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04-14-2011, 09:47 AM   #481
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QuoteOriginally posted by gazonk Quote
I think the confusion boils down to this: It will still be a f/2.8 lens wrt. which shutter speed and ISO you would select for your f/2.8 exposure. However, since the tiny sensor only gets a tiny fraction of all the light that the f/2.8 lens collects, there has to be a catch somewhere. And that catch, of course, is that ISO 100 on those small sensors is about as noisy as ISO 1600 on an APS-C sensor.
Yes, I agree. The problem of course is that when this is ignored, one easily starts thinking that it's somehow superior to have a small sensor, when a larger one can use a lens with a smaller aperture and higher ISO to get the very same image. What I wanted to do is to burst this myth.

04-14-2011, 10:06 AM   #482
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once again you miss the amount of light small or large sensor 2.8 allows much more light to fall on the sensor than 16
and that combined with the rest is what may make it appealing to some. truly for me the appeal would be with a wide lens or a normal and have the ability to pocket and shoot on the street unobtrusively. for certain i can also do this with other cameras that aren't as small, but there is an advantage to a small (hopefully quite) camera. My SLRS work for it (so do my medium format) but they attract a lot more attention than a tiny little camera would. My Rangefinders (aside from the yellow leather covered Fed 5) attract little attention
But as I said this camera isn't aimed at any of us here as a market it is likely aimed specifically at the Japanese market, more specifically Japanese teen girls for the cute or kawaii factor

So what is the APSC model going to be, because it's apparent the nc1 holds little appeal for most of us this is a batter thing to waste our collective time on
04-14-2011, 10:10 AM   #483
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QuoteOriginally posted by ghelary Quote
I've seen this argument from sport photographers prefering APSH to FF for that reason, so this is not purelly retorical. Or on another case, if you are hiking on faraway places, you may not be able to carry lenses long enough for the wildlife photography you intend. But a relatively light 100/2.8 would make equivalent to a 600mm... So this NC-1 could be a very companion of an APSC camera in such cases and certainly lighter than the mentionned 600...
The problem with this is that this is an apple vs. orages comparison. A relatively light 100/2.8 for "NC-1" should be comparared for example to a cheap xxx-400mm zoom on an APS-C (which can be stopped down to compare with the DOF and noise of the "NC-1" combination), and not to some massive 600/4 or whatever

The 100/2.8 for the "NC-1" would be quite expensive as it'd have to be a very high resolution lens, certainly more expensive than a consumer grade 400mm zoom on an APS-C. I don't see how this would be a good companion to an APS-C camera. Simpler and better to just have a a companion lens of the cheap 400mm zoom for the days one doesn't want to carry the 600mm monster.
04-14-2011, 10:22 AM   #484
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I don't disagree that the dslr is the better alternative. it's also in general the larger alternative which is part of the issue. As for poor sensors at this level, well if you compare one of these to a stop down crop on my ds it will likely look better than the ds there just isn't enough in the old sensor. p/s sensors like all others have improved a great deal in the past few years so it's performance though limited by physics may not be as bad as we would make it out to be
and a 100 2.8 on it may well satisfy the soccer moms (another potential market) who want to get in close to the kids and aren't critical of other factors like we are
for them a 30-80 zoom on this camera will likely be small and meet their needs (not fast though, but that reduces the chance of a missed focus)

04-14-2011, 10:28 AM   #485
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QuoteOriginally posted by eddie1960 Quote
once again you miss the amount of light small or large sensor 2.8 allows much more light to fall on the sensor than 16
Wrong.

If we have a FF camera with f/2.8 lens and a NC-1 camera with f/2.8 lens, the FF camera will collect about 30 times or so more light. So if you stop the FF down too about f/16, you'll get about the same amount of photons you'll get with a NC-1 with a f/2.8 lens.
04-14-2011, 10:43 AM   #486
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aperture is a function of ratio of lens size to opening. nothing to do with format. everything to do with the ratio

generally i don't quote wiki but they are more eloquent than i am in this case

The lens aperture is usually specified as an f-number, the ratio of focal length to effective aperture diameter. A lens typically has a set of marked "f-stops" that the f-number can be set to. A lower f-number denotes a greater aperture opening which allows more light to reach the film or image sensor. The photography term "one f-stop" refers to a factor of √2 (approx. 1.41) change in f-number, which in turn corresponds to a factor of 2 change in light intensity.

The specifications for a given lens typically include the maximum and minimum apertures, for example, f/1.4–f/22. In this case f/1.4 is the maximum aperture (the largest opening), and f/22 is the minimum aperture (the smallest opening). The maximum aperture tends to be of most interest, and is always included when describing a lens. This value is also known as the lens "speed", because it affects the exposure time. The aperture is proportional to the square root of the light admitted, and thus inversely proportional to the square root of required exposure time, such that an aperture of f/2 allows for exposure times one quarter that of f/4

how the aperture affects DOF is another story as that is dependent on the size of the film plane, but to measure light passed through the lens 2.8 is 2.8 whether it is on an nc1 or an 8x10 view camera - i wouldn't want to focus an 8x10 at 2.8 my 645 is bad enough- or anything between. otherwise it's use as an exposure measurement tool would be useless
since the nc1 specs aren't actually out it's hopeless to speculate too much. but looking at the likely sister cam the Kenko gives one an idea of what the system could encompass
04-14-2011, 12:15 PM   #487
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QuoteOriginally posted by Asahiflex Quote
As I see it a 200mm lens on the NC-1 is using a cropped image to begin with. So if I use the 200mm on my K-5 and crop it out to match the NC-1's 1120mm equivalent picture I end up with the same image, no? So I could just choose to use the same lens as on the NC-1 (pixel density of the sensors aside).
To a certain extent, but don't forget that when you crop the K-5's file you are magnifying all the noise and aberrations.
04-14-2011, 12:41 PM   #488
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QuoteOriginally posted by Pompous Moronox Quote
This is false

A 200/2.8 lens for this hypotethical tiny sensor camera would still be rather large, not really much at all smaller than the current "regular" 200/2.8s.

However, to match that camera/lens FOV and DOF performance on a FF camera one would need a 1120/16 lens which would not be much bigger, and would be quite a bit cheaper to make - the 1120/16 would be a very easy design, no exotic materials needed and it'd likely deliver higher quality image than the more agressive 200/2.8.
QuoteOriginally posted by Pompous Moronox Quote
Wrong.

If we have a FF camera with f/2.8 lens and a NC-1 camera with f/2.8 lens, the FF camera will collect about 30 times or so more light. So if you stop the FF down too about f/16, you'll get about the same amount of photons you'll get with a NC-1 with a f/2.8 lens.
Yes, you are correct about the photenes. But, if we have a FF camera with f/2.8 lens and a NC-1 camera with f/2.8 lens and both lenses has the same FOV, we have the exact same shutter speed @ ISO 100, for example. So, if we stop down our FF lens to f/16 we will get about 4 stops slower shutter speed on the FF then on the NC-1. Now we have to rise the ISO on the FF to 1600, in order to get a decent shutter speed. Whoops, we just lost the advantage of the large FF sensor, we have now the same FOV, the same DOF and the same noise.
And why would I be interested to buy a ~1120/16? Sure, it might be cheap and small as a 200/2.8. But, no camera will AF with such a slow lens and the view finder will be dark as a cave, so no accurate MF either.

04-14-2011, 02:05 PM   #489
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QuoteOriginally posted by Pompous Moronox Quote
Wrong.

If we have a FF camera with f/2.8 lens and a NC-1 camera with f/2.8 lens, the FF camera will collect about 30 times or so more light. So if you stop the FF down too about f/16, you'll get about the same amount of photons you'll get with a NC-1 with a f/2.8 lens.
What does this have to do with anything? F numbers are normalized such that they will produce constant illuminance (light per unit area), which is the only thing that matters for exposure. A FF sensor may collect 30 times the total light, but it has it spread out over 30 times the area, and thus the illuminance is exactly the same as any other sensor.

Why on earth would a pixel care about what any other pixel gets on the far side of a sensor (or photons hitting the back of the camera)? It only cares about the photons it itself gets. An f/2.8 lens will ensure that for a given scene, a given area will receive the same amount of light, and thus exposure, regardless of sensor size (or focal length). Or are you seriously suggesting that it would need 5 stops slower shutter speed to get the same exposure?

Last edited by Cannikin; 04-14-2011 at 02:51 PM.
04-14-2011, 02:27 PM   #490
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Why would you want to stop down to f/16? And what's the point, that the tiny sensor camera performing at it's best could somehow reach the performance of the larger sensor camera performing at it's worst?
04-16-2011, 05:15 AM   #491
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QuoteOriginally posted by Cannikin Quote
What does this have to do with anything? F numbers are normalized such that they will produce constant illuminance (light per unit area), which is the only thing that matters for exposure. ize (or focal length).
Caninkin. careful you dont get F stops and T stops confused here.
T stops refer to the amount of light "transmitted" through the lens. We dont often get to hear about T stops in general photography, but they are possibly closer to what you are implying then F stops are.

As far as I am aware, F stops are not guarenteed to produce the same amount of light on different size lenses in ratio to aperature size. the f-number is the focal length divided by the "effective"
aperture diameter.

Many have never heard of T stops and indeed their importance is gradually being eroded by modern lens coating that "gather light".
But here is a link for those interested.

F-stops, T-stops, focal length and lens aperture

woody
04-16-2011, 09:28 AM   #492
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T stop info is hard to come by except for lenses used in film production where tstop is a standard because of its accuracy allowing the same scene being shot with 2different lenses to meld better when cut together for instance
Its a great thing but introducing it to still shooting would raise the level of confusion imho
04-16-2011, 11:28 AM   #493
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QuoteOriginally posted by pederd Quote
Yes, you are correct about the photenes. But, if we have a FF camera with f/2.8 lens and a NC-1 camera with f/2.8 lens and both lenses has the same FOV, we have the exact same shutter speed @ ISO 100, for example. So, if we stop down our FF lens to f/16 we will get about 4 stops slower shutter speed on the FF then on the NC-1. Now we have to rise the ISO on the FF to 1600, in order to get a decent shutter speed. Whoops, we just lost the advantage of the large FF sensor, we have now the same FOV, the same DOF and the same noise.
Yes, that is exactly what I've been telling. In other words, the "NC-1" would have no advantage.

QuoteQuote:
And why would I be interested to buy a ~1120/16? Sure, it might be cheap and small as a 200/2.8. But, no camera will AF with such a slow lens and the view finder will be dark as a cave, so no accurate MF either.
Well, this is all hypotethical - a FF could in principle do exactly as good contrast detect autofocus the NC-1 could under these conditions. Also, manual focusing with live view or electronic viewfinder would be equally easy (or difficult) under these conditions.
04-16-2011, 11:53 AM   #494
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QuoteOriginally posted by Cannikin Quote
What does this have to do with anything? F numbers are normalized such that they will produce constant illuminance (light per unit area), which is the only thing that matters for exposure. A FF sensor may collect 30 times the total light, but it has it spread out over 30 times the area, and thus the illuminance is exactly the same as any other sensor.

Why on earth would a pixel care about what any other pixel gets on the far side of a sensor (or photons hitting the back of the camera)? It only cares about the photons it itself gets. An f/2.8 lens will ensure that for a given scene, a given area will receive the same amount of light, and thus exposure, regardless of sensor size (or focal length). Or are you seriously suggesting that it would need 5 stops slower shutter speed to get the same exposure?
You seem to be a bit confused . What you're doing is the classic mistake of comparing a tiny sensor to a tiny crop of much larger sensor, instead of comparing to the whole large sensor. You don't seem to understand that the small image will have to be magnified to match the area of the larger sensor (or to any common size).

In other, simpler words: let's say, for the sake of the argument, that both the "NC-1" and a FF-camera have the same number of pixels and the FF has 30 times the surface area (thus the pixels are also 30 times larger). Now, as you did understand above, the larger pixels will each collect 30 times more light, do they not? And they each contribute equally much to the image, so, the lens of the FF camera can be stopped down lots to match the number of photons each sensor receives.

(And the F-numbers are not normalized in any way as you claim - they just tell the ratio of focal length and (virtual) aperture opening.)

Last edited by Pompous Moronox; 04-16-2011 at 12:12 PM.
04-16-2011, 11:57 AM   #495
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QuoteOriginally posted by Kunzite Quote
Why would you want to stop down to f/16? And what's the point, that the tiny sensor camera performing at it's best could somehow reach the performance of the larger sensor camera performing at it's worst?
The point was that the small sensor does not have any advantage over the large one when it comes to having a long DOF.

(Besides, this tiny sensor shooting at wide open probably would not be an optimal aperture. A lens stopped down to f/16 on a FF is not bad - most lenses perform very well here. And there is no more diffractioin issues here than there is with the tiny sensor at f/2.8.)
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