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04-15-2009, 07:13 AM   #16
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QuoteOriginally posted by Jewelltrail Quote
I am talking Raw. You really should read here: https://www.pentaxforums.com/forums/pentax-dslr-discussion/27334-how-reduce-h...-shooting.html Thanks PentaxPoke
So I looked at those tests where he does three shots at ISO 6400 with EV -1, 0 and +1. Looking at the 0 and +1 shots they expose at 1/45 and 1/20s with f/5.6 and lastly he undoes the exposure compensation in post processing so they all look the same.

Indeed the +1 shot has much less noise than the +0 shot. Maybe I'm being ignorant here but please someone explain to me how is shooting at +1 EV @ ISO 6400 any different than +0 EV @ ISO 3200? Isn't increasing exposure in this manner the very same thing as selecting a lower ISO? Wouldn't he get the very same results as if shooting +0 EV @ ISO 3200?

I perceive it as a contrived method of selecting lower ISO and as much as I try to figure out a different explanation that fails me. Maybe it made a difference with film and the myth lasts?

04-15-2009, 08:40 AM   #17
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QuoteOriginally posted by jbinpg Quote
@kristoffon - Any exposure over 0.3 seconds will cause a separate Dark Frame Subtraction frame (shutter closes and sensor stays on) equal to the length of the original exposure to be taken by the K20D. This happens whether you are shooting RAW or jpeg.

Jack
What does that mean, anything over 0.3 is loosing detail due to noise reduction?Does the K10D do the same thing?

C
04-15-2009, 09:25 AM   #18
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QuoteOriginally posted by cloudswimmer Quote
What does that mean, anything over 0.3 is loosing detail due to noise reduction?Does the K10D do the same thing?

C
No, it's supposed to reduce noise by detecting and removing "hot" pixels and can be disabled (should be "long exposure noise reduction" on the custom settings).
04-15-2009, 05:51 PM   #19
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QuoteOriginally posted by kristoffon Quote
QuoteOriginally posted by cloudswimmer Quote
What does that mean, anything over 0.3 is loosing detail due to noise reduction?Does the K10D do the same thing?
No, it's supposed to reduce noise by detecting and removing "hot" pixels and can be disabled (should be "long exposure noise reduction" on the custom settings).
To add to that, this thread explains what it does and when you might want to turn it on or off. It can't be completely disabled on the K20D, though it can on other models.

04-15-2009, 06:13 PM   #20
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QuoteOriginally posted by kristoffon Quote
Hello all, thread title says all.

- First off, I was a bit disappointed by high iso noise. After all the praise for the K20D's sensor and since it has iso 3200 I expected cleaner high iso but it appears to be about the same as the K200D - max useable is 800, 1600 in a pinch. 3200 isn't usable at all and 6400 a bad joke. I find all the colours look much better and overall IQ is superior, though.
I'm really surprised by this. I find ISO 1600 and 3200 quite usable with the K20. If you are looking at 100% crops you have to remember that the K20 has 40% more pixels so anything at 100% is going to look worse then it really is. Also, even if the high ISO is the same between the two than that is amazing because of that 40% increase in pixels.

I've never used the K2000 but I did have the K10 and the K20 handles high ISO so much better IMO


John
04-15-2009, 06:24 PM   #21
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QuoteOriginally posted by kristoffon Quote
Maybe I'm being ignorant here but please someone explain to me how is shooting at +1 EV @ ISO 6400 any different than +0 EV @ ISO 3200? Isn't increasing exposure in this manner the very same thing as selecting a lower ISO? Wouldn't he get the very same results as if shooting +0 EV @ ISO 3200?
Right. I think this is one of those cases where the detail overwhelmed the general point.

If you go through the thread, his point was that at any given ISO, noise is reduced by exposing brighter. Therefore, you should generally expose brighter in order to get the least noise possible -- hence the reason for the Expose To The Right theme. That can very well mean reducing ISO instead of changing anything else.

Sometimes people complain that "high ISO noise samples" are underexposed to begin with, leading to bad results. I don't think that applies here, since you're comparing two cameras and using them the same way, so if you say the noise performance is about the same, it's kind of hard to argue that!
04-15-2009, 07:58 PM   #22
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I read an article on ETTR with a DSLR today in a photo mag. Can't remember which one now but it is in the current month's crop of mags. Samples provided therein provide proof to me that overexposing by +1 and then dragging down in pp (+1/-1) leads to much lower noise than 0/0 and especially -1/+1. This wasn't a KxxD though I suspect the same applies across the board to other digital sensors.

Jack
04-15-2009, 08:05 PM   #23
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QuoteOriginally posted by Quension Quote
To add to that, this thread explains what it does and when you might want to turn it on or off. It can't be completely disabled on the K20D, though it can on other models.
Hey thanks for that link.That is what I was under the impression of.I have the K20D, but just ordered a K10D body to use for long exposures and to gain a little back in the diffraction department.I also like the high res iso100 samples I've seen on the K10D better than my K20D.

04-15-2009, 08:55 PM   #24
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QuoteQuote:
Quension: Sometimes people complain that "high ISO noise samples" are underexposed to begin with, leading to bad results. I don't think that applies here, since you're comparing two cameras and using them the same way, so if you say the noise performance is about the same, it's kind of hard to argue that!
It is easy to argue that because that is NOT what he is saying. What he is arguing/saying is clearly printed in his thread opening--I'll re-print it for the sake of clarity:

QuoteQuote:
Kristoffon: - First off, I was a bit disappointed by high iso noise. After all the praise for the K20D's sensor and since it has iso 3200 I expected cleaner high iso but it appears to be about the same as the K200D - max useable is 800, 1600 in a pinch. 3200 isn't usable at all and 6400 a bad joke. I find all the colours look much better and overall IQ is superior, though.[/
He argues that "max usable is 800." This is a silly argument. I get awesome shots @ ISO 1600, and so do many other people here at the forum. And I get very good shots at 3200, without any noise reduction. When I use noise reduction, I get even better shots. I would not call them usable, I would call them very good shots. At ISO 6400, I get good shots, not merely usable. Would I print them at poster size--no, of course not. But they make very good 4 x 6 and 5 x 7, and @ 3200 I can print good 8 x 10. For most people, that is better than usable. I have to believe 99 % of prints are done @ 5 x 7 or less.

You must bear in mind, good high ISO shots from a 14.5mp camera is a much better accomplishment than good high ISO shots from a 10mp camera---there is no comparison. This does not mean you can haphazardly take a shot with the K20 @ ISO 6400, and then explode it to full view and expect to see no noise--that kind of notion is pixel peeper manic driven.

The OP is not only discrediting the high ISO performance of the K20, but also of the K200 as well:
QuoteQuote:
kristoffon: " I expected cleaner high iso but it appears to be about the same as the K200D - max usable is 800
I have seen images from the K200 @ ISO 1600 and they are very usable. In fact, in some cases the 1600 shots look excellent--it really does matter who is behind the controls. Anyone can go here Imaging Resource "Comparometer" Digital Camera Image Comparison Page and see, at full resolution, ISO 1600 shots from the K20 right alongside of the K200. According to the OP, this ISO is not usable on either camera.


I'm think the K200 produces on a par with the K20, up to ISO 1600. But one must take into account the 14.5mp of the K20. Also, how can the K200 compete at ISO 3200 & 6400, with any camera for that matter, if it doesn't have that capability. My point is this: just because you can not take good shots at high ISO, don't erroneously conclude that no one can. There are a lot of people who successfully shoot ISO above 800, on both cameras.
04-15-2009, 10:19 PM   #25
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QuoteOriginally posted by Jewelltrail Quote
QuoteOriginally posted by Quension Quote
Sometimes people complain that "high ISO noise samples" are underexposed to begin with, leading to bad results. I don't think that applies here, since you're comparing two cameras and using them the same way, so if you say the noise performance is about the same, it's kind of hard to argue that!
It is easy to argue that because that is NOT what he is saying. What he is arguing/saying is clearly printed in his thread opening--I'll re-print it for the sake of clarity:
QuoteOriginally posted by kristoffon Quote
- First off, I was a bit disappointed by high iso noise. After all the praise for the K20D's sensor and since it has iso 3200 I expected cleaner high iso but it appears to be about the same as the K200D - max useable is 800, 1600 in a pinch. 3200 isn't usable at all and 6400 a bad joke. I find all the colours look much better and overall IQ is superior, though.
He argues that "max usable is 800."
You're pulling that phrase out of context. It's a comparison with the K200D, not a treatise on ISO performance in general. ISO 800 may very well be the max usable for him, since it's thoroughly dependent on how it's used and a subjective sense of whether it's good enough for that purpose. The actual argument is contained in the rest of the sentence: high ISO noise is about the same as the K200D.
QuoteQuote:
The OP is not only discrediting the high ISO performance of the K20, but also of the K200 as well:
QuoteQuote:
I expected cleaner high iso but it appears to be about the same as the K200D - max useable is 800
I have seen images from the K200 @ ISO 1600 and they are very usable.
Fair enough, but remember this is not objective.
QuoteQuote:
I'm think the K200 produces on a par with the K20, up to ISO 1600.
Which is exactly what the OP said.
QuoteQuote:
My point is this: just because you can not take good shots at high ISO, don't erroneously conclude that no one can.
The OP didn't say that. He was giving impressions of two cameras' performances in the conditions under which he uses them. Ease up a bit
04-15-2009, 11:47 PM   #26
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QuoteQuote:
Quension: You're pulling that phrase out of context. It's a comparison with the K200D, not a treatise on ISO performance in general. ISO 800 may very well be the max usable for him, since it's thoroughly dependent on how it's used and a subjective sense of whether it's good enough for that purpose. The actual argument is contained in the rest of the sentence: high ISO noise is about the same as the K200D.
I did not take anything out of context--what was said is what was said. Please re-read what the OP said.

The K20 and the K200 produce great shots at ISOs above 800--it is that simple. You have taken my words out of context though. The 2 cameras produce on a par, but not unsatisfactorily as the OP states; rather, they both produce excellent quality at high ISOs.

There is no more for me to say--best.
04-16-2009, 06:47 AM   #27
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QuoteOriginally posted by Jewelltrail Quote
He argues that "max usable is 800." This is a silly argument. I get awesome shots @ ISO 1600, and so do many other people here at the forum. And I get very good shots at 3200, without any noise reduction. When I use noise reduction, I get even better shots. I would not call them usable, I would call them very good shots. At ISO 6400, I get good shots, not merely usable. Would I print them at poster size--no, of course not. But they make very good 4 x 6 and 5 x 7, and @ 3200 I can print good 8 x 10. For most people, that is better than usable. I have to believe 99 % of prints are done @ 5 x 7 or less.
High iso noise isn't only about "noise". It also means the dynamic range is reduced and thus the range of applicable contrast and the limit to which you can saturate the picture and it will still look good. And that applies to low resolution as well as 100% view. And that can be seen even in the low resolution of the camera's lcd screen.

Of course between no picture and a noisy picture the latter is better but I personally try to limit iso and take a longer exposure as much as I can since I prefer motion blur to funky colors and low contrast and that's the trade off that suits me best. Besides, with fast primes and a flash for macro, I hardly ever feel the need to go above 800 anyway.
04-16-2009, 01:42 PM   #28
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QuoteOriginally posted by Jewelltrail Quote
The K20 and the K200 produce great shots at ISOs above 800--it is that simple. You have taken my words out of context though. The 2 cameras produce on a par, but not unsatisfactorily as the OP states; rather, they both produce excellent quality at high ISOs.
I agree, although I don't dispute that the K20D probably has a slight edge. I think there are two real issues here:

1) Either camera might only produce "excellent" results in certain situations. The idea of exposing to the right is all well and good, but it might require a larger aperture than one has or could use for DOF purpsoes - or indeed, than is actually manufactured - in order to get a shutter speed fast enough to stop subject motion. That is, if you're already shooting at f/2.8 and that's as large an aperture as you're going to get in the focal length you want, and you'd need shutter speeds of 1/4" in order to ETTR, and your subject is not inanimate, then ETTR is not an option. So you will not be able to get the best possible noise performance out of the camera for that shot. That's one reason why reported experiences differ so widely - they are shooting different types of scenes, with different available lenses.

2) Different people have different tolerances for noise. The same shot might be viewed as excellent by one, acceptable by another, and terrible by another.
04-16-2009, 11:01 PM   #29
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QuoteQuote:
Marc Sabatella: 1) Either camera might only produce "excellent" results in certain situations. The idea of exposing to the right is all well and good, but it might require a larger aperture than one has or could use for DOF purpsoes - or indeed, than is actually manufactured - in order to get a shutter speed fast enough to stop subject motion. That is, if you're already shooting at f/2.8 and that's as large an aperture as you're going to get in the focal length you want, and you'd need shutter speeds of 1/4" in order to ETTR, and your subject is not inanimate, then ETTR is not an option. So you will not be able to get the best possible noise performance out of the camera for that shot. That's one reason why reported experiences differ so widely - they are shooting different types of scenes, with different available lenses

Everything you say applies to all cameras. My point is both cameras have usable applications above ISO 800. More objectively, shots taken at & above ISO 1600 can be used to make nice 4 x 6, 5 x 7, and even 8 x 10s--very simple. No point to philosophize and hair split over what defines ISO 3200 or 6400 shooting. There is only one point here.

That point is to address the claim the OP made opening this thread. Since it continues to be muddled in all the sideshows, I will repeat the OP claim for the sake of clarity: "max usable is 800, 1600 in a pinch. 3200 isn't usable at all and 6400 a bad joke." Rather than defend the claim, the OP digresses into a discussion of what defines shooting ISO 3200 and ISO 6400. I think, the whole matter is so obvious, that there is no need to continue.

I only provided Pentax Poke's threads as a means to aid the OP with high ISO shooting. My job is done, thank you for your attention. Peace
04-17-2009, 11:39 AM   #30
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QuoteOriginally posted by Jewelltrail Quote
Everything you say applies to all cameras. My point is both cameras have usable applications above ISO 800.
Of course - I absolutely agree with your observations and conclusions here.
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