Under-exposed and Over-exposed?

hao · Jul 10, 2009

I guess this question has been raised before for many times. Please dont blame me if it is an easy-easy question.

Today, I was trying to shoot a whole bunch of tree with the dusk sky as the background. I got so frustrated in that I got either "underexposed trees with good sky"(metering the sky) or "overexposed sky with good trees" (metering the trees). How do you fix this to get a good picture in this case? thanks for your input.

Another question is: how to get vivid colors in ur pictures right in camera (no photoshop)? thx

musicaleCA · Jul 10, 2009

Probably the best solution to this particular problem is either HDR, or a graduated neutral density filter (GND), which will help to bring down the exposure on the sky. There's probably no way to expose both properly at the same time though without something extra; on or the other is likely far outside of the range of the camera's sensor.

Mark Saint · Jul 10, 2009

musicaleCA is right. i guess that's the main purpose of HDR

Another question is: how to get vivid colors in ur pictures right in camera (no photoshop)? thx

using filters i guess.. but you still have to work-out your pictures in photoshop to get the best results.

Garbz · Jul 10, 2009

This subforum is full of questions of HDR and ND Grad and ND filters where techniques are discussed.
Read my post here for just one example: http://www.thephotoforum.com/forum/beyond-basics/170492-nd-filter-vs-exposure-comp.html

Moglex · Jul 10, 2009

I think people are rather getting ahead of themselves here.

It's obvious from the OP that the poster does not really understand much about the subtleties of exposure.

Graduated ND filters are not an answer to trees against the background of sky for obvious reasons and telling someone who doesn't understand why he can't get both trees and sky correctly exposed at the same time that HDR is the answer is rather like telling someone who's having trouble flying a microlight that they really need a jet fighter.

I'd suggest you get a good book on understanding exposure. It will be interesting and help you get a lot more from your photography.

Dwig · Jul 10, 2009

There are a number of steps to take to "fix" this; the last is to resort to HDR.

The first thing is to set your ISO to the absolute lowest ISO on the camera and shoot a shot 1/2 way between the "good sky" exposure and the "good trees" exposure and then check the histogram to see if there are any significant clipping in the highlights and/or the shadows. You may find that this compromise image, or one near it, is all you need.

Second thing to try is to use the best compromise image from step one and do some Curves adjustment in Photoshop or similar to expande the detail in both the highlights and shadows.

The third thing to try is to take 3 or more bracketed shots at1 1/2 to 2 stop increments and use these to create an HDR image. This is a bit complicated but can deliver excellent results. It does have its problems as you can't shoot your tree against the sky shot on a windy day when the leaves will move between the multiple shots. Sometimes you can replace the multiple original shots with multiple RAW conversions. This is done by shooting one compromise shot in RAW and doing several conversions, one for shadow, one for highlight and one for the middle tones. These three different conversions are then used for the HDR assembly and tone mapping.

dxqcanada · Jul 10, 2009

Digital camera's do not have as much exposure latitude in over exposed areas, but they do have great dynamic range in under exposed areas.
Digital sensors clip highlights quickly, so they will have a tendency of losing data there ... +5 stops would be the top end with higher end DSLR's ... and -10 would be the bottom.

Addition: most DSLR's have a 8 stop dynamic range ... +3 to -5

The best rule for Digital exposure = under expose to retain the Highlights ... then edit the image to bring up the darker areas.

dxqcanada · Jul 10, 2009

... for those of you that have shot film ... expose like you are using Slide Film.

JerryPH · Jul 10, 2009

The reasons questions like this come up is simple lack of understanding of the basics and the limitations of cameras. I suggest you look up The Zone System for digital cameras, once you understand that, your question will be answered.

There are basically 2 ways to do it. Lately, I find way too many people depending on HDR when it can easily be done if you know how to control light. People like HDR becuase t takes no real effort, and the results can be quite acceptable. I just see it as a crutch to fill in for lack of knowledge or understanding. Now HDR can do some really funky shots, and often, I like the look... but when someone is trying to overcome a PHOTOGRAPHIC challenge and using HDR as the answer... well I prefer the method that lets me avoid it. Call me a purist, I don't mind.

Me, I don't want to control the picture in photoshop or photomatix... I want to do it in such a manner that as soon as I click the shutter... it is done.

When you have 2 areas of such extremes such as a ery bright background and a dark foreground, you can use reflectors, lights, strobes or speedlights. In my example, I used a single battery powered speedlight set to 1/2 power.

If I expose for the outside only, this is what I get:

If I expose for the inside, this is what I get:

If I expose for the brightest part of the scene and use flash to balance for the ambient, these are the results:

I have rich tones outside and clear rich range of exposure for the inside.

Now, common sense says that I cannot light a whole forest like this, so, I still have control over the light with knowledge.

1. I can wait until the light drops a bit in the afternoon to get a better balance

2. I can control a smaller area of my shot using 1 or more speedlights

3. I can use reflectors to bounce the light into the areas that I need for fill

These are just a couple of possibilities, and there are many, many more.

My point being, digitally manipulating images is all well and cool... and I am 100% all for it. However, this is photography, and should we not use the knowledge of photography to give us the answers first and leave all the other tools in the box for the times that we are limited?

An example would be if I was trying to take a shot of a huge expanse of forest with nothing more than a camera and it is noon on a VERY bright day, then some subtle HDR or tone mapping would be a solution if you had no flashes to fill in the darker shadowed areas.

SrBiscuit · Jul 10, 2009

wow jerry....nicely done!

hao · Jul 10, 2009

Thank you guys for the input, which is really helpful. And yes I am still reading a book about exposures: "Understanding exposures", which I think is a great one. Any other books you think are great?
Jerry, your pic is great!:thumbup: and your explanation is very helpful. Thank you!!

Jon_Are · Jul 11, 2009

way too many people depending on HDR when it can easily be done if you know how to control light.

So, by controlling light, what you mean is to add artificial light.

HDR is not a crutch or a gimmick, but a legitimate technique that allows the photographer to utilize natural light to get a natural-looking exposure. (I'm not talking about cartoon-y shots of sports cars or Times Square).

Different strokes, and all that, but with properly rendered HDR, you would have had a beautifully exposed scene - using natural light - and you wouldn't have had those shadows from the vase, flowers, clock, curtain rod and curtains.

Oh well, whatever floats your goat.

Jon