Sunday, July 3, 2011

Panasonic LX5 Review: Jpeg Versus RAW

Much has been said about the LX-5's jpeg engine, and to be honest, the output that you get straight out of the camera is not bad at all. Compared to what you would get from the Canon G12, the results lack a bit of bite, but for most purposes, unless you are comparing pictures side-by-side, you won't miss the difference. That said, I agree with the sentiment that nearly every scene that you could shoot with the LX-5 could be better shot with RAW, though I am also certain that not ever scene will require this.

To begin with, the jpeg versus RAW debate is not a real debate... RAW gives you more detail and control. However, if you nail the exposure and white balance correctly at the time of shooting, then the difference is not as great as some would make it out to be. The remaining advantage will come down to how the file is rendered, and in this, a RAW converter will always win against the in-camera jpeg engine, though in some cases it will be close. it just depends on the situation.

Take this scene for example. Even though there is a lot of detail in the foreground, none of it really matters, as it's not the focus of attention. Because the sky is large expanse of a blue and the clouds are relatively large picture elements, the additional acuity 'bite' that a RAW processed version would offer would be minimal to the picture. However, a the RAW file would give extra leeway in adjusting the exposure... and that will alter how the detail that is captured by the camera is emphasized.

Garry Point Park, Richmond, B.C., Canada


Here's another scene. This time there is lots of detail going on, both in the foreground and in the background. However, a lot of it is 'hard' detail, the kind of detail that will show up well regardless of how the file was produced. By this I mean high contrast edges, the hard lines of the skyscrapers or the immediate outlines of the lampposts. Any camera will do fine if your scene has high contrast elements, but the LX-5 is a somewhat modest letdown for low contrast detail... take the trees for example. Even though this isn't a full size crop, you can see the detail is fairly mushy, particularly the lesser exposed trees at the far left of the scene.

Downtown Vancouver, B.C., Canada. Calm peaceful afternoon, not so calm evening... Guess which day this picture was taken?

The following  is a picture of an orchid taken with the LX-5's RAW+Jpeg shooting mode. Exactly the same picture, only the camera has saved the file twice in two different formats. The pertinent details were ISO 80, f/4.0, 1/60 sec, 90mm equivalent focal length and flash. Be warned that if you shoot RAW+jpeg, the write times start getting clunky with this camera.



JPEG Version: At a normal (web) viewing size, the picture is not unpleasing. Colour is fairly accurate, and true to the camera's Leica-approved lens, sharpness is very good within the plane of focus. The leaves are bit washed out by the flash, but overall the picture is serviceable.
Jpeg Out of Camera
RAW Version, as processed by SilkyPix. Default converter settings, but a bit of unsharp mask added as per any RAW workflow. What jumps out immediately is that RAW converter has 'further' rendered the fine detail of the flower petals. In fact, the rendering of the fine detail is so much greater than in the jpeg version, the overall impression of the flower is that the colour is deeper.
RAW, SilkyPix
Here's a 100% crop of the Jpeg version:
Jpeg 100% Crop

And here's a 100% crop of the RAW processed version.
RAW 100% Crop

The difference is subtle, but the RAW converter pulled out more colour in the leaves. This isn't a small thing either... purples are notoriously difficult for digital cameras to get right. The reasons get a bit technical, but at the core of it, the Bayer filter in a modern digital camera has two green pixel sites for every red and blue pixel. This is too match the human eye, which is the most sensitive to light in the green wavelengths, but it also means that our cameras don't capture as much detail in reds and blues as they do greens. Take a snap in your local tulip patch; your pics will have a lot more detail in the leaves and stems than in the flowers themselves. Even though it's a small difference, this orchid is an example is of the extra detail that you can pull from a file if you used a RAW converter rather than relying on the camera. The difference, of course, is context. Some cameras are so dreadful you would want to use RAW all the time to overcome their deficiencies. As of 2011, very few, if any, cameras fall into that category anymore. It's certainly not the Panasonic LX-5. However, if you plan ahead and think about how your picture is going to be used, then saving to RAW will be worth the effort.

For the original LX-5 review see the companion post
http://1000wordpics.blogspot.com/2011/04/panasonic-dmc-lx5-review.html

2 comments:

  1. I have an LX5 and it looks like your photos are showing what mine are -- that the JPG is sharper than the RAW. I'm guessing that this has to do with in-camera sharpening. Is this true? Can the RAW be made sharper than the JPG?

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  2. You can make up some of the difference by turning out the in-camera sharpening, but that will also risk accentuating noise and noise reduction artifacts. It seems that the jpeg engine in the LX-5 isn't quite so sophisticated as doing it on a computer. If it's any consolation, the LX-3 seems to be worse in this regards.

    I keep the intelligent resolution setting on low with my camera. I think it's a good compromise, it sharpens low contrast detail without overdoing it for the harder edges.

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