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09-02-2009, 11:31 AM   #46
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QuoteOriginally posted by Torphoto Quote
Ok so let me get this, this thread says if I shoot my k20D vs the mk2 at 1600 iso and compare with shots from the k7 there is no difference in noise?

but comparing raw shots in similar if not identical conditions my mk2 out performs either by 1-2 stops, the noise from the mk2 at 1600 iso looks like or better than 800 from the k20d and close to the k7's 400 iso, so explain this all again to me?

Hell I can shoot the mk2 to 4000 iso and it looks better than 1600 iso from the pentaxes.

what am I doing worng here?
You're shooting pictures and not doing the maths

09-02-2009, 11:43 AM   #47
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QuoteOriginally posted by Mister Guy Quote
The question becomes: If Pentax, today, made a FF camera with a K mount, would it provide better performance than the K-7?
I'm not sure that's the question, but if it is, then the answer to me is pretty clear.

- In most shooting conditions (especially when the light is good) the advantage of the full-frame camera will be so small as to be insignificant.

- In some extreme conditions (especially when the light is bad) the full-frame camera will be able to take shots of good or reasonably good quality that the APS-C sensor camera can't match.

Which is, I think, the common understanding and why so many wedding photographers (to take the group I know best) prefer to work with full-frame cameras if they can afford them.

Note that, when I say the APS-C sensor can't match the output of the FF camera in certain extreme conditions, I don't mean "can't match without a lot of extra trouble," I mean can't match plain and simple. The Nikon D3X can shoot at, what is it? ISO 25,000 or something ridiculous like that. On my K20D, I don't have ISO 25,000 as an option, so there's no point talking about what I COULD do if the K20D had an ISO 25000 option. I'm not interested in science fiction. And while the Pentax K20D can shoot at ISO 6400, I know from personal comparison with shots from Nikon FF users that the FF image at 6400 is generally going to be considerably better than the K20D image at the same ISO. And I don't think that it's because I, as a photographer, am somehow making a mistake in my shooting.

I'm simply not interested in numbers, except as a means to results. I expect the engineers to be all over the graphs and statistics. As a photographer, I simply want to have the right tool for the job - but I need it to be a tool that I can afford.



QuoteQuote:
I believe, if I'm understanding this discussion correctly, the answer becomes yes with an "if", or no with a "but".

Yes, IF you put the same FA lenses (assuming they cover, of course) on a FF body as a APS-C body, and IF you take the same picture, from the same vantage point, with the same shutter and aperture settings, you'd end up being able to use a lower ISO to take the picture, if it was available, IF you are willing to crop it to get the same field of view, but your depth of field will be slightly different, so IF your subject is within subset of the FF DOV, you will end up with a better picture.

OR

No, you can try and take the same picture, with the same field of view, and same depth of field, BUT you won't be able to take the same picture with the same setting from the same location, and thus your picture is always going to be slightly different, which will probably result in you needing to adjust your ISO to match your new settings, which will negate the advantage.

That's a very real world way of looking at it, because it prompts the more practical question: Is it REALLY the sensor size that is preventing me from taking the picture I want to take? Many people have convinced themselves the answer to that question is yes, but a careful examination indicates the circumstances when that answer really IS yes require much more nuanced construction than is often realized.
I'm sorry, don't mean to be rude, but this is gibberish to me.

The question for me, when I'm shooting, is never What do I have to do here to make this picture look like it was taken by a full-frame or medium-format camera? The question is always and simply, Given the camera I have in my hand, how do I take the best picture I can take right now?

If somebody knows a technique that will allow me to take images with a K20D at ISO 6400 or even 3200 that are as noise-free in output as those taken in the same light by a Nikon D3 or a Canon 5D, I would LOVE to hear that tip.

The rest of this seems to me to be sour-grapes pixel-peeping.

Will
09-02-2009, 11:44 AM   #48
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QuoteOriginally posted by Wheatfield Quote
I love it when people throw in meaningless parameters to create false equivalencies. In this case, the whole DOF thing. If you need the extra low light advantage that a full frame camera can give, you are going to shoot in such a way to ensure that the advantage is utilized.
Throwing in an arbitrary requirement that the "depth of field has to be the same or else there is no advantage" is not a meaningful parameter 99% of the time.
I am sorry if you felt this discussion is meaningless, that was not my intention. But I do like to challenge my own thinking from time to time.

It seems as when comparing low noise performance of different formats, many take for granted that the it should be done by comparing images taken at the same ISO. Since I shoot mostly in Aperture Priority mode, I realized that every time I step down the aperture from its maximum, e.g. to acheive a longer DOF, a FF camera would not give me any benefit noise wise.

Granted, in some cases I would have to sacrifice the DOF I really wanted to have in order to reduce ISO. But then I realized that the situations where I am most likely to be using max aperture is when I am using longer lenses (e.g. for sport or nature/animals). Then looking at prices for these lenses, they seem to be similarly priced if max aperture is reduced roughly by the same amount as the focal length increases, e.g. 200mm f/2.8 and 300mm f/4 cost roughly the same, or 400 f/4 and 600 mm f/5.6.

So, under these conditions, if I get a FF, but spend the same money as before on the lens, e.g. going from a 200 f/2.8 on APS-C to 300mm f/4 on FF, there is no gain in low light performance. Similarily, if I decided to bite the bullet and spend extra money to get the 300 f/2.8 lens in order to benefit from the FF, I would actually get the same improvement in performance by spending the same amount of money on a 200mm f/2.0 lens, without having to buy a FF camera.

At least to me this was a meaningful insight, that it is really how much I am willing to spend on a lens that decides most of the low light performance, not if it is APS-C or FF.

I have to agree though that falconeye did capture the reasoning in a much more elegant way by phrasing it such it is not the sensor size that gives the low noise improvement but actually the lens diameter. But then he has a PhD

Best regards,
Haakan
09-02-2009, 11:46 AM   #49
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QuoteOriginally posted by Torphoto Quote
Ok so let me get this, this thread says if I shoot my k20D vs the mk2 at 1600 iso and compare with shots from the k7 there is no difference in noise?

but comparing raw shots in similar if not identical conditions my mk2 out performs either by 1-2 stops, the noise from the mk2 at 1600 iso looks like or better than 800 from the k20d and close to the k7's 400 iso, so explain this all again to me?

Hell I can shoot the mk2 to 4000 iso and it looks better than 1600 iso from the pentaxes.

what am I doing worng here?
Most likely, you aren't actually taking similar shots in as similar conditions as you think you are. You're more likely taking very differently composed shots, with very different exposure settings, with very different lenses, then comparing them.

Exposure triangle: If you took the same aperture and shutter speed at 1600 and at 400, one of those is either severely underexposed.

If you adjusted the shutter speed and aperture to account for the ISO, you ended up with a different picture.

09-02-2009, 11:59 AM   #50
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QuoteOriginally posted by nostatic Quote
You're shooting pictures and not doing the maths
figures, so all lets stop mesurebating and start shooting
09-02-2009, 12:02 PM   #51
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QuoteOriginally posted by Torphoto Quote
Ok so let me get this, this thread says if I shoot my k20D vs the mk2 at 1600 iso and compare with shots from the k7 there is no difference in noise?
Hi Torphoto,
I am not so good in pedagogy. What I wanted to discuss was if the best way to compare noise performance between different formats is best done by comparing the noise at the same ISO, or if there perhaps are better parameters to use. There is no question that at same ISO, the FF will have roughly one EV better performance.

But, when looking at the changes in FOV, and the impact that has on the lens, it is really the money I spend on the lens that gives me the performance increase (in reality this holds best for focal lengths above normal length), not the fact that I went to FF.

Best regards,
Haakan
09-02-2009, 12:09 PM   #52
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QuoteOriginally posted by WMBP Quote
The question for me, when I'm shooting, is never What do I have to do here to make this picture look like it was taken by a full-frame or medium-format camera? The question is always and simply, Given the camera I have in my hand, how do I take the best picture I can take right now?

Will
Perhaps I'm reading it wrong, but most people seem to get those confused, and it was my understanding that's what this thread attempts to correct. People have a very mistaken habit of looking at a picture and thinking, if I had had a full frame camera, I could have taken this same picture and it wouldn't be so underexposed or noisy. However, it just doesn't work that way. If you have a different format camera in your hand, you have to take a slightly different picture. It doesn't just magically take the same settings and let you push the ISO.

The point of this thread, I thought, was to underline the difference between those two view points. The incorrect view point that thinks, "Hey, FF would let me use a higher ISO so it's automatically better for this picture" and the correct view point that thinks, "Hey, it's dark as a mofo in here and even with a high ISO it's slightly underexposed with all the apertures I have available to me, if I had a FF camera, I'd be able to expose this properly".
09-02-2009, 12:20 PM   #53
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QuoteOriginally posted by Mister Guy Quote
Perhaps I'm reading it wrong, but most people seem to get those confused, and it was my understanding that's what this thread attempts to correct. People have a very mistaken habit of looking at a picture and thinking, if I had had a full frame camera, I could have taken this same picture and it wouldn't be so underexposed or noisy. However, it just doesn't work that way. If you have a different format camera in your hand, you have to take a slightly different picture. It doesn't just magically take the same settings and let you push the ISO.
You have captured exactly my intention with this thread. It seems as most times we are just looking at ISO performance when comparing different sensor format, without reflecting on what other parameters that changes when going from one format to the other and how these will impact the ability to take an image in low lights.

Best regards,
Haakan

09-02-2009, 12:23 PM   #54
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QuoteOriginally posted by Haakan Quote
I am sorry if you felt this discussion is meaningless, that was not my intention. But I do like to challenge my own thinking from time to time.
Haakan, I don't think the discussion is (quite) meaningless, and I too like to challenge my own thinking from time to time. That's all fine. I have found the thread interesting.


QuoteQuote:
It seems as when comparing low noise performance of different formats, many take for granted that the it should be done by comparing images taken at the same ISO.
For what it's worth, the issue for me is almost never what ISO I'm shooting at: it's how much light I'm shooting in. I might add that the quality of the light seems to matter, as well, although I have a lot of trouble explaining that technically.


QuoteQuote:
Since I shoot mostly in Aperture Priority mode, I realized that every time I step down the aperture from its maximum, e.g. to acheive a longer DOF, a FF camera would not give me any benefit noise wise.

Granted, in some cases I would have to sacrifice the DOF I really wanted to have in order to reduce ISO. But then I realized that the situations where I am most likely to be using max aperture is when I am using longer lenses (e.g. for sport or nature/animals). Then looking at prices for these lenses, they seem to be similarly priced if max aperture is reduced roughly by the same amount as the focal length increases, e.g. 200mm f/2.8 and 300mm f/4 cost roughly the same, or 400 f/4 and 600 mm f/5.6.
You lose me here. 200/300 = 2.8/4?? You're saying a 100mm increase in the focal length of a lens = a 1 stop decrease in the aperture?


QuoteQuote:
So, under these conditions, if I get a FF, but spend the same money as before on the lens, e.g. going from a 200 f/2.8 on APS-C to 300mm f/4 on FF, there is no gain in low light performance.
OK, the 1.5x crop factor for Pentax means that the 200mm lens on your K20D has the same field of vision as the 300mm lens on the (hypothetical) full-frame camera. But why do you hobble the lens for the full-frame by giving it a smaller aperture?

I'm getting the impression that you think the 200mm lens, on a Pentax DSLR, somehow EQUALS the 300mm lens on a full-frame camera. Why do you think that? Focal length is focal length. The crop factor is due to the difference in the size of the sensor, not to something in the lens itself. Forgive me if I'm misunderstanding you but that's what it sounds like to me.



QuoteQuote:
Similarily, if I decided to bite the bullet and spend extra money to get the 300 f/2.8 lens in order to benefit from the FF, I would actually get the same improvement in performance by spending the same amount of money on a 200mm f/2.0 lens, without having to buy a FF camera.
There's something very wrong in here. I'm trying to put my finger on it. It's hard for me to do this, because you keep switching from apples to oranges and back.

Why do you say "if I spend the same money"? What's money go to do with it? The issue isn't money, it's absolute capability. It's a simple fact of camera technology that, the higher the price, the fewer the additional benefits. So the question for the consumer is, do you need those additional benefits? A Nikon D3X that costs five times more than a Pentax K-7 (or whatever the price difference is right now) is clearly and objectively NOT going to produce five times better photos in most circumstances. But it is infinitely better in some circumstances, because there are situations where a D3X can take a usable picture and a K-7 simply can't. Do you dispute this?

I also mentioned money. But I mentioned money because I'm talking about reality, not about hypothetical market comparisons. Reality is, when I buy a camera, I make compromises. Full frame camera is bigger, heavier, has shallower depth of field (which is sometimes undesirable) and costs a lot more, and much of the time it doesn't take better pictures than I can take with my K20D. Since I have decided that I don't absolutely require a full-frame camera, I go for the Pentax system because it's cheaper and the image quality is good enough, most of the time. That seems pretty straightforward.


QuoteQuote:
At least to me this was a meaningful insight, that it is really how much I am willing to spend on a lens that decides most of the low light performance, not if it is APS-C or FF.
OK, if you want to believe that, be my guest.

Look, I would LOVE to be wrong here. I would love to discover that this whole "full frame is less noisy" thing is a myth cooked up by Nikon and Canon fans and that the reason my photos are noisier than my Nikon or Canon-using colleagues is simply that I, dummy that I am, have been buying the wrong lenses. I take a lot of photos in churches, in low light, between ISO 800 and 1600 and occasionally a bit higher, using the Pentax DA* 50-135 f/2.8 that I spent close to $1000 on. The results are good, much of the time, and I love the lens. I use it almost exclusively in churches. However, I have seen the work done by other wedding photographers using full-frame cameras with similar lenses. The pictures they take in what seems to me pretty similar light are generally cleaner (less noisy) than mine - not at the same ISO, but absolutely, regardless of ISO. In other words, I don't care if they're shooting at the same ISO or a lower ISO or a higher one: I only care about the output.

I say my colleagues get better results in these circumstances because they're shooting full frame; you seem to say that it's because I'm using the wrong lens. What lens do you suggest I move to, to improve the results I'm getting with my K20D? I'm not asking a hypothetical question. I'm asking a real question. Give me a link to the lens at B&H and I'll consider buying it. Oh, keep in mind that I'm not always shooting at f/2.8 because sometimes that gives me less depth of field than I require.


QuoteQuote:
I have to agree though that falconeye did capture the reasoning in a much more elegant way by phrasing it such it is not the sensor size that gives the low noise improvement but actually the lens diameter. But then he has a PhD
I have a Ph.D. too. Not much help in this discussion though.

Will
09-02-2009, 01:03 PM   #55
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QuoteOriginally posted by Mister Guy Quote
Perhaps I'm reading it wrong, but most people seem to get those confused, and it was my understanding that's what this thread attempts to correct. People have a very mistaken habit of looking at a picture and thinking, if I had had a full frame camera, I could have taken this same picture and it wouldn't be so underexposed or noisy. However, it just doesn't work that way. If you have a different format camera in your hand, you have to take a slightly different picture. It doesn't just magically take the same settings and let you push the ISO.
Trying to get my head around this. I agree that different camera formats necessarily take different pictures. I would add that there simply is no way to compare a full-frame apple to an APS-C apple. In other words, there's no camera that is identical to a K20D or K-7 except for the sensor size. There are always other differences too, in resolution, in the processing engine and noise-reduction routines, etc. I take all of those things together, because, um, that's how they come when you buy a real camera.

But when you say that it's wrong to think "I could have taken this same picture and it wouldn't be so underexposed or noisy" (if I took it with a full-frame sensor), well, I disagree with you, in several ways. And if I do think along those lines, it's because the photos I've seen taken by full-frame cameras in low light are often impressively less noisy than the photos that I take.

Let me take a practical example. Say 2 photographers are shooting the same wedding in the same church, one with a K20D and the other guy with a Nikon D3X. Let me think of a very typical situation: subject distance is 30 ft, shutter speed can't go lower than 1/30th sec. To get the same depth of field (roughly 8 ft), the Pentax setting at 50mm would be f/2.0, while the Nikon at 75mm will stop down to f/2.8 to get the same depth of field. What's the result?

The result is that the two pictures will have pretty similar fields of vision. Depth of field will be nearly identical. But if the Nikon shooter knows how to use his camera, his shot will almost certainly be less noisy. I don't care what ISO the Nikon shooter uses, or what ISO the Pentax shooter uses, for that matter. I will say that I've taken this shot or something very like it hundreds, no, probably thousands, of times and in an "average" church (in my experience) I'd be shooting somewhere between ISO 800 and ISO 1600. Maybe the Nikon shooter would have to boost the ISO slightly because of his smaller aperture, but I'm pretty sure his result would STILL be better.

Now, consider further: I COULD take exactly that shot, using my Pentax 50mm f/1.4; but as a practical matter I tend to use the 50-135 f/2.8. What's the difference? Aside from the fact that the prime is slightly sharper than the zoom at 50mm, the main difference is that, at f/2.8, I've got a few more feet of depth of field. Is this a big deal? NO, absolutely not. In these circumstances MORE depth of field is almost never a problem. And I just want to take the darned picture and have it be sharp and clean and pretty.


QuoteQuote:
The point of this thread, I thought, was to underline the difference between those two view points. The incorrect view point that thinks, "Hey, FF would let me use a higher ISO so it's automatically better for this picture" and the correct view point that thinks, "Hey, it's dark as a mofo in here and even with a high ISO it's slightly underexposed with all the apertures I have available to me, if I had a FF camera, I'd be able to expose this properly".
I'm having trouble understanding this statement.

It SOUNDS as if, in the second ("correct") part of the statement above, you are agreeing with me: In a very low-light situation, a full-frame camera might simply produce less noisy images than my K20D does. Yes, I agree with this. That's what I've been saying all along.

It also SOUNDS as if, in the first ("incorrect view") part of your statement, you're saying that some people think that full-frame cameras are simply and absolutely better FOR ANY PICTURE IN ANY LIGHT because, um, well, why exactly would anyone think this? You say "because full frame would let me use a higher ISO." But that can't be right. Nobody says that because it's generally absurd. I can almost always use a higher ISO on my Pentax K20D, too - because I more or less NEVER use 6400 or even 3200, even though the camera has them. So the point can't be that FF is "better" (if only occasionally) because it let you use "higher" ISO. I suppose there are people who might buy a FF camera just because it "goes to 25,000", you know, like the speakers that the guy in Spinal Tap loved because they "go to 11." Of course, 25,000 on a Nikon D3 is actually different, where "11" on the speakers wasn't. That was the point of the joke.

This seems like a straw man to me, though. I certainly haven't said anything this silly. I've said exactly the opposite. In many if not most situations, especially where the light is good, an APS-C sensor may be able to take a photo that, in terms of image quality, is indistinguishable from a photo taken by a Nikon D3X. Indeed, in good light, a high-end compact camera may be able to do just as well. And a Pentax K20D with a good prime on it may take a BETTER photo than a full-frame camera with a less-than-excellent lens. And finally, a good photographer with a K20D will outshoot Uncle Larry the camera collector with his D3X every day of the week, in any kind of light.

So I fail to grasp the distinction between the two views here. On the one hand you've stated a (correct) view that I agree with and consider non-controversial. On the other hand, your opposing view is nearly devoid of meaning or sense, so I'm kind of lost.

Anyway, this doesn't sound like what Haakan was saying in his initial post. Haakan's point seems to be that he can get FF results in low-light situations by buying better lenses.

Will
09-02-2009, 01:06 PM   #56
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Real World Example

QuoteOriginally posted by Torphoto Quote
Ok so let me get this, this thread says if I shoot my k20D vs the mk2 at 1600 iso and compare with shots from the k7 there is no difference in noise?
Yes, *if you keep all the other parameters listed constant, too* - FOV, DOF, shutter speed. That's the point of this thread - to illustrate how *all* those parameters related. You can't just say you're comparing noise fro one camera to another without also being to sure to control the factors that influence noise. That would be like saying a Geo Metro is faster than a Maserati by testing the Metro going downhill in a tailwind but the Maserati going uphill while wearing snow tires and towing a yacht.

QuoteQuote:
explain this all again to me?
I've already pointed out in a previous response the importance of comparing apples to apples - same FOV, same shutter speed, same DOF and/or lens size. You still haven't said if that's how you were doing your comparison, but I'm guessing no, you weren't. I'm guessing you using a faster shutter speed on the FF camera, made possible by also using a much larger lens that provide much smaller DOF.

But to put a simple real-world measure on this, consider shooting APS-C with a 135/2.8 wide open, at a shutter speed of say 1/60" - a typical low light concert shot for me. To get the same FOV and shutter speed on FF, you'd be shooting 200mm and f/4, and you would get pretty much the same DOF, too. Of course, a 200/4 is already a bigger lens than a 135/2.8, but the diameters at least are the same.

Now, if you're telling you me you can shoot at 200mm, f/4, and 1/60" with your FF camera and get significantly better noise than you can shooting 135mm, f/2.8, and 1/60" on your APS-C camera, then I guess that suggests the "quantum efficiency" of your particular FF camera might be better than that of your particular APS-C camera.

But I'm guessing what's really happening is that you only getting better noise performance by shooting at the same *aperture* on both cameras - that is, shooting 200/2.8. Well, sure. Just as you'd get better noise performance on APS-C if you shot a 135/2, because it would let you cut ISO in half. And in both cases, you'd be greatly increasing the size of the lens, and also greatly decreasing DOF. So if you're comparing shots at the same f-stop on both systems, that's not apples-to-apples - you're slanting the results in favor of the FF system by using a much larger lens on that camera.
09-02-2009, 01:14 PM   #57
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QuoteOriginally posted by WMBP Quote
Haakan, I don't think the discussion is (quite) meaningless, and I too like to challenge my own thinking from time to time. That's all fine. I have found the thread interesting.

For what it's worth, the issue for me is almost never what ISO I'm shooting at: it's how much light I'm shooting in. I might add that the quality of the light seems to matter, as well, although I have a lot of trouble explaining that technically.

Will
Hi Will
I know my pedagoical skills are lacking, but let me try again.

First of all, I agree that ISO is not the primary parameter I set when trying to get a picture, but rather a consequence of other parameters I select (like aperture, shutter speed etc.). This was actually what triggered my thinking in the first place.

Going from one format to the other changes the FOV, that is why I took the example of using a 200mm lens on APS-C and 300mm on FF in order to have the same FOV in the comparisons.

In going from 200mm to 300mm I have two options. Either I keep the front element size the same, and loose roughly 1 EV in light. Then I will have to increase the ISO by 1 EV, and this would negate the 1 EV benefit that the FF sensor has.

Or I go for a 300mm lens with the same max aperture as the 200 mm lens. Then I will get the 1 EV benefit from the FF.

But then one can ask, what if I instead increased the size of the front element on the 200mm lens to be equal to the 300mm lens that I needed to take advantage of the FF. And it turns out that this will give exactly the same gain as I got with the FF and the 300 mm lens.

This is why I like falconeyes statement that the only thing that matters is the size of the lens element, not the size of the sensor.

I agree that adding a cost component to it all might have just added to the confusion, I have to blame that on my budget constraints.

But even taking away the money, when looking at the lenses above the "normal", the max aperture has a tendency to decrease as the focal lengths increases, making it hard to capitilize on the improved ISO performance of FF when looking at same FOV.

Best regards,
Haakan

Last edited by Haakan; 09-02-2009 at 01:20 PM.
09-02-2009, 01:18 PM   #58
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I just saw Marc was faster on the trigger and did a much better explanation then me

Best regards,
Haakan
09-02-2009, 01:20 PM   #59
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QuoteOriginally posted by WMBP Quote
If somebody knows a technique that will allow me to take images with a K20D at ISO 6400 or even 3200 that are as noise-free in output as those taken in the same light by a Nikon D3 or a Canon 5D, I would LOVE to hear that tip.
Get a bigger lens.

It's thinking of ISO as important in itself that is confusing the issue. If you think about it, you don't *really* care about what the ISO number reads - you care what the *shutter speed* is. That is, your *goal* is to take a picture at shutter speed X (let's say 1/60"); the ISO is just a *means* to that end given the aperture you are using. You want that 1/60" shutter speed, but you get to that goal however you can - that means some combination of large aperture and high ISO.

So if your goal is to get that 1/60" shutter speed on your K20D with less noise that you are now, the way you get there is to get a bigger lens - one with a larger maximum aperture. This allows you to use a lower ISO, and hence lower the noise.

So if you're shooting the FF camera at 75/2.8, you will need a 50/2 on your APS-C camera in order to get the same shutter speed and same noise performance. As it happens this *also* gives you the same DOF, which is why that keeps cropping up (sorry) in the discussion, even though everyone knows we ordinarily don't actually care about that as much as the other parameters.

Once again - the only advantage of FF here is that it is generally easier to obtain large diameter lenses for FF than for APS-C. In order to get results on APS-C as good as from a 70-200/2.8 on FF, you'd need a 50-135/2.
09-02-2009, 01:29 PM   #60
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QuoteOriginally posted by Marc Sabatella Quote
It's thinking of ISO as important in itself that is confusing the issue. If you think about it, you don't *really* care about what the ISO number reads - you care what the *shutter speed* is. That is, your *goal* is to take a picture at shutter speed X (let's say 1/60"); the ISO is just a *means* to that end given the aperture you are using. You want that 1/60" shutter speed, but you get to that goal however you can - that means some combination of large aperture and high ISO.
that's silly. Tv priority isn't applicable to every scenario and lowest possible iso = greatest detail = priority overall.
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