Sunday, July 26, 2009

Fuji F70EXR -- High ISO in HR Mode -- How good is it?

I remain tempted by this cam, but the examples on the net so far are not fantastic. Still, for a small sensor it looks like 800 ISO is going to be quite decent. Even shot in HR mode, it is not bad.

1600 ISO on the other hand, looks bloody awful when shot in HR mode. Same issue as the F50fd et al ... photosites overwhelmed and the result is a massive blue cast over everything.

I found some images at this site with which I could explore the detail available. I checked 200 ISO as the benchmark, and then 800 and 1600. There is definitely a threshold effect at 1600 ISO ... noise spikes hugely. I am looking forward to some decent examples appearing on the net in SN mode. But for now, that model image in my last post is about all I've seen.

There are crops available on the original site, so I am not going to repeat those. What I've done is treated the images with Topaz Denoise, a high-grade noise reduction plugin that takes about 5 minutes to clean an image. It is really good at leaving detail while smoothing areas without texture.

Here are the crops for these images, showing that 800 ISO retains highlight detail well, and has tolerable detail remaining in the dark areas as seen in the shutter mechanism in the middle of the lens.

That's some kind of color cast, eh? Edit: I should be clear that this is not quite how they look on the site. I set white balance in ACR from the table, which I take to be white. It is accurate at 200 ISO, so it should be accurate all the way up.

Another thing I've done to these images is clean out the rather high CA. The sad fact is that this is Fuji's newest lens and, not only have they not cured CA, it looks like it is rather rampant :-)

To be fair, this might be purple fringing, but I don't think that'll make me feel any better when it shows up. Expanding the view in photoshop eventually gets up to pixel view, which allows one to count the 19 or so pixel width on the worst spot.

But Shay Stephens' CA Remover plugin continues to perform well for me. So I suppose I could tolerate it should the rest prove to be exciting.

I did a quick processing job on these three (converting the 1600 ISO image to B&W) and they came out pretty good.

That was 200 ISO, which looks quite clean. 800 ISO coming up looks almost as good at this size, but there is less detail in the shutter mechanism.

And finally, the master of disaster ... 1600 ISO. Not good, but remember that this is HR mode. So 1600 ISO on such a tiny sensor is hopeless ... I'll reserve final judgement until I see someone posting samples shot in SN mode. (Beats me why these are 10mp images ...)

Edit: Let me be clear ... this is a *tiny* sensor ... has to be to get that range in the lens ... so this 1600 ISO result in HR mode is not half bad. Few vendors could approach this result from a compact with no RAW capability ...

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