This article was first published in the HDR one magazine, but here you have a version with few more photos :)
Composition is the most important part in any photo. It the same in regular as in HDR photos. It’s not that simple to learn how to see good composition, but there are few simple rules that you can follow to start with.
I personally use these rules all the time, but I don’t think about them anymore. I search for a view that is visually pleasing to me, and that view just fits the rules. You will notice, that if you look at your own photos you like, you will find many of these in it. Composition is really something that is hard to teach. This is my view on it, and I hope it can help some of you.
Lets start with few of my photos I think are composed nicely
1. Forget about the Rule of thirds
Seems a little different that most of the photographers say, but my reasoning is simple. If you do something, do it right. Rule of thirds is the simplistic approach to compositions. Instead of it use the golden ratio rule. I used to go by this rule for a long time, and now I really wish I switched sooner. Sometimes happens to me that I use it, when the scene fits it more, but very rarely or only partially (for instance horizon on the golden ratio rule, vertical split based on the rule of 3rds).
2. Use the golden ratio
So here you can see my reasoning. If you shoot regularly, and you use the rule of thirds, over time you will tent to move towards the golden ration rule. So why not skip the first step completely. As you shoot you will notice that you start to use it without even thinking about it. The difference is subtle, but noticeable. This ratio is based on golden spiral (or Fibonacci Spiral) but it’s easier to looks at it as a grid. The photo is always split in 1.6 to 1 parts. Same as by the rule of thirds, you place the subject of you photo onto a line or onto a intersecting point. You don’t have to be pixel perfect, if you are a little off, it’s not really a problem. You can correct it by cropping or do as I do, leave it be as it is.
For all of you who use Lightroom to crop your photos, you can switch your crop overlay to a golder ration one or a golden spiral one by going to Tools>Crop guide overlay or by pressing O few times. It makes the cropping much easier.
Examples for the use of the rule
3. Don’t center your subject
Really don’t do it. Your photos will look more like snapshots, not photographs. Centering has it’s place in fotography, in special instances (look on the next point) but in most it is out of place. Photos like portraits, irregular shapes, landscapes and much more looks really strange when centered. No examples here as I really try to avoid this.
4. Center your subject
As all rules, there are exceptions. For me the two main reasons to center a photo:
- symmetry – symmetric scenes look great centered. Cathedrals, arches, tunnels.. anything symmetrical. Just center it. But be sure you center it exactly. When you get it a little of center, it will distract the viewer and the overall feel of the photo will be worse. This is much more visible when you use a wide-angle or a fish-eye lens. Even if you stand only few centimeters of the center it will look wrong to the viewers eyes. Try to use live-view on you camera to visualize the final photo and guide yourself by mirrored elements in the scene to get the perfect symmetry. It can be partially corrected in post-processing, but not always.
- reflection – has also a lot to do with symmetry. For me this one is just natural. If you cut off a part of the reflection , because you wanted to avoid the centering, it will look aukward.
Examples for the use of the rule
5. Combine different rules
Why not have a photo symmetrical horizontally and adhering to the golden ration rule vertically. You can use everything at once.
Examples for the use of the rule
6. Use leading lines
The viewer eyes ten to follow lines in the photos. If you position your main subject so, that all lines in the photo lead to it, you will get a visually pleasing photo. Lines like road signs, power lines, train tacks and similar, are great for this. Just look around your subject, and you will find some.
Examples for the use of the rule
7. Use leading light
Similar to leading lines, you can also have what I call leading light. By this I mean brighter areas in your photos. If you leave only one part of your photo brighter then the rest, the eyes of the viewer will be imediatly drawn to it. So it really should be your main subject. This is very visible in high contrast scenes, mostly in night photos.
Examples for the use of the rule
8. Add a foreground object
This is something which you can see all the time paintings. You should try to have foreground, middle-ground and background in your photo. I try to have at least a foreground and a background element. This is not always that easy, especially, when you are trying to capture a landscape photo form a higher location. But one should try. Having a foreground element gives you photo a sense of scale and depth.
Examples for the use of the rule
9. Frame your subject
It’s sometime very nice to add a frame around your photo. By this I don’t mean those frame effects you find in some applications, but a different object, which surround partially or completely your subject. For instance leaving the window in your photo when you are shooting from inside out, or shooting through a tree when taking a photo of a house.
Examples for the use of the rule
10. Add a sense of movement
Especially in shots when one would expect movement (busy streets for instance) a blurred car or person can give more drama and life to the photo. You will loose this “frozen” look, a lot of photos have. I do this more with moving objects than people. Cars, trains, metro, water and similar objects can be used to archive this.
Examples for the use of the rule
11. Level your horizon (or don’t)
When you shoot a landscape photo a leveled horizon is really important. A crooked horizon will look very distracting and makes the photo look rushed and sloppy If you want to have a crooked horizon, go for an angle at least around 30 degrees. At that point it is obvious that you intended to make a crooked image and it no longer looks like an error.
Examples for the use of the rule
12. Look up
This is more of a tip, than a rule, but I noticed that a lot of photographers miss this. When you are at an interesting place, try to look up. Very often you will get a very interesting view and composition of the surrounding area. Looks even better if you use a wide-angle or a fish-eye lens.
Examples for the use of the rule
13. Ignore everything I mentioned here :)
Rules are nice and all, but don’t be limited by them. Just take the photos you want and maybe your style will one day be copied by all other photographers :)
I will end this with two more suggestions. First, try composing you photo directly in camera. If you relay to much on cropping, you will loose too much of what you are trying to capture. Secondly, use a tripod. Using a tripod forces you to slow down and think more about the photo. It’s no longer just point and shoot.
Getting the final look
As you can see, the result from Photomatix is not the final photo. You have to tweak it more to get the final result.
There are two main approaches that you can use, to get the final, desired look in your HDR photo. You can either use basic photo adjustments (curves, levels, contrast, hue/saturation…) in Photoshop or you can use various available plugins.Using the adjustments is harder and takes more time to master, but you have much better control of the result (and better results in the end). Using the plugins is much simpler (usually you just select a preset) and much quicker to learn.I personally use a combination of both approaches, I just use what fits the image. But you always have to be careful. When you can recognize the plugins from the final photo, you have overdone it.I won’t go int photo adjustments here. There are a big part of Photoshop and if you look around you can find many tutorials how to use them. Instead I will show you the plugins and their settings I use the most.
Masking the results in
Same as when correcting problems in HDR’s, these plugins should not be used on the whole photo, but just be masked in where you need it. For instance, you need more noise reduction on the sky, but usually no sharpening.
Imagenomic Noiseware Pro
My prefered way to remove noise from images. As I mentioned in previous part, be care full not to overdo it, as you will lose a lot of detail in your photo. Usually you need more noise reduction in the sky, than in other parts of the photo. Also when you are shooting citiscapes, you should not remove noise on the buildings. You need to keep some detail there.As I shoot mostly on the 5D mark II with the ISO on 100 I don’t go very high on the setting here. Preset weaker noise, with luminance -10 to -5 and color usually -20 to -5. You can easily experiment here, to see how much you need.
NIK Sharpener Pro
Currently my favorite way to sharpen the final image. I always use the output sharpener with the default settings. Only sometime I go up with the sharpness to about 130% and structure to about 10. Also be quite gentle with this, as when you sharpen too much, it’s starts to create artifacts in your image.Sometimes I do a second pass with the unsharp mask (as I mentioned in the previous part). Sharpener pro sharpens the small details very nicely, and the unshapr mask with a higher radius (around 4px) can bring out the bigger ones.Don’t forget to remove the sharpness from the sky and from parts of your image with no details.
NIK Color effects Pro
I used to use this one on all of my images, but not anymore. I do more adjustments directly in Photoshop now. But still this is one great plugin and can help you a lot. For me the most useful presets here are:
The quickest way to correct the colors in your photo. Works very nicely in about 80% of cases. Still it should not be overused. You have 5 settings here:
- Correct Color Cast – corrects colors. If you had bad white balance in your shots, this can really help. Setting around 30-50% works well here. If you don’t change the other settings, this is not that visible.
- Correct Contrast – ads more contrast to your photo.
- Dynamic Contrast – works together with the Correct Contrast. Ads more contrast on smaller scale, so you and up with more details. Both work best at around 30-50%
- Shadows – Pro contrast tends to create a lot of black areas. Move this slider to the right to make them brighter.
- Highlights – same as with shadows, Pro contrast can create very bright areas. Moving this to the right will make them darker
Pro contrast can create a lot of noise, so you should remove the noise before you apply this filter. It also can darken parts of your photo, so adding a levels layer and brightening the mid-tones can help a lot.
If you photo looks too flat, and you want to add more detail to it use this one. But keep it subtle and use it only on the parts of your photo where you need it. For instance on clouds it can look absolutely horrible. Also be careful with a very noisy image. It can take noise as detail and make it worse. You have the following settings there:
Highlights, Midtones, Shadows – adds details in the respective parts of the photo. Usually you need the most detail in the midtones, but settings of 25% in all work very well.
- Saturation – adds more color to your photo. I have noticed that tonal contrast can create very nice colors so it can be an alternative way to saturate your photo.
- Shadows and Highlights – same as by Pro contrast. Move them both a little to the right.
It can happen that you want to use only the detail or only the colors from this effect. If you just want the detail and no change in colors set the Tonal Contrast layer to luminosity. If you want only colors, set it to color.
Similar to tonal contrast, this one also adds more detail into your photo. There are photos where this works wonders, but there are those where it creates a horrible mess. Best used when you have something where you want much more detail.Settings here are simple. Just add as much detail extractor as looks good. Adding a little contrast will give you a better result.
This filter is under portrait category, but can create very nice results also on landscape shots. Especially very noisy clouds and dark clouds get a lot from this effect. Settings here are:
- Glow – how much glow is in the photo. Around 20-30% is usually enough
- Saturation – default settings are very low here. Add more and you will get better results. Around 30% works usually well
- Glow Warmth – can be used to give a photo more warmer or cooler looks. Similar to white balance, but more subtle.
Simulates the effect of a polarizer filter on you lens. Adds a lot of blue into your photo. Best used when you have very bright sky and want to darken it.Changing the Rotate setting will change the color and Strength will change how much of the effect is used.
Nik Silver Effects Pro
This plugin is one of the best ways you can convert your photos into B&W. It is very simple to use and can create stunning results. There are only three settings here, Brightness, Contrast and Structure. Only structure is something new. It adds more detail and micro-contrast into your photo. My favorite preset here is high structure.
Another very popular plugin. Can create a lot of very nice effects on you photos. But same as by all other, don’t overdo it. A subtle effect can create a much more pleasing photo than a strong one. There are a lot of presets in Topaz Adjust, but my three favorite are Photo Pop, Portrait Drama and Spicify.
Another plugin that gives you so many options and results. A lot of photographers use only one from these three (either Color Effects, Topaz or Photo tools) as it is quite a lot to know all the settings in all of them. I haven’t used this one in very long time but still you should give it a try. My two most used presets in this one are Amazing detail finder and Wow Landscape.
And that’s all for this part. This should have been the last part of my tutorial but there will be few more. There still are a lot of thing I can add here.
Before I started with HDR photography, I created a lot of abstract images in Photoshop. This page shows a lot of my works, but so its not just a gallery, I thought I give a little more background on how I learned to work with Photoshop here. I put images in between parts of the text, so this page looks a little more balanced :)
How I learned to use Photoshop
I started with Photoshop around 12 years ago (yes, the time passes by so quickly :) ). I’m completely sure if it was the 6th or 7th version of Photoshop, but I know it was before the CS one. I’ve been experimenting with it also before that, but newer take more time to learn more.
But than one year on the University, when I finally had a PC strong enough to run Photoshop properly (how this sounds silly now, doesn’t it) I started using it more and more, getting hang of the tools, techniques and shortcuts.
I looked at books about Photoshop at that time, but I found them all to be very boring. Each time after I tried to read one, I quit after few chapters. They just read as a manual and I don’t think that they are that helpful anyway. Even now, when it goes to editing, I prefer shorter eBooks, that deal with a certain subject, or go directly to the video.
But as I started, I found myself a simple way to learn, without it being boring. I started doing shorter Photoshop tutorials, few each day, each time from different categories. Just take a look at these two sources of some great easy tutorials, Deviantart and GoodTutorials. On both sites the tutorials are split into multiple categories, and I found the photo editing and drawing categories of Photoshop tutorials the best. And these are the tow sites I used at that time :)
The good things about these tutorials is, that you will have a result quickly enough to keep your attention, and you can try something new each time. Of course over time one needs a better explanation of some techniques/features, that one can’t find in such tutorials, but most things can be just learned by doing.
Another thing that helped me in the beginning, is that I started posting my results online quite soon. Of course not the results of the tutorials, but already my own creations. With the abstract art, I posted it to Deviantart, and later with photos to Flickr. Seeing positive (and even negative) reactions from people can motivate one to keep going and improving ones own skills. One just can’t take things personally, and continue with the work.
A gallery of my art experiments
And here are few more of the images I created while learning (or better said, after I already learned something :)). There are few more images, which can be found on my already very old Deviantart page http://theodevil.deviantart.com
HDR tutorial (ver. 1.0)
I have split this HDR tutorial into multiple parts. Now I’m adding the third part, with the others coming later. So at the end there will be all this:
- Overview (this page) – some general thoughts on HDR
- Taking photos for HDR – I describe different ways you can take brackets for HDR
- Combining and tonemapping your HDR photos – how to tonemmap your photos in Photomatix Pro
- Most common problems and how to correct them – what should be corrected in a HDR photo
- Getting your desired look in HDR – additional steps and plugins you can use on your HDR
What is HDR?
Let’s make it as simple as possible. HDR is a way you combine multiple shots, so you have no overexposed areas and detail in dark areas. That’s all you really need to know.
A lot of people think about HDR’s as these overdone, unnatural photos, which have nothing to do with reality. I call those photos with a “HDR look”. They can be created from any photo, and have really nothing much to do with HDR. I have seen good ones, and bad ones, it’s a lot about the viewers´ taste and preference. Also some of the HDR results, can be created without using the HDR technique. It’s again the photographers decision what he uses (like he can use a Canon or a Nikon camera, but the result is still a photo :) )
There is a certain aversion against HDR photos. But everyone should understand, that HDR is a technique, a part of the final photo. And it depend’s on the photographer, how the final photo looks. HDR on it’s own does not make a good or a bad photo.
I get quite a lot of questions, if my photos really are HDR’s. That’s because people expect that the HDR mentioned look from them. But that’s not my goal. My goal is to find the sweet spot, between artistic and realistic photos, so I like them.
Again, this is very simple. You can’t always set up your light sources. Especially when you only light source is the sun. HDR gives you the option, to capture all the available light and then expose all parts of the photo as you like.
It removes some limitations all current cameras have, and gives you more to work with in post-processing.
At the end it’s your decision. Same as with all photography techniques, starting with HDR is easy, creating a good looking HDR photo is quite hard. So don’t be discouraged, if you can’t get the results you want. It take time and practice.
Feel free to ask any questions and if you find some errors or problems with my HDR tutorial, please let me know.
So lets start with how to take your photos for HDR
So now you have your photos and your tone mapped image. Yous should still keep the original files, as you will need them for few steps. This part is not a step by step one, as you only need to do some parts, based on the photo.
Loading your photos into Photoshop
A lot of the corrections require that you load your original brackets and the final tone mapped image into Photoshop. The quickest way to get your files into Photoshop is to:
- open Bridge
- go into your work folder
- select the source files and tone mapped image
- choose tools-> Photoshop->load into layers
now you have all your photos in Photoshop and loaded into separate layers. I suggest you move the tone mapped image on top of the others.
You don’t have to load all of your source images, just the ones you will probably use (the ones, from which you need parts to correct problems in the tone-mapped image). I load all, for me it’s easier like this.
If you took your photos handheld, or they just dont allign completly, you should align them in Photoshop by:
- selecting all layers
- choosing edit->Auto Align Layers -> select Auto -> OK
This works very well, but not always. Simple way to check your alignment is to change the opacity of the top layer, or just turn it on/off, so you see if the photo moves.
What you need to correct
Each photo is different, but most of the time you have to correct the same problems. The main areas you need to focus are: alignment, movement, overexposed areas, grey whites, very dark areas, colors, halos, noise, sharpness, over-saturation and strange trees.
Some of this is corrected in Photoshop, but some are easier to correct even before, mostly in Photomatix. Also one thing to remember. The better the original brackets, the less you need to correct.
If your photos don’t align properly, it is a big problem for HDR. It creates shadows, ghosts and the whole image looks very soft. The main reason for bad alignment is camera movement when you took your shots. It happens all the time when you shoot handheld, but can also happen when on a tripod.
To get a better alignment you can use align in Photomatix – here you have three options
- no alignment – when you used a tripod and you are sure it didn’t move, also when you have a big moving subject in your photo (like fast moving clouds), selecting no aligment can prevent Photomatix to align based on that subject
- correcting shifts – should be used when shooting from a tripod.
- by matching features – when shooting handheld or when the correcting shifts is not enough. Usually creates very good results.
But if Photomatix is not enough, you still have other options. You can try to:
- combine photos into HDR using Photoshop. Just select the brackets in Bridge and choose Tools->Photoshop->Merge to HDR pro. Photoshop is very good at aligning photos, so it can sometimes create better results. Just save the file it creates as a .hdr file and then open it in Photomatix to continue.
- don’t use all your shot. If you took more shots (5+) it can happen that one or more of them are not aligned with others. For instance little wind while you were taking your shots can cause this. Just look through them and if you see one that is blurry, don’t use it. The information in all other shots should be enough to create a good HDR photo.
- use only one RAW to create your hdr. By using only one, no alignment occurs, so no problems can occur
- create a misaligned HDR from all brackets and a HDR from a single RAW and merge them in Photoshop. Just align them as best as you or Photoshop can, and then by using layer masks correct the parts you need.
If you really can’t create a nice aligned HDR, just use the single RAW method. You can try to mask in part from the original shots, to cover places where it isn’t aligned properly, but this takes a lot of time and the result can vary. I suggest you get a better tripod next time :)
A lot of people struggle with this, but to correct moving subjects in your HDR photos is actually very easy. There are two main approaches you can try, I use them both.
- use Photomatix ghost removal. Select the manual method and choose which areas are ghosted. This works much better if you have more than 3 brackets. You can also use the full automatic method, but the results here are mixed. They can be very good, if you use a lot of brackets (5+) and very bad if you use only 3. The manual works mostly better.
- use layers in Photoshop, to mask in parts of the original photos
By masking using Photoshop layers you can correct many problems you have in your final HDR. You have to place your layers in an order, where you have your tonemmaped inage on top, and the source image you want to use parts of under it. Then select the top one and add a layer mask (the small icon in bottom right, which looks like a grey square with white circle in it). On the layer mask, white means the top layer is used, black the bottom. Grey is a mixture of both. Using a soft brush, at around 20%-30% opacity, start brushing on the layer mask, to reveal the original photo. Continue until the problem is corrected. Add you brush strokes softer on the sides, to create a better mixture of the two layers. If you went two much just switch to white color and brush over the same area, to remove from the mask. Don’t forget to check that you have the mask selected. If you have the photo selected you will paint into it instead of masking.
My favorite approach is to mask in what I need with a stronger brush (40%-50% opacity) and then switch to a softer (15%-20% opacity) white brush and soften the corners of the brushed area, to create the soft transition.
A lot of times you have to use parts from multiple source images (even all). Here you have two approaches you can do:
- after masking in one of the shots, merge it together (select both and Ctrl + E) with the tonemaped image into one layer, and then continue as before.
- group the two layers and then create a new layer mask on the group (check out the screenshot). Like this you can go back to layers you already worked on.
Here you can see how I removed the whole sky from one of the original shots, as the clouds were moving to much. I prefer to group layers, as I go back and forth between different layers and sometimes remix them in between each other.
This layer method of masking is simpler, when you have more brackets at your disposal, as you can find easily one that matches your tonemapped image. In the case none of the ones you have match it sufficiently, you can perform few tweaks on the source image before masking it in. For instance changing brightness, contrast, exposure and other photo tweaks can help.
You can even use a single raw HDR as one of the layers, or a tweaked image from Lightroom.
It can happen that you just don’t have enough brackets, to cover the whole range. Tone-mapping usually creates very rough edges around this area and can make this areas dark, so you should always try to correct this. If you are aware of this before you start your tonemapping process, you can try underexposing your darkest photo in Lightroom by one or two stops, and using it as an additional bracket for Photomatix.
Other option is underexposing it directly in Photoshop and then using layers masks correcting the affected area.
I tent to try shooting brackets, so I have no overexposed areas at all. Only time when this is not possible, is when you shoot into the sun. Just use one of the original brackets to soften the areas, or to completely replace it.
Overall white areas are a problem in HDR. The tone-mapping process tries to get details in them and so makes them look grey and dirty. Masking one of the original shots here is really a must. If you have a white area, white car, snow, or other white object in the photo, you should always make it brighter.
For instance, on the right you can see a winter photo, directly from Photomatix, and after masking and level adjustment in Photoshop.
Very dark areas
The opposite of overexposed areas. Just use one of you lighter brackets to make them lighter. Also Photomatix tends to create detail, where there is none. This usually results in strange artifacts, either red or purple, in your tonemmaped images. The only way to correct this is to mask the one of the original shots back in.
You will see something as in the picture on the left and you have to mask that part. This happens only if you have an area, for which all your brackets are pure black.
Or also known as the blue sky halos. I really suggest trying to get rid of them already in Photomatix. By lowering strength, using higher light smoothing, smooth highlights or luminosity, you can get rid of most of them.
But if it doesn’t work you still can choose one of your brackets, with the best sky and mask the whole sky into your final image. Trying to darken the halo is really hard and the final result are usually not good enough.
The photo on the right is just an example to show how halos look. I haven’t had this problem for a long time.
Also having more brackets reduces the change that you will get the halo. Having softer transitions between them creates better results here.
Noise gets worse in HDR, as the more noise you have in your brackets, the worse it it in the final image. But you should distinct between noise and grain. If you look at your photo in detail you will see the difference. Grain is crated by having a high Strength and Detail contrast in Photomatix. It just tries to add more detail to the photo, and mistakes the noise for detail, creating so grain. It’s usually very visible on cloudy photos. Noise is created by your camera, while taking the shot.
Grain vs Noise looks something like the image on the right.
To get rid of the noise, you should always shoot at the lowest ISO possible. Also having more input brackets can give you better results. For instance with the 5D mark II at ISO 100 and 7 bracket, I have almost no noise in my final HDR’s.
One of the best ways to remove noise is to use Noiseware Pro. This Photoshop plugin is in my experience the best in reducing all noise. If you use it, it should be done in two passes. Once for the sky and once for everything else. This is because we want to keep details in the structures, but don’t need so much in the clouds. So a higher setting for the clouds is still acceptable.
My usual setting here are quite low. I select the default preset and start with luminance around -7 and color at -20 (you usually don’t need color noise reductions). This settings are usually enough when you use ISO 100. But for instances like here, where the ISO was 2000 I had to go much higher.
Another very common problem with HDR, is that the photos are just not sharp. Even when your original photos were sharp, the final one isn’t. There are multiple ways you get get the sharpness back.
Unsharp mask in Photoshop, the easiest and for a long time my most favorite way. Just create a new layer by merging all your layers (Ctrl + Alt + Shift + E) and on this layer use Filters -> Sharpen -> Unsharp Mask. My standard settings here are 100%, 1.6 to 2 pixel radius and 0 threshold. I do this on a separate layer, because I don’t want it on the whole image. For instance you should not sharpen the sky, as it created additional noise. There also is a second approach to unsharp mask, where you choose setting of 10% and a high radios at around 40 pixels. This gives the photo a little different look.
Smart sharpen is another filter in Photoshop. It is popular by some fotographers and it can create similar results to unsharp mask. It can be found under Filters -> Sharpen -> Smart Sharpen. I don’t use it very often but my settings here are around 80% and 1px radius.
The high pass method is a very popular method, done by a lot of HDR photographers. What you do is to sharpen is:
- duplicate the layer
- use Filter -> Other -> High pass on this new layer
- play a little with the number of pixels, until you see the detail you want to have i the final photo. Smaller number work well here (2-4px)
- set the layer to soft light, overlay or luminosity (choose one that works best with your photo)
There are also dedicated sharpening filters, notably the Nik Sharpener, but I will cover that in the next part which is all about plugins.
Too much saturation
Not everything in a photo has the same level of saturation, so it can easily happen that something is over-saturated. For me it usually happens with bright red objects. There are two aproaches you can go here. You either:
- mask the object back from one of the original brackets
- create a hue/saturation layer and adjust the sliders until you are satisfied with the color. I suggest you also use the layer mask, so this saturation change only effects the area where you need it.
You can see this in so many HDR photos. You just can’t have dark clouds during a sunny day. It just looks very unrealistic. It’s fine if you have a stormy or a blue hour shots, but never during a sunny day with a blue sky. Just use masking to brighten them back from one of the original shots.
You will also notice, that when you brighten your clouds, your photo will just look better.
Having trees in your photos, especially when there is no wind, is great. But when they crate one big green mess, they no longer looks so great. As the HDR process removes most of the shadows, it tends to flatten trees. So you should remix them with the original shot, to bring back their texture.
Also the green color on trees and other plants can look really strange if you were shooting during a sunny day. Toning down the yellow color using hue/saturation can give the back a more natural look.