Dilemma with m4/3 lens vs Nikon lens

[sin77]

I am getting a portrait lens for either my Nikon D5100 or Olympus E-PM2.

For APS-C, it would be Nikon AFS 85mm f1.8G which cost around $600 or less via import.
For m4/3, it would be Sigma 60mm f2.8 for around $240 locally.
Please note that m4/3 60mm = APS-C 90mm

For comparisons:
1. Nikon f1.8 lens would give me much more bokeh than Sigma due to the larger aperture and sensor size/format.
2. Shooting with E-PM2 + Sigma 60mm would give me stabilised shot which is very important to me, although I can use a shorter shutter speed with the Nikon lens (due to f1.8) and thus can jolly freeze the subject more.
3. Nikon lens is around 2x the price of Sigma.
4. I will be able to carry two sets of camera systems (D5100 + Sigma17-50 f2.8 OS and E-PM2 + Sigma 60mm f2.8) and avoid switching lenses if I buy the Sigma lens.

Or is there any 3rd party lens for Nikon system that is around 85mm or 105 mm, is stabilised, f2.8 or larger aperturre and is affordable (i.e. $600 or less to import)?

 

[undergrd]

I am getting a portrait lens for either my Nikon D5100 or Olympus E-PM2.

For APS-C, it would be Nikon AFS 85mm f1.8G which cost around $600 or less via import.
For m4/3, it would be Sigma 60mm f2.8 for around $240 locally.
Please note that m4/3 60mm = APS-C 90mm

For comparisons:
1. Nikon f1.8 lens would give me much more bokeh than Sigma due to the larger aperture and sensor size/format.
2. Shooting with E-PM2 + Sigma 60mm would give me stabilised shot which is very important to me, although I can use a shorter shutter speed with the Nikon lens (due to f1.8) and thus can jolly freeze the subject more.
3. Nikon lens is around 2x the price of Sigma.
4. I will be able to carry two sets of camera systems (D5100 + Sigma17-50 f2.8 OS and E-PM2 + Sigma 60mm f2.8) and avoid switching lenses if I buy the Sigma lens.

Or is there any 3rd party lens for Nikon system that is around 85mm or 105 mm, is stabilised, f2.8 or larger aperturre and is affordable (i.e. $600 or less to import)?

Based on your signature, tot you already have the Tokina 50 - 135 f2.8 which covers the 85mm or 105mm and it is already f2.8?

 

[swifty]

Actually m43 60mm would roughly equal 120mm FF or about 80mm Nikon APS-C.
An 85mm on APS-C roughly equals a 63.5mm on m43. Just being a bit pedantic but the calculations are close enough. Actually my calcs aren't exactly right either when you consider the 4:3 vs 3:2 format differences.

1. the Nikon 85mm will give shallower DOF at the same shooting distance. The bokeh quality is subjective and up to you to decide.

4. Sigma also makes a macro 105mm OS f2.8 lens. Probably a touch more expensive but you also get macro capabilities. Do consider the 1.5X crop on APS-C making it 157.5mm FF equiv but it depends on your focal length preferences. This becomes more comparable to the Olympus 75mm f1.8 on m43 focal length wise.

Would you pony up to a Sigma 85mm f1.4? f1.4 gives you two extra stops over the f2.8 lenses - quite significant.
An Olympus 45/1.8 for m43 gives you a 'classic' 90mm equiv on FF and the lens is quite cheap.
Another alternative is the Tamron 60mm f2.0 macro for your Nikon. 90mm equiv on FF with 1:1 macro capability and it's f2 as oppose to the usual f2.8 macros.

 

[kandinsky]

Or is there any 3rd party lens for Nikon system that is around 85mm or 105 mm, is stabilised, f2.8 or larger aperture and is affordable (i.e. $600 or less to import)?

If planning to do posed portraits and you can do without AF, the Samyang/Rokinon 85mm f/1.4 might be a lower budget option worth considering. Currently @ US$275 (amazon), with focus confirmation chip @ US$329 (B&H). This, as well as the Nikkor 85, can be easily used with your e-pm2 with an adapter.

 

[sin77]

Based on your signature, tot you already have the Tokina 50 - 135 f2.8 which covers the 85mm or 105mm and it is already f2.8?

Thanks for reminding. I sold 50-150 f2.8 recently and forgot to update my signature.

 

[sin77]

If planning to do posed portraits and you can do without AF, the Samyang/Rokinon 85mm f/1.4 might be a lower budget option worth considering. Currently @ US$275 (amazon), with focus confirmation chip @ US$329 (B&H). This, as well as the Nikkor 85, can be easily used with your e-pm2 with an adapter.

I prefer to use AF lenses. Thanks for the suggestion.

 

[sin77]

Actually m43 60mm would roughly equal 120mm FF or about 80mm Nikon APS-C.
An 85mm on APS-C roughly equals a 63.5mm on m43. Just being a bit pedantic but the calculations are close enough. Actually my calcs aren't exactly right either when you consider the 4:3 vs 3:2 format differences.

1. the Nikon 85mm will give shallower DOF at the same shooting distance. The bokeh quality is subjective and up to you to decide.

4. Sigma also makes a macro 105mm OS f2.8 lens. Probably a touch more expensive but you also get macro capabilities. Do consider the 1.5X crop on APS-C making it 157.5mm FF equiv but it depends on your focal length preferences. This becomes more comparable to the Olympus 75mm f1.8 on m43 focal length wise.

Would you pony up to a Sigma 85mm f1.4? f1.4 gives you two extra stops over the f2.8 lenses - quite significant.
An Olympus 45/1.8 for m43 gives you a 'classic' 90mm equiv on FF and the lens is quite cheap.
Another alternative is the Tamron 60mm f2.0 macro for your Nikon. 90mm equiv on FF with 1:1 macro capability and it's f2 as oppose to the usual f2.8 macros.

Prefer 85mm (just nice) because my wife already got a Nikon 105 macro, thus Olympus 75 will be redundant.
As for 4/3 at 45mm, I already have a Leica macro lens.