Why does the Fuji F30 have a problem with purple fringing?

[kenbalbari]

In this situation, pretty much any point and shoot will have trouble getting both the subject and the background exposed. The sensor doesn't have enough dynamic range to do both. So if you meter the subject, the sky will be blown out and white. Here is a crop from the above at 100%:

[kenbalbari]

The only other choice there might be to instead expose the sky properly, underexposing the subject:

[Gozinta]

Contriver wrote:

Is there some design characteristic responsible for the purple fringing? Does this also occur on the S6000FD and F31FD?

I haven't noticed any excessive purple fringing with mine.

[kenbalbari]

The above I find easier to clean up in postprocessing. This is the exception to the rule of always get exposure correct first. If you overexpose, you can't get the details back. So, if you must chose between overexposing one thing and underexposing another, you might chose the later if you are going to be able o edit it later.

Here it is brightened up some, and sharpened some as well:

[kenbalbari]

As for how much a problem this is, I don't think it's that big of a deal. It may be enough reason to say that the F30 falls just a bit short of the very best models for outdoor shooting (likely Canon and Panasonic). I think it is still very good outdoors. I'm generally only getting this when the sky is overexposed, with dark branches against it. So you have to be careful about it overexposing the sky.

I think there is one review out there that exagerates the problem just a bit. I think Steves review accurately descibed the camera:

The exposure system did well in most lighting situations, however it did tend to overexpose the sky on very sunny days.

http://www.steves-digicams.com/2006_...i_f30_pg5.html

The best way to prevent this is to keep the sun behind you if possible, lighting your subject as well as the sky. At around midday, it might sometimes be useful to set EV -1/3. In very challenging situations like the above, particularly when shooting from an area in the shade out towards a bright sky, you may have to meter the sky and brighten it up later (or choose to blow out the sky). Fill flash can also help in this spot (but wasn't enough above).

[Contriver]

So let me get this straight, I don't see any purple colors in the photographs you posted. Going by what you say, it sounds like 'purple fringing' has nothing to do with the color purple. It seems that it has to do with the picture being washed out in high contrast situations. Is this correct?

[Contriver]

Is this purple fringing in this picture?

[kenbalbari]

So let me get this straight, I don't see any purple colors in the photographs you posted. Going by what you say, it sounds like 'purple fringing' has nothing to do with the color purple. It seems that it has to do with the picture being washed out in high contrast situations. Is this correct?

Well, the purple fringing is around the edges of the tree branches. It maybe has a slightly purplish hue, but in any case it's not the natural color of those branches. It's pretty clear around the edges of the palm trees in the first example.

In the second example with the tractor, it's really not that noticeable until I blow it up and take a 100% crop of the leaves in the background.

And you can get colors other than purple. More generally this is refered to as chromatic aberation (or CA), which covers purple, blue, or whatever hue your camera prefers to put in there where it doesn't belong. Many people refer to it as "purple fringing" though even when it's not really purple.

This tends to occur only in high contrast situations, such as a dark object against a bright sky. In practice I've really only noticed it with this camera when the sky gets overexposed and washed out. The overexposure is a seperate issue, but the two do tend to go together.

And it's generally really not a big problem, The above are a couple of the worst examples I could find after a couple of months (and over a thousand photos) with this camera. You can see why some people might say they haven't noticed it. You almost have to be looking at 100% crops of your background for it to look like a problem.

But most people will look main subject of the photo, rather than looking for any minor flaw of a few pixels in the background. In fact, I think my first tractor photo above, with the purple fringing in the background, and without any postprocessing (just resized), is probably a bit better overall than my last post-processed photo without any. For one, I think the composition is better. And, when I metered on the sky in the second tractor shot, I also focused on the sky. So I needed to sharpen it up partly because my subject was less in focus. And I probably overdid it a bit with the contrast. I think the tractor in the first shot looks more natural.

I'm not even sure I see it in the photo you posted, but I think there might be some along the treeline, maybe if you took a 100% crop, three might be a bit, particularly along the treetops on the right side.