Today i shot a series of pictures of my house. It was at night with all window and external lights on. I was trying to get a picture which had the lights correctly exposed, and the house light enough. I decided to use HDR. I took 10 images. The highest shutter speed was at 150 and the lowest was at 30 seconds. i combined useing HDR, and came out with unimpressive results. The lights were still blown out, the sidewalk had a greenish tinge, and all the lights had a random blue "blob" on them. What am i doing wrong? Any help would be appreciated.
Hard to say. First off, you probably took too many shots. Each one should be about two stops apart so 10 shots seems a bit much. Second, if the lights were still blown out, they likely were in the shortest exposure you did shoot. You need to be sure to shoot images that cover the full range without overexposing. The random blue blobs is likely an artifact of not having a good exposure for them that did not overexpose.
The greenish tinge on the sidewalk may really be there depending on what street lights or other lighting there may have been. Sodium vapor lights could easily have been slightly green. Even though our eyes compensate for this, the camera does not.
There is also the issue of how you converted the image to 8-bit or 16-bit. HDR images themselves in their native 32-bit form will always look bad since no monitor can display their wide dymamic range. To see them, you have to convert to 8-bit or 16-bit using some sort of tone mapping function. The choices you make here can have a dramatic effect on how the final image looks.
Sorry about posting in the wrong forum. I will keep it in mind next time.
About the exposure, How do you know if the picture is overexposed. I mean you cannot rely on the camera meter right? If the lights are burned out does that mean the picture is overexposed? If that is true then it would be impossible to get a correctly exposed picture, because the house would be in darkeness, if the lights are properly exposed. I am confused, any help would be appreciated.
Check the histogram after shooting each shot. You need shots all the way down until the histogram does not peg against the right hand end of the display. Yes, this will mean at least that last shot will be totally black other than the lights in the windows which will be correctly exposed.
Ok, thanks. I am going to the park tommorow and hoping to catch a sunset plus surronding landscape. I will use HDR to get the image exposed correctly. By the way, how does having alot of shots mess up the HDR utility?
The more shots you have, the harder it is for them to be combined of course, but more importantly, the more likely it is that something won't line up somewhere. You will get sharper results if you have fewer shots.
Thanks for helping me out. This is my first time really useing HDR. One last question i have, actually two last questions. How many shots would you recommend, is 6 or 7 ok? Also do i have to change the shutter speed two or 3 stops every time or would it be ok changing it 5 or 6 stops every time?
Basically, you need as many shots as you need. It depends on how much range the subject has. If you are shooting straight into the sunset for instance you may indeed need 6 or 7 shots. You should generally go for 2 stops between each shot, certainly never 5 or 6. Now if you count clicks of the command dial though, it might take 6 *clicks* (not stops) if your camera is set to 1/3 stop adjustments.
Here's how I shoot my HDR shots. I'm not perfect, but I do get decent head-turning results from time to time... so something here must be right.
1) Tripod.... never without a tripod. 2) Setup on Aperature Priority, choose whatever you want, as long as aperature remains constant throughout the sequence you will be fine. Nothing worse than having several shots with differing DOF's 3) AutoISO MUST be off, or else your exposures may trigger an ISO change mid-sequence. 4) Use either bracketing or EV balance to get your sequence. You want a sequence of three for most cases, but it's completely up to you. I usually shoot a full sequence from -3 to +3 EV in steps of 1.
1) Nikon Capture. Choose the best exposure, perform a white balance on it. Remove ALL other filters, turn them all off. Once you have that shot done, select all shots in the sequence and click Match Settings. This ensures ALL your photos are white balanced and unmodified by any effects. 2) Save as 16bit Tiff using Nikon Capture. 3) Download a copy of Photomatix. Open your sequence. If your smart, you got a wider sequence than you really need, so you can mix and match depending on just how you want your end-result tonally. Open the images in Photomatix. 4) Perform a "Generate HDR", keep all defaults, except "Align images".... you DO want to align the images, so change that. 5) Once that's done. Perform "Tone Mapping". Your presented with a hoard of sliders. Play with them until you get an effect you are happy with. Click OK, and save the result as a 16bit tiff. 6) Use photoshop and perform regular post processing or whatever you feel you need.
It takes a few tries to get the hang of it. Moving those sliders around takes some getting used to, and the effect is almost always too dramatic for most peoples liking. This is why I prefer to tone-down the HDR effect with some photoshop work.
I tend to go for the little surrealness, however a little desaturation, or even overlaying the original exposure over the HDR can produce some VERY interesting effects. I say play with it, I've posted how I get what I get, now make it better
Edit >> Convert to 8-bit or 16-bit initiates the Photoshop equivalent of Tone Mapping. Photoshop provides four methods: "Exposure and Gamma," "Highlight Compression," "Equalize Histogram," and "Local Adaptation." Photomatix has its own way that is different from any of these four but is closest to Local Adaptation.
I know this question is pretty simple, but i am not sure how to copy the original image on to the HDR image. I would like to try it to see what results i get, but i am not sure how. I am useing photoshop CS2.
You should have the 'average' shot from the sequence saved as a tiff still? Open that in photoshop, copy the whole image and paste it as a layer over the HDR copy. Decrease the opacity to 30% and work on alignment if it needs any, then put it back to 100%.
Change the layer mode to Screen or Overlay, even play with the burns or any of the others, play with opacity as well in each of those modes to change the subtleness of change. Tons of options really.
Once again, thanks for all your help guys. i have learned alot about how to use HDR from this thread. I just want to make sure i understand this correctly, during your various exposures, you never want blown out highlights, correct? In other words even the brightest exposure should not contain any blown out highlights?
Not at all really, you can have many blown out highlights, and in most cases you will have many.
Basically what you want to do with your sequence of files is to create a set of exposures that gives detail on everything in the photo. This may mean that to get decent looking textured shadows, your shadow exposure will be mostly blown out.
Don't know if I've worded that right, been a looooong day
Lets say your scene is a car against foilage, with an overcast but bright sky. First expose for the sky, so that the exposure has absolutely no highlights in the sky. Sometimes you may need to take two exposures to get a full dynamic range in a sky. (isolated storms, etc.) Take a shot to expose for the brights properly, then retake another shot to get good detail in the darker clouds.
Next you will want to expose for the foilage or landscape itself. Again, you want to complete dynamic range of it. Check the photos of the sky and see where your at in terms of exposure on the landscape and adjust as needed. Take one brighter one to get good shadow detail, and one darker one to get good detail in the brights. There should be no blown out highlights on the darker one, the brighter one may have a few.
Lastly, the foreground or subject. Again, review what you have. See if you've already got enough detail in both the brights and darks. If you have, your done, if not... simply shoot a couple off, one bright, one dark.
That's the jist of it really, however most of the time I simply setup and shoot a three shot bracket with the first image set to what I consider a correct, or average, exposure for the whole scene. Only in some instances have I actually taken the time to get enough precise exposures.
Hope this helps... again I'm not an expert, but the results are halfway decent enough to sell.
Thanks, to everyone for there help. I took 6 photographs ofa sunset, and got very good results after combining them. It looked alittle unnatural, but the ginal image looked great.
One problem i got however (unrelated to HDR) is that in all the pictures i took, if i zoomed up to about 100% i could see a maze pattern in the picture. It is kind of hard to explain, but right underneath the sun there was a brick building, and the building had a maze pattern on it. What is goin on? The pattern could also be seen in the rays sun. is is something with the camera?