18% Grey scale metering - Manual mode

[ShutterWork]

Hi all,

Basic question again...

Having read 'Understanding Exposure' recently, I am kind of slowly coming out of the cocoon and doing some shooting in Manual exposure mode.

The question now I have though is - whilst shooting in M mode how do I meter my exposure to compensate for too dark (black) or too light (white) objects? Normally in A Mode I would use exposure compensation to turn up/down.

In M Mode is it as simple as sliding the light meter pointer towards +/- side?

Thanks in advance for your replies.

 

[AJQS]

There really is no difference between A and M modes, all that happens in A mode is when you half press the camera wll auto change the shutter speed, in M it won't. Chnaging the exposure compensation is just changing the shutter speed anyway, so it behaves no different in M, you just see it expressed in sutter speeds instead of +/- so many stops. I dare say it still shows you that meter reading as well.

 

[ShutterWork]

There really is no difference between A and M modes, all that happens in A mode is when you half press the camera wll auto change the shutter speed, in M it won't. Chnaging the exposure compensation is just changing the shutter speed anyway, so it behaves no different in M, you just see it expressed in sutter speeds instead of +/- so many stops. I dare say it still shows you that meter reading as well.

Thanks for your post Alan.

So if I am getting this right, you're advising that EC can be used in M mode to create a bias as desired.

Alternatively, can I achieve the same by doing the following?

When I want to underexpose a photo for a very dark/black object all I do this increase shutter speed in M mode (light meter slider to minus) and vice-versa (light meter slider to plus) for a lighter/white object, isn't it?

Thanks..Sorry if I am being bit thick here

 

[HoppyUK]

Hi all,

Basic question again...

Having read 'Understanding Exposure' recently, I am kind of slowly coming out of the cocoon and doing some shooting in Manual exposure mode.

The question now I have though is - whilst shooting in M mode how do I meter my exposure to compensate for too dark (black) or too light (white) objects? Normally in A Mode I would use exposure compensation to turn up/down.

In M Mode is it as simple as sliding the light meter pointer towards +/- side?

Thanks in advance for your replies.

Yes

 

[lensflair]

Yes

+1

In auto modes the camera chooses the settings to 'zero' the meter. EC moves it off zero by changing shutter speed or aperture. In manual you zero the meter by adjusting shutter speed and aperture (and ISO) but you can choose to not have it on zero. Same thing as dialing in EC in auto modes like Av.

Sorry I just reiterated what's already been said.

 

[leaky5]

I see you are using a D5000, so I am assuming it does the same thing as the D90.

Before going to M, make sure EC is set back to 0.0, as EC does effect the meter scale reading when in M.

 

[donut]

if you meter using a grey card you dont put in any exposure compensation ,if you dont have a grey card use tarmac or grass to get the exposure ,

 

[ShutterWork]

Yes

+1

In auto modes the camera chooses the settings to 'zero' the meter. EC moves it off zero by changing shutter speed or aperture. In manual you zero the meter by adjusting shutter speed and aperture (and ISO) but you can choose to not have it on zero. Same thing as dialing in EC in auto modes like Av.

Sorry I just reiterated what's already been said.

Thanks..finally getting some hang of it..

I see you are using a D5000, so I am assuming it does the same thing as the D90.

Before going to M, make sure EC is set back to 0.0, as EC does effect the meter scale reading when in M.

Will do..thanks for the tip. It's really helpful to know as whilst setting so many other things I do forget basic stuff like ISO and WB.

 

[wontolla]

if you meter using a grey card you dont put in any exposure compensation ,if you dont have a grey card use tarmac or grass to get the exposure ,

If you have a Lowepro bag, the inside of that is 18% grey!

 

[ShutterWork]

if you meter using a grey card you dont put in any exposure compensation ,if you dont have a grey card use tarmac or grass to get the exposure ,

Thanks..on that note could I please ask the concept of using a grey card? This is something I have always failed to understand even after reading some stuff over the internet.

I do understand metering (well, I think I do now) and how a camera averages a scene to get middle grey, etc..but haven't really understood how to use a grey card in practical sense (or tarmac/grass).

Sorry if I am being thick again..

 

[johnnypanic]

If you have a Lowepro bag, the inside of that is 18% grey!

Ye Gods, I learn something new eveyday. Have had my bag for ages and I couldn't even have told you what colour it was inside

 

[wontolla]

Ye Gods, I learn something new eveyday. Have had my bag for ages and I couldn't even have told you what colour it was inside

There ya go! Great being part of a fabulous forum, aint it?

 

[HoppyUK]

Thanks..on that note could I please ask the concept of using a grey card? This is something I have always failed to understand even after reading some stuff over the internet.

I do understand metering (well, I think I do now) and how a camera averages a scene to get middle grey, etc..but haven't really understood how to use a grey card in practical sense (or tarmac/grass).

Sorry if I am being thick again..

18% grey, mid-grey, is the tone that sits around the middle of the camera's dynamic range - in the middle of the histogram. If you meter from that tone, it will give maximum range either side for lighter and darker tones to be recorded.

That's the theory, but there's some debate as to exactly what tone different cameras are calibrated to as their exposure reference - estimates vary between 12 and 18%, but 18% is the 'standard' tone that everybody refers to in matters of exposure, for historical reasons if nothing else.

Loweprop bags are not actually 18% grey, though it's a popular myth. They're actually a bit lighter, like roughly 1/2 - 2/3rds of a stop. It's a handy guide that will get you close but will under-expose a bit unless you add some compensation.

 

[ShutterWork]

18% grey, mid-grey, is the tone that sits around the middle of the camera's dynamic range - in the middle of the histogram. If you meter from that tone, it will give maximum range either side for lighter and darker tones to be recorded.

That's the theory, but there's some debate as to exactly what tone different cameras are calibrated to as their exposure reference - estimates vary between 12 and 18%, but 18% is the 'standard' tone that everybody refers to in matters of exposure, for historical reasons if nothing else.

Loweprop bags are not actually 18% grey, though it's a popular myth. They're actually a bit lighter, like roughly 1/2 - 2/3rds of a stop. It's a handy guide that will get you close but will under-expose a bit unless you add some compensation.

Thanks Richard. Still trying to understand the concept of how to use a grey card...

Could I please ask, are grey cards normally used for metering a very bright or very dark objects only ? The reason I am asking this is I tried some portrait/landscape shooting in M mode over the weekend by metering straight off the subject and these photos look okay without using a grey card. As such I am failing to understand the real use of grey cards. thanks.

 

[HoppyUK]

Thanks Richard. Still trying to understand the concept of how to use a grey card...

Could I please ask, are grey cards normally used for metering a very bright or very dark objects only ? The reason I am asking this is I tried some portrait/landscape shooting in M mode over the weekend by metering straight off the subject and these photos look okay without using a grey card. As such I am failing to understand the real use of grey cards. thanks.

Those are some big questions, or at least lengthy answers, but a simple one is don't worry about it. No many people bother to use a grey card much these days - chimp it by checking the LCD, the histogram and blinkies (highlight over-exposure warning). Get that right and the exposure cannot be wrong.

These are things that are not covered in Peterson's book you've been reading, Understanding Exposure and TBH I think he's a bit of a goon in the way he dismisses things like the histogram in a single throwaway line. That book was written for film, and even the latest 'updated for digital' version falls woefully short.

Back to grey cards. They are just a reference, a helpful guide. But you can use any tone of a known value if you then apply the appropriate adjustment. The things is, it's a constant of known value. The plam of your hand is also a good one, if you add 1-1.5 stops to the reading. Or a white card and add roughly 3 stops. Grass is usually about 18% reflectance, tarmac too but both are sometimes dangerously variable.

 

[ShutterWork]

Those are some big questions, or at least lengthy answers, but a simple one is don't worry about it. No many people bother to use a grey card much these days - chimp it by checking the LCD, the histogram and blinkies (highlight over-exposure warning). Get that right and the exposure cannot be wrong.

These are things that are not covered in Peterson's book you've been reading, Understanding Exposure and TBH I think he's a bit of a goon in the way he dismisses things like the histogram in a single throwaway line. That book was written for film, and even the latest 'updated for digital' version falls woefully short.

Back to grey cards. They are just a reference, a helpful guide. But you can use any tone of a known value if you then apply the appropriate adjustment. The things is, it's a constant of known value. The plam of your hand is also a good one, if you add 1-1.5 stops to the reading. Or a white card and add roughly 3 stops. Grass is usually about 18% reflectance, tarmac too but both are sometimes dangerously variable.

Thanks Richard. I knew it wasn't a simple answer , but yes, I am bit more reassured now when you said not many people bother with these (I thought most of them would do this as a routine which I have not been).

As always I was trying to learn too much too soon. Hopefully, should understand better with time and practice, and of course by picking some expert brains here . Thanks.

 

[HoppyUK]

Thanks Richard. I knew it wasn't a simple answer , but yes, I am bit more reassured now when you said not many people bother with these (I thought most of them would do this as a routine which I have not been).

As always I was trying to learn too much too soon. Hopefully, should understand better with time and practice, and of course by picking some expert brains here . Thanks.

You can go as deep as you like with exposure theory, but the bottom line is if you are getting consistently good results, and you know how and why to adjust things if you don't, then that's what matters.

In practise, while few folks use a grey card, there are still advocates of using an incident-reading exposure meter. Basically what matters with exposure is the light falling on the subject, which is often very different to the light reflected back from different tones, eg bride and groom. An incident meter, measures the light falling on the subject, and while the theory is exactly the same as a grey card (or the palm of your hand, or grass etc for that matter) it's a heck of a lot easier with a meter.

If you want to know more about optimum exposure setting, check out Expose To The Right (of the histogram) technique - it's the ultimate trick with digital.

 

[ShutterWork]

You can go as deep as you like with exposure theory, but the bottom line is if you are getting consistently good results, and you know how and why to adjust things if you don't, then that's what matters.

In practise, while few folks use a grey card, there are still advocates of using an incident-reading exposure meter. Basically what matters with exposure is the light falling on the subject, which is often very different to the light reflected back from different tones, eg bride and groom. An incident meter, measures the light falling on the subject, and while the theory is exactly the same as a grey card (or the palm of your hand, or grass etc for that matter) it's a heck of a lot easier with a meter.

If you want to know more about optimum exposure setting, check out Expose To The Right (of the histogram) technique - it's the ultimate trick with digital.

Thanks Richard. This is interesting indeed...will do a bit more research on ETTR..to be honest did browse on this subject a while ago..but didn't really pay attention. Will go back to it now.

Thanks a lot for your helpful inputs.

 

[AJQS]

Thanks Richard. This is interesting indeed...will do a bit more research on ETTR..to be honest did browse on this subject a while ago..but didn't really pay attention. Will go back to it now.

Thanks a lot for your helpful inputs.

Now you've graped the basics of the mystical 18% grey, maybe you'd now like to venture into zone metering, which is a very handy system when combined with spot metering.

 

[ShutterWork]

Now you've graped the basics of the mystical 18% grey, maybe you'd now like to venture into zone metering, which is a very handy system when combined with spot metering.

will do, after resting my grey cells for a day or two..will land up confusing myself again ..but got some veteran brains here to pick..

can't even describe how much have I learnt after joining this forum..!!

 

[HoppyUK]

Thanks Richard. This is interesting indeed...will do a bit more research on ETTR..to be honest did browse on this subject a while ago..but didn't really pay attention. Will go back to it now.

Thanks a lot for your helpful inputs.

You're welcome

Tha basis of Expose To The Right theory is that a) there is a great deal more image data recorded on the right than the left of the histogram, and b) a lot of this potential is often wasted, even with 'correct' exposure.

So if there is scope to push the histogram to the right by adding extra exposure, then the upside is the signal to noise ratio is substantially increased, with the particular upside of much more shadow detail and tone separation, brighter colours and less noise. The danger is that you push the highlights too far and they blow, beyond recovery.

However, there is almost always around a stop of headroom on the Raw file compared to a JPEG, and if you are prepared to selectively sacrifice the unimportant highlights and let them blow (either because they'll blow anyway, or they don't matter) then you can push it even more. Blinkies are an essential guide to this technique, and you have to be careful as you're edging things to the limit, hopefully not beyond.

Then in post processing, you push the tone range to the left, back to its rightful position, but you are still left with much better shadows and less noise.

Can be a risky business, but looks great with the right subject, ones with lots of shadow areas and darker tones. More here http://www.luminous-landscape.com/tutorials/expose-right.shtml

 

[ShutterWork]

You're welcome

Tha basis of Expose To The Right theory is that a) there is a great deal more image data recorded on the right than the left of the histogram, and b) a lot of this potential is often wasted, even with 'correct' exposure.

So if there is scope to push the histogram to the right by adding extra exposure, then the upside is the signal to noise ratio is substantially increased, with the particular upside of much more shadow detail and tone separation, brighter colours and less noise. The danger is that you push the highlights too far and they blow, beyond recovery.

However, there is almost always around a stop of headroom on the Raw file compared to a JPEG, and if you are prepared to selectively sacrifice the unimportant highlights and let them blow (either because they'll blow anyway, or they don't matter) then you can push it even more. Blinkies are an essential guide to this technique, and you have to be careful as you're edging things to the limit, hopefully not beyond.

Then in post processing, you push the tone range to the left, back to its rightful position, but you are still left with much better shadows and less noise.

Can be a risky business, but looks great with the right subject, ones with lots of shadow areas and darker tones. More here http://www.luminous-landscape.com/tutorials/expose-right.shtml

Thanks Richard. Will have a look.