Learning Landscapes - Bracketing and Multiple Exposure Functions

[Downrigger]

Christina: Great discussion/responses
John: Can you meter off different luminosities in your field of difference and infer from differences in EV when you would benefit from merging/HDR? By implication, your comment suggests that would be around 12 stops. (a lot).

[arith]

I think it is something you can work with, but normally I take three bracketed photo's with the first banged up to the right with exposure. But you photo is actually quite nice.

[ajohnw]

Christina: Great discussion/responses
John: Can you meter off different luminosities in your field of difference and infer from differences in EV when you would benefit from merging/HDR? By implication, your comment suggests that would be around 12 stops. (a lot).

Getting 12bits out of raw is a fair amount of work. Usually only small parts of a shot need it. On this shot that might be the very dark part of the trees at bottom left. They might even be clipped due to how the raw was converted or because they are beyond the scope of the camera. If they aren't clipped that can be bought up locally.

As to real HDR it somewhat depends on the approach. To keep it simple say 3 jpgs are produced exposing 3 parts of what ever perfectly Say the exposures happened to be 2 stops apart. These shots could be merged so that the perfect jpg exposure applied to all of it and it would look nothing like what most people would consider to be an hdr shot.. What I find though is that when the exposures are that close they can be difficult to merge and even more so if 1 stop apart as the contribution from each image has to be adjusted. It tends to work at it's best when when the differences are large and also needed but some do it even if not needed. Watch this video to see what I mean.

http://www.youtube.com/watch?v=tHzlmK-S8vo

Gimp but any layer type package can do that sort of thing.

There is no answer to how many EV's the shots should be spaced at but clearly if 12 can cover or nearly so plus or minus 12.would capture very little or nothing at all. As to scanning the scene with a meter I have never found that to be much use. The histogram however does that for you. I suppose some one could increase the exposure by 1 EV at a time and see at what point the left of it showed zero light levels. A conversely but decreasing the exposure and looking at the other end of it, I have my doubts if that would actually work but might be worth trying.

Personally I have only played around with HDR and from that feel that 3 EV is a minimum and a waste of time unless it's needed. In the case of this scene I suspect 2 exposures would be adequate. One good clouds and one shadows but merging might be fun. Going on the appearance of shot Christina could try that. Go back to the raw and produce a good cloud exposure and another for the shadows. That can be done with the exposure compensation. I suspect there maybe 2 EV difference and that should take out a lot of the cloud on the one for the shadows. Then spend some time adjusting the contributions to the final image. It's also possible to adjust each of the images individually. The shadow shot might be more suitable if curves are used to kill the brighter tones even more..

Answering the original question I suspect 1 EV wasn't (might just be the raw conversion) enough and mainly the merging didn't go well. I am not convinced that having 3 shots helps with that aspect when the exposures are that close.

Some time like the ones I linked to on flickr it's easy to merge them. The duck is near black in the water exposure and the water is white in the duck exposure. From memory that is about 3 EV difference from the same raw file. Just quicker and more effective than trying to use curves or carefully adjusting each with a brush. The trouble with curves is that when the black end is lifted the slope of the line changes so the contrast is reduced. Contrast can be used to expand it again but in real terms if all 12 are needed local changes are needed. I think this sort of answers your question.

Most seem to go along the lines of the video. They want an un natural shot but the same technique can be used to improve things too.

John
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[Brownbear]

Hi John,

Thank you so much for your detailed reply and advice. This is my first true try at bracketing an image, and also my first try at putting together such an image. I am also working on my post processing skills so this is a lot for me to absorb and learn.

I don't have much time as some business and personal matters require that I leave for Mexico in a couple of days, and I don't know how long I will be away... But as soon as I return I will revisit this photo and this locale for another try at this shot... It was a beautiful scene... I like your edit far better than mine and since I have the raw file I should be able to do much better and will do.

Interesting thread, and I adore the high key duck... Something else I have to learn to do...

Truly appreciated.

Thank you.

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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[Brownbear]

Hi Steve,

Thank you... It was a first try and obviously I was a little lost... your edit captures the beautiful light that I was trying to capture far better than I managed which means I mucked something up.. The clouds are still too heavy but I will figure that out... I will save this photo and revisit later to edit... Truly appreciated.

I think it is something you can work with, but normally I take three bracketed photo's with the first banged up to the right with exposure. But you photo is actually quite nice.