Similaar Foto tutorials
English
- Espaņol
Equipment
recommendations
Flaat
Picture Styles
Lens tests
Sharpness
- Bokeh

So, how good is this SpeedBooster thing?

 
HOME
 


 
Foto tutorial (English)
Foto tutorial (Espaņol)
 


 
Equipment recommendations US-ES
 


 
Flaat for Canon
Flaat for Nikon
Flaat for the BMC
Flaat for NEX-5N
Old Picture Style Tests
 


 
LENS TESTS
Stills
Stills (fullframe)
Video
Video (lineskip)
Video (fullframe)
Conclusions
APS-C vs Full Frame
ND filters
Other filters


BOKEH TESTS
Summary
Alternative scenarios
 


 
Badly assembled lenses and image quality
Lens mount compatibility chart
ISO on different cameras
High ISO on the 5D3
DIY: DR test chart
RGBWK Bayer sensors


DoF/FoV CALCULATOR
Notes on DoF-FoV
Notes on crop-DoF-FoV


Custom Cropmarks for Magic Lantern on the Canon 550D


How many megapixels do I want?
How many megapixels can I see?


Quick Monitor Calibration Chart


MY VIDEOS


Random rants


Search engine


Some time ago I tested my lenses in APS-C and full frame cameras, and concluded that the bigger sensor made my lenses provide sharper pictures (keeping constant the field of view, that is, comparing a great 50mm on APS-C against a great 90mm in FF).

But my camera has an APS-C sensor. Cue the MetaBones SpeedBooster, an adapter for mirrorless cameras that is, in theory, an optical equivalent to moving to a full frame sensor. Yes, I know it sounds silly, but it works. Read about it here.
When I say it works, I mean it does give you the depth of field of a full frame camera (that is, you get shallower DoF at the same aperture). And bokeh seems to be just as good as it is with the bare lens on a dumb adapter. But will it also be as sharp as a full frame sensor? Let's test it.

There are 3 cameras here, and I know this is a problem: FullFrame is the 5D2 (21 Mpix), APS-C is the 550D/T2i (18 Mpix), and APS-C with SpeedBooster is the NEX-5N (16 Mpix). This puts FF at an advantage, and the SpeedBooster at a disadvantage. But well, unless I get a NEX with higher Mpix count (like a NEX-7), this is what I can do (I could test APS-C without SpeedBooster on the NEX, but I think I did enough already).

Scroll down to see the results.

MY CONCLUSION:
The speedbooster gives me an extra stop of light, and the FoV and DoF of a full frame camera, with no negative effect on sharpness or bokeh, so it's a great buy. I think it gives me an advantage in terms of sharpness too, but it's quite small, definitely smaller than moving to a real Full Frame sensor.

TO ELABORATE A BIT...

The SpeedBooster delivers a small sharpness increase. Plus, the DoF and brightness advantages make it a winner. But it's not as big an improvement as actually going Full Frame.

For example, take the 90mm Elmarit with the SpeedBooster. It is slightly sharper than both the 50mm or the 90mm on APS-C without SpeedBooster. But it is not as sharp as the 90mm on Full Frame. If all I have is the NEX-5N and I have to take a portrait, 90mm+SB is slightly better (sharper in the center, about the same in the corners) than 50mm with the standard adapter. But 90mm on FullFrame would be a lot better.

But the DoF and brightness advantages make the SB even better. I can take that portrait with the following settings:
* APS-C with standard adapter, 50mm lens set at f/2
* APS-C with SpeedBooster, 90mm lens set at f/2.8
With the same ISO and shutter speed, I'll get the same FoV, DoF and exposure in both cases. Now, looking at the tests, it's easy to see which option has the lead: because I can close the lens a bit, the one with the SpeedBooster is sharper both in the center and in the corners! Not as good as actually going Full Frame, but an improvement for sure, with no downsides whatsoever.




please visit my equipment recommendations









CENTER - 100% crops
 
 
f/1.4
f/1.8
f/2.2
f/2.8
f/3.5
f/5.6
f/9.0
Leitz 24
speedbooster
-
-
-
Canon 24
fullframe
-
-
-
Canon 24
APS-C
-
-
-
Leitz 35
speedbooster
-
-
-
Leitz 35
fullframe
-
-
-
Leitz 35
APS-C
-
-
-
Leitz 50
speedbooster
Leitz 50
fullframe
Leitz 50
APS-C
Leitz 90
speedbooster
-
-
-
Leitz 90
fullframe
-
-
-
Leitz 90
APS-C
-
-
-


CORNER (focusing at corner) - 100% crops
 
 
f/1.4
f/1.8
f/2.2
f/2.8
f/3.5
f/5.6
f/9.0
Leitz 24
speedbooster
-
-
-
Canon 24
fullframe
-
-
-
Canon 24
APS-C
-
-
-
Leitz 35
speedbooster
-
-
-
Leitz 35
fullframe
-
-
-
Leitz 35
APS-C
-
-
-
Leitz 50
speedbooster
Leitz 50
fullframe
Leitz 50
APS-C
Leitz 90
speedbooster
-
-
-
Leitz 90
fullframe
-
-
-
Leitz 90
APS-C
-
-
-





FURTHER TESTING
Now that I know it's not as sharp as full frame, I run all tests on a NEX-5N, always with the same settings, so now the Mpix difference is not an issue, and you can also look for things like color casts, differences in contrast, etc.
 





CENTER - 100% crops
 
 
f/1.4
f/2.0
f/2.8
f/4.0
f/5.6
f/8.0
Leitz 50
speedbooster
-
Leitz 50
APS-C
-
Leitz 90
speedbooster
-
-
Leitz 90
APS-C
-
-


CORNER (focusing at corner) - 100% crops
 
 
f/1.4
f/2.0
f/2.8
f/4.0
f/5.6
f/8.0
Leitz 50
speedbooster
-
Leitz 50
APS-C
-
Leitz 90
speedbooster
-
-
Leitz 90
APS-C
-
-





CENTER - crops from images downsized to 1920x1080
 
 
f/1.4
f/2.0
f/2.8
f/4.0
f/5.6
f/8.0
Leitz 50
speedbooster
-
Leitz 50
APS-C
-
Leitz 90
speedbooster
-
-
Leitz 90
APS-C
-
-


CORNER (focusing at corner) - crops from images downsized to 1920x1080
 
 
f/1.4
f/2.0
f/2.8
f/4.0
f/5.6
f/8.0
Leitz 50
speedbooster
-
Leitz 50
APS-C
-
Leitz 90
speedbooster
-
-
Leitz 90
APS-C
-
-





THE PORTRAIT QUESTION
So, if I want to take a portrait, 50mm on regular adapter, or 90mm on speedbooster? Looking at the results above, I already know the answer, but let me arrange the results a bit better just for this.
 


CENTER - 100% crops
 
Leitz 50 standard f/2.0
Leitz 90 speedbooster f/2.8
-
-
Leitz 50 standard f/2.8
Leitz 90 speedbooster f/4.0
-
-
Leitz 50 standard f/4.0
Leitz 90 speedbooster f/5.6
-
-
Leitz 50 standard f/5.6
Leitz 90 speedbooster f/8.0
-
-


CORNER (focusing at corner) - 100% crops
 
Leitz 50 standard f/2.0
Leitz 90 speedbooster f/2.8
-
-
Leitz 50 standard f/2.8
Leitz 90 speedbooster f/4.0
-
-
Leitz 50 standard f/4.0
Leitz 90 speedbooster f/5.6
-
-
Leitz 50 standard f/5.6
Leitz 90 speedbooster f/8.0
-
-


Copyright Similaar 2011 -- similaar.feedback@gmail.com -- @Similaar
Similaar is a participant in the Amazon Services LLC Associates Program and the Amazon EU Associates Programme, two affiliate advertising programs designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com and amazon.es.