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06-05-2009, 10:42 AM   #196
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QuoteOriginally posted by Marc Sabatella Quote
That's kind of a misleading way of putting it, according to my understanding. It's not like the camera is arbitrarily preventing you from using ISO 100 - it's that the feature works by shooting underexposed at lower ISO and then pushing the results in its processing. Whatever ISO you specify, the camera actually shoots one stop slower. In order to allow you select ISO 100, that would require the camera to support ISO 50, but it doesn't.

In other words, when you use D-range at ISO 200, you really *are* shooting at ISO 100 (with one stop underexposure that is corrected in the processing in order to provide the greater range).
The key from my perspective is that I get ISO 200 levels of noise rather than ISO 100 levels of noise when I use D-Range. Not that ISO 200 has significant levels of noise, but when I'm shooting and want the best quality for a limited dynamic range scene, I would use ISO 100. For slightly larger dynamic range, D-R is good, but higher dynamic ranges, I go back to ISO 100 and use multiple exposures.

I can never quite decide if D-Range is a useful compromise for general shooting or not.

06-05-2009, 04:28 PM   #197
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QuoteOriginally posted by jfsavage Quote
The key from my perspective is that I get ISO 200 levels of noise rather than ISO 100 levels of noise when I use D-Range.
Actually, I think you'll find in some areas of the photo you could get *more* than ISO 200 levels of noise, depending on how the levels are distributed. But yeah, it's basically a digitally-simulated ISO 200 on average, with some areas pushed *more* but others ppushed *less*, thus yielding the increased dynamic range.

QuoteQuote:
I can never quite decide if D-Range is a useful compromise for general shooting or not.
I'm convinced not, at least if you don't min doing a bit of PP. No way some computer algorithm is going to figure out a better way to finesse the exposure curve to get the results *I* want than I could. So if there are situations where I need more dynamic range than the camera can capture, I'll underexpose the "average" as much as necessary to preserve the highlights I care about, and then play with curves and local contrast enhancement *myself* to bring the shadows to get the results *I* want in terms of balancing detail and noise.

Which isn't to say the feature wouldn't be useful if you aren't comfortable working with exposure curves or local contrast enhancement. But I'll often take a bunch of similar shots, PP one to my liking, then simply copy the settings to the others, so it's not like I spend a ton of doing this. And of course, I don't bother doing any of this at most of the time - just in situations where I'm concerned with the dynamic range.
06-06-2009, 08:35 AM   #198
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QuoteOriginally posted by Marc Sabatella Quote
Actually, I think you'll find in some areas of the photo you could get *more* than ISO 200 levels of noise, depending on how the levels are distributed. But yeah, it's basically a digitally-simulated ISO 200 on average, with some areas pushed *more* but others ppushed *less*, thus yielding the increased dynamic range.



I'm convinced not, at least if you don't min doing a bit of PP. No way some computer algorithm is going to figure out a better way to finesse the exposure curve to get the results *I* want than I could. So if there are situations where I need more dynamic range than the camera can capture, I'll underexpose the "average" as much as necessary to preserve the highlights I care about, and then play with curves and local contrast enhancement *myself* to bring the shadows to get the results *I* want in terms of balancing detail and noise.

Which isn't to say the feature wouldn't be useful if you aren't comfortable working with exposure curves or local contrast enhancement. But I'll often take a bunch of similar shots, PP one to my liking, then simply copy the settings to the others, so it's not like I spend a ton of doing this. And of course, I don't bother doing any of this at most of the time - just in situations where I'm concerned with the dynamic range.
Have you done a direct compare with ISO 100 -1EV and ISO 200 D-Range? I assumed the K20D firmware tweaked the response curve to produce different results, but I have no basis for that assumption ;}
06-06-2009, 09:01 AM   #199
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No, I have not. Just seeing the few pictures posted by others, seeing the specific disclaimer about shadow noise in the K20D video Pentax put out (featuring John Carlson, as I recall!), the fact that, as I said, I like to be in *control* of my curves, plus the fact that shooting JPEG holds no interest for me and I'm not sure how well it might work with my preferred RAW converter - the bottom line is that I really have no interest in really testing the feature to any extent. Like I said, I'm sure it works well enough for what it does, just as I'm sure that shooting in "Green mode" works well enough for what it does. But still, I prefer to do these things myself, so I can get the results *I* want.

06-06-2009, 07:48 PM   #200
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Flickr: Discussing k20d Expanded Dynamic Range opinions in Pentax K20D / Samsung GX-20

QuoteQuote:
The biggest technical limitation to today's digital and video cameras is their horrible highlight overload characteristics.

Film overloads gracefully. It's natural. We're used to the way highlights look on film. This graceful overload curve is called a shoulder.

...

Digital has no shoulder and there is no gradual overload.

...

[What EDR does is prevent the] typical nasty color shifts we see on over exposed areas [with digital capture].
06-06-2009, 08:04 PM   #201
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QuoteQuote:
The biggest technical limitation to today's digital and video cameras is their horrible highlight overload characteristics.
I don't agree. Correct me if I'm wrong but the dynamic range of digital image processing is better than slide film and at least as good as negative film. Definitely, high ISO performance is better.

That means you just have to adjust your exposure habits to digital technology and avoid local overexposure.

Analogue audio goes into dynamic compression much more gracefully than digital audio as well, but digital audio gives you such a headroom of dynamics that -- with appropriate level control -- digital audio has the edge by far when it comes to dynamics.

Artificial shoulder curves eat up dynamics. The only justification of using them is when you cannot anticipate the dynamic range. If you may be surprised by high levels (be it audio or imaging) then shoulder's dampen the impact but you pay by sacrificing dynamics.
06-07-2009, 02:34 AM   #202
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QuoteOriginally posted by Class A Quote
If you may be surprised by high levels (be it audio or imaging) then shoulder's dampen the impact but you pay by sacrificing dynamics.
And unlike audio, clipped highlights don't destroy your hardware (aka tweeter)
06-07-2009, 09:51 AM   #203
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QuoteOriginally posted by Class A Quote
I don't agree. Correct me if I'm wrong but the dynamic range of digital image processing is better than slide film and at least as good as negative film. Definitely, high ISO performance is better.
That is my understanding. But the dynamic range of the real world is still too great for our current sensors, so anything that can be done to extend the DR is a good thing.

I've not read anything about the K-7 D-Range equiv, other than the fact that there are more options/levels.

06-07-2009, 06:04 PM   #204
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Another one John-
Can the SR be turned on either permanently (which I would like so it's in an always ready state, great for sport, and I know some Pentax person from this forum put this to Japan a while ago), or on a time selectable basis, eg. 10 or 20 seconds?
06-09-2009, 05:43 PM   #205
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Busy John must be. Wait we must.
06-10-2009, 07:47 AM   #206
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QuoteOriginally posted by Arpe Quote
Another one John-
Can the SR be turned on either permanently (which I would like so it's in an always ready state, great for sport, and I know some Pentax person from this forum put this to Japan a while ago), or on a time selectable basis, eg. 10 or 20 seconds?
Not that I am aware of.
06-10-2009, 10:27 AM   #207
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Does the K7 have a MTP/PTP transfer mode to allow third party tethering?
06-10-2009, 05:06 PM   #208
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Hi John-

Not so much a question about a K-7 feature, necessarily...

Do you know if Pentax has any plans to bring back the Student rebate program that expired last June? There are many reasons why student discount programs are good for business: bringing new, young consumers into a system that they quite possibly will invest in for many years, getting young people excited about a brand (Apple comes to mind), and simply helping out college students like myself :-)

I'm travelling to and studying in China and London for a year on scholarships and grant money, and would DIE for a new k-7 to take with me, and a small discount would make it all that much more possible.

Any hope?
06-10-2009, 05:36 PM   #209
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QuoteOriginally posted by JCPentax Quote
QuoteOriginally posted by Arpe Quote
Another one John-
Can the SR be turned on either permanently (which I would like so it's in an always ready state, great for sport, and I know some Pentax person from this forum put this to Japan a while ago), or on a time selectable basis, eg. 10 or 20 seconds?
Not that I am aware of.
Bugger .
06-12-2009, 10:10 AM   #210
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Can you manually set for example 1/3s or 1s shutter speed in video mode?
Would be great for some timelaps action.
Or are the "timelapse" function expanded past those 99 shots we have had with K20D?
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