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03-15-2010, 08:18 PM   #736
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I keep seeing high ISO performance mentioned as an advantage for FF over MF. There were some posts by michael reichman related to the 645D over on the luminous landscape forums basically outlining that the difference in ISO performance is really a misconception: due to MF's significantly greater DR (including the shadows), underexposing ISO 1600 on a MF sensor by two stops and then pushing to ISO 6400 in post and then comparing at equal output sizes, the result should stack up pretty well against a native ISO 6400 shot from the D3. Again, this is coming from Reichman, who has extensive experience with using and getting the most out of a wide range of both MF and FF gear. I found that very interesting.

The operational speed remains a significant advantage to current FF cameras in most situations.

03-15-2010, 09:17 PM   #737
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The same way K-x costs far less per pixel than a 5DII.

I wonder who's gonna foolishly waste his money on a 5DII.


QuoteOriginally posted by 24X36NOW Quote
$235.00 per megapixel for 645D

$81.26 per megapixel for A850

You were saying about bang for buck??
03-15-2010, 11:29 PM   #738
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QuoteOriginally posted by cousinsane Quote
The same way K-x costs far less per pixel than a 5DII.

I wonder who's gonna foolishly waste his money on a 5DII.
people that are looking for certain things in a camera that the k-x that doesn't have nor is capable of doing. and I dont believe that having those things are foolish at all.
03-16-2010, 12:07 AM   #739
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QuoteOriginally posted by er1kksen Quote
I keep seeing high ISO performance mentioned as an advantage for FF over MF. There were some posts by michael reichman related to the 645D over on the luminous landscape forums basically outlining that the difference in ISO performance is really a misconception: due to MF's significantly greater DR (including the shadows), underexposing ISO 1600 on a MF sensor by two stops and then pushing to ISO 6400 in post and then comparing at equal output sizes, the result should stack up pretty well against a native ISO 6400 shot from the D3. Again, this is coming from Reichman, who has extensive experience with using and getting the most out of a wide range of both MF and FF gear. I found that very interesting.

The operational speed remains a significant advantage to current FF cameras in most situations.
I do strongly believe that the greater DR (11-12 stops) of the MF is a big boost in increasing exposure while retaining and salvaging IQ at it's best as compared to a camera with a HIGH ISO (3200-25,600) performance which sacrifices IQ. I think this is more of a large DR versus High ISO debate. but seeing how this goes, the large DR of the MF seems to get the upperhand.

ISO 100 IQ results on the MF is a no-brainer since this is where the MF is really strong. but what I'm interested is the IQ at ISO 400-1600 of the MF. now if Pentax did somehow improved it's camera's IQ performance and able to produce even an ISO 200 IQ at ISO 800 (maybe up to 1600), that would really be something.

03-16-2010, 12:44 AM   #740
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Is the DR so much better? 11.5 EV, according to dxo the kx scores in at 12.5.
03-16-2010, 01:06 AM   #741
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DXO ?
C'mon, where will this stop?
03-16-2010, 02:16 AM   #742
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QuoteOriginally posted by Gimbal Quote
Is the DR so much better? 11.5 EV, according to dxo the kx scores in at 12.5.
Invalid comparison
(You may find more about this in this thread, e.g. by myself.)
03-16-2010, 02:24 AM   #743
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That would be interesting, but the thread is over 700 posts...

03-16-2010, 02:30 AM   #744
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QuoteOriginally posted by 24X36NOW Quote
$235.00 per megapixel for 645D
$81.26 per megapixel for A850
$6.76 per megapixel for SL30
...


Anybody better?

[source: Samsung SL30 / ES15]
03-16-2010, 02:38 AM   #745
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QuoteOriginally posted by falconeye Quote
$6.76 per megapixel for SL30
...


Anybody better?

[source: Samsung SL30 / ES15]
Sure:
Amazon.com: Little Tikes 35mm Camera with Flash and Film: Toys & Games

Since everybody knows that 35 mm film is as good as 40mp digital, that's $ 0.30 per mp
03-16-2010, 03:53 AM   #746
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QuoteOriginally posted by Gimbal Quote
That would be interesting, but the thread is over 700 posts...
This is all based on Kodak's official product specification, Pentax DR statement is a direct copy (after unit conversion). An actual measurement could yield better or worse results.

But to summarize, MF sensors outperform FF and APS-C sensors in terms of noise and dynamic range. Not per square-mm but in total. The myth goes differently but this is due to the many apples to oranges comparisons
03-16-2010, 04:41 AM   #747
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QuoteOriginally posted by 24X36NOW Quote
I'm just commenting on the posts that assert that the 645D is D3X competition. I fully realize that almost nobody is cross-shopping medium format and 35mm format. The idea (not commenting on your post, but the "theme" of many others) that the cropped 645D somehow "eliminates the need" for a 35mm FF format is ridiculous, and though the cropped 645D may look like a good deal for someone shopping other medium format systems, it certainly isn't going to look like a cheap camera to someone shopping FF 35mm format. Nor will it compete with a FF 35mm format camera on many other fronts, e.g., frame rates, auto focus speed, ISO range, available lenses, etc.
Sorry if I took you the wrong way. We can agree on different camera systems for different needs... no doubt.
03-16-2010, 04:51 AM   #748
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QuoteOriginally posted by falconeye Quote
This is all based on Kodak's official product specification, Pentax DR statement is a direct copy (after unit conversion). An actual measurement could yield better or worse results.

But to summarize, MF sensors outperform FF and APS-C sensors in terms of noise and dynamic range. Not per square-mm but in total. The myth goes differently but this is due to the many apples to oranges comparisons
Thanks.

So if I'm reading this right, when down sampling the 40Mpix picture to approximately 8Mpix it will beat the K-x with 0.2 EV in DR (IF you stay at base iso, otherwise it will not beat it). But if you stay at the original "screen"-resolution (after all, the high resolution is what this camera is all about) you will not beat the K-x. You will still have the high resolution, but the DR is nothing special, is that correctly understood?

Last edited by Gimbal; 03-16-2010 at 05:01 AM.
03-16-2010, 07:43 AM   #749
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QuoteOriginally posted by Gimbal Quote
Thanks.

So if I'm reading this right, when down sampling the 40Mpix picture to approximately 8Mpix it will beat the K-x with 0.2 EV in DR (IF you stay at base iso, otherwise it will not beat it). But if you stay at the original "screen"-resolution (after all, the high resolution is what this camera is all about) you will not beat the K-x. You will still have the high resolution, but the DR is nothing special, is that correctly understood?
Both, dynamic range and noise are properties which depend on spatial frequency (just like audio noise depends on frequency too). E.g., how would you define dynamic range for film which doesn't have pixels at all?

A spatial frequency-independent discussion of the properties is impossible (except in the internet, of course ).

--
Just to illustrate one detail: There is no need to downsample to have a high dynamic range at low spatial frequency. It is in the image anyway. If you printed the image, you would have slightly better shadow (black) detail but still much better gray and white detail!
If you would draw SNR over spatial frequency, the 645D curve would be above K-x for all frequencies, with K-x having zero SNR at the high end (diue to lack of sensor sampling resolution).

Last edited by falconeye; 03-16-2010 at 07:53 AM.
03-16-2010, 08:01 AM   #750
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QuoteOriginally posted by Gimbal Quote
Is the DR so much better? 11.5 EV, according to dxo the kx scores in at 12.5.
please read Emil Martinec : Dynamic range and DxO - Luminous Landscape Forum
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