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That's basically what micro 4/3 cameras are doing. As far as I know they all can do distortion correction in-camera for JPEG output, and the prime lenses are ge

by Saris 5y ago

That's basically what micro 4/3 cameras are doing. As far as I know they all can do distortion correction in-camera for JPEG output, and the prime lenses are generally quite cheap and very compact. For example Panasonic has a 25mm f/1.7 lens that is 125 grams and costs $150 brand new. Of course you can also buy similar focal length lenses that are huge and weigh over a pound, while spending $1500+. But I don't know how much advantage those really give except in specific rare situations.

dharma1 5y ago
I like m43 cameras, but the depth of field with that sensor size is nowhere near that of full frame
sudosysgen 5y ago
I disagree. The Panasonic 25mm f/1.7 is equivalent to a 50mm f3.4 on full frame. For 150g on full-frame you can get a 50mm 1.8, at a cost of 150$ brand new. So on full frame at a similar weight and at the same price you get superior optics. If you really care about the weight, the 40mm 2.8 has the same weight and the same price but superior optics again. All modern FF cameras do distortion correction too. M4/3 lenses are not especially decided to trade-off distortion for sharpness anymore than full-frame.
- Zak 5y ago
  Whether you should apply crop factor to aperture depends on whether you're interested depth of field, or exposure. You may or may not be able to adjust ISO to get comparable results at 50mm f/3.4 depending on which cameras you're comparing.
  - sudosysgen 5y ago
    If you adjust ISO you will get more noise. Noise is decided by the quality of the sensor, and the solid angle of light that hits each point on the sensor. The solid angle as it happens also decides depth of field. So it is always true that you should apply crop factor to aperture. ISO is just not the correct factor to describe gain because an inverse crop factor is applied to it in effect. So at the same exposure and shutter speed, at f/3.4 on FF you will get the same image with the same amount of noise as you would at f/1.7 on M4/3.
    - Zak 5y ago
      You'll have to set ISO higher to get the same image at f/3.4 as you would at f/1.7 on a smaller sensor because the intensity of the light is reduced. I'm interested to learn more about the effect of light angle on noise. Do you have a source that talks about this? I didn't find anything useful in 2 minutes of searching the web.
      - sudosysgen 5y ago
        No, the intensity of light is not reduced. ISO is not gain. In other words, ISO 200 on full frame is the same as ISO 100 on M4/3 in terms of what actually happens inside the sensor. This is because of how the ISO standard is written. As for light angle, it's a consequence of the second law of thermodynamics, that translates in optics as the conservation of étendue. Basically what this means it that the amount of light captured from a light source is equivalent to the solid angle of light from that light source onto the entrance pupil - whose size is the focal length divided by the f number. So basically, what determines in the same scene how much light is received by the sensor depends on the size of the aperture in milimiters. So on a sensor of the same efficiency, it's the physical size of the aperture that determines how much light is captured.
        Zak 5y ago
        The intensity of the light is reduced because the aperture is the same diameter (50/3.4 = 25/1.7), but the light has to cover four times the area. To get the same exposure with double the f number and the same shutter speed will require four times the ISO. > what determines in the same scene how much light is received by the sensor depends on the size of the aperture in milimiters That's true, but the amount of light is not the intensity of light.
        sudosysgen 5y ago
        It's the amount of light that decides the amount of noise. Yes, you will need four times the ISO. But you will get exactly the same amount of noise.

by Saris 5y ago

dharma1 5y ago

I like m43 cameras, but the depth of field with that sensor size is nowhere near that of full frame

sudosysgen 5y ago

I disagree. The Panasonic 25mm f/1.7 is equivalent to a 50mm f3.4 on full frame. For 150g on full-frame you can get a 50mm 1.8, at a cost of 150$ brand new. So on full frame at a similar weight and at the same price you get superior optics. If you really care about the weight, the 40mm 2.8 has the same weight and the same price but superior optics again. All modern FF cameras do distortion correction too. M4/3 lenses are not especially decided to trade-off distortion for sharpness anymore than full-frame.

Zak 5y ago
Whether you should apply crop factor to aperture depends on whether you're interested depth of field, or exposure. You may or may not be able to adjust ISO to get comparable results at 50mm f/3.4 depending on which cameras you're comparing.
- sudosysgen 5y ago
  If you adjust ISO you will get more noise. Noise is decided by the quality of the sensor, and the solid angle of light that hits each point on the sensor. The solid angle as it happens also decides depth of field. So it is always true that you should apply crop factor to aperture. ISO is just not the correct factor to describe gain because an inverse crop factor is applied to it in effect. So at the same exposure and shutter speed, at f/3.4 on FF you will get the same image with the same amount of noise as you would at f/1.7 on M4/3.
  - Zak 5y ago
    You'll have to set ISO higher to get the same image at f/3.4 as you would at f/1.7 on a smaller sensor because the intensity of the light is reduced. I'm interested to learn more about the effect of light angle on noise. Do you have a source that talks about this? I didn't find anything useful in 2 minutes of searching the web.
    - sudosysgen 5y ago
      No, the intensity of light is not reduced. ISO is not gain. In other words, ISO 200 on full frame is the same as ISO 100 on M4/3 in terms of what actually happens inside the sensor. This is because of how the ISO standard is written. As for light angle, it's a consequence of the second law of thermodynamics, that translates in optics as the conservation of étendue. Basically what this means it that the amount of light captured from a light source is equivalent to the solid angle of light from that light source onto the entrance pupil - whose size is the focal length divided by the f number. So basically, what determines in the same scene how much light is received by the sensor depends on the size of the aperture in milimiters. So on a sensor of the same efficiency, it's the physical size of the aperture that determines how much light is captured.
      - Zak 5y ago
        The intensity of the light is reduced because the aperture is the same diameter (50/3.4 = 25/1.7), but the light has to cover four times the area. To get the same exposure with double the f number and the same shutter speed will require four times the ISO. > what determines in the same scene how much light is received by the sensor depends on the size of the aperture in milimiters That's true, but the amount of light is not the intensity of light.
        sudosysgen 5y ago
        It's the amount of light that decides the amount of noise. Yes, you will need four times the ISO. But you will get exactly the same amount of noise.