# 1" sensor versus APS-C

Started Aug 15, 2013 | Discussions thread
 Like? 1
 Re: 1" sensor versus APS-C In reply to ultimitsu, Aug 21, 2013

ultimitsu wrote:

nigelht wrote:

No. Your claim is that the same amount of light hits the sensor given the same shutter speed.

This is incorrect and you have shown no documentation/equation otherwise.

I think we can reduce much of the debate down to this.

You think regardless of the sensor format, for the same FOV and shutter speed, the same f-ratio result in the same amount of light falling on to the sensor.

Yes. Provide a reference if this is trivially false.

And I am saying it does not. All that does is resulting in the same light intensity to the same area.

Which is illuminance on the sensor.

The total amount of light falling on to the sensor is proportional to the aperture opening (the area, measured in mm2) which is also in proportion to the sensor area. I am also saying, for the same FOV and shutter speed, same aperture opening would result in same amount of light falling onto the sensor.

This is incorrect as the total amount of light falling on the sensor is a function of ratio of focal length and aperture size and shutter speed. Not just aperture alone.

Every single reference states this. Ratio. Not just aperture size. Ratio.

FOV is nowhere in the equations or definitions to compute illuminance.

Did I summarise this correctly?

You are asking me to prove this. To be honest I have a hard time believe this needs to be proved. I would have thought it is as plain as 1+1=2. One would think a simple visualisation of the aperture opening would have made it clear.

One would think if this were trivial you could point to a simple equation or reference that would state this. What you're doing is hand waving.

Sensors have an absolute sensitivity. High ISO performance is not JUST marketing. The D4 sensor is not good at higher ISOs over the D3200 just because of marketing.

You are completely confused as to what "iso settings" is in a camera.

Think about this. D600's iso goes up to 6400, K5 goes up to 51200. which one has better high ISO?

"What ISO a camera purport it can handle has no bearing on its image quality."

No, I'm not confused. That some manufacturers are more "aggressive" in their marketing is why rules of thumb like "don't go above ISO 1600" existed. In current gen sensors this rule of thumb is now higher.

The difference is sensel size. 2.86µ vs 7.3µ on the D4 and 4.8µ on the D800. Noise quantization (aka photonic noise) is higher on the V2 sensor because the sensel size is much smaller. This doesn't change just because you crop.

Oh... you are one of those who still stuck on the mindset that pixel size is the cause for noise...

Because it is a fact that smaller sensel sizes are more susceptible to photonic noise. The underlying physics haven't changed even if it can be mitigated.

Or perhaps DXOMark and everyone else is wrong about photonic noise too.

Let me ask you this then. Why does D800, D600, D4 all have more or less the same high ISO performance despite the fact that D4's pixels are 50% larger than D600 and 125% larger than D800? (and D600's pixels are 50% larger than D800)

Except that they don't. The D600 has better DR at low ISO (14.2 EV vs 13.1 EV) and the D4 better at higher ISO (starting at ISO 400) with the D4 with a steeper fall off around ISO 9600.

http://www.dxomark.com/index.php/Publications/DxOMark-Reviews/Nikon-D600-sets-high-bar-for-sensor-image-quality/Comparisons

No, ISO is a measure of the sensitivity. Hence the name: ISO Sensitivity. You can calculate the amount of light (aka brightness) to not saturate based on that sensitivity.

That is piles of misinformation piling on top of other misinformation....

And yet all you have in support is a blog post from a random person while these references are from Nikon, wikipedia (weak but better than random blog post) and every other photography site.

The proper meaning of ISO is a standard for brightness. Different film had different sensitivity thus they can produce images of the same brightness under different exposure. those that can produce output twice as bright would have ISO rating twice as high.

ISO states:

"ISO 12232:2006 specifies the method for assigning and reporting ISO speed ratings, ISO speed latitude ratings, standard output sensitivity values, and recommended exposure index values, for digital still cameras. ISO 12232:2006 is applicable to both monochrome and colour digital still cameras."

http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=37777

CIPA states.

"Standard Output Sensitivity’ is a physical measurand defined by light responsiveness of cameras (imaging systems). ‘Recommended Exposure Index’ is a recommended index for exposure based on the image quality sensory evaluation by camera vendors. Therefore, these two factors have conceptual differences, however both serve as similar exposure control functions when using a camera, and they are used as indexes to describe a ‘practical sensitivity’ indicating the necessary amount of light for a camera (imaging system).

These two should be used separately in accordance with the purpose just as both ‘ISO speed’ and ‘Exposure Index’ (the former was established based on the light sensitivity of film, and the latter is based on the image quality sensory evaluation of film vendors) have been used depending on the purpose of silver halide cameras. .

Thus, this standard defines both of these as sensitivity of a digital camera. At the same time, comprehensive specification terms for catalogues are stipulated."

http://www.cipa.jp/english/hyoujunka/kikaku/pdf/DC-004_EN.pdf

Oh wait, I'm sure that CIPA and ISO are using the wrong terminology. :roll:

In digital cameras, sensor has only one, fixed sensitivity. The ISO setting that you select on your camera amplifies the signal that were recorded by the sensor (up to a point, after which brightening is software).

Most sensors of the same generation has more or less the same efficiency at converting light fallen onto it into data. Rightnow they all sitting at about 50%, that is D800, D600, D4, and V2.

So the D4, D600 and D800 sensors have "more or less" the same performance characteristics as the D3200 and V2 sensors?

Man, those D4 buyers are seriously getting ripped off.

"ISO sensitivity is the ability of a sensor to provide a defined response for a given level of lighting."

http://www.dxomark.com/index.php/About/In-depth-measurements/Measurements/ISO-sensitivity

But do you understand what they mean by that? or are you just throwing random shots again?

Yes. Do you?

"Photography is built on the three pillars of exposure: shutter speed, aperture and sensitivity. Shutter and aperture are controls for adjusting how much light comes into the camera. How much light is needed is determined by the sensitivity of the medium used. That was as true for glass plates as it is for film and now digital sensors. Over the years that sensitivity has been expressed in various ways, most recently as ASA and now ISO."

http://www.nikonusa.com/en/Learn-And-Explore/Article/g9mqnyb1/understanding-iso-sensitivity.html

That is the very kind of misuse of terminologies the exposure vs brightness article was correctly criticizing.

You'll have to do better than one blog post to state that everyone else, including the standards organization, is wrong.

or that lens speed doesn't exist.

Rubbish.

Prove it.

Prove what? I told your from the very start what lens speed meant.

Yes, by assertion. Now provide a reference. Which I notice I keep asking for and you keep not delivering despite claiming all this is very basic information. If so then you should be able to point to a half dozen photography 101 sites and support your point.

The brightness of iso 100 image are exactly the same across different format, but the image quality are not. Image quality is the core of this discussion, not brightness.

No. The core of the discussion is that the Nikon 1 provides a useful tradeoff of DOF for size and weight. Nikon 1 users trade smaller size/weight and higher buffer performance for IQ and resolution for the same cost.

That is not what this discussion is about at all. You are clearly lost as what is being discussed.

The discussion is all about tradeoffs.

No this discussion is about optical nature of small lens with small f-ratio. Not about general capability or user suitability of 1.

You were attempting to refute that the 1 has smaller lenses for the same equivalent focal length and aperture.

Which is wrong.

Our 18.5mm f1.8 is equivalent to f4.9 on the 50mm with respect to DoF. Not aperture.

You need to get through your head that aperture is the opening hole, it is measured in mm.

And you need to get through your head that you need to provide a reference or proof rather than simply repeating yourself if you expect to convince anyone.

Especially when every photography site states different.

"All lenses have a maximum aperture, and all NIKKOR lenses list the widest possible aperture on the lens barrel. Some zoom lenses will detail something like f/3.5-5.6 on the lens barrel or 1:3.5-5.6 (below right). These numbers, the 3.5 and the 5.6, are referring to the maximum aperture or widest opening the lens can achieve for each end of the zoom range. Some higher end lenses can maintain the largest aperture throughout the entire zoom range, so only one number is detailed (below left)."

http://www.nikonusa.com/en/Learn-And-Explore/Article/g3cu6o1r/understanding-maximum-aperture.html

Yep, that is just more misuse of terminology.

I guess we should all bow down to your extensive knowledge and Nikon, ISO and CIPA are simply clueless...never mind every other photography site uses the exact same terminology as well.

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