What is HDRI and how do I achieve it?

[Joey D]

HDRI, I know what is means (High dynamic range imaging) but what exactly is it? And how do I go about getting it? Is it based on the camera or is it something I can do in a program like Photoshop?

I keep seeing people talk about it and I see pictures with it and it looks amazing! I tried looking it up on wikipedia but got uber lost in the explanation, so if someone can give me the idiots version that would be the most helpful.

But yeah, here's a picture with it.

I think it looks absolutely amazing and since I would like to get more into photography I would like to know how to achieve pictures that look similar to these.

Thanks!

 

[CDailey]

From what I understand, to make an HDR image you need to take a picture of the subject at different exposures. I've read anywhere from 6 to 8 different exposures will work. Then you layer them on top of each other a certain way in an image editing program and there you have it. I've never actually tried it so don't take the previous as the gospel.

 

[exigeracer]

Basically, some light is exposed at lower exposures that the higher exposures doesn't get and viceversa. Bracketing (same picture with different exposures) 6 or 8 different images gets a variety of light across the range of those 8 individual pictures, and combining them all in PS puts that whole range into one image.

Simple stuff. Some programs cheat and achieve similar images with only one picture, but the real thing is more complicated but ultimately more rewarding.

Keep in mind "HDRing" a picture won't make it good. If a crappy photographer takes a crappy set of pictures, the HDR will still be crappy.

http://www.hdrshop.com/

http://backingwinds.blogspot.com/2006/10/how-to-create-professional-hdr-images.html

 

[Perfect Balance]

Would this be considered HDR? I tried something in photoshop, and I'm not sure if it looks like HDR, or if it just look like I turned up the contrast a bunch.

 

[niky]

Nope, that's different. See, turning up the contrast washes out the road in the picture and darkens the shadows on the car.

I use that sometimes for dramatic effect, but I often take multiple exposures and, if I have a tripod, I actually do "mix and match" different exposures to achieve the effect I want.

But for the top picture? That would take at least a dozen different exposures, and a hell of a lot of photoshop time.

 

[exigeracer]

There are programs that can run your photograph sets into HDRs in seconds, but you have to know some basic digital media first, calibration curves and such...

www.hdrshop.com

 

[Perfect Balance]

See, turning up the contrast washes out the road in the picture and darkens the shadows on the car.

I didn't turn up the contrast a lot, but the end result looks like that's all I did.

 

[niky]

It's quite hard if you have a single photo to work from.

A better way is to work on a balancing map... I don't use Photoshop myself, just a similar product, so I don't know what it's called there... basically, it allows you select the current shadow value (darkest area), highlight (brightest) and gray (pick something that looks... errh... gray), and then reset them to a set of standard values (usually 10, 155, 245, or something like that). The tool balances out the color and corrects it, as well as giving you more definition in the shadows and the bright areas.

Also, you can manually select areas that you want to adjust brightness in, so that you don't wash out areas that are bright enough already. I do a lot of this, simply because I'm a crappy photographer.