There is no magical size/weight advantage

Started Mar 5, 2014 | Discussions thread
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Re: What "exactly" is an equivalent lens as regards to the sensor size?
In reply to IVN, Mar 10, 2014

IVN wrote:

nigelht wrote:

nigelht wrote:

olyflyer wrote:

That's exactly it. Not only to you, but to everybody else. Those lenses are not equivalent, only equivalent to the half... or one third if you are generous, ignoring other, sensor and IQ related issues, like same ISO = more noise if the sensor is smaller.

This is false and assumes that the sensel sensitivity is identical across large and small sensors. There are 1" BSI sensors in production consumer cameras. Are there FF BSI sensors in production consumer cameras?

The LENSES are indeed equivalent in terms of exposure or the ISO would be different. The fact that noise changes at the same ISO is true if I stuck the same lens on a 1" Nikon camera vs 1" Sony camera.

LENS equivalence never has anything to noise performance of a sensor since what sensor it is paired with changes over time or between manufacturers.

Otherwise no lens is rarely ever even equivalent with itself whenever it is placed on a different body and that's just silly.

No, it's not silly. Look at it like this: if I have a D610 and a 50/1.8 and a V1 and 18.5/1.8, I can use the same ISO and aperture with both to achieve the same shutter speed, but the FX combination offer 2.7 times shallower DOF and 2.7 times less noise at the same settings. It was shown many a time, that sensors of different sizes, that are on the same tech level (which means the opposite of comparing the V1 with the D200...), the noise difference is indeed equal to the difference in size.

Practical example: D610+50/1.8 @ ISO3200 and f/1.8 will have 2.7 times less noise and shallower DOF than V1+18.5/1.8 at the same settings.

NOW, if you want to achieve the same level of noise and DOF in the same situation with the V1, you would need a 18.5mm f/0.67 lens. That would be an equivalent lens to the 50/1.8 on the D610.

You have to show me evidence that noise and size is a linear relationship for same generation sensors.

I chose the number 2.7 for simplicity. In practice a D610 will have orders of magnitude better noise performance than the V1. DxOMark rates the D610 still acceptable at ISO2952, while the V1 is rated acceptable at ISO346. That's over 3 stops of high ISO advantage, even though the D610's sensor has 2.4 times as many pixels.

You also assume that all FF sensors performs identically as well as all 1" sensors.

No I don't, but it's not important, whether one particular FX sensor is 3 stops better than one particular 1" or 3.1 stops better than the other. It's important that the advantage is that huge.

Except they don't. Nikon traded IQ for PDAF vs the route Sony took.

Even Sony's sensor is nothing compared to a FX sensor.

Likewise an entry level dslr sensor is not as good as the flagship dslr sensor.

Again, the difference between the D800's 36MP and D6x0's 24MP sensor at high ISO is very, very small.

Finally, at base ISO the noise difference will be far less than at the extremes.

Even at base ISO V1's files have a lot of noise, especially if you do a lot of PP.

You make it sound like, taking photos is only ever about noise and DOF. And all these comparison of lenses are pointless. First you argue that only identical lenses can be compared, equivalent FOV lenses can't, ultra wide angle lenses are special lenses and can't be compared also. If that's the case, what is there to compare? There is no such thing as identical lens or sensor. If you must make a conclusive comparison, you'd need 2 lenses from the same production line from the same batch of samples, using the same batch of components, same batch of glasses. Same slice of wafer, same mega pixel, same manufacturer for the senor. ONLY then you can make a proper comparison.

Normal people don't go buy a Golf GTI and expect it to perform like a Carrara GT. Given the price of the N1 to the FF, what is there to compare or complain about?

Usually people don't go buy a lens solely base on DOF either. FOV must go first, e.g., who's going to buy a huge tele for indoor use? No matter how great the DOF is. Similarly who's going to buy a wide angle lens to shoot birds?

So to compare size and weight, you must compare lenses base on FOV and not "identical lens", because we are talking about practical use here and not theoretical use.

Normal people would chose a suitable lens base on his required FOV first, then other parameters, such as sharpness, speed, CA, distortion........ etc.

If for example, I need a lens that can reach 300mm, I could have a AF-S 300mm f4 or the 30-110mm, the size difference is huge, but of cause I hear you cry, one is a prime. But then even if you compare it to the 70-300mm the size difference is still significant. The 300 f4 meanwhile is about 8X more expensive, is it 8X the lens? Hard to say, even if it is, the 30-110mm is still decent enough as a lens. Given it's price, it's an absolute bargain if you ask me. The 70-300mm is also much more expensive, about 4X the price. Is it 4X the lens? Doubtful!

In short had you titled your post, "There is no magical size/weight advantage In Theory". There wouldn't have been such a big debate and would be much more helpful to the "newbies". Posts like these only increase confusion.

Bottom line is, I'd look at it like a go kart. I love go karts, they are fun but absolutely useless on road and illegal. No one in their right mind would compare a go kart to a proper car. That's what I love about the N1. The best thing about it, is not trying to pretend to be a DSLR. It is what it is. It is a system camera that is cable of taking good photos and is of reasonable size to handle and to carry around. If you can't ultize it's advantage / ability, maybe it's not always the camera's fault. And yes, the size and weight of the lenses to cover a similar distance compare to a FF camera is a lot smaller.

 Nung's gear list:Nung's gear list
Nikon D7000 Nikon 1 V1 Nikon AF-S DX Nikkor 35mm f/1.8G Nikon AF-S Nikkor 300mm f/4D ED-IF Tokina AT-X Pro 11-16mm f/2.8 DX +10 more
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