Hi Alfred. One thing that's cool about using a focal reducer like the Speedbooster Ultra is that it gives you one stop of light more, BUT the depth of field remains the same as the lens. So on my Sigma 24-105 f/4, I get the light of f/2.8 but my DOF remains at f/4. That's a really great thing!

Hi Chad. I've done some tests now and the DOF definitely changes with my Canon lenses I use with the Speedbooster. I strongly disagree with that statement. (If it carries any importance for people, well, that's another thing...)

Chad is correct. The depth of field is determined soley by the optics of the lens so adding a speedbooster or putting the lens on a camera that has a smaller sensor than full-frame does not change the lens. The lens is still the same lens. It may feel to you like the depth of field has changed because the the field of view has has changed -- but any change you think you see to the DoF is just an illusion.

Well, I know nothing about the maths but I'm sure the difference in these pictures are not imagined. Canons 40mm wide open and stopped down, to it's "normal" 2.8.

There is a rumor that Sony will come out with a PZ zoom like the PZ 28-135 but with a range more to the wide angle range. The rumored range is 18-105. If so this might be a good multi-purpose lens with none of the ergonomic issues of the kit lens. It should also be sharper than the Canon 24-105 (which I never much liked and sold early on). Admittedly I shoot stills more than video, but many folks have a similarly low opinion on the optics of the 24-105. When I used Canon DSLR's, I found the Canon EF-S 17-55 constant f/2.8 to be much better optically, but this lens is an EF-S mount...). When I went to Canon full-frame DSLR's I bought the EF 24-70 f4.0L IS. Much better than the 24-105.

OK my bad fro not being more specific and exact. Apparently the DOF is made to be like a full frame camera, however the bokeh is not affected.

From the Metabones site:

How does Speed Booster® affect the depth-of-field?
The short answer is Speed Booster® on an APS-C sensor gives essentially the same depth-of-field effect as if a full-frame camera body were used.

The long answer is complicated. If we are referring to depth-of-field in the mathematical sense, that depends on the aperture, magnification and circle of confusion (CoC). Magnification in turn depends on distance and focal length. The 50mm lens now becomes a 35mm lens which behaves very differently in terms of perspective. The question is, do we still keep the distance the same? Should the CoC be kept the same? There are many missing variables we need to choose and fill-in before we could get a meaningful answer. When people claim Speed Booster® does not change the depth-of-field, they usually neglect to state the implicit assumption that the distance is kept the same (thereby changing the object size) and the CoC is kept the same. The same logic would lead to the conclusion that an APS-C camera has the same depth-of-field as a full-frame camera, too, which under the same implicit assumptions is mathematically true (the depth-of-field formula is format-size-agnostic, after all), but with which many people would disagree from practical experience.

However, when most people ask about depth-of-field, they are not interested in mathematics, but rather, they are after a certain kind of shallow depth-of-field "look". If this is the case, the short answer above applies.

How does Speed Booster® affect bokeh?
From practical experience, Speed Booster® has negligible effect on bokeh. In most cases the resulting bokeh is that of the lens alone. Speed Booster® does not leave its own "character" or "signature" in the pictures. It is very neutral.

http://www.metabones.com/article/of/faq

There is a rumor that Sony will come out with a PZ zoom like the PZ 28-135 but with a range more to the wide angle range. The rumored range is 18-105. If so this might be a good multi-purpose lens with none of the ergonomic issues of the kit lens. It should also be sharper than the Canon 24-105 (which I never much liked and sold early on). Admittedly I shoot stills more than video, but many folks have a similarly low opinion on the optics of the 24-105. When I used Canon DSLR's, I found the Canon EF-S 17-55 constant f/2.8 to be much better optically, but this lens is an EF-S mount...). When I went to Canon full-frame DSLR's I bought the EF 24-70 f4.0L IS. Much better than the 24-105.

I bought the Sigma 24-105, f/4 Art lens because in all the shootouts I watched, the Sigma was much sharper than the Canon 24-105. I'm really liking the Sigma Art lens, but it is a half pound heavier. That's not a biggie because I use a tripod for almost everything. Generally it seems like Sigma is killing it with their quality. I've got my eyes on their 50mm f/1.4 now.

There is a rumor that Sony will come out with a PZ zoom like the PZ 28-135 but with a range more to the wide angle range. The rumored range is 18-105. If so this might be a good multi-purpose lens with none of the ergonomic issues of the kit lens. It should also be sharper than the Canon 24-105 (which I never much liked and sold early on). Admittedly I shoot stills more than video, but many folks have a similarly low opinion on the optics of the 24-105. When I used Canon DSLR's, I found the Canon EF-S 17-55 constant f/2.8 to be much better optically, but this lens is an EF-S mount...). When I went to Canon full-frame DSLR's I bought the EF 24-70 f4.0L IS. Much better than the 24-105.

That would be wonderful if true.

There is a rumor that Sony will come out with a PZ zoom like the PZ 28-135 but with a range more to the wide angle range. The rumored range is 18-105. If so this might be a good multi-purpose lens with none of the ergonomic issues of the kit lens. It should also be sharper than the Canon 24-105 (which I never much liked and sold early on). Admittedly I shoot stills more than video, but many folks have a similarly low opinion on the optics of the 24-105. When I used Canon DSLR's, I found the Canon EF-S 17-55 constant f/2.8 to be much better optically, but this lens is an EF-S mount...). When I went to Canon full-frame DSLR's I bought the EF 24-70 f4.0L IS. Much better than the 24-105.

Yes, but a sony 18mm would still only work out to 27mm with the FS5 crop factor.

True, but better than, what is it...~45mm? with the current offering, and in a lens designed for videography.

I'm just using the Sigma 24-105mm f4 with the Speedboster ultra, which makes it effectively a 25-110mm f2.8. The combo is cheaper than the PX 28-135mm, and performs better. Sony zooms aren't as good quality as their primes relatively speaking.

Using the same Sigma Speedboster combo with great results. Also the Sigma 70-200 as well. F2.8 becomes F2

Has anybody tried this one with a speed booster? Canon CN-E 18-80mm T4.4 COMPACT-SERVO

"Has anybody tried this one with a speed booster? Canon CN-E 18-80mm T4.4 COMPACT-SERVO"

It's a new lens, just announced and not yet available to buy/shipping later this year. It is designed for 35mm sensor cams with EF mount. It will NOT work with a Metabones Speedbooster as the image circle will be smaller than what the 35mm sensor size needs - think EXTREME vignetting with big black corners in the frame!

The "normal" Metabones Mark IV EF to Sony E-Mount should work but that is yet to be proved on a Sony cam such as FS7 or FS5 - but of course the FOV (Frame of View) range would remain the same as what's marked on the lens (18-80mm) and there will be no "F stop boost.

Thanks Andy!

Speedboster Ultra / focal reducers only work with full frame glass on an apsc/super35 sensor. But the cheaper ones work.

Well, we have a lot more experience, now, with the FS5 cameras. We still use the 18-105mm "kit" lenses a lot. But, when possible, we are using my still camera lenses quite a bit.

I have a shelf full of Nikon glass, but a few months ago I started buying Zeiss primes for my Nikon, and we are using them on the FS5 bodies and the FS700.

The kit lens is pretty darn good, but it can't hold a candle to the Zeiss glass.

So far we have the Zeiss 15, 21, 55 Otus, 100 macro, 135mm APO, 25mm Batis and 85mm Batis.

Not using a Speed Booster adapter. Just accepting the crop, for now. Last week we set up a quickie "talking head" interview in a plant. Put up two LED panels on stands, and had someone holding a "camera mount" LED light on the end of a monopod, to be the hair light. Shot it with the 135mm APO Zeiss. It's so crisp it looks like a green screen shot, though it wasn't.

Yes, the camera is important, but we all will buy a lot of cameras. Money put into good glass is an investment.

Eventually we'll probably look at PL lenses. Sigh.

Wooden Camera has an E mount to PL lenses adapter. That is what Jeff Berlin used to make a feature-length movie using Leica Summicron C lenses on a Sony A7R ii.