your goal should always be to properly expose the shot. While you were shooting, did you have a look at the histogram every now and again? It will give you an idea whether your exposure is "in the ball park" or completely out. Some people are real experts in histogram evaluation, but I'm not one of them. At this point, I just have a look to see if it's generally where I think it should be, given the subject. If you're having to correct a couple EVs in post, then your exposure wasn't right, and the camera's histogram would have shown that to you had you looked.

Let me re-state. Shooting sports, the part of the equation that I fix is aperture (wide open); then I solve for minimum shutter speed of 500 via my ISO variable. This is meant to get me (and it does) to where I am exactly properly exposed per my in-camera metering (i.e., inside the viewfinder). My histos are always "in the ballpark" -- they're just middle humps instead of being ETTR, in general.

LiquidAir · March 6, 2008

KED wrote:

This has been very much on my mind based on recent shoots, and just yesterday I stumbled upon a link to an "arodney" article on this topic but quite honestly, it was WAY over my head. So I will give a little detail on the specific scenario:

Shooting outdoors in RAW, aperture priority, wide open (2.8), adjusting ISO as needed to keep shutter speed at or above 500. In post, everything warranted pushing exposure up, in a wide range from .25 to almost 2.0 (and in most cases blacks down too). That's fine if that's what is to be expected under these circumstances, but is there anything to be gained from in-camera exposure compensation in this scenario? Doesn't in-camera exposure compensation just force one of the three variables?

I know this is basic and I know that I've touched on a similar topic before (I searched!), but that related to Manual mode and not RAW. Thanks in advance.

Lets see if I have this right:

You had your camera in Av mode at f/2.8. Lets say you started at ISO 100, you metered on a subject and the camera chose 1/250s. To boost the shutter speed you compensated by adjusting the ISO to 200. Was that your general process?

For the moment I am going to assume that is was and discuss exposure compensation in this context. If you had set EC+1 in the prior scenario, the camera would have metered 1/125 instead of 1/250 which would have forced you to bump the ISO to 400 to maintain your desired shutter speed. Exposure comensation effectively determines the target brightness for the final image. If you feel that meter is giving you images that are too dark, the right answer is to dial in exposure compensation to correct. That is always the right answer if you are shooting in P, Av or Tv mode whether you are shooting RAW or JPEG. In manual mode you can either use EC or make the correction in your head as you dial in the manual settings.

KED · March 7, 2008

LiquidAir wrote:

Lets see if I have this right:

You had your camera in Av mode at f/2.8. Lets say you started at ISO 100, you metered on a subject and the camera chose 1/250s. To boost the shutter speed you compensated by adjusting the ISO to 200. Was that your general process?

For the moment I am going to assume that is was and discuss exposure compensation in this context. If you had set EC+1 in the prior scenario, the camera would have metered 1/125 instead of 1/250 which would have forced you to bump the ISO to 400 to maintain your desired shutter speed. Exposure comensation effectively determines the target brightness for the final image. If you feel that meter is giving you images that are too dark, the right answer is to dial in exposure compensation to correct. That is always the right answer if you are shooting in P, Av or Tv mode whether you are shooting RAW or JPEG. In manual mode you can either use EC or make the correction in your head as you dial in the manual settings.

Yep, it has now "clicked" and for me, thanks to all of you. I should never have related RAW and exposure in my mind. Thanks and sorry, I still have a lot to learn.

rwells · March 7, 2008

LiquidAir wrote:

In manual mode you can either use EC or make the correction in your head as you dial in the manual settings.

Is this something new I need to know about

KED · March 7, 2008

rwells wrote:

Is this something new I need to know about

Nope, under control now even without you (but not easily).

pathfinder · March 7, 2008

Randy,
Using Exposure Compensation in Manual Mode would be kind of like taking coal to NewCastle wouldn't it?

Since you are using match needle metering in Manual Mode anyway, you can read Exposure directly from the meter in the viewfinder at the time of metering. Being able to dial in + or - EC in Manual Mode would just confuse me, Randy

rwells · March 7, 2008

KED wrote:

Nope, under control now even without you (but not easily).

No,

I was refering to the statement that in manual you can use EC.

LiquidAir · March 7, 2008

rwells wrote:

No,

I was refering to the statement that in manual you can use EC.

Now that you mention it, I don't think my camera will let me set an EC in manual mode. I wish I could though. In manual mode I often spot meter on a white target and adjust the needle to around +2ish which pegs the meter. If I could, I'd love to have a +1 EC in manual mode so white was around the +1 mark and middle grey was around the -1 mark. I never spot meter for shadows, so I really don't care about anything below middle grey.

Scott_Quier · March 12, 2008

KED wrote:

These were extraordinarily variable conditions between 3 -- 5 pm EST, ranging from heavy overcast with and without snow to bright sunlight, the latter mostly at the end. I simply metered in-camera (evaluative) for "correct" exposure, with ISO as the variable as described above. How could Av mode be used other than "properly" under those circumstances? I understand that "Exposure Compensation really does not refer to RAW" as a concept. The entire point of my post is whether in-camera exposure compensation even matters when shooting in RAW. I'm sure I am the one who is missing something here, but of course I am the one asking the questions!

I believe one root cause to the issse to be that which I have highlighted, above.

If one remembers that the camera loves 18% gray and wants to push everything there, and if there is snow in the scene, the camera is going to tend to cause under-expsoure, anything from 1/2 stop to 2 full stops, depending on the amount of the bright white stuff in the scene.

Now that you mention it, I don't think my camera will let me set an EC in manual mode. I wish I could though. In manual mode I often spot meter on a white target and adjust the needle to around +2ish which pegs the meter. If I could, I'd love to have a +1 EC in manual mode so white was around the +1 mark and middle grey was around the -1 mark. I never spot meter for shadows, so I really don't care about anything below middle grey.

Of course there's no EC in manual mode. EC is to over-ride the programming of the computer in camera. When in manual mode, you are the computer. It just makes sense - what are you going to do - over-ride yourself?

LiquidAir · March 12, 2008

Scott_Quier wrote:

Of course there's no EC in manual mode. EC is to over-ride the programming of the computer in camera. When in manual mode, you are the computer. It just makes sense - what are you going to do - over-ride yourself?

What I want to do is shift how the "needle" displays in the viewfinder. Right now, if I want to manually dial in +2 stops from the in camera meter (usually the spot meter), the display in the viewfinder is pegged so I can't tell the difference between +2 and +5. The way I get there is by dialing in +1 stop on the display and then pushing 3 clicks on the dial, but that is a hassle.

pathfinder · March 12, 2008

What Ken is really asking for, is a meter for Exposure Compensation in the viewfinder, that allows three or even four stops + or -, not the typical +/- 2 stops seen in our cameras.

I can understand that desire, if one is metering in Spot Mode. Makes perfect sense. Probably not as needed in Evaluative mode, but in Spot Mode, it would be very helpful.

Rhuarc · March 12, 2008

pathfinder wrote:

What Ken is really asking for, is a meter for Exposure Compensation in the viewfinder, that allows three or even four stops + or -, not the typical +/- 2 stops seen in our cameras.

I can understand that desire, if one is metering in Spot Mode. Makes perfect sense. Probably not as needed in Evaluative mode, but in Spot Mode, it would be very helpful.

If I got Ken's meaning, instead of showing -2/0/+2, the meter would now show 0/+2/+4, or even +2/+4/+6. You coudl of course shift it the other direction and have it show more in the NEC also.

ccpickre · March 19, 2008

Not that I know what I'm talking about, but if the subject was backlit outside, that could effect the metering too. The camera would think the photo is ok, but the subject would be underexposed (something that I learned the hard way last year at 2 in the afternoon shooting the Little 5 bike races at IU).

On a different note, I was completely unaware you could use EC in manual, since you are controlling the exposure manually with all the fancy schmancy settings.

rwells · March 19, 2008

ccpickre wrote:

On a different note, I was completely unaware you could use EC in manual, since you are controlling the exposure manually with all the fancy schmancy settings.

You can't...

KED · March 19, 2008

ccpickre wrote:

Not that I know what I'm talking about, but if the subject was backlit outside, that could effect the metering too. The camera would think the photo is ok, but the subject would be underexposed (something that I learned the hard way last year at 2 in the afternoon shooting the Little 5 bike races at IU).

On a different note, I was completely unaware you could use EC in manual, since you are controlling the exposure manually with all the fancy schmancy settings.

Randy is correct, of course, and I have sewn a lot of confusion here in a couple of respects. First, RAW has nothing to do with it, except that it gives you some extra latitude in PP to fix exposure.

More importantly, and this is where there has been a failure to communicate to some extent, exposure is a zero sum game between the variables of ISO, shutter speed and aperture. As I'm now seeing it, the concept of "exposing to the right" -- at least when one has a minimum acceptable shutter speed as in sports shooting -- only has relevance when one is not starved for light. If I'm already shooting in Av mode wide open and pushing ISO to 800 or higher, then adjusting EC can only do one thing and that's lower my shutter speed. For this particular shooting genre, the only practical application of EC/ETTR would be in relatively abundant light where the shutter speed compromise might be from, say, 1250 to 800 -- immaterial when it comes to eliminating motion blur.

I'm getting abundant shooting opportunities in heavy overcast here in the Northeast, so I'm gonna switch to manual, shoot wide open, push the hell out of ISO and see how that works.

ccpickre · March 19, 2008

Ok. Thanks Randy. I mean, I know I'm not supposed to believe my dad until I learn it the hard way. But I was pretty sure he told me the same thing

KED wrote:

More importantly, and this is where there has been a failure to communicate to some extent, exposure is a zero sum game between the variables of ISO, shutter speed and aperture. As I'm now seeing it, the concept of "exposing to the right" -- at least when one has a minimum acceptable shutter speed as in sports shooting -- only has relevance when one is not starved for light. If I'm already shooting in Av mode wide open and pushing ISO to 800 or higher, then adjusting EC can only do one thing and that's lower my shutter speed. For this particular shooting genre, the only practical application of EC/ETTR would be in relatively abundant light where the shutter speed compromise might be from, say, 1250 to 800 -- immaterial when it comes to eliminating motion blur.

I'm getting abundant shooting opportunities in heavy overcast here in the Northeast, so I'm gonna switch to manual, shoot wide open, push the hell out of ISO and see how that works.

I knew all that, I just wanted to make sure there wasn't some technological change I hadn't heard about

Be careful pushing the ISO for shutter speed. Higher ISOs tend to flatten the image (low contrast and color saturation). And shooting at 1/2000 when 1/1000 is sufficient is kind of a waste in my experience. I've rarely had to go over somewhere between 1/800 and 1/620 when I've shot sports. so find that happy medium and lower the ISO so your photos don't get bland.

KED · March 19, 2008

ccpickre wrote:

And shooting at 1/2000 when 1/1000 is sufficient is kind of a waste in my experience.

Not gonna happen in the heavy overcast conditions I'm talking about. This is pushing ISO just to stay above shutter speed of 500, and I'm now thinking that for lacrosse (college men's level), 800 or above is optimal (for stickhead and ball, not bodies).

ccpickre · March 20, 2008

KED wrote:

Not gonna happen in the heavy overcast conditions I'm talking about. This is pushing ISO just to stay above shutter speed of 500, and I'm now thinking that for lacrosse (college men's level), 800 or above is optimal (for stickhead and ball, not bodies).

I don't know. I shot field hockey on overcast days, at about 500 and did alright.

I can't imagine having to push the ISO in overcast days though. Unless your shutter speeds really are THAT fast. Just seems odd to me. I love overcast days. Lighting is so even for me

Scott_Quier · March 20, 2008

ccpickre wrote:

I don't know. I shot field hockey on overcast days, at about 500 and did alright.

I can't imagine having to push the ISO in overcast days though. Unless your shutter speeds really are THAT fast. Just seems odd to me. I love overcast days. Lighting is so even for me

Might be the difference between overcast where the clouds make like a really nice softbox and overcast where the clouds are a massive gray blanket. Difference of 3 or 4 stops of light I would think

ccpickre · March 20, 2008

Guess I haven't seen one of those days in a LONG time. And I never shoot in those situations

KED · March 20, 2008

ccpickre wrote:

I don't know. I shot field hockey on overcast days, at about 500 and did alright.

I can't imagine having to push the ISO in overcast days though. Unless your shutter speeds really are THAT fast. Just seems odd to me. I love overcast days. Lighting is so even for me

At the HS/college level, a lacrosse ball can be shot at 95+ MPH, presumably with the stickhead moving essentially that fast at the point of release. I've shot field hockey (my daughter plays), and the only thing going 95 MPH is my mind asking when the game is gonna be over!

KED · March 20, 2008

Scott_Quier wrote:

Might be the difference between overcast where the clouds make like a really nice softbox and overcast where the clouds are a massive gray blanket. Difference of 3 or 4 stops of light I would think

MGB seems to be the rule so far. I'm not experienced enough to look at light and equate it to stops (I wish I were), but it's big-time stops for sure; and when I think of it relative to what shutter speeds I'd be getting in sun with identical settings, I'm pretty sure you are right in the ballpark.

ccpickre · March 20, 2008

KED wrote:

At the HS/college level, a lacrosse ball can be shot at 95+ MPH, presumably with the stickhead moving essentially that fast at the point of release. I've shot field hockey (my daughter plays), and the only thing going 95 MPH is my mind asking when the game is gonna be over!

I usually space out and try to wrap my mind around a game that has a score lower than a futbol game.

Exposure Compensation in RAW

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