Forum: Pentax K-3 & K-3 II
03-08-2014, 01:38 PM
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es that is Bobn2 and DSPographers method.
Yes I've look at the sharpening quite closely. I've tested a couple of methods on the raw files of both cameras. I find not all sharpening is the same. Here is what I've found:
DCU 5 sharpening is quite good with either camera however with the K3 it can sharpen quite strongly without halo's. I don't like the interface particularly and I rarely use DCU. But it can provide good results. It is particularly good for dialing in the camera JPEG settings as you can test what settings work and them set them in the camera.
DXO 9 uses its lens software algorithms very well on the K5 and K3. I've used them against a variety of lens and the effects are very good. No halos on either the K3 or K5 but on the K3 I can use stronger sharpening without fear of making it overly crunchy. The extra resolution of the K3 is very apparent when using DXO9 relative to what can be done with the K5.
Once I've used DXO I typically work the keepers further in CS6. Some things I may do are use the unsharp mask (high radius, low amount) for microcontrast and sometimes I may use hi pass blending or smart sharpen depending on what effect I'm after. The K3 can take this sort of thing better than the K5. (I don't use all three together)
I've had very good results with Nik plugins and the K3 responds very nicely to both the sharpener and the noise reduction software. Good stuff there.
Perfectly Clear does a very good job on both the K5 and K3 files. The results are very good on the K3 at its default settings and I find I don't need to tune that filter much. It sharpens the photos nicely without halos. This plugin is simply great.
I've also tried Raw Therapee with similar results. So the bottom line I find is this:
I can sharpen K3 files further than I can K5 and maintain the integrity of the image better. For my workflow and what I'm looking for noise is not a concern up to 1600 on either. Past that and I find the noise similar with the K3 degrading a bit quicker (on the K3) if the pixels are peeped at 100% for both. I put that down to the inherent NR being applied on the K5 - there is default NR on the K3 but it is clearly less. Note that if the images are sized so that the image appears magnified the same - apparent magnification then the results for noise are similar but the detail on the K3 is much better. Once NR software is applied at 3200 and above the result is similar however I find that the K3 can still retain more detail despite the increased application of NR over the K5 at 3200 and above.
One thing that I find I need to watch with the K3 is the suppression of the reds in the photograph when addressing color noise. More NR is required on the K3 than the K5 and this can cause some color suppression if one is not careful.
As to read noise on the K5 and K3 similar read noise. Sensorgen calculated the read noise of the K5 at 1600 is 1.9 and I calculate the K3's read noise at 2.3 at 1600. The delta likely would be inside the manufacturing, measurement and calculation error of the method. I've calculated the QE for the K5 at 46% and the K3 at 48% which again is pretty much a wash. What is different is the Full Well Saturation. The K5 is higher than the K3 hence its better DR. This higher saturation provides the K5 benefits that the K3 offsets at higher ISO with trading the SNR for resolution (it has a fair amount it can trade for example Imaging Resource estimated the K5 resolution on a test at 2100 lines and the k3 on a similar test with similar method of interpretation as 2700 lines - so it has about 28% more resolution on THAT test - YMMV) - that works to a point and for me that cross over appears to be about 6400 depending on the content of the picture. But even then we are only talking about a half stop of DR at the same ISO between two class leading cameras. For me the gains of the the K3 resolution more than addresses the better Full Well Saturation point of the K5 particularly at the light levels and lenses I intend to use it with. I'm of the opinion that the K3 sensor is pretty much using the same design and manufacturing process as the 16 MP sensor. The difference is in the size of the pixels and their inherent FWC. We did not get anything new per se we just got more of it.
But I do like the results and all the calculations provide is comfort that the K3 is (as per my observation and again YMMV) indeed providing better IQ than the K5, and up to 3200 clearly better.
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Forum: Pentax K-3 & K-3 II
03-07-2014, 05:44 AM
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HI DOSDAN
I calculated that the sat point of the K3 at base ISO - 94 (100) the read noise was 3.33, Saturation 24500 and DR 12.84
See K3 Read Noise, Sat and DR: Photographic Science and Technology Forum: Digital Photography Review for a bit more. QE is fairly high at 48%
The K5 is quite a bit better in its saturation calculated at 47159 from Sensorgen. I used the same method as Sensorgen.
The tradeoff in pixel noise levels on the K3 vs K5 is that we have many more pixels on the K3. So when sized and viewed similarly the apparent noise is similar.
I have the K3 and K5. In most situations its very hard to tell which photo the K3 versus the K5 took. However the resolution difference is quite noticeable.
I find that under 3200 the K3 has better IQ. Above that its about the same due to noise and what I need to do to mitigate it - I lose most of the improvement in resolution to mitigate the noise. Below 1600 and in particular below 800 the I find the K3 is quite a bit better in many ways.
Although I shoot raw mostly I have been quite happy with the default tuning of the JPEGs. Now that I've spent some time tuning the parameters I like them better than my Olympus. And that is saying something.
Jim
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