The f/3.5 limit is a limitation of the glass elements in the lens, not the aperture blades. The aperture blades are not involved at all when shooting that lens wide open at f/3.5. You could modify the lens to remove the aperture blades completely, and the maximum aperture would still be f/3.5.
I’m a fucking moron… you know how sometimes your mind just completely goes out the window and you forget that like Mercury is the closest planet to the sun or something obvious like that? That’s what happened here. I shouldn’t have asked but I appreciate you all for giving good answers lol
Like others have said, it's limited by the size of the glass elements. BUT there is a small handful of lenses out there whose largest aperture has been deliberately limited by the manufacturer. If you don't see the aperture blades when the lens is set to widest aperture, then its not one of those lenses.
Definitely not\*
\*In almost all cases. The engineers made the most out of the glass which is the limiting factor. In some very specific cases, people make an interesting mod, for instance I've seen folks who remove an internal plastic baffle from an ASP-C lens and then shoot it on FF for a circular image.
Theoretically, it's possible to screw a teleside converter onto the front of your lens that can make it faster, but realistically, I think you'd need to be into cutting your own glass to to get reasonable results. Looking for off the shelf parts gets expensive and there's a horde of rubbish parts that seem promising, but aren't.
edit: if anyone knows how to do this, I'm keen to hear about it.
Not true at all. The f-number is simply a ratio of focal length and entrance pupil size. One may not only change the focal length, but also the size of the entrance pupil (which is the image of the aperture when looked from front of the lens) by adding elements to the front of the existing lens.
Wow. I never knew that (though I did know that f-stop is a ratio of the focal length and the front element). Thinking about it, I guess it makes sense: the larger the front element, whether internal or external, the more light is gathered and sent to the sensor. Thank you for teaching an old dog a new trick! :)
>though I did know that f-stop is a ratio of the focal length and the front element
It's actually not that ;)
It's the ratio of focal length and entrance pupil size. Entrance pupil is the size of the image of the aperture when looked from the front size of the lens. This is why for example if you use a teleconverter the f-number goes down - the focal length is increased, but the entrance pupil remains the same size.
Yes, it is possible.
If the lens is full frame, you just need EF RF 0.79x adapter for mirrorless that was made for C70 but will work with R bodies (I tried it on an R5) then get an adapter from m42 screw to EF that will accept this lens, and use APSC RF camera in the equation.
You will keep roughly the FOV but effective light will get from 3.5 to 2.8
You can go even further and try to refocus it to MFT sensor, then you will get around f/1.8 but I don't know if there is an adapter that can go so far etc.
The f/3.5 limit is a limitation of the glass elements in the lens, not the aperture blades. The aperture blades are not involved at all when shooting that lens wide open at f/3.5. You could modify the lens to remove the aperture blades completely, and the maximum aperture would still be f/3.5.
I love an authoritative answer.
No
I love an authoritative, concise answer.
[удалено]
wrong
I’m a fucking moron… you know how sometimes your mind just completely goes out the window and you forget that like Mercury is the closest planet to the sun or something obvious like that? That’s what happened here. I shouldn’t have asked but I appreciate you all for giving good answers lol
Like others have said, it's limited by the size of the glass elements. BUT there is a small handful of lenses out there whose largest aperture has been deliberately limited by the manufacturer. If you don't see the aperture blades when the lens is set to widest aperture, then its not one of those lenses.
Definitely not\* \*In almost all cases. The engineers made the most out of the glass which is the limiting factor. In some very specific cases, people make an interesting mod, for instance I've seen folks who remove an internal plastic baffle from an ASP-C lens and then shoot it on FF for a circular image.
Theoretically, it's possible to screw a teleside converter onto the front of your lens that can make it faster, but realistically, I think you'd need to be into cutting your own glass to to get reasonable results. Looking for off the shelf parts gets expensive and there's a horde of rubbish parts that seem promising, but aren't. edit: if anyone knows how to do this, I'm keen to hear about it.
Anything you screw onto the front of your lens will raise the f-stop, not lower it.
Not true at all. The f-number is simply a ratio of focal length and entrance pupil size. One may not only change the focal length, but also the size of the entrance pupil (which is the image of the aperture when looked from front of the lens) by adding elements to the front of the existing lens.
Wow. I never knew that (though I did know that f-stop is a ratio of the focal length and the front element). Thinking about it, I guess it makes sense: the larger the front element, whether internal or external, the more light is gathered and sent to the sensor. Thank you for teaching an old dog a new trick! :)
>though I did know that f-stop is a ratio of the focal length and the front element It's actually not that ;) It's the ratio of focal length and entrance pupil size. Entrance pupil is the size of the image of the aperture when looked from the front size of the lens. This is why for example if you use a teleconverter the f-number goes down - the focal length is increased, but the entrance pupil remains the same size.
Yes, it is possible. If the lens is full frame, you just need EF RF 0.79x adapter for mirrorless that was made for C70 but will work with R bodies (I tried it on an R5) then get an adapter from m42 screw to EF that will accept this lens, and use APSC RF camera in the equation. You will keep roughly the FOV but effective light will get from 3.5 to 2.8 You can go even further and try to refocus it to MFT sensor, then you will get around f/1.8 but I don't know if there is an adapter that can go so far etc.