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11-16-2010, 03:11 AM   #376
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Thanks but that's not a 1:1 comparison.
The K-x is 12MP vs. 16 and the K-x applies raw NR which the D7000 doesnt.

Therefore, a comparison at 1600 would be more interesting. Moreover, the first rescale step sharpens up the image (overcomes Bayer softness) rather than reduces the noise. DPReview has run into that trap when they studied the effect of resize and came to a wrong conclusion. Therefore, both cameras should be studied at 6MP and sharpening should be set to 100% 0.7px prior to resize.

Another way would be to compare readability of fine detail. The K-5 has a small edge in the samples shown. However, it's unclear if it is just from the higher resolution.

11-16-2010, 04:05 AM   #377
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QuoteOriginally posted by falconeye Quote
Therefore, both cameras should be studied at 6MP and sharpening should be set to 100% 0.7px prior to resize.
Isn't sharpening supposed to be performed after resizing, rather than before?

Dan
11-16-2010, 04:25 AM   #378
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QuoteOriginally posted by dosdan Quote
Isn't sharpening supposed to be performed after resizing, rather than before?

Dan
Dan,
My personsal take at this is this:
There are two distinct sharpening operations. The first is to compensate softness from the image taking procedure, i.e. motion blur, lens softness, AA filter, Bayer demosaicing etc. In an ideal case, this involves an USM of 0.5px 100% and is never zero. It is done to the original pixels, i.e. at 100% size. Real rather than ideal cases typically need USM with 1 or 2px width, or even more. Also, at higher ISO, it is wise to skip this step for photography rather than measurbation.

The second case is sharpening after resize which is to compensate the blur from the downscale operation. The optimum sharpening parameter depends on the exact rescale operator and amount of rescale.

LR supports the first case in its development module and the second case in its export dialog.

Because we want to compare sensors, we don't need the second sharpening as it is applicable to both. The first one is important though. Because, if we don't sharpen to counteract the softening from the demosaicing we will just make the image sharper on downscale w/o reducing the noise as much as it should.
11-16-2010, 11:23 AM   #379
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QuoteOriginally posted by falconeye Quote
Thanks but that's not a 1:1 comparison.
The K-x is 12MP vs. 16 and the K-x applies raw NR which the D7000 doesnt.
Therefore, a comparison at 1600 would be more interesting.
Comment is fair enough
my comparison was never intended to be 1:1 -
exactly as you said K-x is a mere 12Mp and the K-5 or Nikon D7000 are 16+Mp.

However I just wanted a "look-see" to see whether the latest new generation of dSLRs that are on the leading edge - show substantial visible improvement over the K-x's performance at High ISO.

I am sure that measurements will show both the K-5 and D7000 are "better" - as the DxO figures do - but to my eyes there isn't enough substantial improvement visually.

Now looking at it another way -
when the K-x came out there were many who wished there was a "K-7" with the K-x sensor -
well, the K-5 has done better than that with a 16Mp sensor that performs measurably better than the K-x -
but for my eyes even though it may well be measurably better - visually it would seem at least for JPGs there isn't a dramatic and immediate significant improvement (at least for the Nikon D7000,
I will reserve my comments until the same test sample of the K-5 are available)
- unlike the comparisons say of the K-x to the K-7 at high ISO
(which was another non 1:1 comparison of 12Mp vs. 14.6Mp)

11-16-2010, 11:53 AM   #380
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Just remember that with the increased resolution density you get more latitude to crop your image.
11-16-2010, 01:05 PM   #381
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QuoteOriginally posted by falconeye Quote
TThe K-5 has a small edge in the samples shown. However, it's unclear if it is just from the higher resolution.
===================================

Speaking of that , did you get your K-5 to review yet? Links?

Rite
11-16-2010, 03:00 PM   #382
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OK - Imaging-Resource has just posted some of its standardized test sample of the Pentax K-5 the (studio) Still Life (the also useful Indoor Portrait, No Flash series is not up yet)

I fully understand that this cannot be a 1:1 comparison, and it is limited in scope -
but I just wanted a "look-see" if this new generation of dSLR which shows measurable improvement in the DxO figures also shows it visually in real-world photos -

I am particularly interested in JPGs at High ISO - when compared to the Pentax K-x which is acknowledged currently as one of the best High ISO performers.
(RAW versions are also up, so one could do that same comparisons of those)

ISO6400 -




ISO12800 -




Subjectively to my eyes there does seems a slight improvement in IQ with the K-5 - but probably not enough for me to say use ISO12800 for anything other than emergencies - I think perhaps in the default JPG settings the K-5 may be using a little more NR as evidenced by the red patch comparison - not that I hasten to add the K-x image is anything to write home about.

For me I think I can just make out a visual improvement - although it is obviously very worthwhile - it is probably not enough to make any real-world difference for me in my photography - YMMV -
of course for those who had been hoping for a K-7 with a K-x sensor -
the K-5 seems to have exceeded this.
11-16-2010, 04:06 PM   #383
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QuoteOriginally posted by UnknownVT Quote
of course for those who had been hoping for a K-7 with a K-x sensor -
the K-5 seems to have exceeded this.
Indeed!

11-16-2010, 04:07 PM   #384
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QuoteOriginally posted by ManWithCamera Quote
Indeed!
+1.
11-16-2010, 04:15 PM   #385
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QuoteOriginally posted by UnknownVT Quote
but I just wanted a "look-see" if this new generation of dSLR which shows measurable improvement in the DxO figures also shows it visually in real-world photos

For me I think I can just make out a visual improvement - although it is obviously very worthwhile - it is probably not enough to make any real-world difference for me in my photography - YMMV -
of course for those who had been hoping for a K-7 with a K-x sensor -
the K-5 seems to have exceeded this.
You will probably get a better view of the differences once NR is adjusted on the K-5. At this stage, it looks as though it is far to strong to retain any detail.

Having said that, the RAW files are where you will most notably get a better view of what each sensor is capable of. At which point, I think the K-5 quite clearly shows it's stuff in contrast to the Kx or Kx sensors.
11-17-2010, 01:11 PM   #386
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QuoteOriginally posted by JohnBee Quote
Having said that, the RAW files are where you will most notably get a better view of what each sensor is capable of. At which point, I think the K-5 quite clearly shows it's stuff in contrast to the Kx or Kx sensors.
I posted the below in another thread - but thought it was relevant here.

I wanted to see how the current leading edge dSLRs - Pentax K-5, Nikon D7000 and Canon 60D compared and the dpReview of the Canon 60D comparison was most useful -
the main shortcoming is the lack of skin tone - other than the picture of a face in the right of the target.

I included the Pentax K-x for 2 main reasons -

1) acknowledged currently as one of the best High ISO performers.
2) new K-r seems to be similar in performance - so this may give an indication of how the K-r may compare.

I do realize the K-x cannot be a 1:1 comparison since the K-x (K-r) are 12Mp vs the 16+Mp of the other leading edge dSLRs - but it was interesting/educational comparing them.

Looking at the High ISO -

ISO 6400 -






For grins I also compared at
ISO 12800 -


These new 16+Mp dSLRs are amazing with relative image quality that are visually matching the "best" 12Mp at High ISOs - the Nikon D7000 JPG engine appears to do well especially when comparing the Martini label - with the K-x a kind of second - and I agree with JohnBee that the K-5 noise reduction seems a bit heavier and blurs away details (esp in the ISO 12800 comparisons) -
but at ISO 12800 one really ought to be working in RAW and reduce the noise using a more specialized program.

I have said this earlier for those who wished for a K-7 with a K-x sensor -
the K-5 has more than exceeded that.
11-18-2010, 12:56 AM   #387
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QuoteOriginally posted by UnknownVT Quote
OK - Imaging-Resource has just posted some of its standardized test sample of the Pentax K-5 the (studio) Still Life (the also useful Indoor Portrait, No Flash series is not up yet)
Wait for their reshoot before discussing the IR test shots! The K-5 shots were back-focussed and shot at f/5.6 (f/8 for other cameras).
11-19-2010, 01:07 AM   #388
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QuoteOriginally posted by dosdan Quote
So this will probably reduce clipping headroom. But if you apply a little bit of negative EVcomp in camera, you still have an awful lot of DR to work with in PP when you boost EV, manipulate the tone curve or dodge.
Am I correct in my understanding of a K-5 feature called something like "High Dynamic Range" which essentially does this automatically by reducing exposure (ISO) by one stop?
11-19-2010, 03:54 AM   #389
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QuoteOriginally posted by secateurs Quote
Am I correct in my understanding of a K-5 feature called something like "High Dynamic Range" which essentially does this automatically by reducing exposure (ISO) by one stop?
Yes, it is called "Highlight Correction: On". Formerly known as D-Range.
The K-5 has another feature called HDR but it takes 3 images and combines them into one.
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