Test/ First Impression S1RII does birds

[GeorgeHudetz]

...on the other hand, the 24 MP sensor is less sensitive to diffraction than the 44, and, likewise, will not show the IQ degradation of the 2.0x TC as much as a higher resolution sensor would. So maybe the pixel-level IQ differences between the two setups are not all that great.

 

[Jan.Wedekind]

Just to add to George’s point: now that I upgraded from the S1 to S1Rii, I would not want to go back. It’s like having a built in 1.4x and that’s exactly how I use hybrid zoom on zoom lenses and crop zoom on primes.

Noise at 6400 ISO is also very well overall.

I am seriously considering getting the Sigma 500 too and letting go off M43 altogether, which now I basically only use for wildlife.

 

[ALAIN]

Regarding "diffraction with tele-converters"
I'm trying to recall some memories... ... ... old memories ... ... ... of optical concepts :

Perhaps every body is ok ... : I read that :

"A teleconverter (or focal length multiplier) is an optical accessory placed between the lens and the camera body to increase the effective focal length of the lens. Typically, it multiplies the focal length by a factor (1.4x, 1.7x, 2x, etc.), allowing for additional zoom.

Diffraction and Teleconverters​

Diffraction is an optical phenomenon that occurs when light passes through a narrow aperture (such as the lens diaphragm). It limits image sharpness, especially at very small apertures (high f-numbers, e.g., f/16 or f/22).

A teleconverter itself does not directly cause diffraction, but it can worsen its effects for several reasons:

1. Light Reduction: A teleconverter generally reduces the amount of light reaching the sensor (for example, a 2x converter reduces the effective aperture by 2 stops: a lens set to f/2.8 becomes f/5.6). This may lead photographers to close the aperture further to compensate, increasing the risk of diffraction.
2. Smaller Effective Aperture: Even if you don’t change the aperture setting on your lens, adding a teleconverter reduces the effective aperture. For example, a lens set to f/4 with a 2x converter behaves like an f/8 lens. If you close the aperture further (e.g., to f/11), the effective aperture becomes f/22, which increases diffraction.
3. Optical Quality: Some low-quality teleconverters may introduce optical aberrations, but diffraction remains primarily linked to the effective aperture.

Conclusion​

The teleconverter does not create diffraction, but it can encourage its occurrence by reducing the effective aperture and pushing you to use smaller apertures. To minimize diffraction, avoid closing the aperture too much, especially when using a teleconverter."

 

[GeorgeHudetz]

Regarding "diffraction with tele-converters"
I'm trying to recall some memories... ... ... old memories ... ... ... of optical concepts :

Perhaps every body is ok ... : I read that :

"A teleconverter (or focal length multiplier) is an optical accessory placed between the lens and the camera body to increase the effective focal length of the lens. Typically, it multiplies the focal length by a factor (1.4x, 1.7x, 2x, etc.), allowing for additional zoom.

Diffraction and Teleconverters​

Diffraction is an optical phenomenon that occurs when light passes through a narrow aperture (such as the lens diaphragm). It limits image sharpness, especially at very small apertures (high f-numbers, e.g., f/16 or f/22).

A teleconverter itself does not directly cause diffraction, but it can worsen its effects for several reasons:

1. Light Reduction: A teleconverter generally reduces the amount of light reaching the sensor (for example, a 2x converter reduces the effective aperture by 2 stops: a lens set to f/2.8 becomes f/5.6). This may lead photographers to close the aperture further to compensate, increasing the risk of diffraction.
2. Smaller Effective Aperture: Even if you don’t change the aperture setting on your lens, adding a teleconverter reduces the effective aperture. For example, a lens set to f/4 with a 2x converter behaves like an f/8 lens. If you close the aperture further (e.g., to f/11), the effective aperture becomes f/22, which increases diffraction.
3. Optical Quality: Some low-quality teleconverters may introduce optical aberrations, but diffraction remains primarily linked to the effective aperture.

Conclusion​

The teleconverter does not create diffraction, but it can encourage its occurrence by reducing the effective aperture and pushing you to use smaller apertures. To minimize diffraction, avoid closing the aperture too much, especially when using a teleconverter."

Yes, the TC does not cause diffraction, but it does exaggerate it. The important point to remember is that diffraction is always present, regardless of the aperture. It's just a question of whether or not it degrades the final digital image, which is a function of the sensor pixel pitch (and aperture, of course). So, at F5.6, while there is diffraction present, you can't detect it in the resulting 24 or 44 MP image. However, the TC - which enlarges the image that is projected onto the sensor - will enlarge the effects of diffraction (and all lens aberrations). So, from a diffraction standpoint, that F5.6 lens will look like an F11 lens when a 2.0x tc is used. And thus, diffraction effects - when the F5.6 lens is wide-open - will be visible (in my experience) on a 44 MP sensor, but perhaps not on a 24 MP sensor. Stop the lens down one stop (to a lens-native F8) and now the diffraction will be that of an F16 aperture, which will be visible on the 24 MP sensor as well.

 

[ALAIN]

The exaggeration of defects such as diffraction is exactly what I notice with my Leica 180 2.8 apo:
- when I add 1 x2 Leica apo TC (on the 60MP M11), I see a slight degradation, but the resolution "with TC" is still better than "the crop without TC."
- when I add 2 x2 Leica apo TCs (on the 60MP M11), it's not as good as the crop; I only use 2 x2 TCs for observation (with a 7mm telescope eyepiece or the 12.5mm TO-R).

For the moment, I have the 500 5.6 Sigma and I'm waiting for a TC-2011 + a 24-60 2.8 Lumix, purchased second-hand (14-day return policy). I'm going to order the S1II camera (unless I'm convinced to go for the S2RII, but I already have what I need in high resolution, but it's not very comfortable for moving subjects in low light) on Monday and receive it early enough to try the TC-2011 on the 500mm. We'll see if it can handle closing down a bit...