Metabones speedbooster: is there any reason to get full frame now?

http://www.eoshd.com/content/9474/prototype-metabones-speed-booster-equipped-nex-7-vs-full-frame-5d-mark-iii

What do you think? Slap one of these puppies on any NEX and you're in full frame land. Even better, you've got lower F stops for all your lenses.

A 35mm/FF sensor has twice the area, so it collects twice the light.  This affects noise, resolution and color accuracy, especially at higher ISO speeds.  Having better lenses for NEX is nice, but it doesn’t really improve the sensor.  Not that there's anything wrong with the NEX sensor, of course.

This is like 1.4 TX but with 1/1.6 "magnification". It makes the 135/2, for example, a crappy 85/1.2 lens. Like the cheap wide angle adapters that you can screw on top of your lens but in this case, it goes to the back of the lens.

No, it is not better. 135/2, for example becomes 85/1.2 but that is on crop, so it is equivalent to 135/2 again.

You don't understand: for the same lens with the telecompressor, all of the same light is collected - it's just concentrated into the APS-C area.

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Erik

If it has the same FOV, same DOF, and collects the same amount of light,  how does it become "crappy?"

There is a huge difference where you put the optics.

It's no better than than the 135/2 on FF but it's also not worse.   There is not much size difference between a 135/2 and an 85mm/1.2 but there is a huge size difference between a 50mm f/1.8 + compressor and a retrofocus 35mm f/1.2.

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Erik

So there we have it. This looks like it will shake up the market; I wonder why it has not been commented on more here. While the speed adapter is about $600, it'd still be a savings of more than $1000 coupled with a new Nex-7. Assuming the Nex-8 comes out soon, the savings could be even more. People will now be able to keep their crop cams and get the FF look for a song (almost).

I'll be very interested in more reports once it comes out. Thus far I've gotten a very positive review from a video oriented user who used it with two lenses. I've yet to see a teleconverter that I'd decide on with only a single review with only 4 MP samples and two lenses. It all hinges on how well corrected the internal optics of the adapter are, it might be something that works very well for video (at least until the 4k revolution) but isn't quite there for stills. So I'm cautiously optimistic.

If it's even remotely good BlackMagic should buy them now, that eliminates the main issue that keeps the BMCC from being a very, very low cost RED, the lack of lenses.

Not with limited or no auto-focus, electronic viewfinders, and poor battery life.  I doubt it will make much difference for still photographers.

However, if Pentax created a K-01 type camera with this built-in, then there might never be a Pentax FF body.

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Erik

Yes, I do understand. The operative word is "collects."

The sensor can accept and process only a certain amount of light before the wells fill up.  A wider aperture on a lens doesn’t improve the sensor’s ability to convert light into electricity.  However, doubling the surface area does exactly that.

You can’t turn an APS-C sensor into a 35mm sensor simply by improving the ability of a lens to pass light.

There are also things like resolution, corner performance, bokeh. Constructing an 85/1.2 lens by taking a well designed 135/2 lens and putting an adapter on the back does not sound to me as a great design. In the center, I expect the combo to work well though.

And your point is?

That is what I said, too (in terms of light gathering).

I don't think that word operates the way you think it operates:

1. The most common use for this adapter (i.e. fast lenses used in low light) does not saturate the sensor so full-well capacity is irrelevant
2. Smaller pixels have lower read noise so DR is not a significant factor either

It's not perfect - the question will be if it's close enough for most common use cases.

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Erik

This interpretation is correct. Another way to say this is that the crop camera would still be able to shoot at ISO no lower than 250-300 in equivalent terms.

We'll have to wait and see if it's great or merely good - but given the reputation of the optical designer, it's not likely  to be "crappy" for most mid-range lenses.

That your comparison is totally off the mark -- particularly by invoking "cheap adapters."  The requirements of a lens for a 35mm SLR with a mirror puts fixed bounds on the degree of freedom that make putting the lenses in the back much easier -- just like a Canon 1.4x TC is much better than a front mounted converter.

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Erik

Even the best lens designer cannot cheat nature.

The only reason I mentioned cheap WA adapters was to explain the mechanics of the adapter. It was not mean to be a proof that the IQ would suffer. You misunderstood it.

You seem to be misunderstanding the intention of my first post.  I only said that this adapter has no bearing on the performance of the sensor.  An APS-C sensor will still have all of the characteristics of an APS-C sensor.  And the only reason I said that was because OP said:

“Slap one of these puppies on any NEX and you're in full frame land.”

My point was that yes, the lenses will behave more-or-less as though they are on a 35mm/FF camera, but the captures won’t be improved to match the quality available from the larger sensor.

More importantly, I'm not saying that this adapter won't provide any benefits at all.  I understand what it does and why it could sometimes be very useful.

I don't think it's that the sensor improves, but the heretofore rarely produced lenses equivalent to those easily accessible for full frame, just became vastly more common.  Take a common prime or zoom kit on any full frame camera (35/1.4 50/1.4 (or 1.2) 85/1.4 or 135/2 or 24-70/2.8 and 70-200/2.8.  Other than Olympus's still slow f/2 zooms, there have never been attempts to make true equivalents to these lenses for smaller sensors.  These adapters just made acquiring lenses really close to any of those very achievable, but allows smaller sensors to retain their depth of field advantage as desired (for things like macro, even if it's small).  It gets really interesting if someone can make one that works well with the BMCC's crop even if it doesn't quite get it to Academy 35mm.

It has bearing on how the noise and capacity of the sensor can be utilized, i.e. starting with the same  50mm f/1.8 lens:

APS-C: ISO 1600, 35mm@f/1.2, 1/60th

FF: ISO 3200, 50mm@f/1.8, 1/60th

Both sensors receive the same amount of total light. Brightness will be the same. Noise will be the essentially same. DOF will be the same. FOV will be the same. Resolution in lp/ph will be the same. What is the difference you are referring to relative to this scenario?

You have not yet explained what part of the capture will be inferior -- assuming equivalent technology in the FF vs. APS-C. Yes, for a somewhat contrived case (shooting at wide open on the beach where you can't lower the ISO or raise the shutter speed) there is a potential difference, but mostly not.

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Erik

Just because you don't understand does not mean it's cheating or magic. Microscopes and telescopes have used this technique for years.  It just so happens that we have a combination of camera systems -- one with a larger image area but also larger than "normal" registration distance and others with smaller image area, small registration distance and large mount diameters -- that make this technique optically and mechanically feasible for these cameras.  In theory, you might be able to so something similar for Hasselblad lenses and Leica bodies, but there was no economic justification for it.

The mechanics are a simple tube - nothing exotic (again just like a Canon TC.)

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Erik

Don't patronize me. If you cannot keep it civil, do not reply to my posts.

It is a tube with glass inside, a.k.a. lens.

You don’t yet understand what I’m saying.

The larger sensor can capture and process twice as many photons per exposure as the smaller sensor.  This has nothing to do with the lens or the aperture, but it has everything to do with signal-to-noise ratio, and this impacts DR, resolution and color as the ISO rises.  Given similar technology, the larger sensor will always perform better in this regard over the entire image.

What you’re saying would be correct if you crop an APS-C-sized portion of the FF image, but that’s not what we’re discussing.