Histograms

[manncer]

:?: :?: :?:

I read a paragraph on the following Web site: http://www.rogercavanagh.com/helpinfo/05_whatnow.htm

"The LCD on the camera is much brighter than the D30. Even at the lowest setting, it can give a misleading impression of image exposure: pictures that look nice and bright in the LCD turn out to be under-exposed. Do not be fooled, use the histogram!"

How does this help? I am not familiar with histograms?

Thanks,
manncer

[PacAce]

:?: :?: :?:

I read a paragraph on the following Web site: http://www.rogercavanagh.com/helpinfo/05_whatnow.htm

"The LCD on the camera is much brighter than the D30. Even at the lowest setting, it can give a misleading impression of image exposure: pictures that look nice and bright in the LCD turn out to be under-exposed. Do not be fooled, use the histogram!"

How does this help? I am not familiar with histograms?

Thanks,
manncer

I guess that would depend on what kind of camera you have. Not all cameras have histograms displayed on the LCD.

[manncer]

:oops:

I have a 10D

Sorry

[VicGlass]

:?: :?: :?:

I read a paragraph on the following Web site: http://www.rogercavanagh.com/helpinfo/05_whatnow.htm

"The LCD on the camera is much brighter than the D30. Even at the lowest setting, it can give a misleading impression of image exposure: pictures that look nice and bright in the LCD turn out to be under-exposed. Do not be fooled, use the histogram!"

How does this help? I am not familiar with histograms?

Thanks,
manncer

Manncer,

Do not give up so easily, nor be embarrassed. BTW the 10D does have a histogram available for each shot taken.

I've experienced exactly what that paragraph describes. My pics looked okay in the LCD but when I got them into Photoshop they were underexposed. In otherwords I had a tendency to underexpose my shots.

Looking at the histogram after each shot is important since it tells you if you've captured a good tonal range. That means that there are values all the way from left to right. When you underexpose you'll see the graph "goe flat" on the right. The right represents highlights, the left represents shadows. It is better to overexpose than underexpose. Why? The number of pixals captured is not a linear representation in the histogram. What does this mean? If you divide the historam into fours, the number of pixels represented in each of the quadrants is not equal. A huge number of the total is represented in the right most quadrant, i.e. the highlights. The least number of pixels is represented in the left most quadrant, i.e. the shadows. So if you underexpose you do not capture a huge amount of data.

One last thing. The histogram is the most important tool in understanding and correcting your image. Please read this short article:
http://luminous-landscape.com/tutorials/expose-right.shtml

If you need more info or help, shout.

[Jesper]

Have a look at these pages about histograms:

Understanding Histograms (http://luminous-landscape.com/tutorials/understanding-series/understanding-histograms.shtml) from Luminous Landscape
A Practical Guide to Interpreting RGB Histograms (http://www.sphoto.com/techinfo/histograms/histograms.htm) by Steve Hoffman

The histogram is the most important tool on your digital camera to check if the exposure is correct.

[Roger_Cavanagh]

Manncer,

No-one has ket mentioned how to get the histogram display on your 10D - so in case...

When you are reviewing a picture in the LCD, press the Info button. You can also set the Review option in the LCD menu to have the histogram automatically displayed when the newly taken image appears in the LCD.

Regards,

Roger

[Laziferous]

The least number of pixels is represented in the left most quadrant, i.e. the shadows. So if you underexpose you do not capture a huge amount of data.
True, but if you blow out some highlights, there is no way to retrieve some detail out of them, because they have been recorded as white. At least if you under expose you can tweak it a bit, even if you do lose some detail. The details in blown highlights are gone forever. Better some, than none, right?

Although a grossly under exposed shot is just as bad as an over exposed one. There isn't really much to be done with it... apart from moving it to the recycle bin :P

[VicGlass]

The least number of pixels is represented in the left most quadrant, i.e. the shadows. So if you underexpose you do not capture a huge amount of data.
True, but if you blow out some highlights, there is no way to retrieve some detail out of them, because they have been recorded as white. At least if you under expose you can tweak it a bit, even if you do lose some detail. The details in blown highlights are gone forever. Better some, than none, right?

Although a grossly under exposed shot is just as bad as an over exposed one. There isn't really much to be done with it... apart from moving it to the recycle bin :P

Yes, and conversely the shadows can be lost (i.e. never recorded) in the same way. The general rule is to "expose (to the) right" (reasoning is here http://luminous-landscape.com/tutorials/expose-right.shtml

It is surprisingly easy to shoot (to the) right AND not overexpose if one understands lighting situation and how to meter properly.

[manncer]

:D


Thank you!

manncer

[Laziferous]

It is surprisingly easy to shoot (to the) right AND not overexpose if one understands lighting situation and how to meter properly.
Yes, I understand the reason, and also histograms. I think maybe we misunderstand one another.

What I mean is, it is much easier to recover from a slightly under exposed shot, as opposed to a slightly over exposed one. Of course, as I said above, a grossly under exposed shot is equally as worthless as an over exposed one. If you're only dealing with 1 stop or less though, under exposure is easily corrected, and over exposure is not.

So my general point was that this:
It is better to overexpose than underexpose.
is in my opinion, false. We can agree to disagree though 8)

[VicGlass]

Laziferous,

We are on the same page and saying the same thing about exposure and histograms. Under exposure to me means gross under exposure, that is, flat lining much of the right quadrant. Your picture is quite good, but try smiling for next portrait :)

[Laziferous]

I thought maybe we were just misunderstanding one another. Happens easily on the internet. I also have a bad habit of not articulating what I'm trying to say on the first shot :? :)

My avatar? Haha, that's just a silly picture my wife took of me when I was wearing a sombrero. I tend to make weird faces when someone points a camera at me... I'm used to doing the pointing myself :D

Me (http://gallery.bytephoto.com/data/3023/6CRW_4756.jpg)