HDR Nighttime Shooting Tips
HaveCameraWillTravel
Registered Users Posts: 72 Big grins
Hello, and it's the time of year to take advantage of all the holiday lighting that will soon be put away for next year. HDR is a great tool for capturing the colors of holiday lighting. If you've tried taking a picture of a lit Christmas tree, you soon find out what a large dynamic range is required to reproduce both the color in the bright centers of the bulbs, AND the detail in the darker tree needles and background. One picture can't do both, but HDR comes to the rescue here. But HDR software is just like any other: GIGO (garbage in, garbage out.) To get a good series of nighttime images for your HDR software, here are some tips, followed by two shots for illustration:
1) Use a tripod, shut off image stabilization, use remote or cable shutter release. At the least, use a self-timer.
2) Manually focus on the subject, or initially auto-focus, then switch to manual to lock the focus in place.
3) Shoot RAW for more detail and less noise.
(If you can only shoot JPEG, set white balance around 3600K. "Tungsten" or "Incandescent" tends to give a cold
cast to the lights)
4) Turn off sharpening and set saturation to normal. Set long-exposure noise reduction on if you have it.
5) Shoot at the lowest ISO possible (usually 100, some cameras go down to 50)
6) Set aperture priority (or keep the aperture constant), change the only shutter speed.
7) Take your exposures one stop apart. If you find out you only need them two-stops apart you can just load every
other shot. Better to have and not need...
8) Don't shoot if it's windy, or if the subject(s) is(are) moving. You'll end up with ghosting, unless that's your intent.
9) Set the shutter on the first image to overexpose so much that the darkest areas are at least in the midtones.
10) Keep increasing shutter speed and shoot until the last picture is so underexposed that there are no blown highlights anywhere (usually in the centers of the bulbs.)
As I mentioned in another thread, I had an issue with Photomatix, that it was producing black spot artefacts on my Christmas lights shot. A fellow member gave me that critical last tip - make sure NOTHING is overexposed in the final exposure for the HDR set. The pictures below are both final tonemapped output from Photomatix, cropped down to show the artefacts easily. They do differ in contrast and detail, because they were processed with different settings. As they are certainly "nothing to write home about", they are just here for illustration:
HDR output when the most underexposed image I loaded in had blown highlights.
Now, when I included the last underexposed image which had no blown highlights.
Hope this information is helpful. Happy shooting!
Art
1) Use a tripod, shut off image stabilization, use remote or cable shutter release. At the least, use a self-timer.
2) Manually focus on the subject, or initially auto-focus, then switch to manual to lock the focus in place.
3) Shoot RAW for more detail and less noise.
(If you can only shoot JPEG, set white balance around 3600K. "Tungsten" or "Incandescent" tends to give a cold
cast to the lights)
4) Turn off sharpening and set saturation to normal. Set long-exposure noise reduction on if you have it.
5) Shoot at the lowest ISO possible (usually 100, some cameras go down to 50)
6) Set aperture priority (or keep the aperture constant), change the only shutter speed.
7) Take your exposures one stop apart. If you find out you only need them two-stops apart you can just load every
other shot. Better to have and not need...
8) Don't shoot if it's windy, or if the subject(s) is(are) moving. You'll end up with ghosting, unless that's your intent.
9) Set the shutter on the first image to overexpose so much that the darkest areas are at least in the midtones.
10) Keep increasing shutter speed and shoot until the last picture is so underexposed that there are no blown highlights anywhere (usually in the centers of the bulbs.)
As I mentioned in another thread, I had an issue with Photomatix, that it was producing black spot artefacts on my Christmas lights shot. A fellow member gave me that critical last tip - make sure NOTHING is overexposed in the final exposure for the HDR set. The pictures below are both final tonemapped output from Photomatix, cropped down to show the artefacts easily. They do differ in contrast and detail, because they were processed with different settings. As they are certainly "nothing to write home about", they are just here for illustration:
HDR output when the most underexposed image I loaded in had blown highlights.
Now, when I included the last underexposed image which had no blown highlights.
Hope this information is helpful. Happy shooting!
Art
Gonyea Galleries
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Comments
I can't see your images. Is it on your end, or my end?
Kolibri,
Sorry, my bad. The problem was the syntax I used to post the linked images. The way I altered the URL to the image so it would display would only work on Google Chrome (which is my main browser, and why I was unaware of any problem). I bet you were using a different browser, which couldn't parse out my link properly. I fixed the links by looking at earlier posts, and discovered MY error. Strange problem indeed, that IE could not see the images, yet Chrome did!
I went back to my post and edited the image links to have the proper syntax, and now they work in other browsers: I tried Safari, Mozilla, IE, and Chrome, all with success, so you should now see the pictures if you return to my original post. Sorry for the inconvenience.
Art
I've seen those blacked out highlights in some tonemapped HDR images I've made. Do you know what algorithm photomatix was using on your shots? I didn't even try to do photograph any christmas lights this year.
The blacked-out highlights do not appear if you are just doing Fusion. But once you use either Tone Compressor or Details Enhancer, voila, they appear. It didn't seem to matter what settings I used in either mode, except one: Temperature. You get some weird colored pixels in the highlights if you are in a tonemapping operation, and you set the color temperature Cooler than you shot it. Setting it warmer does not create this artefact. This even can happen if you've used a full set like I recommend (last image has NO blown highlights, which may be as much as 6 stops underexposed!).
Photomatix is a great product, though, so long as you give it the right input and try not to have to cool down your preview before final processing. I would at least try these tips and take full advantage of those colorful lights while they are still on.
Good Luck,
Art
P.S. Am I spelling "artefact" correctly, with an "e"? The usage I've seen is that it differs from "artifact" when it refers to images, but I could be wrong. I lost a spelling bee as a kid for spelling "potatos" (reminds me of Dan Quayle...)