Alpha_Geist wrote:
I have a few question regarding the Oly m4/3 sensor and the Metabones Speed Booster adapter.
Has anyone used it on their Oly? If so, how is the f/no. affected with the speed booster on the m4/3 sensor? I know the speed booster improves light gathering/speed by 1 stop, and the focal length is widened by 1.42x (.71 for the adapter and 2x for the m4/3 FF equivalent focal length = 1.42x), but the f/no. is still faster.
- Example -
50mm f/2 lens Speed Boosted on a m4/3 camera becomes:
FOCAL LENGTH maths
50mm x .71 = 35.5mm x2 (for FF equivalent focal lengths on m4/3 sensor) = 71mm
F/no. maths
f/2 -> 1.4 from speed booster, but then becomes a f/x for FF equivalent?
I'm getting a bit tripped up with FF equivalent conversions with m4/3 sensors and throwing in a Speed Booster only added to it.
I've been looking at the Oly and Fuji offerings and have been swayed by the IBIS of the Oly. ...Show more →
The focal length will become .71x. The physical aperture will stay the same size. Since we think of aperture in porportion to focal length, and F changes, the demoninator in our F stop will change by .71x.
Of course, when comparing to another format, we also have to consider aperture equivilence.
So for example, my Rokinon 85mm F/1.4 on the speedbooster becomes a 60mm. The entrance pupil (effective aperture) also happens to be 60mm (85mm/1.4 = 60mm). Since that did not change, but the focal length does, the maximum F-stop is reduced to 1 -- (60mm(new focal length)/x = 60mm(aperture size), solve for x).
To compare to a different format, we use crop factor to account for focal length and depth of field equivilence. Mounted on the OM-D, this speedboosted Rokinon at 60mm F/1 gives an equivilent shooting experience (depth of field and angle of view) to a 120mm F/2 on full frame.
kponds wrote:
The focal length will become .71x. The physical aperture will stay the same size. Since we think of aperture in porportion to focal length, and F changes, the demoninator in our F stop will change by .71x.
Of course, when comparing to another format, we also have to consider aperture equivilence.
So for example, my Rokinon 85mm F/1.4 on the speedbooster becomes a 60mm. The entrance pupil (effective aperture) also happens to be 60mm (85mm/1.4 = 60mm). Since that did not change, but the focal length does, the maximum F-stop is reduced to 1 -- (60mm(new focal length)/x = 60mm(aperture size), solve for x).
To compare to a different format, we use crop factor to account for focal length and depth of field equivilence. Mounted on the OM-D, this speedboosted Rokinon at 60mm F/1 gives an equivilent shooting experience (depth of field and angle of view) to a 120mm F/2 on full frame....Show more →
Wow!! Saw those over on the Landscape forum and did not know they were shot with the E-M5!! Very nice....and inspiring!!
Just curious, Brian - have you had these printed and if so, what size? I've always been curious to see how large of a print those with an E-M5 are able to print.
A photo I've taken with a E-M5 has been printed in 4'x6' for a exhibition wall. It turned out pretty alright but it wasn't meant to be a fine art print.
