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09-27-2010, 04:07 PM   #1
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The K-5 has the DR to match!

A recent post on dpreview, by a member called "Joe Ogiba" points to a few comments and measurements by GordonB and Falk Lumo.

The bulk of it being that the K-5 not only has the DR to match the D700 FF sensor, but has the DR to match!


According to Falk;
if...Gordon's preliminary impression prevail(and He stresses the IF), then the K-5 "could" perform in the same league as a medium format cameras only to be beaten by the finest of the DR performers(S5 Pro, D3X etc).
So all that's left now, is the color space

The blog in question: Falk Lumo -- my Pentax K-7 story

edit: Due to a misunderstanding in the original comment, it was necessary to edit the original quote provided in this post.


Last edited by JohnBee; 09-27-2010 at 05:28 PM.
09-27-2010, 04:44 PM   #2
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QuoteOriginally posted by JohnBee Quote
Falk wrote:
At 16MP, the K-5's resolution corresponds to a dynamic range of 13.0 EV in DxO's terms.
That's an incorrect citation.

I wrote:
QuoteQuote:
If Gordon's preliminary analysis holds true (he looked at an ISO 1600 PEF too), then a pixel's full well capacity is on par with a K-x and dynamic range of a K-5 pixel should exceed its 0.021% (dynamic range as defined by an SNR of 0dB). A value of 0.017% at K-5's resolution would correspond to a dynamic range of 13.0 EV in DxO's terms. That would be a stunning value.
I've meanwhile somewhat clarified the sentence.

A measurement of the SNR 0dB dark value hasn't been done yet. Gordon's preliminary analysis just hints that the dark value may be even lower than that of the K-x. Therefore, my use of subjunctive mood is essential. Please, cite me literally or use your own words but not as a quotation. Thank You.

Last edited by falconeye; 09-27-2010 at 04:50 PM.
09-27-2010, 04:44 PM   #3
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The same guy also said that the K5 will be sold at the same price as the D7k. Pentax corporate was so stunned by the price of the D7k that they weren't sure what to price the K5 at. They had planned to price it at the D300s or 7D level. He said Pentax Germany is the only entity to figure it out (so far). He seemed pretty confident about this. If this is true, it would be most welcome news as I, for one, believe we have the superior camera this round.
09-27-2010, 04:55 PM   #4
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QuoteOriginally posted by JohnBee Quote
A recent post on dpreview, by a member called "Joe Ogiba" points to a few comments and measurements by GordonB and Falk Lumo.

The bulk of it being that the K-5 not only has the DR to match the D700 FF sensor, but has the DR to match!

Falk goes on to call it a stunning(DxO) mark or value!

So all that's left now, is the color space

The blog in question: Falk Lumo -- my Pentax K-7 story
At ISO 100, IF, and that is a big IF, it test out to be true that would be great. He is being subjective though and doing the math to ascertain potential DR. Not the same as an actual test. I would be more interested if the sensor can hold onto a decent DR at ISO3200 or even 6400. The RAW sample certainly looks a bazillion times better than my K7 in this regard, but I will wait till some actual tests are done.

09-27-2010, 04:58 PM   #5
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QuoteOriginally posted by falconeye Quote
That's an incorrect citation.

I wrote:

I've meanwhile somewhat clarified the sentence.

A measurement of the SNR 0dB dark value hasn't been done yet. Gordon's preliminary analysis just hints that the dark value may be even lower than that of the K-x. Therefore, my use of subjunctive mood is essential. Please, cite me literally or use your own words but not as a quotation. Thank You.
Okay, so there was clearly some confusion on my parts with what was being said in your original phrasing. However... in my own attempt to simplify the explanation further, I clearly made things worst.

However, I'm still not entirely clear on the entire context of the comment(despite your changes) at this stage and since I'd like to adjust my original post to match I wondered if you could just lay it out there in the simplest form possible

Also, I completely missed that I quoted an edited portion of your comment(copy pasted from dpreview).
I'll keep a closer eye on such things from now on.
09-27-2010, 05:13 PM   #6
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QuoteOriginally posted by JohnBee Quote
I wondered if you could just lay it out there in the simplest form possible
Well, the paragraph in question applies to anybody familiar with the way DxO measures dynamic range.

For everybody else, it means that as far as Dynamic Range is concerned, if Gordon's preliminary impression prevails (a big if!), then the K-5 (and D7000 too probably) perform in one league with medium format CCD cameras and are only beaten by Finepix S3/5 Pro and D3X.
09-27-2010, 05:16 PM   #7
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QuoteOriginally posted by falconeye Quote
Well, the paragraph in question applies to anybody familiar with the way DxO measures dynamic range.

For everybody else, it means that as far as Dynamic Range is concerned, if Gordon's preliminary impression prevails (a big if!), then the K-5 (and D7000 too probably) perform in one league with medium format CCD cameras and are only beaten by Finepix S3/5 Pro and D3X.
Alright, thanks for that.
I'll edit the quote to convey something more appropriate.
09-27-2010, 06:34 PM   #8
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We already know this is Sony's sensor. It has very good dynamic range but its still slightly less than the K-X. Image Resource shows this on their Sony A55 review.

09-27-2010, 06:57 PM   #9
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QuoteOriginally posted by atomiccow Quote
We already know this is Sony's sensor. It has very good dynamic range but its still slightly less than the K-X. Image Resource shows this on their Sony A55 review.
What I find strange is that the K-5 ISO6400 RAW looks more like an A55 ISO3200 RAW with reference to noise.
So I was wondering... if this was possible, then is it plausible to expect more DR as well?
09-27-2010, 07:19 PM   #10
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Keep in mind that A55's membrane eats some portion of the light. (and can have ghosting)
09-27-2010, 09:25 PM   #11
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QuoteOriginally posted by falconeye Quote
Well, the paragraph in question applies to anybody familiar with the way DxO measures dynamic range.

For everybody else, it means that as far as Dynamic Range is concerned, if Gordon's preliminary impression prevails (a big if!), then the K-5 (and D7000 too probably) perform in one league with medium format CCD cameras and are only beaten by Finepix S3/5 Pro and D3X.
Falk - THANK YOU for answering all my specific K-5 questions on your excellent K-5 Preview:

Falk Lumo -- Pentax K-5 hands-on preview
09-27-2010, 09:50 PM   #12
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QuoteOriginally posted by falconeye Quote
That's an incorrect citation.

I wrote:

I've meanwhile somewhat clarified the sentence.

A measurement of the SNR 0dB dark value hasn't been done yet. Gordon's preliminary analysis just hints that the dark value may be even lower than that of the K-x. Therefore, my use of subjunctive mood is essential. Please, cite me literally or use your own words but not as a quotation. Thank You.
Aha! A new topic: subjunctive mood.

I think it's ironic that the reference is from one whose native tongue, if memory serves, is not English. Not surprising to me, given the states of education in the US and other countries, just ironic.

You never fail to inspire me, Falk. Thanks.
09-28-2010, 03:36 AM   #13
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THANK YOU Falk for this great preview. I was a bit afraid that you wouldn't come back after the drama (not your fault) in the other unfairly closed thread.
09-28-2010, 03:54 AM   #14
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Thank you for your review, Falk. Most interesting reading. I'd highly recommend it to anyone before they pass an opinion on K-5.
09-28-2010, 04:01 AM   #15
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Yes, thank you Falk for a very thorough summary of the K5. Having someone like yourself on the ground there really is beter than me being there myself, since there is no way that I would have been able to touch on all the things that you analyzed there.

I definitely think that the sensor is exciting. I love shooting with the K7 already -- it just feels better to shoot with than my K20 and if the few quibbles are fixed on it, it could be "the last camera" I "need" for quite awhile (and I bought a K100, K10, K20 and K7).
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