Lr2

[Cowboy13]

Why might a photographer prefer to shoot slightly underexposed images rather than overexposed ones?

[raevyncent]

Because a darker image can be lightened, but blown highlights are gone forever?

[Cajungaltx]

Originally Posted by raevyncent

Because a darker image can be lightened, but blown highlights are gone forever?

+1... if shooting in RAW, the data is there to do just that. If I have an image that is slightly underexposed... I'm happy... I can fix that in LR... but overexposed? Take it again... cause while the recovery slider 'can' fix somethings... it doesn't always work.

[zebulus]

Originally Posted by raevyncent

Because a darker image can be lightened, but blown highlights are gone forever?

+2.I usually always shoot in RAW and underexpose.

[Imagebuffet]

Originally Posted by raevyncent

Because a darker image can be lightened, but blown highlights are gone forever?

Couldn't the same be said of blown shadows?

[zebulus]

Originally Posted by Imagebuffet

Couldn't the same be said of blown shadows?

Your not a RAW user, are ya?

[Cajungaltx]

okay... i just found some information... that actually says we are wrong (for shooting underexposed v. overexposed) in how we are handling it.

LINKY HERE:


Raw is different than JPEG

As many of these photographers graduated to shooting raw, many of them continued to intentionally underexpose to protect highlights. In fact I’ve heard respected photography teachers tell their students to do this. However, raw files are very different than JPEG files. They not only contain a huge amount of information, but due to the linear nature of a raw file, much of it’s capture bandwidth is dedicated to the highlights regions. In fact, with a standard raw capture 50% of the file’s information is used to record the brightest stop. To better understand this, take a look at the graph below.
The linear nature of a raw file means that as each stop gets darker, 50% less information describes it.

The linear nature of a raw file means that as each stop gets darker, 50% less information describes it.

This graph shows the six stop exposure range of the typical raw file with a total of 4096 distinct tones, ranging from black to white. Stop #1, the brightest stop, contains 2048 tones, or 50% of the total tonal bandwidth contained in the file. Stop #2 contains half as much as stop #1, which is 1024. This halving of tonal ranges continues with each successively darker stop.



As you can see by the histogram in the graph, this file was intentionally underexposed using the JPEG exposure philosophy. This results in half of the information available to describe this file not being used because it wasn’t used to describe highlights that weren’t captured. To make matters worse, only 1.6% of the file’s bandwidth is used to describe the darkest shadows.

This is a problem because when less information is used to describe shadow detail, noise becomes more of a problem. This noise is accentuated when the histogram is moved to the right in post-processing to lighten, compensating for the underexposure. If the file had been properly exposed, (moving the histogram one stop to the right), not only would all of the bandwidth have been used to capture the highlights, but the shadows would have moved one stop to the right where twice as much information would have been used to describe them.-

[doctahjones]

Originally Posted by Cajungaltx

okay... i just found some information... that actually says we are wrong (for shooting underexposed v. overexposed) in how we are handling it.

LINKY HERE:


Raw is different than JPEG

As many of these photographers graduated to shooting raw, many of them continued to intentionally underexpose to protect highlights. In fact I’ve heard respected photography teachers tell their students to do this. However, raw files are very different than JPEG files. They not only contain a huge amount of information, but due to the linear nature of a raw file, much of it’s capture bandwidth is dedicated to the highlights regions. In fact, with a standard raw capture 50% of the file’s information is used to record the brightest stop. To better understand this, take a look at the graph below.
The linear nature of a raw file means that as each stop gets darker, 50% less information describes it.

damn, can't argue with all that!

excellent reference katy.

[Cajungaltx]

Thanks Dallas!

[venchka]

OK, here is a JPEG. Everyone knows JPEGs are crap. Here is a JPEG on a monitor. Even worse. But I promise the highlights aren't blown out in the original. If they were, this photograph would be a disaster. It's not great now, but the range of tones is very wide. There isn't any POP. It's not that kind og subject.

[doctahjones]

Originally Posted by Cajungaltx

Thanks Dallas!

hah, sorry Donna

[ronocnikral]

i don't know if I understand all that, especially since they are talking about a RAW file being linear??? all over a lognormal plot...I'm an engineer and that is difficult to understand.

But, I perused the link and here is what I do understand...

"It’s always best to nail an exposure"

or use HDR...

[Digigeek]

Isn't Donna's post the whole essence of "shooting to the right" to preserve the highlights?

[jeffkohn]

Originally Posted by Imagebuffet

Couldn't the same be said of blown shadows?

I suppose, but:

1) Our cameras have more dynamic range below middle gray than they do above it, and with today's sensors the noise has gotten so good that a lot of information can be recovered from the shadow areas.

2) Completely black shadow areas are almost always less distracting/unpleasant than blown-out white areas. In fact they can be aesthetically pleasing, giving an image a sense of depth. (Of course you wouldn't want your main subject underexposed to this extent).

jeffkohn added 9 Minutes and 10 Seconds later...Double Post Merged Below

Originally Posted by Cajungaltx

okay... i just found some information... that actually says we are wrong (for shooting underexposed v. overexposed) in how we are handling it.

LINKY HERE:


Raw is different than JPEG

It's true that when shooting raw it can be beneficial to "expose to the right"; it's not so much about the number of levels, but rather the fact that the sensor has a better signal to noise ratio in the upper stops. So once you shift the exposure back to the left in the RAW converter you'll end up with cleaner shadows. But even with RAW, you still don't want to blow-out bright portions of the image that you care about (as opposed to specular highlights which you probably don't care about).

Expose to the right is a useful technique when the contrast range of the scene you're shooting fits within dynamic range of the camera. When you're faced with a scene contrast that exceeds your dynamic range there's no silver bullet. You can either expose to avoid clipping highlights and hope to recover the shadows/mid-tones in post, or you can expose for your subject and let the shadows/highlights fall where they may. The only other real option is using grad filters and/or combining bracketed exposures.

[Imagebuffet]

I don't know why the article says that JPEG is not linear. I guess that would be a function of the compression algorithm. The camera sensor, itself, responds linearly to light intensity. So, if JPEG is not linear, it is due to something that happens after the image has been captured by the camera. Film, of course, has a non-linear response to light.

I have been trying to get the hang of the "expose to the right" (of the histogram) philosophy for a few years, now. I know, my photos often don't show it. Nevertheless, when I'm editing, I try to shift everything to the right (I'm probably mistaken in doing this, though; I probably should have exposed to the right, then edited to the middle).

And, yes, I shoot RAW.

When I shot the Florida Mountains in Deming, New Mexico, last November, I accidentally over-exposed the images by 2 dots (are these stops? I don't know; I haven't seen anything that lets me know what a stop is on my camera). I was extremely disappointed, but I decided to see what I could do in Elements. To my surprise, they don't look half-bad. The JPEG shows just about everything blown out, but I recovered it all from the RAW:



The photo above is from my manual adjustments in Elements. The photo below is automatic levels set by Elements. For some reason, Elements sometimes does not adjust the red and/or blue channels completely.



The downside that I see to over-exposure is that it invites camera jiggle. I usually hand-hold my camera, and, even if I don't, my shooting time is often interrupted, so the faster I can expose a shot, the better.