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03-30-2011, 09:03 AM   #886
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QuoteOriginally posted by Pentaxor Quote
these looks like ISO 1600 on the K-7.
Agreed.

03-30-2011, 09:22 AM   #887
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Continuation of earlier post...

This is a(sort of) second part to my previous post.

The exercise here was to see how far I could push this K-5 RAW file before it began showing signs of break-down. In this case, I post processed the file in ACR and Denoise, with an emphasis on NR. Though I did not yet reach selective NR processing(as commonly done with the K20D/ISO6400 files). And so I guess there is still a little headroom left on the usable image side of things.

As per the original post, this file began as an ISO6400 shot. However, it was underexposed to preserve highlights and push processed afterward. Though I'm not quite sure what ISO it would qualify at, but If I had to guess, I'd say most likely somewhere near the 12.8K range.

The original RAW:


Fully processed:


The only complaint I have(at this point) is that the file did show a magenta cast(see pony tail area). However, I'm not sure if this is either a bi-product of the PP, or the eV push processing. But it isn't enough to get in the way of printing the image at 1:1 so I guess it isn't really a big issue at this stage of things.

...the end
03-30-2011, 02:39 PM   #888
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You've cleaned that portrait up very nicely John. Certainly workable.

The K-5's in-camera NR isn't the best, but I don't have much better options available to me (just PS) and as I don't shoot at those crazy ISOs often I can't justify investing in those decent NR programs available today.

Pentaxor, I'd say ISO 12800 is more like ISO 2000-2500 on the K-7/K20D as I often manage to get quite clean ISO 1600 images from my K20D when exposed right. ISO 25600 like ISO 4000-5000 on K-7/K20D and ISO 51200 like nothing seen before (not all that useful IMO, probably like ISO 6400 on the K20D).
03-30-2011, 02:52 PM   #889
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QuoteOriginally posted by Ash Quote
as I don't shoot at those crazy ISOs often I can't justify investing in those decent NR programs available today.
I think a lot of people regard Topaz deNoise as one of the tops -
but another top contender is NoiseWare -

There is a Free NoiseWare Community Edition that does most of the essential NR stuff........

Noiseware Community Edition Standalone 2.6
Standalone application.
Freeware, Save as JPEG, Automatic noise profiling (see features)
<Free Download for Windows>
Requirements: Windows XP/Vista/Windows 7, 256MB RAM, 10MB HDD

03-30-2011, 02:59 PM   #890
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Quite a good one Vincent. Good suggestion - for those on Windows OS.
03-30-2011, 04:10 PM   #891
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JohnBee... In my opinion--unless this was simply a test for noise--you went about this backwards. I would have exposed to the right for her face to get maximum sensor info and then backed off in PP. Any highlight blowout would be in background in this setup, but seeing how it is all blurred out it seems of little importance so you can easily deal with it with highlight recovery slider. I think you would find you'd get a better color representation and would have less of that unattractive pallor I notice on her face. Just my two cents.
03-30-2011, 06:01 PM   #892
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QuoteOriginally posted by lectrolink Quote
JohnBee... In my opinion--unless this was simply a test for noise--you went about this backwards. I would have exposed to the right for her face to get maximum sensor info and then backed off in PP. Any highlight blowout would be in background in this setup, but seeing how it is all blurred out it seems of little importance so you can easily deal with it with highlight recovery slider. I think you would find you'd get a better color representation and would have less of that unattractive pallor I notice on her face. Just my two cents.
I was thinking the same thing, but said nothing, because I am still learning myself.
03-30-2011, 06:04 PM   #893
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QuoteOriginally posted by Ash Quote
Y

Pentaxor, I'd say ISO 12800 is more like ISO 2000-2500 on the K-7/K20D as I often manage to get quite clean ISO 1600 images from my K20D when exposed right.
true enough Ash. although I was referring to it being underexposed. that is why I try to avoid push-processing with the K-7 inorder to avoid those things. the K-5 excels with underexposed images without having to worry about banding and noises. this also avoids blowing up highlights.

03-31-2011, 12:50 AM   #894
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QuoteOriginally posted by lectrolink Quote
JohnBee... In my opinion--unless this was simply a test for noise--you went about this backwards. I would have exposed to the right for her face to get maximum sensor info and then backed off in PP. Any highlight blowout would be in background in this setup, but seeing how it is all blurred out it seems of little importance so you can easily deal with it with highlight recovery slider. I think you would find you'd get a better color representation and would have less of that unattractive pallor I notice on her face. Just my two cents.
QuoteOriginally posted by jgredline Quote
I was thinking the same thing, but said nothing, because I am still learning myself.

Hi guys, thanks for your comments and suggestions.

To help understand what type of exercise this was, I'd like to tell you a little about the scene and settings and approach used for this particular shot. The first thing to note was the sensitivity needed to cope with the scene(ISO6400). And the second was where the only light-source in this case was that of backlighting(no fill light). This made for rather difficult lighting conditions as it inevitably lead to a few phenomenons with exposure.

1. Blowouts in the background
2. Higher ISO

However... for this particular exercise, I chose to use no more than ISO6400 in an effort to avoid the effects of low level NR. and secondly, to retain as much DR as possible within the file for post(DR goes down as sensitivities increase). And since ISO6400 doesn't leave much headroom for highlight recovery, I chose to preserved highlights(head band) by exposing to the left and push processing the scene afterward so as to take advantage of the K-5's enormous shadow recovery capabilities.

As for processing, the final edit was done with Alien Skin Exposure using a "Kodak E100S cross process filter"(film sim.).
Granted its not everyone's cup of tea, but I've always been a huge fan of the film.

Hope this helps and thanks for sharing you're ideas!

Last edited by JohnBee; 03-31-2011 at 03:35 AM.
03-31-2011, 03:51 AM   #895
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I think it turned out nicely, John. Backlighting has a real tendency to kill shots one way or another. In this situation, cameras have a tendency to under exposure, but more than that if you choose to blow out the back ground, I often see flaring destroying contrast.
03-31-2011, 06:16 AM   #896
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QuoteOriginally posted by Pentaxor Quote
true enough Ash. although I was referring to it being underexposed. that is why I try to avoid push-processing with the K-7 inorder to avoid those things. the K-5 excels with underexposed images without having to worry about banding and noises. this also avoids blowing up highlights.
Sure, the versatile DR of the K-5 is a welcome capability, particularly in the lower ISOs and enabling less reliance on HDR for high contrast scenes.

But what has impressed me quite remarkably is the amazing retention of detail the K-5 has at high ISOs. Whilst I'd probably never think of using ISO 51200, I trialled up to ISO 25600 with some great results. It made me think that there was no end to the detail I could pull out with each ISO stop I went to.

Starting from ISO 1600:



100% crop:



ISO 3200:



100% crop:



ISO 6400:



100% crop:



Another ISO 6400 example:



And at 100%:



ISO 12800!:


(no noticeable shadow noise or banding!)

100% crop:



Trying to bring out the luminance noise more here:
ISO 12800:


and still no banding...

100% crop:



But wait, there's more:
What to expect from the expanded ISOs?
Check out the detail at ISO 25600:



And at 100%?:

... not bad.

And what's more, all of these shots were taken with a consumer lens: the DA 55-300.
03-31-2011, 06:23 AM   #897
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Another example shot at a circus venue with harsh tungsten flash lighting coming from a distant front right of the camera, and very dim ambient lighting otherwise:

ISO 12800:



A 100% crop:



And another at 12800 to be convinced the results were no fluke:



100% crop:



EXIF is intact on all the uncropped images for proof that I'm not making all this up. Again shot with the 55-300.

Seems sensor technology knows no bounds.
Pentax: bravo on the K-5.
03-31-2011, 11:05 AM   #898
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QuoteOriginally posted by Ash Quote
Another example shot at a circus venue with harsh tungsten flash lighting coming from a distant front right of the camera, and very dim ambient lighting otherwise:
ISO 12800:
And another at 12800 to be convinced the results were no fluke:
EXIF is intact on all the uncropped images for proof that I'm not making all this up. Again shot with the 55-300.
Seems sensor technology knows no bounds.
Pentax: bravo on the K-5.
Those are very impressive Ash - indeed Bravo! Pentax
I tend to limit myself to ISO5000 (@10Mp) on my K-x -
I think I may have to give ISO12800 another chance.

Ah, but isn't the K-5 just one of the best at HighISO?
Indeed it is - but so are the K-r and K-x - at least in actual photos -
and another acknowledged HighISO leader currently is the Nikon D7000 -

so here are some useful side-by-side comparisons @ ISO12800
(a little unfair and not 1:1 comparing 16Mp with 12Mp)
But one's own eyes can be the final judge
(I obviously have my opinion - it's worth no more than anyone else's -
so I'll refrain from any comments on these comparisons)

Source: dpReview on Pentax K-5

default JPGs -
Face:


fine details:


JPGs are for sissies?

RAW -
Face:


Fine details:
03-31-2011, 01:28 PM   #899
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My above samples Vincent were shot in RAW, saved as JPEGs in ACR without sharpening or denoising, and had a touch of USM applied in PS. They look better than the RAW examples given above.

The D7000 examples look like they've had significant sharpening added to them, which would be the same for all the Pentax dSLR samples if they'd been sharpened. I'm surprised the K-x's ISO 12800 came up so clean - I certainly haven't had that kind of success with my own.

My experience so far with high ISO is that intuitively it degrades DR and therefore the microcontrast of the resultant images, making it 'easier' and more susceptible to highlight blowout and loss of shadow detail. The K-5 images seem to handle this phenomenon reasonably well.
03-31-2011, 01:52 PM   #900
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QuoteOriginally posted by Ash Quote
I'm surprised the K-x's ISO 12800 came up so clean - I certainly haven't had that kind of success with my own.
So am I, that's why I don't even think abut shooting ISO12800 on the K-x even when I deliberately shoot at 10Mp to get a smidgen better noise "self-cancellation".

I think often one's perception of noise and sharpness is very dependent on the subject and the relative size being photographed.

That's why opinions vary/differ so widely - test shots at dpReview.com and Imaging-Resource.com - are supposed to be under controlled conditions and repeatable - whereas our own tests - are mostly "casual" and ad-hoc.

No I do not doubt results shown - especially on something like noise - which can be seen for oneself - like I also agreed my own shots with the K-x at ISO12800 do not do as well as dpReview's and certainly not like your K-5 samples.

However looking at those dpReview comparisons - gives me a little hope that perhaps it's me rather than the equipment that may have a failing........

Last edited by UnknownVT; 03-31-2011 at 01:59 PM.
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