Maximising dynaic range

[will69]

I have been using my canon 40d for a couple of years now and I am in general very pleased with it, however I have always struggled with my perception of about a 5 stop dynamic range.

A trawl through the dpreview.com archieves show that they have tested the 40d as having a 9EV usable ynamic range.

http://www.dpreview.com/reviews/CanonEOS40D/page20.asp

I believe I am correct in equating stops with EV in this context. I also see that further down the review it talks about the differences in dynamic range achieved from the camera as a jpeg and adobe camera raw conversions ... leading me to think that my issues are operator error in PP rather than a camera problem.

I usually shoot in RAW and I use lightroom exclusively for PP. How can I get a better DR in my shots??? Any advise would be welcomed.

 

[tdodd]

To maximise DR you want to expose as brightly as you can, without going too far and saturating the important highlight details. The technique is called "Expose To The Right" - ETTR. You can read more about it here - http://www.luminous-landscape.com/tutorials/expose-right.shtml.

If you pursue this technique, as I often do, you may end up with images that look too bright, and washed out, but because you shot raw you can correct the "overexposure" by adjusting levels. In so doing you will be able to reduce visible noise. This is a much better approach than underexposing and then trying to brighten things up later, which will make noise look worse, especially in the shadows. Do not enable HTP. It wastes a full stop of DR for raw shooters.

Another article on "digital exposure" - http://ronbigelow.com/articles/exposure/exposure.htm
Use the camera's RGB histogram to help you nail those perfect ETTR exposures - http://ronbigelow.com/articles/camera-histogram/camera-histogram.htm

 

[Chappers]

Having just read the article I'm a bit confused.

They state that when comparing the JPEG image to the RAW image processed in ACR the JPEG had a better dynamic range. However looking at the graph and reading what they say, the RAW image has at least an additional stop of data. I would have thought that would indicate that the RAW image had a wider range.

One problem may be that all the data especially RAW is converted into 8 bit data for screen viewing and printing. The latter is especially a limiting factor as the amount of ink that can be laid down does influence the final result.

There is undoubtedly more data in a RAW file compared to a JPEG. ( I've been looking for an article that i read a few years ago about exactly this scenario, but can't find it). It's all down to how you process the data as to what you get out of it

By the way you are correct in reading stops as EV's in this case