Thread: Post your HDR pictures

Mike I noticed that you did a 5 Shot HDR

what increments did you use and do you have the option to take a 5 shot bracket or did you just do each one manually?

I assume you did two either side of the original

Colors are due to different types of light bulbs.

3 images with one stop either sides.

I used the 50mm lens thus the pin-sharp image

Another eye catching photo. Bravo!

Originally Posted by mike_ie

Thanks for the replies - that Pumori shot is certainly up there on my list of favourites.



Room with a View - Mountain farmsteads in Sagarmatha National Park, Nepal, on the way to Mt. Everest.

Camera: Nikon D7000
Lens: Lens AF-S DX NIKKOR 18-105mm f/3.5-5.6G ED VR
Focal Length: 42mm
Aperture: f/16
ISO: 100

Originally Posted by dullbird

Mike I noticed that you did a 5 Shot HDR

what increments did you use and do you have the option to take a 5 shot bracket or did you just do each one manually?

I assume you did two either side of the original

The camera I currently use is a Nikon D7000, which only allows for a three bracket exposure - one of the very few things I don't like about the camera. So I bracket manually, usually by preprogramming the U1 and U2 programmable modes, and careful tripod work. I try to judge the best bracketing exposures based on the lighting conditions, but if I remember correctly, for these shots the sequence was -1.7, -0.7, 0, 0.7, 1.7, and you're right, symmetrical either side of zero.

I usually bracket around 1.7 but I have never done it manually with the 5 shots..

Maybe I will try it..

the only thing I find when I do the HDR stuff is I get Halo's I have never looked into why though...do you know why they occur?

As far as I know, the halo-ing is caused by bad tone mapping between high contrast areas in the image, for example where building meets sky. The software can't decide automatically what the correct tone mapping should be for that area. I've generally found that for most images, manually adjusting the highlights will get rid of halos in the resultant image. With the likes of HDR Efex, you can also apply local tone mapping, and correct local areas of the image without changing the overall result.

Originally Posted by dullbird

I usually bracket around 1.7 but I have never done it manually with the 5 shots..

Maybe I will try it..

the only thing I find when I do the HDR stuff is I get Halo's I have never looked into why though...do you know why they occur?

Halos are an error from the software you use and are caused because you have wound the setting up by more than that set of images can handle.

The longer answer is that they occur because HDR is a trick. The dynamic range of a jpeg image is 8 bits. Raw images are 12-14 bits. So you already capture more than you can display. Then you add in a bracketed series and you have masses more different levels of light (& colour) than you can ever display. Hence you use HDR software to fiddle with it so that you see the bits that you want to see and discard the bits that you don't need. Nothing in perfect and when it discards some data you do need it looks odd, psychedelic or the halos you mention.

HDR uses the concept of relative contrast. This is best seen in this common illusion:


In the illusion A&B are exactly the same shade. If you don't believe me click here: Proof of Checkershadow Illusion

You eye interprets the image based on knowing what a chess board looks like, what a shadow is, etc. and uses the narrow dynamic range of a jpeg and a monitor to outwit itself. B looks light because it is beside something dark. A looks dark because it is beside something light.

HDR software does the same sort of thing to subtly shift the brightness levels, contrast, etc. to make an are stand out based on the brightness levels immediately around it. In part of the processing is makes the lighter areas beside the darker ones lighter, and gently blends the change.

When you are trying to get too much compression it has to make the area beside the dark area very bright. This is because in your image set of 5 frames you have huge changes in light level.

This gives the software two ways to to make a slightly dark area look darker. It can actually make it darker, which may cost you some details in a black shadow, defeating the whole point of HDR. Or it can make the area beside it brighter - creating the illusion that it is dark. Sometimes this works, sometimes there just isn't the range available to do this giving the halo you see.

So to remove halos, turn down the compression (or play with other settings), or load up all the bracketed images in photoshop and use a layer mask to burn through to one which happens to have that area correctly exposed. This technique is detailed here:

HDR Tutorial Part 3

Cheers, Steve

Here are three from the Tuesday evening Photowalk when Trey Ractliff came to Sydney.








Cheers, Steve