[Winder]

I'm assuming from a quick read that there is no chance of this ever being an adapter I could use on my K5 with Pentax lens

Trevor

Not unless they make a 645 to 36x24mm version. It really only is a benefit to EVIL APS-C or M4/3.

[Winder]

no you cannot

but it would be amazing to have k-01 with this adapter build-in from factory in the space of mirror box (where k-01 has wasted space) and evf, I would but it immediately even knowing that you cannot use most DA lenses...

If Pentax would redesign the K-01 with a sensor that had PDAF built-in, add an EVF and build this adapter into the camera they would have a much better camera, but the adapter is selling for more than the camera right now.

[Winder]

http://www.metabones.com/images/metabones/Speed%20Booster%20White%20Paper.pdf

[HSV]

Since the flange distance reduction is basically a requirement for this technology to work and considering that the only AF booster is the EF to NEX...the best that we can hope for a K-mount SDM to NEX.

I think that this device will be revolution at some point...a 300$ used NEX + 600$ booster = 900$ FF body.

[Unsinkable II]

It make the Fuji system look better to me because I have some older Olympus, Contax, Canon FD glass that I could use on the Fuji body. It has nothing to do with Fuji lenses. The adapter allows you to use FF glass on an APS-C body (which the Fuji is) and get better results. It seems way off the mark because you don't know where the mark is..... stating it politely....

Fairy-nuff

[kadajawi]

It does not look like there is a K-mount planned. None listed.

Not sure that is ever going to happen (and if, then only for the K-01). The optics need to be right where the sensor is, so in the case of the K-01 the optics need to protrude into the camera quite a bit. Also Pentax is kind of a niche market for what is already a niche product.

Just thought of something:
The full frame Pentax. APS-C sensor, but with these optics built into the camera. Maybe user removable, or can be moved out of the optical path (so you have APS-C when you want to). Mirror box would have to go, so it would probably be more like a Sony alpha. But Pentax is looking for some differentiator... The design could be retro... so there is space to the left of the sensor to fit the optics. Actually, the Speed Booster looks fairly slim. Could it slide underneath or above the light path without increasing the size of the camera? As in flip out of the way, to where the pentaprism would usually be?
I mean: APS-C sensors have gotten pretty good these days. With the adapter lenses are brighter, thus the light sensitivity advantage of a FF sensor wouldn't be that big. You'd get a camera that can natively support APS-C and FF lenses at full resolution. Your 80-200 suddenly turns into a 80-300. To me that sounds like a wet dream...

Should have read further, I wasn't the only one with the idea. Do it Pentax. Just do it.

PDAF will come, I'm sure. Sony will sooner or later offer the sensor to other manufacturers too. Pricing... yes, the adapter is expensive, but perhaps also because of the small scale production. Plus Pentax makes lenses, so they may be getting a better price? FF sensors are also expensive, with this Pentax can get most of the benefits of a FF sensor, but with a cheaper APS-C sensor (of which they also can get more, since it'll be used in all Pentax cameras). Even if it costs a bit more than a real FF camera, wouldn't it be worth it?

[Winder]

Metabones Speed Booster adapter – full review | EOSHD.com

LensRentals.com - Metabones Magic?

[JonPB]

I believe this is called a "condenser" lens, because it takes larger image circle and condenses it into a smaller circle. It would make lens defects physically smaller, but if the sensor has higher resolution then you're back to square one, but with the additional defects of a new lens.

APS-C sensor, but with these optics built into the camera. Maybe user removable, or can be moved out of the optical path (so you have APS-C when you want to).

I like it. I'd trade my optical viewfinder for a condenser lens that could be moved in or out of the optical path without removing the lens. This would allow me to mount a 35mm 135-frame lens and quickly move to a 24mm angle of view without worrying about the sacrifices of a zoom.

[Fogel70]

I like it. I'd trade my optical viewfinder for a condenser lens that could be moved in or out of the optical path without removing the lens. This would allow me to mount a 35mm 135-frame lens and quickly move to a 24mm angle of view without worrying about the sacrifices of a zoom.

A reason why this is difficult to do, is that the condenser shortens register distance, so to fit it inside K-mount the optical design has to be made more complex for shifting register distance further back, or make the sensor or lens mount shift position.

I don't think this type of design will be very successful, as it probably end up more expensive than a FF DSLR.

[Clavius]

A reason why this is difficult to do, is that the condenser shortens register distance, so to fit it inside K-mount the optical design has to be made more complex for shifting register distance further back, or make the sensor or lens mount shift position.

I don't think this type of design will be very successful, as it probably end up more expensive than a FF DSLR.

JonBP wants to have the condensor lens(es) inside the camera itself. Yes, it will shorten the registry distance. But no, that doesn't matter because the condensor lens will become the "new back of the lens", which would be a lot closer to the sensor.

It's actually a way of having lenses that protrude into the camera body, where the mirror used to be, without the danger of accidentally destroying mirrors, when such lenses are attached to regular DSLRs. So it would be a good reason to keep K-mount and not go for a shorter registry distance. Allowing Pentax excellent backwards compatibility to be kept perfectly intakt.

I like the idea, you could have a full 6-lens kit and two formats with you, while you only carry 3 lenses and small body. It also complies with Pentax low form factor policy. Having both pseudo-FF and APSC in a small APSC sized body. Having 3 small primes providing 6 different focal ranges.

Yes, costs would be an issue. A cheaper way of achieving this would be to have the condensor to appear in the form a "drop-in-adapter". With a cool name, maybe even referring to the ltd range. Which makes the adapter optional. And because it's drop, there won't be any need for elektronic contacts to connect body with the lens. A nice product for aftermarket sales. Just as interesting as any other teleconverter.

I just can't get my head around sensor pixel densities and diffraction limits. Would such a speedbooster omit the pixel density limit of APSC format?

[NickLarsson]

I think that this device will be revolution at some point...a 300$ used NEX + 600$ booster = 900$ FF body.

Yep, at this price it's almost a no-brainer... hi Sony here I come :-/

[Rondec]

It doesn't seem like this will trully assuage the full frame crowd (me among them), since there will certainly be some image degradation with the adapter and all of the lenses will be manual focus. With the actual cost of full frame cameras being below 2000 dollars at this point, unless these drop in price, I don't see them being a big seller...

[JonPB]

JonBP wants to have the condensor lens(es) inside the camera itself. Yes, it will shorten the registry distance. But no, that doesn't matter because the condensor lens will become the "new back of the lens", which would be a lot closer to the sensor.

Correct. Replace the mirror/prism assembly with a lens assembly. Switching it in or out would work like mirror lock-up, taking a moment to flip a toggle but not having to remove the lens.

I just can't get my head around sensor pixel densities and diffraction limits. Would such a speedbooster omit the pixel density limit of APSC format?

I've never formally studied optics or even physics, so take my thoughts as ignorant musings. But let's take the issue to the extreme: what if we mount a 6x7 lens on a Q camera with a (theoretical) condenser lens between them? My rough estimate is that these systems have about 7 stops' worth of size difference between them. Would a "50mm equivalent" (angle of view) lens for the 6x7 camera then be 7 stops brighter on the Q? It seems unlikely that the 1:2.4/105mm lens would become an effective 1:0.21/9mm lens. Basically, something must be wrong with this reasoning or f/1.2 would hardly be considered an extreme aperture. If this reasoning held, though, the diffraction limitations imposed upon smaller sensor cameras would be avoided by using larger aperture lenses.

Cost is an issue: for most photography, it will be cheaper to design the lens itself rather than a universal adapter. Size, too: it makes no sense to buy a pocketable camera to use with a prime lens that weighs several times more than the camera. (And that flip-away lens I'd like to replace the mirrorbox with? Yeah, that lens would need a diameter of at least 43mm, while the K-mount only has 45.5mm between mount and sensor. Doable, perhaps, but not drop-in simple.) But I still come back to the idea that this is too good to be true, that there's some optical reason lenses won't work this way. Makes me wish I had studied optics or had a good textbook on the subject.

[Mistral75]

(...)

I've never formally studied optics or even physics, so take my thoughts as ignorant musings. But let's take the issue to the extreme: what if we mount a 6x7 lens on a Q camera with a (theoretical) condenser lens between them? My rough estimate is that these systems have about 7 stops' worth of size difference between them. Would a "50mm equivalent" (angle of view) lens for the 6x7 camera then be 7 stops brighter on the Q? It seems unlikely that the 1:2.4/105mm lens would become an effective 1:0.21/9mm lens. Basically, something must be wrong with this reasoning or f/1.2 would hardly be considered an extreme aperture. If this reasoning held, though, the diffraction limitations imposed upon smaller sensor cameras would be avoided by using larger aperture lenses.

(...)

There is a physical limit to the "brightening effect" of the focal reducer: the actual diameter of the lens mount. When the "reduction ratio" reaches a certain value, depending on the mount's diameter any further decrease in this ratio also reduces the size of the entrance pupil (think: "the size of the pupil as seen from the sensor through the lens, the focal reducer and the lens mount"). There is therefore a cap on the maximum aperture a focal reducer allows to reach.

This cap is f/0.9 with the Metabones Speed Booster: a Canon EF 85mm f/1.2 L + Speed Booster becomes a 60mm f/0.9 and not a 60mm f/0.85 (1.2 x 0.71 = 0.85).

[Fogel70]

JonBP wants to have the condensor lens(es) inside the camera itself. Yes, it will shorten the registry distance. But no, that doesn't matter because the condensor lens will become the "new back of the lens", which would be a lot closer to the sensor.

The condenser work by moving the image plane closer to the lens, so if you want to be able to use the camera with and without the condenser you need to compensate for this somehow. It might be possible to use optics for this, but I'm not sure. Otherwise you have to shift sensor or lens mount to compensate for the different register distance with and without the condenser inside the camera.




This is why the "Speed booster" is more compact than adapters without the condenser.