Problem with exposure range

JeremyHopper · May 22, 2007

Hi, I've been doing digital photography for a few years now and have gotten around the basics and all without many problems. I've been completely satisfied with my work up until recently where I've been paying more attention to detail because I'm going to be doing some landscape photography, mainly autumn and winter oriented shots.

I've noticed that when I take a picture with exposure metered to a foreground object, let's say a tree, the exposure is WAY off for brighter objects like the sky and such. When I take a picture metered for sky exposure then the foreground objects are really dark! I've read that this is dynamic range and that digital cameras have the lowest dynamic ranges of imaging equpiment, with the human eye having the most dynamic range. Does this mean I have to switch to film photography to get the shots I want? Here's some examples of what I mean:

In this shot, the trees are fine, but the sky is washed out.

In this shot, the sky looks great, but look how dark everything else is!

I know for a fact that this picture was taken on film, and I know that my camera would not be able to take this picture. Number 1, either the sky would be washed out or the ground would be too dark, and Number 2, I wouldn't be able to get the right exposure. (see below)

I've found that when I change a stop in exposure trying to get it right it's very drastic. It makes it impossible to get the correct exposure. I've also heard that changing a stop on a film camera is not as drastic. Do I need a better camera? Is my metering system out of whack? I'm using an Olympus E-500 with 8 MP. Could shooting in RAW format help in any way? Any help would be greatly appreciated. If you guys need any more information just ask. Thanks!

ksmattfish · May 22, 2007

I don't know the specifics of your camera, but most of the DSLRs with an APS-C or larger sized sensor have a similar dynamic range as color negative film, at least when shooting raw. Even if people want to argue that neg film has a stop more dynamic range, that's not enough to solve your problem. Many film landscape shooters are using transparency films, most of which have even less dynamic range than neg film or DSLRs. You would have similar problems with film.

Some solutions:

Shoot near sunrise or sunset: the sky is darker then

Neutral density filters: allow you to block some of the exposure of the sky

Polarizing filter: will darken blue sky

Post processing: adjustments such as the Shadow/Highlight filter in Adobe Photoshop

Exposure blends and HDR: take multiple shots of the same subject exposing for different parts of the scene, and then combine them yourself or with software actions in post processing

BW neg film probably has close to twice the dynamic range of most DSLRs, yet because of the ease of very precise, digital post processing tools I am often able to make final prints via Photoshop that have the appearance of more dynamic range than I am able to get out of my traditional BW darkroom.

JeremyHopper · May 22, 2007

Interesting. I have found that around 4 or 5 in the afternoon the sky is better. I have tested out HDR photography and the results... well I'm working on that, right now it's less than spectacular. A graduated ND filter might be the answer for some of my shots, I have looked into that. I know I HAVE to get a polarizing filter. I've always wanted one. I will experiement shooting in RAW. I'll post if the results are any better. Thanks for your reply!

ksmattfish · May 22, 2007

Another solution would be to use a flash to light the foreground.

JeremyHopper · Jun 4, 2007

Well I finished testing out things with the RAW files with not much of a difference. Thanks for all your help!

EOS_JD · Jun 4, 2007

JeremyHopper said:
Interesting. I have found that around 4 or 5 in the afternoon the sky is better.

best times to shoot is in the hour after sunrise and in the hour before sunset.

EOS_JD · Jun 4, 2007

JeremyHopper said:
Well I finished testing out things with the RAW files with not much of a difference. Thanks for all your help!

Learn how to post process. You may need to make more than one coversions of the RAW file and merge them using layer masks.

Alternatively it will be better to take 2 or three shots of the scene (exposed for both sky, midground and foreground) then merge in photoshop.

fmw · Jun 4, 2007

There are limits to the dynamic range a camera sensor can record. One way to deal with it is to use HDR (high dynamic range) post processing. This method takes a number of exposures something like the first two above and then combines the exposures into a single image. It requires a motionless subject and a tripod, but it is a way to record a subject with an extreme dynamic range in way that film could never do.

Without such a technique you need to decide which result you want and expose for it, just like you did.

The best time of day to shoot, by the way, depends on the subject and the desired result. Time of day isn't a solution to a high dynamic range problem.

EOS_JD · Jun 4, 2007

fmw said:
The best time of day to shoot, by the way, depends on the subject and the desired result. Time of day isn't a solution to a high dynamic range problem.

Sorry FMW - you are quite right

JeremyHopper · Jun 5, 2007

I know, and don't think dynamic range was my problem. I've seen HDR pictures and the contrast is really low.

Sw1tchFX · Jun 5, 2007

JeremyHopper said:
I know, and don't think dynamic range was my problem. I've seen HDR pictures and the contrast is really low.

That's what more post-production is for. You don't' just use an HDR images straight out of Photomatix or whatever other software you would be using. All my HDR's are high contrast, becuase I go through a step by step process for my HDR photographs.

for something like this, HDR is the way to go.

JeremyHopper · Jun 29, 2007

Sw1tchFX said:
That's what more post-production is for. You don't' just use an HDR images straight out of Photomatix or whatever other software you would be using. All my HDR's are high contrast, becuase I go through a step by step process for my HDR photographs.

for something like this, HDR is the way to go.

I have thought about that. I'm still looking into it though.

Garbz · Jul 1, 2007

RAW will not increase dynamic range, just colour detail. This helps in that if you take a picture exposed for the sky (highlights) in RAW, you can suck some foreground detail out with the curves tool in photoshop. But there is limits to this and you'll be amplifying noise as well.

The picture number 3 can easily be done on a digital camera. Look at the lighting. In 1 and 2 you are shooting against the setting sun. In 3 the foreground is lit by it. Furthermore the sky looks like a polarising filter has brought it down a bit. It's not a matter of film vs digital here, but rather how to solve the pesky problem of dynamic range that both must fight. I personally don't like the HDR way. I have yet to get a decent HDRable photo. I prefer to change angles or play with strobes or reflectors to brighten the subject in my photo.

glaston · Jul 6, 2007

I personally don't like the HDR way. I have yet to get a decent HDRable photo.

What do you mean by "HDRable"?
There's a formula for generating an HDR image. You basically have to calculate the number of exposure levels needed by taking a measure of the brightest highlights to the darkest shadows.
You also have to end up with a 32bit floating point image for the full dynamic range to be preserved in the image.
Simply compositing 16 bit images of different exposures won't generate a true 32bit float HDR image. It will clip the values to fit within the dynamic range of 16bits per channel.
You have to specifically generate an HDR image using an application that can combine the different images into the 32bit float mode, and save to an actual HDR file format such as OpenEXR, .hdr, or radiance.

If I have misunderstood your point, sorry.
I don't know what you mean by "HDRable".

jon_k · Jul 6, 2007

I've got an E-500 8mp as well.

These are general challenges of photography. It's not because the camera isn't good enough. I'm sure even a film camera could have had similar results with those pictures.

In a situation like your first two photographs, you as a photographer and artist should pick on what is important. You can't get the best of both worlds, the camera will expose for the sky or for the landscape. There's compromises though. Like a graduated ND filter, or a polarizer. An HDR would help as well. Maybe if you find a middleground between underxposed landscape and overexposed sky, then you could tweak the rest in Photoshop. All these variables are part of the challenge of making well exposed photograph.

I've got a polarizer, and a GND filter for my e-500 and sometimes those help in a situation such as this. A polarizer wouldn't have helped you here as it seems the sun wasn't at a 90 degree angle, or close to it. A GND might have helped. If you made an HDR, it would have certainly helped.

The biggest problem was the sun was setting, which made available light on the landscape very low, but plenty in the sky. Thus, you'd expose for the landscape and get a blown out sky... if you exposed for the sky your landscape would be dark. A graduated ND would have helped make the sky darker, so the landscape could more properly expose. I'm sure some combination of GND filter could have done it for you in this shot. Better yet, a HDR would have done better I think.

Disclosure: I consider myself a major amateur still learning the basics... but from what I have read on here and applied in the field, what I have said makes sense to me.

Ignore anyone on here who says "If you want an amazing picture, you need an amazing camera!" Amazing pictures were taken by Ansel Adams and the like who have used cameras were more simple then a disposable from Wal Mart. It just takes passion, good lighting, and some good composition, a tad of luck, and a beautiful subject!