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11-17-2009, 11:07 AM   #31
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QuoteOriginally posted by jerrymouse Quote
The good thing is K-x makes F/2.8 pancakes effectivelly F/2.0 (in terms of low light performance). I was thinking of trading one of my DA 35 and DA 40 for FA 35. Now I don't have to - DA 35 became low light lens with usable ISO 3200 (6400 & 12800 for B/W).
I try to avoid LBA with that logic, until I think of what I could have with the high-ISO and fast glass. The extra stop of ISO would turn that FA35 into a f/1.4 And who doesn't want that?

11-17-2009, 05:04 PM   #32
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Thanks for the good work. Very interesting.
I had a quick look at the pictures here and from my K100D, and here's my conclusions on pairings that appeared similar:

K100D 1600 vs K-x 3200
I initially thought K100D ISO 1600 and K-x ISO 3200 have comparable noise.
I actually I went back and fed the K-x 3200 DNG through dcraw (using ufraw) as I did for K100D's i was comparing to. There's a fair degree of noise reduction in the K-x JPG here for this advantage. But comparing 1600 to 1600 they seem very similar, K-x's a bit better. The K-x 3200 does seem better than K100D's though.

K100D 1600 vs K7 1600
comparing K100D ISO 1600 and K7 ISO 1600 JPG have similar noise, but the K7 has 'cleaner' data. It seems like there is less chroma noise. Unfortunately thats a Raw vs JPG comparison.
On opening the DNGs with dcraw. Not as big a difference as I had expected. Hard to say which is better.

K-x 3200 vs K7 1600
K-x ISO 3200 and K7 ISO 1600 seem to have similar level of noise.
But again throughout it's range the K7 seems to hold more detail. By that I mean the noise is less artifactual/chroma based, seems to have less noise reduction applied. On opening the DNGs some of the difference in JPGs is due to K-x's heavier noise reduction.

overall the K-x does have a little less noise, but I don't think its a full stop better.
Keep me happy with my K100D for a bit longer. I would like a bold yellow camera though.
11-18-2009, 07:15 AM   #33
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i've compared k7 3200 and kX 3200 and images placed at Imaging Resource "Comparometer" Digital Camera Image Comparison Page

it seems that kX looks like 2/3 stops ahead of k7 (3200 is obviously better, while 6400 is "almost as good as"
11-23-2009, 10:42 PM   #34
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First off, thank you for taking the time to provide these samples! I only shoot raw, so actually having raw files to play with using my own work-flow really gives me a good idea of what the two cameras are capable of.

One thing that becomes clear when you start looking at the images: The K-x is performing luminance noise reduction on its raw files at ISO 800 and above, where the K-7 is doing very little or none at all. The chroma noise reduction also seems to be a touch stronger on the K-x, if only barely.

I added 1/3rd of a stop to the K-x samples in order to match the K-7's exposure, and exported them with no sharpness and no noise reduction in lightroom. After that, I ran all the shots ISO 800 and above through the default setting in Noiseware. My impressions are as follows:

ISO 100-400: The K-7 is showing more detail in fine textures, namely on the front lens cap of the X70.

ISO 800: The K-7 is still showing more detail, but the K-x has slightly less noise. In the end the two factors cancel out, making both cameras even.

ISO 1600: The K-x takes the lead, though the differences are nearly imperceptible at web viewing resolutions. The biggest difference can be seen on the indented text on the Sony Cyber Shot's grip, where the K-7 is noticeably blurrier. Maybe about a 1/4th to 1/3rd stop improvement over the K-7.

ISO 3200: This is where things start to get messy for the K-7. Easily about a 1/2 stop improvement for the K-x here.

ISO 6400: By now the K-7 is in full-on meltdown mode. The K-x is over 3/4ths of a stop better.


I am planning on upgrading to a K-7 this spring, and this definitely puts my mind at ease after reading so many negative comments regarding its ISO performance. Once you take into account the different levels of in-camera noise reduction, the K-x isn't taking full-stop(or more) advantages over the K-7, as it initially appeared. Nevertheless, both cameras are impressive in their own way. Although the K-7's raw files show a lot of noise, the grain pattern is very tight and even with no signs of banding or purple splotching. The K-x, on the other hand, delivers usable ISO 3200 and 6400 for half the price and half the effort in post.

11-23-2009, 11:18 PM   #35
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How did you determine that it adds luminince NR at 800?

Re: Compare the K-X to the K-7 High ISO RAW without noise reduction??: Pentax SLR Talk Forum: Digital Photography Review

btw, only a couple RAW converters don't apply NR when set to 0 NR.
11-24-2009, 12:02 AM   #36
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QuoteOriginally posted by Eruditass Quote
How did you determine that it adds luminince NR at 800?

Re: Compare the K-X to the K-7 High ISO RAW without noise reduction??: Pentax SLR Talk Forum: Digital Photography Review

btw, only a couple RAW converters don't apply NR when set to 0 NR.
I just got the impression looking at the K-7 and K-x files side by side at 100%. The K-7's grain pattern is always very pronounced, where as the K-x shows some of the smoothed over look in the gray and shadow areas. When applying some luminance reduction to the K-7 files, the grain starts to look very similar to the K-x output.

Even if some amount of NR was applied with a 0 setting, I still was running all the files through noiseware. The goal was to compare the final product, rather than the immediate result straight of the camera. In any event, the K-7 files cleaned up more than the K-x shots using the same settings, while maintaining an equivalent amount of detail.
11-24-2009, 12:07 AM   #37
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I'm only referring to your comment that the K-7 starts later than the K-x, which starts NR in RAW at 800.

I mentioned the NR 0 setting because perhaps that could've led you to believe the K-x was applying at 800, not because I didn't understand your goal in the comparison.
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