HDR & Sharpness

[duncan22]

I have been very impressed by photographs taken using HDR and wondered if it was still possible to have a sharp HDR photo ? Or does the process of combining 3 or more images using photomatix or similar software cause a reduction in sharpness ?
Could the photographs be sharpened in lightroom or similar program prior to combining them or is this a non starter ?

[anglefire]

The process of creating the HDR using photomatrix or what ever does tend to soften the image, but then if you are taking a landscape, for example, unless the wind is non-existant, you will get movement in the trees etc and clouds etc.

Doing building etc, that isn't a problem (Apart from the sky) but for perfect register, then a tripod and preferably mirror lock up is required.

I must admit most of my HDR's are hand held - but normally because it something that I happen to take rather than plan on doing!!

I tend to take the RAW files straight into Photomatrix, so they don't get sharpened before hand. I wouldn't suggest sharpening first, because you will have to sharpen at the end.

[flake]

Yep there will be a loss of sharpness in HDR, also in stitched images too, but more troubling can be the introduction of artifacts. Normally I don't sharpen images as it depends what they are to be used for, storing/saving an unsharpened image means it can be sharpened as application demands, it's not possible to remove the sharpening and it's better to do it all in one operation.

Even with a tripod and remote release & mirror lock up you're going to lose sharpness it's just something to do with the software blending three or more images.

You might consider using a program by Topaz Labs which helps to give the 'HDR' look and adds sharpening, and 'smart' saturation + contrast with easy to use sliders.

[Robster]

A great book which has a lot of usefull information about HDR and how to improve sharpness is the HDR PHOTOGRAPHY Photo workshop by Peter Carr and Robert Correll.
the book gives you a assignment for each chapter which you ccan post on the web www.pwassignments.com
you can get the book on Ebay for about £20
also the Infra red book of the same title is good.
Best of luck
Just remember it easy enough to merge the images but its in the finer adjustments that make the picture and it takes time to get right, just play about and have fun with it.

[ap4a]

Originally Posted by Robster

you can get the book on Ebay for about £20

You can get it for £16 from Amazon at the moment

Pete also has a HDR tutorial available for free on his site: http://www.vanilladays.com/hdr_tutorial/

[chris-p]

HDR tutorial wise, I've written an FAQs type thing (here) but the best and most complete HDR tutorial available on the web (and for free) is http://www.naturescapes.net/072006/rh0706.pdf. It's a 10MB pdf file but well worth the download.

[SaucySam]

Some cameras have a bracketed exposure mode that ALSO can be configured so it automatically takes the shots with 1 depression of the shutter release, or like the Olympus E-3, ISO bracketted exposures that are processed in-camera, the positioning is identical, because the shutter has in fact only fired once, and then saved 3 versions of the same image. This means that when merging your 3 shots, you don't get any image position variation, which on the finished shot, might look like blur, but is because the camera position has moved between each shot.

[flake]

A single shot with the exposure dragged up & down does not make an HDR. Highlights will still be burned out and clipped shadow detail will still be dark. The whole point of HDR is in the name, getting a wider dynamic range because a single image cannot accomodate it.
A lack of sharpness is not a case of camera movement, it's a product of the software process, which is also seen in stitching, and also in focus stacking.

[duncan22]

Another excellent book (£12 from Amazon including P&P) is Complete guide to High Dynamic Range by Ferrell McCollough.
It has some stunning photographs and whilst it concentrates on photomatix it also compares photos from other types of software such as FDR, Artizen, Dynamic photo HDR and even a few examples of the HDR facility in Photoshop.