Best raw converter pentax k5




















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Notify me of new comments via email. Notify me of new posts via email. Creativity through Simplicity. Skip to content. Share this: Facebook Email. Like this: Like Loading Eric, I don't really know if these specifications are derived from real ones or not and how many errors there might be if they are, but I really hope that the new camera does not have 14 bit raw or if it does offer it, it offers the option to turn it off as Nikon cameras that offer it do.

From measurements on the However, Pentax went back to 12bit raw for the K20D and K7. Don't know why. DR is distance from ground noise to photosite saturation.

Number of bits is how you split that range for each channel. K10D was 12 bit as well -- Pentax claimed the processing was bit or something like that, but that didn't seem to have much of an impact on anything. It does not help to suppose all kinds of assumptions that do not exist. As others already pointed out, the sensor characteristics are not improved. In the RAW data at least, there are now many more shades of blue.

The K10D was 12bit with 22bit processing. Although the RAW data has only 12bit colors, the JPEG processing pipeline took those numbers and converted them to 22bit adding zeroes before working on them mathematically produce the image. So rounding errors from bit truncation were avoided. Worth remembering that any output you are likely to be looking at is no better than 8bit, it all gets downsampled in the end. This reference might make things a bit clearer for you. The use of high quality amplifiers also matters.

Have a look at the section on DR particularly the graph and its explanation at 5a. That the s is not better than the D90 is proof that Nikon cut some corners somewhere, not that the theory is faulty. Considering the impact that going to 14 bit has made on the depth of the buffer, I would hope that there is in fact some increase in DR.

Engineering is all about selecting the best compromise to match your product requirement. It would make no sense to reduce the number of frames that the buffer is capable of without actually gaining some performance in another area. JPG image creation matter.

That's right. Thanks for the clarification. This affects the apparent noise vs. As to the dark shadow detail limit, that is placed by the black read noise, which I can see from raws available from the Sony A55 are at about the same level as that of the K-x.

Thus, I expect that the real Dynamic Range DR for the sensor from the brightest clipping level to the "noise floor" limit will be about the same as that of the K-x or about The intensities that are being assigned with the extra bit depth is really just better defining the noise levels.

MightyMike suggested another alternative that might just make sense: Previous Pentax cameras have been criticized at DPR for not having as much raw "highlight headroom" as competing models.

What if the extra two bits were at the top bright end of the range and extended the raw format's capacity to capture normally overexposed highlights without clipping, where they could be recovered by judicious application of tone curves and other raw processing? Would that not make the camera score very highly? Another benefit of doing this is that compressed raw file sizes would not likely increase that much in that these top levels would only generally be used by the small percentage of bright normally overexposed specular highlights, whereas using them as the least significant bits just generally captures high levels of random noise which is hard to compress and would make the files about four MBytes larger on average.

In short from the above, it is very unlikely that 14 bits used other than as MightyMike suggested in extending the clipping limit would give any larger a real analogue range. If we are to believe the specifications we have been given, I doubt that the limit is the imaging engine used as it seems it is still Prime II just as for the K-7, K-x, and K-r, all of which use 12 bit processing although there is a 14 bit Analogue to Digital Converter ADC available.

Richard, even with the very best sensor with the lowest black read noise coupled with a zero noise conversion, the only place one would actually be able to see the difference due to very high bit depths would be in the very deep deep shadows. For instance, if we had a large sensor with an electron well depth of , electrons per photosite and a dark read noise of two electrons, we would have a Dynamic Range DR of 50, : 1 and could justify even a bit conversion.

However, we would only enjoy that low noise up to where the shot noise was very low, so that by the time the Signal to Noise Ratio SNR got up to about 4, : 1 at the electron level or 7.

Blue sky is much brighter than this, and only a few stops below the clipping level for normal exposures, and 14 bits would not make one little bit of difference in the amount of noise in these blue skies, as all of those extra fine shades will just be blurred together by the noise even if we were actually able to pick them out.

However, those eight non-linear bits are quite a bit different than the 12 or 14 linear bits in the raw image file, as the Tone Response Curve TRC applied in the conversion to viewable eight bit images actually compresses the bright levels and expands the dark levels in a way that more-or-less matches our human eye's and monitor's response to luminance levels in that we aren't actually able to perceive all of the levels given by eight bits when our eyes are fully adjusted to the full range from full bright to maximum dark , as we can only actually perceive about discrete steps between those levels.

Generally, we need at least about at least 10 "good" linear raw bits in order to convert to a normal eight bit JPEG with reasonable image quality. No, the reason that the Nikon Ds is not better at DR than the Nikon D90 even though the Ds can capture 14 bit raw image files is that the sensor dark read noise is not smaller than the least significant bits of a bit range at the ISO sensitivity gain levels used for the D and Ds.

To further confuse the issue, the D90 and D use some "sneaky" form of chroma Noise Reduction NR to make the noise appear to be lower even though this is at the cost of slightly reducing detail retention, especially in the deep shadows.

I can't see that Pentax would actually reduce the size in MBytes of the buffer between the K-7 and the new top level K-5, although they may not have been able to increase the amount of buffer memory due to not redesigning the circuit boards to any large amount and not wanting to reduce battery life.

Let's say that the K-7 had about MBytes of buffer, which makes sense at about five frames per second fps in that about three frames would be flushed to flash memory in the about three seconds of continuous shooting time, which would then require space for about 14 raw files in the buffer or about My theory about why the eight raw buffer limit exists also with an accordingly low JPEG buffer limit at maximum continuous rate is Pentax's typical conservative specification policy and the existence of these extremely high maximum ISO's in extended ISO mode.

To me, it makes sense that the actual raw buffer limit is just proportionally less than that of the K-7 considering the larger pixel dimensions and the faster continuous shooting speed, such that 15 raw captures would seem to be about right for exactly the same shooting environment and ISO sensitivity settings.

We look at RAW files converted with dcraw, an excellent freeware raw converter. There will always be differences between RAW converters, in terms of the sort of demosaicing algorithms they use the processes by which they convert the separate Red, Green, and Blue data sets to an array of full-color RGB pixels , but dcraw seems to use a fairly generic algorithm that delivers good sharpness with relatively few artifacts, and can be counted on to not apply any noise reduction if you don't want it to.

Click on any of the crops below to see the corresponding full-sized image. The noise reduction applied is pretty subtle, though, nothing like the heavy-handed approach used in earlier Sony SLRs. Still, it's something we'd rather not see in RAW files, as it does impact fine detail.



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