Saturday, August 23, 2008

One Shot HDR - D300 14-BIT NEF RAW - Green Heron Closeup

I've been enjoying using the D300's 14-bit RAW files for a little while now.

Shooting RAW lets me gain latitude. I'm still trying to get the exposure right as shot, but by exporting jpgs from the NEF file at different exposure level and merging them back in Photomatix the level of color and shadow and highlight detail increases nicely.

Read on for this example done of a closeup photo of a Green Heron - 1 Shot HDR (D300 14-bit NEF).

Because CS2 doesn't support the D300 RAW files I use the DNG converter first on the RAW file(s). For a while I was cherry picking the ones to convert. Now I've started to convert all the images (and have plans to get in the habit of deleting the original RAW files. I haven't had the guts to do this yet without first backing up the RAW files to DVD file backups.)


Here's the 3 exports from the NEF/RAW file:
-1.1


-0.1


+1.1



Here's the initial HDR image tonemapped. The few things I always do when tonemapping are:
1 - strength 70-90%
2 - light smoothing one below max (medium-high)
3 - adjust white and black points a lot. This is more important than almost any of the other settings. It allows me to set where the clipping happens at both ends of the exposure. Limiting the amount of light ranges that the 8-bit image has to render frees up a lot of room in the image for mid tones.



HDR tonemapped jpg processed in CS2 for exposure (again). My trick here is to duplicate the background layer, and then change its blending mode to MULTIPLY. This has the effect of increasing the contrast. To adjust the strength of the increase in contrast I change the opacity of this top layer. One of the effects of the HDR/tonemapping process is to decrease the contrast. So, I think it is needed to make the images look realistic again after the processing.


To create a new layer with all of the layers merged, while not flattening the image I hit Ctrl-Alt-Shift-E which stamps all of the visible layers in to a new layer.

And here's the final (flickr) image cropped on the sides and drop shadow and frame added.


This was shot with off camera flash on a TTL cable. I was shooting in Shutter mode at flash synch speed of 1/250th and had a little minus exposure compensation. In a more controlled environment I would shoot in manual mode. The flash output was set to manual though at around 1/4 to 1/8th power and was off to camera left sitting on my backpack (ie 1 foot above ground level, nearly the same height as the bird ~15 feet away).


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3 comments:

Roberto Saccon said...

Great tutorial. I am using Aperture and Hydra HDR plugin (but I am absolute beginner at HDR), there you can directly generate a single-shot HDR from a RAW-file. Unfortunately the Hydra plugin has at its current version only few adjustment settings, so for advanced users it is not good (yet).

Avi Revivo said...

Excellent tutorial! thanks a lot for the information.

PaiasoLoco said...

Brilliant. Thanks for your post. Exactly what I was looking for. How much heavier is the 14bit version of the NEF file?