The photographs in this project are all created using a photographic process referred to as HDR (or HDRI). HDR stands for High Dynamic Range and is a process which involves taking multiple photographs of the exact same thing. Though the photographs are of the same subject, they differ in one very important way: each one is exposed differently. For example, the first photo may be very dark, with the second a bit lighter, the third lighter still and so on until the last photo which will be very bright. This is called bracketing and any digital SLR camera can be set to automatically bracket exposures. For HDR, bracketing insures that we get properly exposed highlights, shadows, and everything in between. For example, the windows in a church are very bright, while other areas, such as the backs of the pews, are often in dark shadows. The difference in brightness is so vast that a single photograph is unable to capture the entire range. Most of the photos in this project are made of 9 individual images. Below is an example of 9 auto bracketed photos taken 1 stop intervals at The Cathedral Of St. John The Baptist in Savannah, GA as described above:
The photo marked zero above represents the way the camera would have chosen to expose the photo with everything set to auto. This is a reasonable approximation of the way most people’s photos would turn out. Among the many obvious shortcomings of the photo are the overall lack of details and the yellow color cast. Here it is a bit larger:
We could, of course, choose to increase the exposure to give us more overall light in the church. However, we still run into the issue of losing details in shadows and highlights. Here is a larger example of the photo marked +2 above:
Once the 9 photos are taken I then run them all through a program called Photomatix. What Photomatix does is take the 9 individual images and combine them into one superior image which keeps the best parts of each. The result is one photo in which you can see all the bright, dark, and mid tones clearly. When my images come out of Photomatix they look very “flat” and are in need of a lot of work. I never get a usable photo straight out of Photomatix. Here is an example of the same 9 photos from above once I have processed them. Notice it doesn’t look so great, but the color balance has improved and there is information in all parts of the image, meaning there are no blown out highlights or blocked up shadows which are noticeable in the above 9 individual pictures.
I go over my workflow in more details farther down, but from there I process the photos in Adobe Lightroom 5 for general adjustments and Adobe Photoshop where I use layers and masks to isolate individual areas of the photo in order to better adjust them individually. I may also bring in parts of other images to replace inferior sections. This is responsible for really bringing the contrast back to the overall image. Finally I go back into Lightroom where I make some simple final adjustments. Here is the final image after these last steps:
1. APERTURE PRIORITY – This will ensure that your aperture remains the same throughout the range of exposures. If you use Program, or another setting, your aperture will vary between the individual exposures, thus your depth of field will change. Thus, parts of your image will be more in focus in some of the photos than the others. When you process this you are left with sharp and blurry over one another, resulting in something in the middle.
2. AUTO EXPOSURE BRACKETING – I usually shoot 9 exposures at 1 stop intervals, though since my upgrade to the Nikon D800 I sometimes only need 5 or 7. Most Canon cameras will have a limitation here in the sense that they will only let you auto bracket 3 exposures, but you can do it at 2 stop intervals.
3. RAW – Since we are trying to get as much information from the scene as possible (a high dynamic range) we want to use RAW files to retain the maximum amount of the info we capture.
4. APERTURE – Almost always f/8 or f/11, taking into account my focal point to maximize my depth of field.
5. METERING – Standard metering. A 9 exposure range often means you don’t need to compensate any because you will capture such a wide range, but there are occasions where you may need to adjust it to get the best range possible.
6. ISO – As low as possible, trying not to exceed ISO 400 (since I’m on a tripod a long exposure is no problem).
7. ACTIVE D LIGHTING – Normal. Again, since we are shooting RAW I don’t feel this matters too much.
8. COLOR SPACE – Adobe RGB
9. SET CUSTOM WB – There is always a sharp contrast between the light indoors and the light coming in the windows. Dialing in the wb generally results in less editing later.
10.PICTURE CONTROL – Set to Standard so as to keep better dynamic range. Since we are shooting RAW this is not too big of a deal.
My Work Flow:
1. Shoot 9 exposures at 1 stop intervals.
2. Save files to computer.
3. Import into LR5
4. Adjust color temperature, if needed, to the RAW files in LR (I sometimes do general adjustments to the RAW files in Nikon Capture NX2 and then process those files).
5. Export exposure set to Photomatix via the LR plugin. (This lets LR, which does a better job, convert your RAW files instead of Photomatix)
6. I used to process in PM using the Tone Mapping and Details Enhancer settings, adjusting to retain as much info as possible, not to produce a final, usable image. I have since mostly changed my approach and now I am most frequently using Exposure Fusion as I think I get more realistic results while still yielding images that are full of light. I don’t have specific settings I consistently use for each slider.
7. Save and Re-import into LR
8. Adjust in LR
- Color balance
- Color temperature
- Lens profile correction
- Reduce noise (if necessary, though usually I do not).
9. Export to Photoshop
- Select individual elements, make them layers, and adjust accordingly. Isolating parts of the photo often makes it easier to adjust and produces better results.
- dodging highlights can often bring back some contrast
- Smart Sharpen 30-70%
- Save, which automatically re-imports the photo back into LR as “filename-edit”. All the layers are saved.
10. Fine tune color balance, contrast, etc. for more consistent results between each photo.
Camera: Nikon D800
Tripod: Manfrotto 055 carbon fiber
Tripod head: Gitzo GH1781QR
1. Sometimes people will remark about these HDR photos not quite looking like the scene does in person, and they would be correct. However, neither do the traditional photographs take are taken in these spaces (just see the examples above). It seems there is often a misconception that if something is shot in HDR then it is automatically supposed to look exactly like we see it in person. HDR does not necessarily show a scene exactly as we see it in person, but strives to show scenes more like the manner in which the human eye sees.
2. HDR has a wide range of applications, but I chose to shoot these in HDR in order to solve a problem. HDR does not in and of itself produce a superior photograph.
3. Use a tripod. Any movement between exposures can result in some weird stuff. Some can be cured by the above mentioned masking process, but some of it will ruin the image.
4. Make the most of your depth of field. It is tempting to set the aperture to f/22 to cover this entire area but the problem with that is that you are lowering the performance of your lens. By shooting somewhere in the middle (I use f/8) you will get better sharpness. Keep in mind that depth of field extends both in front of and behind your focal point. Thus, you can focus a bit in front of the back wall and your depth of field will reach all the way back, as well as be further extended towards you, and you will retain optimum lens performance.
5. You will probably find that wide angle lenses are really a blessing indoors. When one stands in a building they have the ability to turn their head and look around them. A photograph only offers a limited view. By shooting very wide angle it increases the ability to “look around” of sorts to better place one in the building you’re photographing. However, you also increase distortion with ultra wide angles lenses. Be mindful that the more of an angle at which you photograph something the more apparent this distortion will be.
6. More exposures aren’t always better. For one, the more you have the higher the chances of getting movement. I have had occasions where 5 exposures came out better than 9. So really only use as many exposures as you need to fit the range of the scene you are shooting.
7. Photomatix has the ability to process just a single RAW file instead of using a range of exposures. You can try it out and see what you get; sometimes it’s cool and sometimes it’s frightening.
8. Photomatix is but one HDR processing software of many. There are others you should try to see what works best for you.
Hopefully this has shed some light on my process. Thanks for reading.