Ohanaware s guide to HDR Photography

Transcription

1 Ohanaware s guide to HDR Photography Copyright 2010 Ohanaware.com

2 Preface Like those of you who are eagerly reading this guide, I too am interested in learning HDR Photography and I practice HDR Photography as often as possible. HDR Photography can produce some amazing results, that are simply not possible otherwise. When I first started to learn HDR, I read as many different tutorials as possible. Most of these tutorials are geared towards using equipment and software that would tally into the thousands of dollars range. This was disappointing and frustrating, why should HDR Photography only be for those who can afford it? So I set about researching and developing ways to create HDR photos without the need to spend thousands of dollars, in fact my mission was to enable you to enjoy the world of HDR without spending a penny! I have discovered and written about 6 methods, each with a list of requirements and various advantages/disadvantages. I ve written which one I think yields the best result, and provided an example of each method, allowing you to judge with your own eyes. There should be a method that will work with your current digital camera. To end the guide, I ve written about some equipment I ve purchased to aid me with HDR Photography and why I purchased it. Finally thanks to my wife, who s sat by my side in the cold, the wet and the blistering heat while I take photo after photo. Sam Rowlands Ohanaware s Guide to HDR Photography Written by Sam Rowlands ( First Published: October 2009 Copyright 2010 Ohanaware.com Share this guide with family, friends and co-workers. Share via Twitter, Share via Facebook, Share via . While distribution of this guide is allowed, reproduction of any part of this guide is strictly forbidden without prior written authorization from the author. 2

3 Contents What is HDR Photography: Explanation & Diagrams How do I make my own HDR Photos: How To Take Photos For HDR Auto Bracket :: Best Quality Manual Multi-Exposure :: Better Quality Handheld Auto Bracket :: OK / Better Quality Handheld Single RAW :: OK / Poor Quality Handheld Single Photograph :: OK Quality Using Software To Create & Tone Map HDR Images! Method Examples and Comparisons! What makes a good HDR? HDR Software: This list only features software that was made available or updated in Name Version Price URL HDRtist 1.2 FREE ImageFuser FREE lang=en&subject=imagefuser&texttag=im agefuser Bracketeer 4.0 $ Dynamic Photo HDR 4.6 $ Hydra $ Photomatrix Pro $ Photoshop CS4 $ photoshop/photoshop/ HDR Equipment Suggestions. 3

4 What is HDR Photography? Single photo direct from the camera HDR, created from 5 exposures HDR stands for High Dynamic Range, which basically means an image which can store more light values than traditional digital cameras & computer can display. All this information is then compressed in such a manor that it can either produce a more realistic image or a more dramatic and punchier image. Notice in the right hand image, the clouds are visible, where as they re lost in the highlights of the left hand image. Below are the 5 exposures that were used to create the above HDR, you can clearly see the difference in light ranges. Using some math, the light value for each pixel is calculated based upon all these different exposures, it s then stored using a higher precision system than the traditional image methods. Once it s finished the dynamic light range is too vast to be shown on a computer screen, so we have to have to use some more math to compress the light values down to a range that can be displayed on a computer screen. The last stage is called tone mapping. On the next page you ll see a table, which tries to demonstrate the differences in light ranges. 4

5 Human Eyes: Digital Camera s & Displays: Multi-Exposures: HDR Image: Tone Mapped HDR: Light Range Table The first thing you ll notice when looking at this table, is that the human eye can see a broader range of light than a Digital Camera can capture or than a Computer screen can display. The you can see that the multiple exposures gather a similar range of light and once processed produce a High Dynamic Range Image which contains a light range close to the human eye. Lastly, the tone mapped image has compressed this light range so it ll fit onto a LDR (Low Dynamic Range) display. 5

6 How do I make my own HDR photos? Making HDR photos isn t as difficult, expensive or complicated as some believe. You can make HDR looking images from any camera and true HDR images from almost every camera. As HDR software choices are fairly simple and using most HDR software is a breeze, the difficult part is actually taking the photo. How do I take photos for HDR? Taking photos for HDR really depends on what camera and accessories you have, also on what situation you are in. The key thing to think about when shooting photos for HDR; will this make a good photo regardless of it being HDR. While HDR can be used to make photos really pop, but if the image is boring or dull to begin with, HDR may not help it. Let s start by looking at the various methods, required features and the quality of the result. You may wish to double check with your camera manual to see if your camera has such a feature or how to use such a feature. Once you ve decided on which method is suitable click on the method header to read the guide for that method. Auto Bracket :: Best Quality Requires: Auto Exposure Bracket (also known as AEB) Function and a tripod. Advantages Cleanest results. A single shutter press. Wider range than a single photo or RAW. Disadvantages Difficult when in motion or too windy. Requires setting up the camera. Requires setting up the tripod. Manual Multi-Exposure :: Better Quality Requires: Tripod Advantages Wider range than a single photo or RAW. Can produce cleaner results. Disadvantages Have to adjust settings per exposure. Requires setting up the tripod. Any movement will ruin the final HDR. 6

7 Handheld Auto Bracket :: OK / Better Quality Requires: Auto Exposure Bracket Function and a steady hand. Advantages A single press of the shutter. Wider range than a single photo or RAW. Disadvantages Requires setting up camera. Too much movement will ruin the HDR. Can produce cleaner results. Handheld Single RAW :: OK / Poor Quality Requires: RAW format capability on the camera Advantages Wider light range than a single photo. Single press of the shutter. Can be used for motion or in windy conditions. Disadvantages Final HDR can be quite noisy. Not as much range as multi-exposures. Some HDR software won t use a single RAW. Some HDR software won t use JPEGs created from a single RAW. Handheld Single Photograph :: OK Quality No Requirements Advantages Single press of the shutter. Can capture motion or in windy conditions. Disadvantages Not enough light range to create an HDR, can only tone map the images. Some HDR software won t use a single JPEG. 7

8 Auto Bracket :: Best Quality Requires: Auto Exposure Bracket (or AEB) and a Tripod. When shooting bracketed images for HDR processing, you should shoot in an "Aperture Priority Mode" so that each image has the same aperture. This prevents problems caused when the camera in its default mode if it decides to shoot your set of images at different apertures (which will cause image alignment problems due to depth-of-field differences.) The Auto Bracket is the best way to product high quality and perfectly aligned HDR images. It s the most heaviest on requirements as it requires your camera to have an Auto Exposure Bracket function and a Tripod. You may wish to check with your camera s manual to see if it has such a function and how to use the function. To continue, I m going to assume that you have a tripod, the Auto Exposure Function and know how to use them. 1. Setup your tripod and attach your camera to your tripod. 2. Setup your camera so that you are ready to take the photo. 3. If you have the capability to manually specify the white balance do so, also if your camera features a focus lock (AF/AE Lock) or manual focus, focus the camera on the subject and lock the focus. 4. Enable the Auto Exposure Bracket function of your camera (check your manual if needs be). Set the range to be the widest possible, +/- 2 is a good position, however +/- 1 is better than none. 5. If you have a remote control or cable release, let go of the camera and use the remote control/cable release to take the picture. If not use the camera s timer, set it to 2 seconds, click the shutter button and let go of the camera. This step minimizes camera movement. 6. Congratulations, you ve take your first HDR! If you check your camera you should have a series of exposures that may look like the below. Now that you have your HDR images, you ll need to skip ahead and read the paragraph on Using Software To Create & Tone Map HDR Images. 8

9 Note: While is most cases you shouldn t need to lock the focus, I have come across situations where at least one of the exposures wasn t focused. It s only happened a couple of times but it does ruin the HDR. 9

10 Manual Multi-Exposure :: Better Quality Requires: A Tripod. If your camera doesn t feature the Auto Exposure Bracket feature you can still make an HDR, it just takes longer and requires a tripod of some sort. There are two ways to accomplish this technique, during the day I ve not noticed any difference, but at night the second technique provides much better results. The second method does require a full manual mode on your camera and is a little more tricky to use. Technique 1 :: Exposure Compensation 1. Before you start you need to figure out how to adjust the exposure compensation on your camera. I d suggest checking with the camera manual, you may need to change the mode of your camera to "P". You may wish to spend a few minutes playing with the exposure compensation, adjusting it to -2 or +2 and back to Setup your tripod and attach your camera to your tripod. 3. Setup your camera so that you are ready to take the photo. 4. If you have the capability to manually specify the white balance do so, also if your camera features a focus lock (AF/AE Lock) or manual focus, focus the camera on the subject and lock the focus. 5. Set your exposure compensation to -2, this will make the picture dark. 6. If you have a remote control or cable release, let go of the camera and use the remote control/cable release to take the picture. If not use the camera s timer, set it to 2 seconds, click the shutter button and let go of the camera. This step minimizes camera movement. 7. Congratulations, your first exposure! 10

11 8. Change the exposure compensation to 0 and take the second photo, using the remote/cable or timer like the first photo. 9. Change the exposure compensation to +2 and take the last photo. Remember to use the remote/cable or timer, so that you minimize camera movement. Technique 2 :: Using Full Manual Mode Note: Because this technique relies on Shutter speed, it may not work in bright light. 1. Before you start you need to figure out how to use the full manual mode, check with your camera documentation if needs be. When you are in the manual mode, you need to be able to tell your exposure, this is done via an exposure meter. 2. Setup your tripod and attach your camera to your tripod and point your camera at your subject. 3. Set the white Balance, Aperture, ISO and lock the focus onto your subject. 11

12 4. Now increase your shutter speed so that the exposure meter reads -2, this will make the picture dark. 5. If you have a remote control or cable release, let go of the camera and use the remote control/cable release to take the picture. If not use the camera s timer, set it to 2 seconds, click the shutter button and let go of the camera. This step minimizes camera movement. 6. Congratulations, your first exposure! 7. Now you need to reduce the shutter speed, so your exposure meter reads 0, then take the photo in the same way as before. 8. For the last exposure, reduce your shutter speed one more time so your exposure meter reads 2, and take your last photo. If you re using the timer to take each exposure; consider this, most HDR Software offers image alignment, so it s possible to speed up taking manual photos by not using the timer and relying on the image alignment to fix any minor alignment problems. Reduces motion, but might get slightly misalignment. Now that you have your HDR images, you ll need to read the chapter on Using Software To Create & Tone Map HDR Images 12

13 Handheld Auto Bracket :: OK / Better Quality Requires: Auto Exposure Bracket This method is identical to Auto Bracket :: Best Quality except that you don t use a tripod. So basically follow the Auto Bracket :: Best Quality but skip the Tripod steps, and try to keep the camera as steady as possible while it s taking the bracketed photos. At this point I would recommend that you use a Tripod to get perfect alignment, however some situations don t allow for a Tripod. If the movement of the camera is too great, the resulting HDR is useless and wasted. While is most cases you shouldn t need to lock the focus, there have been a couple of times where one or more exposures wasn t focused and the resulting HDR was ruined. See the examples below of a Suzuki Grand Vitara, the HDR software managed to align most of the image, but it couldn t handle the cars in the top right hand corner and for this example, (which isn t great anyway) the HDR is ruined. Before Alignment 13

14 After Alignment Close up of mis-alignment 14

15 Handheld Single RAW :: OK / Poor Quality Requires: The ability for your camera to save photos in a RAW format. RAW images are basically raw camera sensor data, before it s been turned into a photo. Camera settings are also stored in this file. It allows you to make alterations later and then create the image. For HDR, this is great as more dynamic range is stored within a RAW file (there are exceptions). You can use this when the subject is moving or when the camera is moving. Some HDR software may also be able to use your RAW file directly. There s a bunch of serious disadvantages to shooting a single RAW, for instance the end result will never be as clean multiple exposures. Any image imperfections are multiplied. Some RAW formats don t contain more dynamic range than a JPEG. This technique is not compatible with Photoshop CS3, it does not create HDRs from a single RAW, nor does it like multi-exposures developed form a single RAW image. The technique I m going to suggest may seem like overkill, but when working with HDR software I ve found that this technique produces the best results. 1. Set your camera to store photo in it s RAW format. 2. Take the photo. 3. Open your RAW processing software, and load in your RAW photo. Personally I d recommend using the software which ships with your camera, as this generally produces better results than generic software. 4. Develop the photo as it is and save it with the file name of Normal. 15

16 5. In your RAW development software, adjust Exposure Bias (maybe Exposure Compensation or Exp.Bias.) down -2. Develop the photo and save it as Dark. 6. Next adjust the exposure again to +2 and save the developed photo as Light. Now you have your multiple exposures from a single RAW image, move onto the chapter Using Software To Create & Tone Map HDR Images. 16

17 Handheld Single Photograph :: OK Quality Requires: Digital Camera, nothing else. This technique is not really HDR, as we are skipping the HDR step and simply tone mapping a regular photograph. This method is know as FHDR (Fake HDR) or Pseudo HDR. However it does allow everyone to accomplish the much sought after HDR look, even if their camera isn t able to take photos for HDR or simply don t have the time or patience for taking photos for HDR. If your camera has an icontrast, Dynamic Range Optimizer (DRO) or High Dynamic option, enabling such an option will pull more detail out before you Fake-HDR it and can make a much stronger image. Not all HDR software will allow you to tone map a JPEG, the process may be slightly different from the normal HDR generation and tone mapping. HDRtist: To tone map an image in HDRtist, you only need to open it. Either drag the image into the HDRtist window, or use the Add Photos toolbar button or Open.. from the File menu to open the Open File dialog, and select your photo. Use the Strength slider to adjust the tone mapping. Bracketeer: Doesn t have a tone mapping facility for a single JPEG. Dynamic Photo HDR: When Dynamic Photo HDR starts up, click on the Create HDR button on the far right hand side. A new dialog appears, within this dialog click on the Add Images button. Navigate to your photo and open them. In the next step Dynamic Photo HDR will ask you if you want to do a FULL HDR or a Fake HDR. I recommend choosing the Fake HDR and clicking OK, in the next dialog I d recommend choosing Ps Halo-Matrix. Hydra: Simply drag your photo into Hydra or use the + button to choose your photo. In the Info pallet, click on the Merge tab and about half way down the window, ensure that Tone Mapping is checked. and the choose the tone mapping method. Photomatrix Pro: Doesn t have a tone mapping facility for a single JPEG. Photoshop: Doesn t have a tone mapping facility for a single JPEG. 17

18 Using Software To Create & Tone Map HDR Images Once you ve taken your photos for an HDR, you need to merge them into an HDR. Then you can Tone Map the HDR so that it ll display nicely on the computer screen. Different HDR software use different techniques to create their HDR images, I ll show you to how to create HDR images using the software listed on the contents page. HDRtist Either drag your images into the HDRtist window, or use the Add Photos / Open menuitem on the File menu to select your images. HDRtist will then import those images, and automatically create the HDR preview and tone map it you. If your images are not aligned you can use the Align Photos button on the toolbar. Use the Strength slider to adjust the Tone Mapping. 18

19 ImageFuser Either drag your exposures into the ImageFuser window or select Open Bracketed Set from the file menu. Once you ve imported your images ImageFuser will update the preview for you. If you need to align your images, click on the Use Align_Image_Stack checkbox, then click on the Align Preview checkbox to see the preview aligned. You can use the Enfuse tab panel to fine tune your finished result. When you re ready click on the Save Enfused Image button. 19

20 Bracketeer: Drag each image into an individual image well in the Drag Source Images Here window. Bracketeer will then auto update the preview. If your images need aligning, click the Auto Align Source Images button at the bottom of the Drag Source Images Here window. 20

21 Dynamic Photo HDR: When Dynamic Photo HDR starts up, click on the Create HDR button on the far right hand side. A new dialog appears, within this dialog click on the Add Images button. Navigate to your photos and multi select to add them. If you need to align the images, make sure that Align Files in Next Step is checked. Then click on OK. When it s finished rendering the HDR, you ll be asked if you want to Tone Map the HDR, which you do so click on Tone Map HDR. In the Tone Mapping window, you ll see the various methods listed on the left, along with a bunch of various options. Personally I use the Ultra-Contrast method and don t adjust anything else. When you re happy, click on the Process and Save button. 21

22 Hydra: Simply drag the images into the Hydra window. If you need to align the images, click on the Align tab in the Info window, then check Align Images, and finally click Auto Align Images. Next click on the Merge tab and click on HDR. Then check Tone Mapping and can choose between the different methods from the popup menu next to Method. 22

23 Photomatrix Pro: When the program opens, you need to click on the Generate HDR button, then a small dialog will appear. You can either drag your photos into this window or use the browse button to choose which images to use. Then a further dialog might appear asking you to specify the Exposure compensation of each image, if it doesn t match I d advise you set it now as there is no way to change it later. Lastly a dialog will appear with a bunch more options, the one to worry about is the Align source images option, if your images were taken without a tripod. Say okay to that dialog and a little while later, you ll have your HDR image. Now you need to click on the Tone Mapping button in the floating palette besides your image. This will take you to the Tone Mapping options. In the tone mapping options, you have two tabs, the first is the details enhancer and the second is tone compression. Personally I leave it on Details Enhance and then start adjusting the bars until I see what I like. There are no magic numbers here, each image is different and can require manual adjustment to make it look great. 23

24 Photoshop: Launch Photoshop and select Merge to HDR from the Automate menu on the File menu. This will open a new dialog, from here you have to click on the Browse button to navigate and open your images. If your images need aligning, check the Attempt to Automatically Align Source Images checkbox. Then the OK button. This will produce the HDR Dialog, click OK and now you have your HDR. To tone map this HDR, you ll need to reduce the depth of the image. You can do so by selecting either 16 Bits/Channel or 8 Bits/Channel from the Mode submenu of the Image menu. When the dialog opens, you can choose your method by selecting it from the Method Pop-Up menu. The Local Adaptation method is the method I d use, click on the Triangle button to reveal the curve, you can use this to adjust the contrast of the image. Again there is no magic numbers here folks and different images require different settings. 24

25 Method Examples & Comparisons. Below are examples of different methods and some comparison information. I used HDRtist as the software for HDR Generation and Tone Mapping. Auto Exposure Bracket with Tripod. Auto Exposure Bracket Without Tripod. Manual Exposure with Tripod. Single JPEG. Single RAW, Multi-Exposed +/- 2. Single RAW processed in HDR software. 25

26 100% Crops showing detail/damage of each one. Auto Exposure Bracket with Tripod. This is our base. Auto Exposure Bracket Without Tripod. You can see areas that don t quite fit & edges need cropping in a photo editor. Manual Exposure with Tripod. Movement between photos ruined HDR. Single JPEG. Lacking in detail in trees and bright ares. Single RAW, Multi-Exposed +/- 2. Murky and lacking of detail, noise evident. Single RAW processed in HDR software. Really noisy and colors are offset. 26

27 What Makes A Good HDR? That s a million dollar question, it s like saying how I can make something that everyone will love. Truth be told, I cannot tell you. What I can tell you are things I ve learnt that really help. Is it a good image to begin with, there s nothing worse than spending all that time making an HDR only to discover that it s dead boring! Always think about how else can I take this photo? If you re really stuck, default back to the thirds rule (if you can). This image was taken using the thirds rule. With the thirds rule, it s fairly simple. Break the image into 3 equal sections and try to squeeze something interesting into each section, the example above, while not perfect contains something in each section. When photographing landscape or buildings try to make sure that there is background detail, especially in the sky. You need just enough to make it interesting. Contrasty scenes (where part is too bright and another part is too dark) work quite well as before and afters. Night shots are really great when done in HDR. 27

28 HDR Equipment Suggestions While the main aim of this guide is to help people get into HDR with the digital camera that they already own, I felt that as I had purchased equipment to aid myself with HDR, it may be helpful for readers of this guide to know what I purchased and why. Transcend 8 GB Class 6 SD Card ($20) When shooting photos for HDR, you ll want a large capacity memory card. Today 8 GB is standard, it can easily hold 1, megapixel JPEGs at high quality or 10 minutes of HD video. The reason why I choose this card over others, is simple. It s a class 6, which means FAST write times, at the price of a class 4! Having a faster card minimizes the time it takes for the camera to write out the image and reduces the time between exposures. Spare Battery ($10-$80) Never leave home without one! There is nothing worse than having the battery run out while you are mid shooting or missing a photo because your battery is flat. Personally I stick to genuine batteries, but many people I know get on well with third party batteries. If you want a genuine battery, shop at well-established retailers. Watch out for Amazon and ebay auctions that claim to be genuine, but supply you with fakes. I got caught out, but I was able to get my money back. Joby Gorillapod ($20-$50) This little tripod is indispensable, it s small enough to fit in the pocket of my shorts and yet does the job of stabilizing the camera. Because of it s design it can be wrapped around objects such as fences, lamp posts and trees. I take this little guy with me where-ever I go. Again stick to a well know retailer, I had 2 fakes before I managed to get an original. [See the guide to identifying a fake Gorillapod] Lenspen ($10-$15) About the size of a whiteboard marker, this little guy has a brush on one end and special cleaning tip on t other end. Use the brush to brush away dust and dirt, use the cleaner to remove grime and replace the lens coating. 28

29 Takara TD-1931, 4.3ft Light Weight Tripod ($15 - $27) This was the most recent addition, probably one of the most useful too. It really helps to get good clean HDR images, especially when in low light. Folds as small as a foot and a half, complete with a carrying bag. When we re off shooting photos, this guy ll come with me. Seem s Takara is harder to get hold of in the US, but any light weight reasonable height tripod should do. Panasonic LX3 ($420 - $600) This camera is the perfect mid-step between a pocketable compact and a feature-laden DSLR. It s small enough to fit in the pocket of my shorts, yet it features Auto Exposure Bracket upto +/- 3, RAW file format, better image quality than a compact, Full Manual Mode, with control over focus, Aperture and shutter speed (perfect for night HDR), 24mm wide-angle lens (perfect for landscape). It s price is in-between a Compact and a DSLR, so if you re looking for a pocketable HDR camera, this is the one! [Read DPReview s Review] Note: This camera was released in the summer of 2008, and at writing (Oct, 2009) Panasonic are still adding new features via FREE software updates! 29

30 The End Thanks for reading Ohanaware s guide to HDR Photography, I hope that the information within this guide has proved useful and helps you on your way with the beautiful world of HDR Photography. Share this guide with family, friends and co-workers. Share via Twitter, Share via Facebook, Share via . While distribution of this guide is allowed, reproduction of any part of this guide is strictly forbidden without prior written authorization from the author. 30