I normally shoot my D80 in JPG mode, because I like the way the JPGs end up looking, and I have had a hard time manually processing the .nef files to look as nice to my eye.
Sometimes the image storage mode on the camera gets changed inadvertently, and I end up with a day's worth of .nef files and no JPGs.
Is there some tool I could use to process these .nef files to .jpg using a computer (mac) in the same way that the camera would have done?
Yes, the camera has "presets" that are applied to the image to give it some more contrast, saturation, etc. It's very common for people to want to switch back to JPEG because RAW images look flat when you start out. It's important to still use RAW though, because you can add in your artistic vision a lot more effectively with more sensor data.
To answer your question, you can actually download the Nikon's (and Canon's) presets and apply them to the RAW image. Matt Kloskowski over at Lightroom Killer Tips posted up the latest batch here. Using these presets, you can apply the same settings that your camera does in JPEG and give you a better starting point. It's easy to do this in batch as well, or even on import by selecting the preset in the import dialog.
I'd highly encourage that you continue shooting RAW and simply apply the preset to give you a better starting point.
@stan rogers was correct in his comment to my original question. ViewNX provides these tools, no need to resort to paid software.
From stan:
select all of the pictures and apply a Picture Control then do a File→Convert Files...
To duplicate it exactly, you'd need to understand exactly what the camera does between the sensor and the finished JPEG. I'm sure Nikon knows, but I'm also sure they're not telling beyond what they cover in the owner's manual. You can, with some experimentation, approximate it. There are two major categories of changes you need to deal with:
The first is how the camera enhances (or attempts to enhance) the image after it has been captured. This normally involves setting white balance and applying some combination of adjustments to sharpening, contrast, brightness, hue and saturation. Your best bet would be to work with a few raw images and their camera-produced JPEGs side-by-side to see if you can find a set of basic changes that work.
Nikon's more recent bodies have a feature called D-Lighting that lightens the darker areas in the image. This is the same thing done by the Fill Light control on some processing software does. There's an "Active" flavor of this feature that adjusts the camera's exposure program for maximum dynamic range after the processing happens. You won't be able to compensate for this after the fact because you can't change the exposure.
The second is compression of the finished image into a JPEG, which happens after all of the processing outlined above happens. You can get an idea of how much compression is applied by setting your camera to save a RAW and JPEG for each image, shooting some pictures and converting the RAW to a JPEG using your processing software. Keep changing the compression level until the processed JPEG is about the same size as the one produced by the camera.
Jrista's comment covers the batch processing issue pretty well. Most of the major programs have an "apply settings and export in batch" feature.
If you haven't done much with raw images, I'd encourage you to spend some time tinkering with them using a good processing program (LightRoom, Bibble/AfterShot, etc.). You can get quite a bit more out of raw files with minimal work, and the results can be much more rewarding.
IrfanView can batch convert Raw files for you to any format you would want, using a GUI.
I shoot deliberately in raw, and my photography routine is follows:
Here's the NEF2PNG script: https://github.com/gurkanctn/NEF2PNG (It requires Python to run.)
If you are using Adobe Photoshop or the like you should also have access to Camera Raw. This will enable you to process your RAW files.
Keep in mind that a RAW file really is just like a film negative (or to be more precise a slide film -- as you get a positive image). It records everything the camera sensor can "see". Settings like white balance, sharpness etc get added to the image after the data is captured by the sensor.
The best way I learned was to do a search on YouTube for "RAW processing" or "NEF processing". You may also want to search for these terms and the name of the software you are using.
Another useful publication I found is NPhoto magazine from the UK. They are geared towards Nikoln cameras only and are written for Beginner and Intermediate users. They include a section each month on what to do with your files.
Hope this helps.
