BMCC variant Metabones Speed Booster works on GH3 and GH4 to give 1.28x crop, almost full frame look!

[andy lee]

yes on ebay have a look

 

Mitakon (Zhongyi) Lens Turbo make one , its good I have the Nikon verson

[KarimNassar]

this thread was a very interesting read, thanks to all who participated to the discussion

[leo]

Did anyone checked how heavy the chromatic aberrations are with a speedboster ? it's bad, purple fringing never leaves the image and you can't correct it in lightroom :).

Why bother, get a 1.2 lens or a nokton and lose the canon lens.

[Andrew Reid]

Did anyone checked how heavy the chromatic aberrations are with a speedboster ? it's bad, purple fringing never leaves the image and you can't correct it in lightroom :).

Why bother, get a 1.2 lens or a nokton and lose the canon lens.

 

Hmm. Purple fringing at F1.2 on any lens is there. Even the Canon 50mm F1.2L. Same with the Nokton.

 

When you stop down on the Speed Booster chromatic aberrations and fringing disappear.

[dishe]

@dishe, Orangenz, araucaria, Inazuma:

 

Maybe you're right. I just always felt that nothing could reach the sDoF (and quality of bokeh) of a fast lens on a 5D, for instance. I have the M-SB too.

 

Again, you've clearly missed the point of the focal reducer concept. I feel like the author of this comic right now:

https://xkcd.com/1053/

 

You're one of today's lucky 10,000!

Go back and read all the reviews of the initial speedbooster when it came out. It really does effectively make your sensor act like it was larger. Everyone agrees on this, it isn't up for debate anymore. I know a guy who actually sold his 5D to get a Sony FS100 and use the same lenses on the speed booster. Same DOF and bokeh, but due to condensed photons, it also gets brighter (a 28 f/2.8, for example, renders the same FOV and DOF as it would on a full frame, but gets the amount of light gathering of f/2.0, effectively allowing you to turn down the ISO for the same exposure and same exact looking FOV and DOF). 
 

In contrast, if you are using a m4/3 speedbooster, you aren't getting the full effect because you are still at a crop compared to full frame. Its closer to full frame - 0.7x closer, to be more precise, effectively giving you a 1.4x crop instead of the 2.0 you started with. That's a bit wider than your average Canon APS-C camera, but still not quite photographic FF. Its somewhere in between. You CAN get the FF look with the NEX adapter, since it starts at APS-C already, or with more focal reduction, which is what Andrew was telling us with this story.

[dishe]

 

yes on ebay have a look

 

Mitakon (Zhongyi) Lens Turbo make one , its good I have the Nikon verson

 

Or the RJ version, both have EOS to M4/3, but no electronics. For that we'll have to wait for the Metabones. Meanwhile, I have Samyang glass and adapted vintage Nikon F-mount lenses running through the EOS adapter like a champ. Occasionally I'll use a native EOS lens and stop it down with an EOS body first. Not the most convenient way to go about it, but it's all we have at the moment.

[MattH]

 

If at 4k the GH4 with BMCC Speed booster has a 1.4x crop, then does that mean it could still possibly work with the Sigma 18-35mm? That would be sweet.

 

It should work.  If the bmcc speed booster does reduce by 0.64x, then the cinema 4k crop factor actually works out at 1.59.  Ultra HD works out at 1.67.    Diagonals of 27.16mm and and 25.84mm respectively, where the diagonal for nikon/sony apsc is 28.3mm.

 

But as it sounds like it could fuck up your shutter It would be best sticking with the normal speed booster which shouldn't even vignette in 1080p video mode (but will in stills mode).

[leo]

Andrew, not to the extent found on speedbooster.

And the question now is how much you need to stop down to get rid off purple fringing, corner softness and vignette ? if you end up at 1.8 then what's the point ? no full frame look on 2x crop sensor at 1.8, or at least not so much SDOF you would get on FX.

There is no cheating with speedboster, you eighter get the best lenses or a full frame sensor that shoots 4k.

I have seen speedbosters on gh3 and the purple fringing is wayyyy worse than a dedicated lens from Panasonic, the purple fringing is much thicker on speedboster and quite visible.

[kurth]

@dishe

 

because the photons are now condensed.

that'd be quantum photons , right ?

[richg101]

the issue causing confusing with relation to dof and fov with different sized sensors is that people make the assumption that a bigger sensor gives you shallower depth of field.  This is actually incorrect.  The depth of field of a lens never changes with sensor size, but rather the field of view changes with the depth of field remaining the same.  

 

The effect is a wider field of view with the same depth of field.  As a result, on a bigger sensor you can use a longer lens and get the same fov, and thus create shallower dof for the given same field of view.

 

 

rather than removing crop factor, the focal reducer is simply changing a lens for a bigger format into a lens for a smaller one.  

 

on a typical speed booster of 0.7x your 50mm f1.4 full frame lens turns into a 35mm f1.2 apsc lens.

on this 'special' m4/3 focal reducer it'll change your 50mm f1.4 lens into around a 28mm f0.95 m4/3 lens 

[Nikkor]

Why hasn't andrew already uploaded some tests (on the gh3, with stills)? I demand them now!

[Andrew Reid]

Andrew, not to the extent found on speedbooster.

And the question now is how much you need to stop down to get rid off purple fringing, corner softness and vignette ? if you end up at 1.8 then what's the point ? no full frame look on 2x crop sensor at 1.8, or at least not so much SDOF you would get on FX.

There is no cheating with speedboster, you eighter get the best lenses or a full frame sensor that shoots 4k.

I have seen speedbosters on gh3 and the purple fringing is wayyyy worse than a dedicated lens from Panasonic, the purple fringing is much thicker on speedboster and quite visible.

 

You're very confused aren't you.

 

It isn't all about aperture and you're really highly dramatising any issues. Soft corners, vignette, purple fringing, are really not much of an issue compared to the lens used normally wide open on a larger sensor. In fact the image in the centre of the frame gets sharper. I suggest you use one before critisising!

 

You do get true Super 35mm rendering of the lens with Speed Booster and that means all the characteristics of a larger sensor.

 

Instead of using a 25mm for example you can use a 35mm lens. Longer focal length = shallower depth of field.

[andy lee]

Having just got my Speedbooster this week and from all my tests I would agree with Andrew on this.

Sharper, faster, wider , to the naked eye it all loooks good!

Im not bothered about issues of fringing; corners etc etc , if I have to actually go looking for it by zooming in , then its not really an issue for me etc ,,thats for pixel peepers

 

in the real world it looks better ....so Im using it from now on.

[richg101]

Having just got my Speedbooster this week and from all my tests I would agree with Andrew on this.

Sharper, faster, wider , to the naked eye it all loooks good!

Im not bothered about issues of fringing; corners etc etc , if I have to actually go looking for it by zooming in , then its not really an issue for me etc ,,thats for pixel peepers

 

in the real world it looks better ....so Im using it from now on.

 

 

indeed.  since the focal reducer comes into its own when the wider fov and a shallow dof are desired, the benefit of the pronounced centre sharpness and these fov/dof aesthetic qualities tend to lend themselves better up close since they draw the viewer into the detail you are directing them to via dof and centre sharpness.  

 

Aim the lens at a tree at infinity and the CA will appear greater and edge sharpness will appear degraded, however this is more to do with the fact that the lens itself (rather than the optical quality of the focal reducer) is no longer having as much of its edges cropped away.  9 times out of ten, if you see CA on tree branches or telegraph poles in the distance its because the actual lens is wide open (in which case the ca would already be there before the focal reducer adds its degradation in the corners).

 

It should be noted that using a lower power focal reducer (such as a 0.7x rather than this special version which is stronger) will yield overall better image quality at the edges when wide open since more of the lens image circle remains cropped away - as everyone knows, the image quality of a lens mostly degrades at the edges when wide open with softening, CA and darkening.  

 

Use of wide angle medium format lenses (40mm, 50mm) and a focal reducer will yield good results since the image circle is that much bigger, you're staying within the better portion of the image circle and also compressing the resolving power to obtain better lpp/mm numbers. 

[wwjd]

 

yes on ebay have a look

 

Mitakon (Zhongyi) Lens Turbo make one , its good I have the Nikon verson

 

 

You have one of these... is it pretty clean?  Venturing into 4K video I want the clearest possible glass I can afford.  Won't be shooting ANY stills, so that is not my concern.   Do these Mitakon's measure up well compared to METABONES stuff?

[dishe]

Andrew, not to the extent found on speedbooster.

And the question now is how much you need to stop down to get rid off purple fringing, corner softness and vignette ? if you end up at 1.8 then what's the point ? no full frame look on 2x crop sensor at 1.8, or at least not so much SDOF you would get on FX.

There is no cheating with speedboster, you eighter get the best lenses or a full frame sensor that shoots 4k.

I have seen speedbosters on gh3 and the purple fringing is wayyyy worse than a dedicated lens from Panasonic, the purple fringing is much thicker on speedboster and quite visible.

 

Its strange to me that people are still confused about what a speedbooster does or does not do. :P

I find it strange that you are comparing this to a native Panasonic micro4/3 lens. They tend to be super sharp and clinical, often to a fault- they lack character and feel too much like video at times. Those of us using adapted glass are doing so because we prefer the look compared to native clinical variations. There are few things as cinematic looking as a vintage set of primes actually designed for film- but sometimes they come with uncontrollable side effects because of the less-than-perfect coatings. 

Here's the thing I feel you are missing: Those lenses would display chromatic abberation / fringing with or without a speedbooster.  You imply that the speedbooster is causing this somehow, but I believe that is incorrect. Its often just a quality of the lens- the focal reducer does not make them WORSE at all- in fact, sometimes it actually makes them BETTER. In my experience, since the optics are reduced, the fringing and imperfections get smaller as well. Not to mention the reducer has some coatings of its own that help reduce reflection and glare that cause uncontrolled flaring in the first place. The bottom line is that my vintage lenses actually are IMPROVED by throwing it on a speedbooster/lens turbo/etc versus on a straight up adapter!

Now, if you wanted to mount a modern FF clinical looking lens that doesn't have any flaring/etc on a speedbooster, that might give the effect you apparently are looking for. I sounds like you've seen some tests of character lenses on a reducer and have decided to compare it to a native clinical lens. That's apples and oranges, my friend. 
 

@dishe

that'd be quantum photons , right ?

 

Um... maybe? Technically a photon is a quantum, but I'm not sure what that adds to my explanation. I'm just saying the light is gathering together and therefore being intensified. Much like holding a flashlight to the wall and getting closer to it, the image circle gets smaller and more intense because the light isn't spreading out as much. More light, smaller circle, more FOV and shallower DOF. 

WHY ARE WE STILL DEBATING THIS? THE CONCEPT WAS EXPLAINED TO DEATH ALL OVER THE INTERNET OVER A YEAR AGO! I feel like anyone interested in this concept would have understood it at this point. 

 

You're very confused aren't you.

 

It isn't all about aperture and you're really highly dramatising any issues. Soft corners, vignette, purple fringing, are really not much of an issue compared to the lens used normally wide open on a larger sensor. In fact the image in the centre of the frame gets sharper. I suggest you use one before critisising!

 

You do get true Super 35mm rendering of the lens with Speed Booster and that means all the characteristics of a larger sensor.

 

Instead of using a 25mm for example you can use a 35mm lens. Longer focal length = shallower depth of field.

 

Right. Didn't we have this discussion a year ago? Its like the DSLR video revolution all over again... Yes, people are using "still cameras" for video now. You didn't know that? Ok. Can we fast forward this part of the conversation to get to the news already? KEEP UP PEOPLE!
 

You have one of these... is it pretty clean?  Venturing into 4K video I want the clearest possible glass I can afford.  Won't be shooting ANY stills, so that is not my concern.   Do these Mitakon's measure up well compared to METABONES stuff?

There are some interesting tests all over the internet. The first knock offs were pretty terrible (Fotodiox Light Cannon, for example), softening the image all over the place. They've gotten better, the general consensus is that the Speedboosters are the best (consistently sharp and flare free), and there's an apparent toss up between the RJ and Mitakon lens turbo models (My research pointed to the RJ being sharper in corners and less flaring than the Mitakon, Andy's research concluded the opposite, so I suppose it is arguable), followed by all the cheaper knock offs in similar flavors. The cheap knock offs are a crap shoot as far as quality of the optics. Whichever you buy, make sure it is the latest version and batch, because they have improved the coatings from the original runs. 

[andy lee]

You have one of these... is it pretty clean?  Venturing into 4K video I want the clearest possible glass I can afford.  Won't be shooting ANY stills, so that is not my concern.   Do these Mitakon's measure up well compared to METABONES stuff?

 

Ive started off shooting 16mm then 35mm film in the early 1990's and this is without a doubt the one thing I have bought with the most 'wow factor ' since then.

I was gobsmacked as to how good this Mitakon Lens Turbo is ......its staggeringly good!!

 

I have the Nikon version and bought it just to use on my Angenieux designed Tokina AX-T Pro Series 1 28-70mm f2.6 zoom lens

 

Now this is a very very good lens on it own!! once I put the Lens Turbo on it - it became a STELLER LENS!!

 

Im now getting sharp peaking blue all over my image on my Panasonic g6 it is noticable sharper and brighter and now wider!!!

 

it has a very very good cinematic look to it , so I highly recomend you get one !!

[andy lee]

hey Dische - some news

I have been reading that RJ was somehow involved in making the castings originally for the Mitakon Lens Turbo , as RJ runs a CNC machining company in China - RJ then did their own version of a Speedbooster which is what they are selling now

 

So both may well be very good similar ish items??  this may explain why both are good

 

unless someone has both to try side by side we are still non the wiser

I only have the Mitakon Lens Turbo and it kicks ass !! Im very happy with it!!

[JBraddock]

BTW, in case someone is waiting for it, I talked to RJ and he said that lens booster for C/Y mount will be out in 3 to 4 weeks.

[andy lee]

yeepee!! Yashica primes and Carl Zeiss Vario Sonnars here we go!!