Auto Exposure Bracketing vs Post processing

[cauger61]

These are my recent attempts with landscape photography (Nikon gear D5300). I am disappointed with the photographs but unable to diagnose where the problem lies. The images are overexposed and they have focusing issues as well. My queries are: where do the catch lie. Was that with the shutter speed in relation to focal length (the inverse rule) or was that due to 18% grey rule or what? What else I should have done? Could auto-exposure bracketing have saved the situation? Or should I have used ND or CP filters? Can these images be fixed in post-processing, say by Lightroom?


https://tva1.sinaimg.cn/large/006y8m...31900u0kjs.jpg
EXIF: P* mode; 92mm [70-300mm f/4.5-6.3 nikkor]; iso Auto; 1/320; f/7.1; Exp. comp: 0;


https://tva1.sinaimg.cn/large/006y8m...31900u0he4.jpg
EXIF: Landscape mode; 35mm [35mm f/1.8g nikkor]; iso Auto; 1/400; f/11; Exp. comp: 0;


https://tva1.sinaimg.cn/large/006y8m...31900u0qvg.jpg
EXIF: Landscape mode; 70mm [70-300mm f/4.5-6.3 nikkor]; iso Auto; 1/200; f/10; Exp. comp: 0;

[DanK]

Sanjib,

I think you are asking the wrong question. You are asking which tools to use without first asking which problems you want to solve.

For example, you asked about bracketing. What problem would you be trying to solve by bracketing? Bracketing is used when the dynamic range of the scene--darkest to lightest--exceeds the capacity of the camera. When that happens, you have whites or blacks that lose detail. There is no evidence of that in your photos. In fact, quite the opposite. Here is the histogram of your beach photo:



This shows that the dynamic range of the photo is somewhat limited and that you are not getting truly dark areas.

And that in turn points to one of the problems with these photos: they lack dynamic range and contrast. This has nothing to do with the inverse rule, which is to avoid motion blur. It also has nothing to do with where you focused.

So, I think you need to start by asking a different set of questions. What specifically do you think is a problem? Only after you identify specific problems can anyone tell you what tools to use to fix it.

To illustrate this, I did a very quick and incomplete edit of the beach photo in Lightroom. First, I leveled the horizon. Then, using the curves tool, I pulled up the black point (moving the bottom of the line to roughly the left edge of the histogram). then I used the same tool to add contrast, pulling the darks down a little and the lights up somewhat more. Because all of the images are hazy, I added a slight dehaze adjustment. Because that darkens images, I then increased the exposure slightly.

Note that with the exception of leveling the horizon, all of these adjustments were aimed at the same problem: the lack of "pop" because of the limited tonal range.

I hope this helps

Dan

[cauger61]

This shows that the dynamic range of the photo is somewhat limited and that you are not getting truly dark areas.

And that in turn points to one of the problems with these photos: they lack dynamic range and contrast. This has nothing to do with the inverse rule, which is to avoid motion blur. It also has nothing to do with where you focused.

Thnx Dan. Can you pls. tell me what I should have done at the time of shooting so that those post-processing issues would not have arise at all? Also what would you comment on this picture? Does it suffer from the same mistake!!
https://tva1.sinaimg.cn/large/006y8m...31900u0kjs.jpg

[DanK]

Sanjib,

There is nothing you can do in shooting the image to avoid limited dynamic range. You have to compensate in postprocessing.

The photo of the palm trees does suffer from a similar problem, but it is more complicated. There are a few dark areas, so a simple histogram looks better, but the dark areas are primarily the bushes in the foreground and bits of the trees. Most of the image is very hazy, and I am guessing that it was very hazy the day you took it. Severe haze is very difficult to fix. you could try the same tools I used on the beach photograph and see how well they work. I can't try that now--have to get back to some work.

Dan

[cauger61]

Sanjib,

I am guessing that it was very hazy the day you took it. Severe haze is very difficult to fix. you could try the same tools I used on the beach photograph and see how well they work. I can't try that now--have to get back to some work.

Dan

Thnx a lot Dan. No, it was a hazy day, though may not be a very sunny morning. Anyway, I shall try with your tools to see what ultimately comes out and get back, if you of course do not get disturbed. With best regards.

Sanjib

[Shadowman]

Sanjib,

I was just testing out the auto exposure bracketing on my D5200 and went through quite a few test shots. One thing I always do whenever bracketing is make sure I've set the camera to what I believe is the optimum exposure and then bracket around that image, I also check to see if the camera's going to give me any warning codes, such as flash indicator or blown highlights. Were you getting a blown highlight warning with your test shot; if you did so?

[DanK]

John,

While your comment may help Sanjib understand bracketing, I think it may confuse him in the current thread. He is trying to figure out what he could do better with these three photos. He's not asking how best to bracket when there is a reason to bracket. There is no hint of either highlight clipping or shadow clipping in any of the three. On the contrary, all three have slightly limited tonal range. So for purposes of his specific question, I think the answer is that bracketing isn't relevant because he doesn't have clipping.

Dan

[royent]

Can I suggest that the originals are lacking in clear sunlight. I remember being told that if you don't cast a shadow, don't take a photograph. ( That was in the days of the Box Brownie. )

Roy

[pschlute]

I remember being told that if you don't cast a shadow, don't take a photograph.

Looks like you and I must sit on hands a lot then Roy, as we live in England

[xpatUSA]

...or was that due to 18% grey rule or what?

What is "18% grey rule" please, Sanjib-ji? Google finds nothing ...

[Shadowman]

John,

While your comment may help Sanjib understand bracketing, I think it may confuse him in the current thread. He is trying to figure out what he could do better with these three photos. He's not asking how best to bracket when there is a reason to bracket. There is no hint of either highlight clipping or shadow clipping in any of the three. On the contrary, all three have slightly limited tonal range. So for purposes of his specific question, I think the answer is that bracketing isn't relevant because he doesn't have clipping.

Dan

Dan,

Perhaps not, but considering the questions he asked (...where do the catch lie, focal length/inverse rule) and the output he indicated (not focused, overexposed) and the settings he used, helping him step back to choosing the correct or close to it settings will help him next time he thinks he needs to bracket. There wasn't an issue with the focal length/shutter speed used, so having the camera set to AUTO ISO and where in the frame he focused could be a possible issue considering he is letting the camera make most of the decision making, so being aware of and responding to any camera warnings/indicators would help him out and anyone trying to help him.

[cauger61]

Sanjib,

Were you getting a blown highlight warning with your test shot; if you did so?

Thnx u John, for the suggestion. It actually didn't occur to me what could be the consequence of my camera setting at the time of shooting. I was so engrossed with the scene that I had chosen the P mode and then adjusted the shutter to capture the receding waves. I shall definitely try your method with my next attempt and get back to you people. With best regards.

Sanjib

[Manfred M]

Sanjib - one of the most important features that your camera has to tell you about the exposure is the histogram. It is also one feature that seems to be very much misunderstood. The most important thing to recognize is that histograms (there are two types; luminosity and colour; as seen in Dan's postings) show a distribution of pixels that your camera has collected.

The most important aspect of any histogram is found at the extreme left and extreme right hand sides. Anything at the extreme left hand side tells us that the camera was unable to record any data because that part of the image exceeded the camera's ability to record anything other than pure black. Likewise any pixels at the extreme right hand side are so bright that the camera was unable to do anything other than record them as pure white.

Sometimes we see crushed shadow details on the left hand side, but "room" on the right hand side. This tells us that the image may have been underexposed and we need to change our exposure to capture this data either by manually adjusting exposure or by using the camera's exposure compensation functionality. A similar situation occurs when we have blown out highlights and the image is likely overexposed. Here manual settings or use of exposure compensation in one of the automated modes is warranted.

There are cases where we see clipping at both the left hand side and right hand side. When this happens, we might wish to consider bracketing the shots and get exposures that are a stop or two underexposed or a stop or two overexposed. These can then be blended using various techniques like HDRI, exposure fusion or manual blending in post to get a picture that has the whole dynamic range.

Exposure bracketing in pretty well any other situation is not usually going to be useful.


For scenes like the ones you have shown, opening up the exposure like Dan has shown is a very common way of correcting the issue you have in these images. One would not do this would be a scene shot in a foggy setting where the dynamic range of the image is likely to look better without the additional contrast that this technique will give you.

[DanK]

Thnx u John, for the suggestion. It actually didn't occur to me what could be the consequence of my camera setting at the time of shooting. I was so engrossed with the scene that I had chosen the P mode and then adjusted the shutter to capture the receding waves. I shall definitely try your method with my next attempt and get back to you people. With best regards.

Sanjib

Sanjib,

As Manfred's post explains, the histogram will tell you whether you clipped at either the dark end or the light end (that is, running up against the top or bottom, which shows a loss of detail). The histogram clipping at the bright end is is the same information you would get from a blown highlight indication on the camera. (Well, almost the same.) Your histograms show that you did not have blown highlights because the histograms don't reach the right-hand side. (See Manfred's post.) So in this case, there was nothing wrong with your exposure, and there was no need to bracket. The problems arise from the lighting, not from a setting on the camera.

Dan

[pschlute]

Histogram is the best tool by a country mile in any camera today. Years ago we had to make a note with pen and paper of each shots exposure details and the dog had usually eaten said scrap of paper by the time the photos had come back from the lab.

[cauger61]

OK thats great Dan!! In that case, as you have mentioned in your opening post [#2], can one use the HDR capability of dSLR? I find that nikon-usa website highlight that in a great way!! I mean, they claim that to be a dedicated feature of nikon dslrs to take advantage with as the catch word now-a-days "HDR Photography".

With regards,

Sanjib

[Manfred M]

OK thats great Dan!! In that case, as you have mentioned in your opening post [#2], can one use the HDR capability of dSLR? I find that nikon-usa website highlight that in a great way!! I mean, they claim that to be a dedicated feature of nikon dslrs to take advantage with as the catch word now-a-days "HDR Photography".

With regards,

Sanjib

Sanjib - HDRI = High Dynamic Range Image.

The histogram that Dan shows tells us that this is actually a low dynamic range image, so HDR is not an appropriate tool to fix this shot

[DanK]

Sanjib,

to elaborate on what Manfred wrote, both exposure bracketing and HDR (which typically uses exposure bracketing) are ways of dealing with scenes that have dynamic range greater than your camera can handle. This would be shown by a histogram that reaches both ends and piles up at at least one end.

You don't have that problem. Look again at the histogram. It doesn't come close to reaching across the whole range from dark to light. That is what Manfred means by low dynamic range. That is one reason why your images look so drab and low in contrast.

So again, I suggest that you stop focusing on tools, like exposure bracketing, HDR, changing shutter speed, changing focus, etc., and instead start by asking: what is the problem? The main problem in this images is that you have a low dynamic range, shown by the narrow histogram. The tools that are relevant are only the ones that address that specific problem. You can address the problem with the tonality controls in Lightroom or Photoshop if you use them--in Lightroom, the "basic" panel sliders and the tone curve, and in Photoshop, the curve and levels adjustments. None of these other things are relevant for dealing with low dynamic range. They are distracting you from the specific problems in these specific photos.

Dan

[cauger61]

OK; then what precautions and/or settings should have been taken and/or followed at the time of shooting so that such issues do not arise at all? or what Dan has commented [#4], there is nothing that could be done other than post-precessing!!

Thnx & regards,

Sanjib

[DanK]

OK; then what precautions and/or settings should have been taken followed at the time of shooting so that such issues do not arise at all? or what Dan has commented [#4], there is nothing that could be done other than post-precessing!!

Thnx & regards,

Sanjib

Sanjib, there is nothing you can do with the camera to make an image have a greater dynamic range than the scene shows. The camera is simply capturing the range that is present in the scene. The only options for a low dynamic range scene are to leave it that way or increase the dynamic range in postprocessing.

Dan