Learning Landscapes - Bracketing and Multiple Exposure Functions

[Brownbear]

I wonder if someone could simplify/clarify the use of bracketing and multiple exposure functions in camera in terms of their use for landscapes.

Bracketing... I understand its usefulness as being able to take several exposures of one scene, in order to expose correctly for both the sky and the land and combine in PP for the perfect exposure.

Multiple Exposure....

In Bryan Peterson's book Understanding Exposure this function is used for a landscape of flowers with a wee bit of camera movement to create a sense of movement and produce richer colours in a flower landscape.

On my Nikon D7100 camera if one selects auto gain, the camera automatically combines the photos which appeals to me because it minimizes post processing.

The Nikon D7100 manual it states that multiple exposures produce colours noticeably superior to software-generated photographic overlays created from existing images.

It also states that the amount of gain is adjusted according to the number of exposures actually recorded (gain for each exposure is set to 1/2 for 2 exposures, 1/3 for 3 exposures etc....) It is not clear what Gain is but I expect it is referring to exposure compensation? And if that is the case I would think that if I set my Auto Gain to 6 exposures it would take 6 images at different exposures (albeit very small differences in the exposure increments as compared to -2,-1, 0, +1, +2 say in bracketing) and combine them in one image, in camera?

ie; This morning while photographing mountain landscapes I was thinking that the use of the Auto Gain function would combine a series of images into one image producing richer colours and a more balanced exposure, but I'm not certain if this is the case (ie. the varying exposure part is not obvious in the viewfinder)

Also in the camera manual it states that in continuous high-speed or low speed release modes that the camera will continue to produce multiple exposures while the shutter-release button is pressed. Will this work the same way with a remote release?

The manual also states that if single photo is selected, multiple exposure shooting will end after the the first photograph, which I presume means that if I press the shutter release button just once my camera will take and combine the number of images I have input into the auto gain mode, until I turn off the auto gain function?

The manual has no reference to what happens when one uses multiple exposure with auto gain in the mirror-up mode?

I realize that is a lot of questions but I'm trying to learn about all the features on my camera and understand the practical use of the multiple exposure mode on my camera in terms of landscapes, and neither my camera manual or my reference books explain it clearly.

In brief, I would like to know the uses of Multiple Exposure in landscape photography.

Thank you.

[CBImages]

Wow what a lot of questions Christine, let's look at them 1 at a time.

1) Gain?
I have to say I haven't heard the term 'gain' used in relation to stills photography, as I understand it gain is a way for the digital circuitry to amplify a video signal to make it brighter. Are you sure you weren't looking at the 'video' section of your camera's handbook?
I may be wrong but just check it again to make sure.

2) HDR
Is used, as you correctly describe, to make sure you capture the full range of tones in a high contrast scene ie all the details in the bright highlights and all the dark shadow detail, then combine these images into one.
You usually select how many exposures you camera will take (1, 3, 5, or 7) and how big the exposure compensation will be between each exposure (usually 1 stop or 2 stops). If you take 5 exposures with a 2 stop difference between them your images will effectively be +4, +2, 0, -2, -4.
I usually set my camera on a tripod, set for high speed continuous shooting, start live view and then depress my remote release. I use live view to prevent the mirror slapping open and shut between exposures and thus risking camera shake. I keep the remote pressed and count the 'clicks' of the shutter and then take my finger off after the 5 exposures have been taken.

When you upload your 5 bracketed exposures to your computer you have a choice of how to blend them together, the easiest would be to use Merge to HDR in Photoshop or you could use a standalone application like Photomatix.

There really is so much to go into but I would advise that you will learn so much more by just going out and trying it for yourself than reading about it. You have the basics, just enjoy yourself and experiment - then post your results so we can see how you are getting along. Of course we can try to answer your questions too!

Happy snapping

[Brownbear]

Hi Chris,

Yes, likely too many questions. Thank you for your reply.

Multiple Exposure and Auto Gain is definitely in the photography mode and also described as photography in Bryan Peterson's book titled Understanding Exposure... I think it is unique to some Nikon cameras and a few others.

See the paragraph titled Multiple Exposure

http://www.imaging-resource.com/PRODS/D7000/D7000A5.HTM

Here is another link explaining the multiple exposure mode

http://www.ephotozine.com/article/mu...ndscapes-13401

To the best of my understanding it is similar to HDR but not the same but I imagine that it works similarly so your explanation of HDR is helpful. I will print it and save it for the day I try HDR.

Thank you.

[CBImages]

Ah it's 'Multiple Exposure' - basically you are taking 1 exposure on top of the other.
Say you are out at night and want to take a photo of the moon as it crosses the sky, you can take 1 exposure with the moon in one position, then wait a period of time and take a second image with the moon in another position. The camera then superimposes one image on top of the other.
It isn't anything you can't do in Photoshop but it just happens 'in camera' and the 'gain' refers to the way the two images are blended together.

Here is a quick tutorial I found for you :- http://www.lightstalking.com/shootin...aits-in-camera

Hope it helps

Chris

[Brownbear]

Hi Chris,

Yes. Thank you. The link you provided is informative and helpful. I experimented with it this morning just to gain a basic understanding of this camera function. It is not what I thought it was but very interesting indeed.

Ah it's 'Multiple Exposure' - basically you are taking 1 exposure on top of the other.
Say you are out at night and want to take a photo of the moon as it crosses the sky, you can take 1 exposure with the moon in one position, then wait a period of time and take a second image with the moon in another position. The camera then superimposes one image on top of the other.
It isn't anything you can't do in Photoshop but it just happens 'in camera' and the 'gain' refers to the way the two images are blended together.

Here is a quick tutorial I found for you :- http://www.lightstalking.com/shootin...aits-in-camera

Hope it helps

Chris

[NorthernFocus]

Christina, I believe the multiple exposure you are refering to is essentially an in-camera HDR process. The camera combines multiple exposures into a single image by selecting the mid-tones from each image and combining them. That's basically HDR. I read through the manual when I first got the camera and am aware of the functions but haven't tried them. I'd suggest doing exactly that. You don't have to wait till you're out in the field. Just set up the camera on a tripod in your living room or in the back yard and fire away. That's one of the beauties of digital. You can experitment to your heart's content and get immediate answers.

The use of the term gain is odd. Basically the ISO setting in digital cameras is in fact a gain adjustment in the image sensor circuitry. The typical usage of the term gain refers to adjusting the sensitivity/amplification in electronic circuits. When you increase the ISO setting in a camera you are basically making the sensor more sensitive to light by turning up the gain. But I have no idea why Nikon that term is being used in the context that you describe. Now I'm curious and will have to look up that section of the manual.

[mknittle]

Christina, I find it much easier to remember things if I do them one step at a time and move on to the next. occe fimilar with the next step I go back and work my way from the beginning.

[NorthernFocus]

In typical Nikon fashion, the manual was not what I'd call "illuminating" on the multiple exposure topic. But the other sources you quoted did help. Seems that the multiple exposure mode is intended to allow multiple exposures in the traditional sense (i.e. capturing motion, multiple subjects in a scene, etc.) but applies processing similar to HDR to avoid blowing highlights/lightening shadows. One of the sources states that with "gain turned on" the exposure averaging takes place to protect shadows/highlights. With it off, it simply adds the pixel values to those on the image "below".

[Brownbear]

Hi Dan,

Thank you. I think it is different than HDR and while I now understand that one could take a photo of the moon on one side of the vista and the mountains on the other side of the vista, and that the images would be combined in-camera automatically. I also thought(perhaps I was just wishful) that this mode might work something like HDR and combine exposures to offset the dynamic range, ie; expose for the sky and the land a little better than just one shot, with extra rich colours. ie; like bracketing with the camera combining the different exposures but that does not seem to be the case.



Yes, my experiments using this mode destroyed a beautiful sunrise. Lesson learned, experiment at home before trying in real life.

Thank you for explaining the real meaning of gain. Appreciated.

Christina, I believe the multiple exposure you are refering to is essentially an in-camera HDR process. The camera combines multiple exposures into a single image by selecting the mid-tones from each image and combining them. That's basically HDR. I read through the manual when I first got the camera and am aware of the functions but haven't tried them. I'd suggest doing exactly that. You don't have to wait till you're out in the field. Just set up the camera on a tripod in your living room or in the back yard and fire away. That's one of the beauties of digital. You can experitment to your heart's content and get immediate answers.

The use of the term gain is odd. Basically the ISO setting in digital cameras is in fact a gain adjustment in the image sensor circuitry. The typical usage of the term gain refers to adjusting the sensitivity/amplification in electronic circuits. When you increase the ISO setting in a camera you are basically making the sensor more sensitive to light by turning up the gain. But I have no idea why Nikon that term is being used in the context that you describe. Now I'm curious and will have to look up that section of the manual.

[Stagecoach]

Yes, my experiments using this mode destroyed a beautiful sunrise. Lesson learned, experiment at home before trying in real life.

Hi Christina,

That is a very important observation/statement you have made. For experimenting and trialling there's no need to go far to find a suitable subject generally.

Grahame

[Mike Buckley]

Christina's Nikon D7100 has an HDR capability that is distinctly different from the multiple-exposure capability she is asking about. So, it's reasonable to assume that the multiple-exposure capability does not function as HDR.

[Manfred M]

Wow what a lot of questions Christine, let's look at them 1 at a time.

1) Gain?
I have to say I haven't heard the term 'gain' used in relation to stills photography, as I understand it gain is a way for the digital circuitry to amplify a video signal to make it brighter. Are you sure you weren't looking at the 'video' section of your camera's handbook?
I may be wrong but just check it again to make sure.

Technically this is quite correct as the camera's sensor has an amplifier circuit built into each individual sensor element. When increasing the camera's ISO setting one is turning up the gain. I'm really not sure why video and still cameras use different terminology for doing the same thing.

[jcuknz]

Hi Dan,

Yes, my experiments using this mode destroyed a beautiful sunrise. Lesson learned, experiment at home before trying in real life.

Not aginst experimenting at home but rather if you do experiment in the field you also make a back-up using proven methods'

So often we read of people thinking they will get some new equipment for an occasion and it is obvious they will not have time to practice with it.

[Brownbear]

Thank you to everyone for your replies... I reviewed my experimental photos and indeed they were very interesting... Two suns in some images, super dense clouds and even what look like double and triple clouds, and indeed the clouds do convey a sense of motion.

I think if the multiple exposure function was a useful tool for photography by now a lot of people would have jumped in to say they use it etc... I will just chalk this up as another learning experience and one more camera mode that I know at least a wee bit about. I expect that the only thing I might every try it for would be a flower landscape as in Bryan Peterson's book... for the sense of motion and colour.

For anyone who does have any interest here is a thread that I found on the topic.

http://www.nikonians.org/forums/dcbo...90&page=#23291


A big thank you to all.

[rpcrowe]

Christina,
Just a comment on one segment of your post...

"Bracketing... I understand its usefulness as being able to take several exposures of one scene, in order to expose correctly for both the sky and the land and combine in PP for the perfect exposure."

Correct but, auto exposure bracketing (AEB) is not just for acquiring exposures to be combined into a single high dynamic range image. Bracketing can be used to ensure that you have at least one optimally exposed image when shooting in chancy exposure situations.

This was a matter of course for many professional photojournalists of the past when shooting important jobs, especially when using the old Kodachrome roll film which had ASA (same as ISO) levels as low as 12 (that's right "twelve", no typo there) and virtually no exposure latitude at all. It was pretty well restricted to photographers who had a high budget for their shoots because it increased the film and processing costs by a factor of three. It was also a pretty tedious way to shoot because each exposure change had to be done manually. Additionally it required the photographer to carry a large bulk of film.

Today's DSLR cameras (and I think a few bridge cameras) have built-in auto exposure bracketing that will adjust the shutter speed, aperture or both to give you one exposure below the meter reading, one exposure at the reading and one exposure above. The amount of difference in exposure can be selected by the photographer up to the limits of the camera. My 7D allows up to 3-stops between each exposure. You can also combine AEB with exposure compensation which is great for snow scenes or night scenes.

All Canon DSLR cameras, some Nikon DSLR cameras and perhaps cameras of other brands have the ability to, when auto exposure bracketing and burst mode is selected, fire three or more (depending on the camera model) bracketed exposures each time the shutter is pressed and then stop firing until the next time the shutter button is pressed.

In addition to ease of shooting the digital camera allows you to shoot many exposures at no cost. Memory is pretty inexpensive these days...

AEB is also a pretty valid way to ensure that you come back with correct exposures when you are on a once in a lifetime trip. Additionally it is a good way to learn exposure control by seeing which types of scenes do well at the meter readings and which type scenes benefit from increased or decreased exposure.

[Brownbear]

Thank you. Good to know.

[Brownbear]

Hi Richard,

I tried auto bracketing yesterday on a mountain, cloud, sky and water scene. I used exposure compensation ie; exposure as set, and then with plus 1 and minus 1. I just noted your comment on obtaining different exposures by setting the aperture and shutter speed. Wouldn't this cause problems with different DOF and movement in leaves and clouds? Did I do this wrong by using exposure compensation? In camera the exposures look as they should. ie; one exposed fairly well, one with the sky blown and one with dark clouds....

When I get around to uploading the files, do I post process each raw file in LR to make the best of each, and then merge the jpegs in Elements 9?

Or do I change the raw files to dng files in LR, and then open in Elements 9 and merge the raw files as is into one perfectly exposed image?

When I combine the images are they going to have that very heavy look as is created with HDR and multiple exposures? ie; dense clouds.

My apologies for all the questions but now that I have tried bracketing I'm not sure what to do with the images in PP.

Thank you.

Christina,
Just a comment on one segment of your post...

"Bracketing... I understand its usefulness as being able to take several exposures of one scene, in order to expose correctly for both the sky and the land and combine in PP for the perfect exposure."

Correct but, auto exposure bracketing (AEB) is not just for acquiring exposures to be combined into a single high dynamic range image. Bracketing can be used to ensure that you have at least one optimally exposed image when shooting in chancy exposure situations.

This was a matter of course for many professional photojournalists of the past when shooting important jobs, especially when using the old Kodachrome roll film which had ASA (same as ISO) levels as low as 12 (that's right "twelve", no typo there) and virtually no exposure latitude at all. It was pretty well restricted to photographers who had a high budget for their shoots because it increased the film and processing costs by a factor of three. It was also a pretty tedious way to shoot because each exposure change had to be done manually. Additionally it required the photographer to carry a large bulk of film.

Today's DSLR cameras (and I think a few bridge cameras) have built-in auto exposure bracketing that will adjust the shutter speed, aperture or both to give you one exposure below the meter reading, one exposure at the reading and one exposure above. The amount of difference in exposure can be selected by the photographer up to the limits of the camera. My 7D allows up to 3-stops between each exposure. You can also combine AEB with exposure compensation which is great for snow scenes or night scenes.

All Canon DSLR cameras, some Nikon DSLR cameras and perhaps cameras of other brands have the ability to, when auto exposure bracketing and burst mode is selected, fire three or more (depending on the camera model) bracketed exposures each time the shutter is pressed and then stop firing until the next time the shutter button is pressed.

In addition to ease of shooting the digital camera allows you to shoot many exposures at no cost. Memory is pretty inexpensive these days...

AEB is also a pretty valid way to ensure that you come back with correct exposures when you are on a once in a lifetime trip. Additionally it is a good way to learn exposure control by seeing which types of scenes do well at the meter readings and which type scenes benefit from increased or decreased exposure.

[Loose Canon]

Hi Christina!

Sorry I’m late (as usual). Sorry I can’t add anything (as usual). But that never seems to stop me (as usual)!

Compositing (which is what you are looking at) is (for me) a very cool and essential option.

When I shoot bracketed (auto, or AEB), I always shoot in Av to keep the DoF consistent. Also, I keep the ISO set at whatever I want it set at (as opposed to any "auto" setting). And always on a tripod. Set the number of shots I want (usually 3-5) and what different exposures I think I might want. A lot of times a single stop difference (-1, 0, +1) will do it. To help figure out what you may need just get a meter reading on the brightest and darkest areas of the scene before you shoot the bracket and see what how they meter compared to the overall average.

So using Av and keeping the ISO constant, the determining factor of the multiple exposure values will always be the shutter. Hence the tripod and also so that the point of view doesn’t change for the bracketed shots. Its way easier to combine later if your shots are consistent.

When I bring the RAW’s into ACR I adjust them pretty much consistently. This is where I work on each shot for compositing. Whatever WB, etc. I choose I carry over all the bracket shots in ACR. A lot of times I’ll batch process them. I’ll (hopefully) have consistent shots (except for the exposure values, of course) to head on into my editor to work with.

I haven’t checked Elements (I have v6 which is way behind what you have) but I try to first combine in Photoshop by layers/masking. I also have a copy of Photomatix which I like for some brackets, but I always tone it way down to keep it from looking over-nuked. I typically do the merging of the brackets first, and then merge all visible layers to add the finishing touches to a single layer same as I would any single shot (keep layering as needed from the merged layer which will be your new starting point to further edit your merged brackets result).

I shoot a lot of landscapes bracketed, but I also do a lot of composites (which is what a merged bracketed scene is) in the studio.

I’d have to go into my Olde Tyme version of Elements (v6) to see what could be done but I know for sure its possible because I have done it before. Just been a while!

This is a bracketed landscape composite (three shots bracketed at a 1 stop difference pre-processed in Photomatix and then on into Photoshop):



An archetecture composite, same exposure values with each shot, but with different lighting zones (this was around 16 differently lit shots composited):



This is also a merged composite from the studio: (same exposures, different lighting zones, same concept of compositing):



I haven’t used multiple exposure much in practical use yet (either the in-camera feature or manually). So I couldn’t say much about that. But what I do know is that it is a compositing technique only done in-camera.

What to do with them? Of course you want to get the best areas of each shot to produce the end result.

How to do that? Several options (techniques) available. Depends on what you want for your result.

Perhaps if you post some bracket sets some Knowledgeable Soul will blow in and help you work your way through! If not, nothing lost, eh (Canadian for “huh” which is Missourian for “eh”!)?

[Brownbear]

Hi Terry,

Thank you for your detailed and very helpful reply. A printer reply for sure! (ie for my future reference)

All beautiful images, and I would never have guessed that the glass image was a bracketed shot.

I tried bracketing for the first time a few days ago, using Aperture priority, iso 100 (fixed), 3 shots, one just right, plus +1 and -1. Mirror up and remote release.

I googled the subject and sort of figured it out, processed in LR (for the sky in one image and the trees in the other) and then merged the layers in Elements 9 (thanks to you I'm becoming more familiar with layers)

However my result looks very nuked, which to me means that the sky and land look heavy, overly dense.... ie; not natural

F18 SS 1/13 iso 100

Nuked image (combined exposure)



Middle Exposure (more natural)



Neither image captures the true beauty of the scene and lacking foreground because of an ugly fence in the foreground (although next time around I am going to climb the fence)

Can you tell from my image what I did wrong in PP when combining?

Thank you.

[ajohnw]

Colin might chime in here Christine. I doubt if there was any need to take 2 or more exposures for merging when they are that close together. It's possible to get that much variation from a single raw file even more at the dark end. Adjusting the contribution from each image will be fun too.

What I tend to do is make sure I get a realistic shot of the sky and it's clouds especially the clouds. Bracketing can be used for that. I would go for perfect clouds in the jpg preview with no clipping at all. I am not sure what you are after but very quickly did this.




I took your middle exposure and used curves to bring up the dark area as much as I could without spoiling the sky.Mid tone to highlights left as is.I Then used a brightening brush on the highlights in the trees to the left set to mid tones. Next the same on the trees to the right plus the beach except mid tone darkening this time.

Decided that the trees in the distance needed a bit more definition so did that with mild tone mapping which also emphasised the gradation in the clouds to what I feel is an acceptable level and last a very weak unsharp mask to define the trees a little more. The tone mapping could be skipped and more brightening brush used I suspect but it also part gets round the effects of mist.

If you haven't got anything to clone out the fence install the GIMP but don't use it until you are happy with all other aspects of the image. On the other hand if working from a jpg the curves adjustment could be done there.

The problem with this landscape shot is that our eyes adjust as we look around at individual areas in the scene with our central vision..The eye has a huge dynamic range. You could adjust this image to mimic that I suspect.

You could handle the curves part from raw. Raw conversion software usually has it. It's normally preset to a straight line from black bottom left to white top right. In this case you would add a point in the middle of the line, usually by clicking it and then drag the bottom left up and down till you get what you want. Best way to find out how to use it is to play with it but frankly your camera is easily capable of producing a jpg that could be processed more than the above one needs especially at the dark end. Best find out what your camera can do as per this recent thread but frankly I wouldn't try and compensate for raw if you use the histogram for exposures. Some latitude at that end is a good idea.

What do you meter off of when the scene is not evenly lit in landscape?

As to merging this might amuse you. From one raw file and had specular highlights. When the difference is this great that is the time to merge shots. Bracketing for that would 3 + stops. Most cameras will capture 12 stops that can be bought out with PP.

http://www.flickr.com/photos/4899461...7631399852866/

I could add more water detail to the final image but the duck was back lit after all. I like realism too.

PS I often put any old junk on flickr. I suspect I will remove lots of them at some point.

John
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