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03-20-2010, 09:50 AM   #1
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645D dynamic range

From the interview:

"The Kodak sensor itself is already very clean compared to previous MF sensors generations and Kodak might in fact be a bit conservative when they quote 11.5 stops as being the sensor DR. "

So this camera has actually more than 11.5 stops dynamic range? That is twice as much as the K7!

03-20-2010, 01:20 PM   #2
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QuoteOriginally posted by Pål Jensen Quote
From the interview:

"The Kodak sensor itself is already very clean compared to previous MF sensors generations and Kodak might in fact be a bit conservative when they quote 11.5 stops as being the sensor DR. "

So this camera has actually more than 11.5 stops dynamic range? That is twice as much as the K7!
When I go from shooting my BW film to my K7, is see that right away. Highlights on the K7 get blown real fast. So I'm not surprised its twice as much.
03-21-2010, 02:13 PM   #3
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It's supposed to have built in HDR. I wonder if they're talking about the "take multiple shots and combine" type HDR, or if it's more of a reference to the dynamic range. Could you imagine doing HDR with a camera that has that kind of dynamic range?
03-22-2010, 01:28 PM   #4
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QuoteOriginally posted by HawaiianOnline Quote
It's supposed to have built in HDR. I wonder if they're talking about the "take multiple shots and combine" type HDR, or if it's more of a reference to the dynamic range. Could you imagine doing HDR with a camera that has that kind of dynamic range?
if it really has embedded HDR - shoot me. then again I can't believe they put it on the new DSLRs and then why people flaunt it as a positive rather than some throwaway gimmick.

QuoteOriginally posted by tuco Quote
When I go from shooting my BW film to my K7, is see that right away. Highlights on the K7 get blown real fast. So I'm not surprised its twice as much.
Do you use highlight correction? From dpreview (Pentax K-7 Review: 18. Photographic tests (DR): Digital Photography Review) DR is about 8.6 ev. The K7 is certainly helluvalot better than my K10D in terms of keeping highlights under control.

03-29-2010, 08:07 AM   #5
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Please, read my posts here:The 645D dynamic range discussion is full of misunderstandings.

And then, there aren't yet measurements, just Kodak's spec of SNR 69.3 dB. This would translate to 11.5 EV with textbook arithmetic or 12.7 EV with a DxO style definition. But again: not comparable yet as Kodak can define "their" SNR in whatever way they want...

So, I decided to calibrate DR using a known point of reference:
The Hasselblad H3DII 39. These are my findings:

DxO: DR print=12.52EV, DR pixel= 11.37EV, SNR=1 at 0.038%
Kodak KAF-39000: 71.4dB => SNR=1 at 0.027% or DR pixel=11.86EV

So, the Kodak figure may be 0.49EV too optimistic.


Using this calibration point, I obtain the following DR figures for Pentax products:
For Pentax 645D:
Kodak KAF-40000: 69.3dB => DR pixel=11.51EV [-0.49EV] => DR pixel=11.02EV, DR print=12.18EV



DxO Dynamic Range (print)
Pentax 645D: 12.2 EV (best possible projection by Falk Lumo)
Pentax K-x: 12.5 EV
Pentax K-7: 10.6 EV
Pentax K-m: 11.4 EV
Pentax K200D: 11.4 EV
Pentax K20D: 11.1 EV
Pentax K10D: 11.6 EV


And please, never ever quote DPR dynamic range figures. They measure JPG settings and are complete BS in a sensor discussion.
03-31-2010, 10:51 AM   #6
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QuoteOriginally posted by falconeye Quote
Please, read my posts here:
Pentax K-7: 10.6 EV
.
How do you get 10.6 stop dynamic range out of the K-7? Mine have 5-6 stops at the most....
03-31-2010, 11:04 AM   #7
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QuoteOriginally posted by Pål Jensen Quote
How do you get 10.6 stop dynamic range out of the K-7? Mine have 5-6 stops at the most....
Many definitions for DR exist. Your's obviously differs from DxO's. Just subtract 5 from DxO's figures and you should be fine. There is no such thing as an absolute scale for DR.
03-31-2010, 11:33 AM   #8
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QuoteOriginally posted by falconeye Quote
Please, read my posts here:The 645D dynamic range discussion is full of misunderstandings.

And then, there aren't yet measurements, just Kodak's spec of SNR 69.3 dB. This would translate to 11.5 EV with textbook arithmetic or 12.7 EV with a DxO style definition. But again: not comparable yet as Kodak can define "their" SNR in whatever way they want...

So, I decided to calibrate DR using a known point of reference:
The Hasselblad H3DII 39. These are my findings:

DxO: DR print=12.52EV, DR pixel= 11.37EV, SNR=1 at 0.038%
Kodak KAF-39000: 71.4dB => SNR=1 at 0.027% or DR pixel=11.86EV

So, the Kodak figure may be 0.49EV too optimistic.


Using this calibration point, I obtain the following DR figures for Pentax products:
For Pentax 645D:
Kodak KAF-40000: 69.3dB => DR pixel=11.51EV [-0.49EV] => DR pixel=11.02EV, DR print=12.18EV



DxO Dynamic Range (print)
Pentax 645D: 12.2 EV (best possible projection by Falk Lumo)
Pentax K-x: 12.5 EV
Pentax K-7: 10.6 EV
Pentax K-m: 11.4 EV
Pentax K200D: 11.4 EV
Pentax K20D: 11.1 EV
Pentax K10D: 11.6 EV


And please, never ever quote DPR dynamic range figures. They measure JPG settings and are complete BS in a sensor discussion.
Thanks for your overview

03-31-2010, 12:25 PM   #9
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QuoteOriginally posted by guidoanselmi Quote
if it really has embedded HDR - shoot me. then again I can't believe they put it on the new DSLRs and then why people flaunt it as a positive rather than some throwaway gimmick.
There was a thread here recently that shows quite well just how effective the K-7's HDR feature is for real estate-type shooting.
04-30-2010, 09:00 AM   #10
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Allow me to add my add my 2 cents! We must still compress DR for most
output. If we're just trying to get the shot, I have a few suggestions.
1. Stationary outdoor subjects--landscapes. Bracket your exposure and then use the
Photoshop high dynamic range utility in the file menu. (CS2 or better?). Works pretty well!
2. I also have good luck a B+W ND 0.6 graduated filter--the kind where you have 2 stops of ND tapering off to nothing over half the filter length. Since the maximum ND reduces the brightness of what is typically the brightest part of the scene (upper sky), dynamic range contracts.

Keep in mind you can use these methods even you've got 12 stops of DR (though I remain skeptical of any assertion made by manufacturers concerning digital performance).
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