mizzi

Joined on Dec 11, 2009

Comments

Total: 4, showing: 1 – 4
On article What is equivalence and why should I care? (2505 comments in total)
In reply to:

Jared_Willson: Equivalence is not silly, it's just limited in its application. If you have:

- 2 cameras, one FF and one M43
- The same subject distance in both cases
- The same megapixel count in each camera (twice the linear pixel density in the M43)
- Twice the focal length in the FF lens (for the same subject framing)
- The same shutter speed selected in each
- A selected f/stop in the M43 that is two stops "faster" than the FF camera
- A selected ISO in the FF camera that is two stops higher than in the M43 camera

Then equivalence states that you should get identical pictures. Same resolution, same exposure (since the ISO difference and f/stop difference will cancel out), same depth of field, same amount of motion blur, same signal to noise ratio (since ISO difference will be canceled by better performance of larger pixels).

It won't work in low light where read noise becomes more critical, but it's good to a first approximation.

a 35mm/1.8 for a FF corresponds to a 17/1.0 m43 lens
unfortunately this lenses are not on the market because they are not sold a lot.
but compare the nikon 35/1.8 and the olympus 17/1.8
nikon 7cm length and 305gr
oly 3.5cm length and 120gr
i'm sure with the size/weight of the nikon you may reach 17/1.0 with a m43
but you are right: on the wide angle side you have some advantages with a FF.
but on tele side you are better with m43 if the size a weight are the same
this is the reason why all superzooms have a small sensor.

Link | Posted on Aug 13, 2016 at 22:11 UTC
On article What is equivalence and why should I care? (2505 comments in total)
In reply to:

Jared_Willson: Equivalence is not silly, it's just limited in its application. If you have:

- 2 cameras, one FF and one M43
- The same subject distance in both cases
- The same megapixel count in each camera (twice the linear pixel density in the M43)
- Twice the focal length in the FF lens (for the same subject framing)
- The same shutter speed selected in each
- A selected f/stop in the M43 that is two stops "faster" than the FF camera
- A selected ISO in the FF camera that is two stops higher than in the M43 camera

Then equivalence states that you should get identical pictures. Same resolution, same exposure (since the ISO difference and f/stop difference will cancel out), same depth of field, same amount of motion blur, same signal to noise ratio (since ISO difference will be canceled by better performance of larger pixels).

It won't work in low light where read noise becomes more critical, but it's good to a first approximation.

NO! one uses bigger sensor size if you want to mount bigger lenses.
a very small lens on a FF is as difficult to build, like a very big lens on a small sensor camera. it has nothing to do with the pixel size or the number of pixels.

Link | Posted on Jul 16, 2016 at 13:27 UTC
On article What is equivalence and why should I care? (2505 comments in total)
In reply to:

mizzi: Thanks for this article! i'm a physicist and try to explain this my colleagues since a long time.
But i think we should also specify for each camera the equivalence ISO which corrects the influence if the equiv. aperture. if the aperture is corrected by 2 stops the lowest ISO value should be corrected by 2 stops too.
low light capability of a camera is to capture a an image at a given exposer time! nothing else.
If you play the game a bit more comparing similar cameras with different sensor sizes you can explain why cameras with a long zoom ranges all have a small sensor.
if have written a similar article 8 years ago comparing a d300 and a fz20 camera.
http://www.mizzi-computer.de/home/digicam/noisefilter3.html
Both cameras are definitely NOT state of art, but today everything is the same game with a higher performance only.
Perhaps we should also consider to specify something like a equivalent quality for a given subject! Thanks again for your article!

Yes indeed you can crop the larger sensor image, but if you compare e.g. a fz1000 f4,400m/eqiv. with a A7 and a 4/100mm and crop the image of the A7 by a factor of 4 to get the 400mm reach of the fz1000, the A7 loose the comparison. it delivers a 2MP image with a horrible image quality. And note both cameras have the same size. also the low light capability is better with the fz1000 because the fz1000 can be rendered down to 2MP which reduces the noise dramatically.
I think that we should really have entities describing this features. equivalence aperture/focal length is fine but equivalence ISO should be also included.

But is also clear that the A7 wins the game if you compare images taken at 100mm/eqiv. thus equivalence ISO depends on the focal length just the same as the aperture.

Link | Posted on Jul 16, 2016 at 13:10 UTC
On article What is equivalence and why should I care? (2505 comments in total)

Thanks for this article! i'm a physicist and try to explain this my colleagues since a long time.
But i think we should also specify for each camera the equivalence ISO which corrects the influence if the equiv. aperture. if the aperture is corrected by 2 stops the lowest ISO value should be corrected by 2 stops too.
low light capability of a camera is to capture a an image at a given exposer time! nothing else.
If you play the game a bit more comparing similar cameras with different sensor sizes you can explain why cameras with a long zoom ranges all have a small sensor.
if have written a similar article 8 years ago comparing a d300 and a fz20 camera.
http://www.mizzi-computer.de/home/digicam/noisefilter3.html
Both cameras are definitely NOT state of art, but today everything is the same game with a higher performance only.
Perhaps we should also consider to specify something like a equivalent quality for a given subject! Thanks again for your article!

Link | Posted on Jun 26, 2016 at 11:44 UTC as 123rd comment | 2 replies
Total: 4, showing: 1 – 4