Patent: Improved EF to EF-M Adaptor

[Loswr]

Fun fact: If you put Speedbooster optics (focal reducing) in the eos-m adapter, it would turn the EOS-M cameras into a Fullframe mirrorless for 200$ new body.

No it wouldn't, it would give you lens equivalence but it would do nothing for COC and noise, characteristics inherent in a sensors size.

Yes it would. Effectively.

the Sb elements do not increase the physical sensor size, obviously.

Sorry, but you are incorrect...for the exact reason you provide: the SB elements do not increase physical sensor size. Therefore, as PBD states, CoC is not affected; also, optical resolution still suffers from the need for relatively greater enlargement compared to full frame.

 

[Coldhands]

Fun fact: If you put Speedbooster optics (focal reducing) in the eos-m adapter, it would turn the EOS-M cameras into a Fullframe mirrorless for 200$ new body.

No it wouldn't, it would give you lens equivalence but it would do nothing for COC and noise, characteristics inherent in a sensors size.

Yes it would. Effectively.

...

The speed-booster is a novel concept and certainly has its uses, but it is far from the panacea you're trying to present it as.

A) It gives a FoV and DoF approximately equal to a full frame lens on a native camera, not exactly. The image angle is still slightly narrower and the effective aperture slightly smaller.

B) The noise equivalence only holds true if the the comparable FF sensor has in ISO advantage of less than or equal to one stop over APS-C (the amount of light added by concentrating the FF area onto APS-C), as you yourself have already pointed out.

C) The resolution achieved by FF lens + SB on APS-C is nowhere near the resolution of the lens on a native FF camera. Although centre sharpness is similar when the lens is stopped down, corner sharpness suffers, as well as overall sharpness at larger apertures. Also chromatic aberrations are much more severe.

D) The dynamic range will not match a FF sensor as the smaller pixels have a smaller electron well. Throwing more photons at them won't help anything.

Even setting aside all if these points, it only takes a few moments of logical reasoning to conclude that if a speed-booster really was a "silver bullet" that gave all the benefits of FF without the actual sensor size, then we would all be using cameras with tiny sensors and optics with this effect built-in. The fact the we don't is testament to the fact that this method has drawbacks that are significant enough to relegate it to a niche product.

It really us the silver bullet. Just try it. I am shooting 99% A7 quality with an APS-C A6000, it's magical. In fact, the a6000 was a much inferior camera than before I used the SB and effectively turned it into FF. It's exactly the same field of view, the same DOF, and the same aesthetic people love about FF. The fact why we're not all using tiny sensors and SB-like elements is because you still need a large FF lens, and on the engineering side of sensors a very small one cant be made to match a FF one, but with the APS-C vs FF, they're freakishly close. In fact, many APS-C sensors out perform FF ones in many ways and vice versa, for example a D5300 vs 5D mk III, but the 5D givea better images (even though it has
ower DR and resolution) because it has that FF aesthetic.

I have no benefit from marketing focal reducers, I am just someone who used them and saw they gave me a FF sensor with no drawbacks (the well made ones), in fact they even improve lens sharpness a bit and improve the NTF charts performance, so I thought I'd share an idea on the EOS M adapter. I do believe that making such an adapter would be a very good approach even compared to making more expensive FF versions of the EOS M, I saw that with the A6000 + SB vs FF A7. I think if Canon made an EOS-M + SB adapter virtually all users would be stunned by the FF images compared to a normal adapter and that most people would'nt be able to tell 5D vs eos M + SB apart, as I ser with the A6000 vs A7 here.

It's a magical invention and effectively turns an APS-C to a FF. The only downside is AF and lens communication issues that's why it'd be almost perfect if Canon themselves did it instead of Metabones.

All you've done with this statement is regurgitate your previous argument with more hyperbole and the addition of a few more blatant fallacies. Since you fail to provide any factual or compelling responses to my statements, I'm not going to bother to elaborate on them in order to further drive home the point.

Meanwhile, your counter-argument regarding the question of why speed-boosters are not the norm completely misses the point. Since we are referring to "large FF lenses" regardless of whether they are attached to a native FF camera, or an APS-C + SB, the former combination would not be the most common if the latter were just as capable and provided a smaller, lighter, cheaper package.